Journal articles on the topic 'Lunar daily variation'

The paper describes the lunar daily (L) variations at fixed lunar ages and the lunar monthly (M) variations at fixed solar hours in horizontal magnetic intensity (.H) at Kodaikanal for the low sunspot period, Jan, 1951 to Dec, 1955; and for the high sunspot period Jan. 1956 to Dec, 1960. The lunar daily variations at any of the seasons or solar activity epochs are found to follow Chapman's phase law: L=Cn sin [n~+(.n-2)v+an]. With the increase of solar activity the phase of Ls wave remains constant for each of the seasons, but the amplitude increases during D. and E. months and slightly decreases during the months, The lunar semi monthly (.M2) waves at fixed solar hours vary with the solar time in the same way as the electrojet current, i.e., the amplitude starts increasing with sunrise reaches a maximum near noon and decreases to a low value by sunset. The ratio of lunar semidiurnal (LB} wave to the solar semidiurnal (82) wave for any of the seasons decreases with solar activity. The amplitudes of LB or M2 wave at Kodaikanal are much smaller than the corresponding values at Huancayo indicating the longitudinal variation in the lunar daytime effects in H along the magnetic equator. The lunar semimonthly tides for the daytime hours are predominantly under the control of lunar time during the D. months and of lunar age during the J .months.

Penentuan suatu model parsial hari tenang variasi medan geomagnet di stasion geomagnet Tondano merupakan fungsi Date of Year (DOY), Lunar Age (LA), dan Local Time (LT). Diperoleh tiga model parsial hari tenang variasi medan geomagnet yaitu = g(DOY), = h(LA), dan = m(LT). Kontribusi dari DOY terhadap hari tenang variasi medan geomagnet sangatlah kecil (sebesar 0,784.10-3 %). Kontribusi faktor fisis lainnya diduga berperan terhadap hari tenang variasi medan geomagnet . Informasi hasil analisis model parsial variasi hari tenang terhadap usia bulan menunjukkan adanya anomali di sekitar lokasi pengamatan. Model parsial hari tenang variasi medan geomagnet yang diperoleh akan membentuk model empiris dari hari tenang. Model empiris akan memberikan informasi gangguan geomagnet untuk kegiatan survei geofisika di perairan Sulawesi Utara. Kata kunci : Model parsial, hari tenang, variasi medan geomagnet, DOY, LA, LT, Tondano. Determination of partial model from quiet daily geomagnetic field variation ( ) at geomagnetic station in Tondano is a function of Day of Year (DOY), Lunar Age (LA) and Local Time (LT). It obtains three partial models of quiet daily geomagnetic field variation, those are = g(DOY), = h(LA), dan = m(LT). Contribution from DOY to the quiet daily geomagnetic field variation ( ) is very small (around 0,784.10-3 %). Another contribution of physical factor presumes to play role to quiet daily geomagnetic field ( ). Information of analysis result of quiet daily partial model to lunar age indicates anomaly occurrence around the observation location. Partial model of the obtained quite daily geomagnetic will form empirical model of quite day. This empirical model will provide any information about geomagnetic disturbance for geophysical survey in North Sulawesi Waters. Keywords: Partial model, the quiet daily variation, geomagnetic field variation, DOY, LA, LT, Tondano.

Growth and survival of larval fishes is highly variable and unpredictable. Our limited understanding of this variation constrains our ability to forecast population dynamics and effectively manage fisheries. Here we show that daily growth rates of a coral reef fish (the sixbar wrasse, Thalassoma hardwicke ) are strongly lunar-periodic and predicted by the timing of nocturnal brightness: growth was maximized when the first half of the night was dark and the second half of the night was bright. Cloud cover that obscured moonlight facilitated a ‘natural experiment’, and confirmed the effect of moonlight on growth. We suggest that lunar-periodic growth may be attributable to light-mediated suppression of diel vertical migrations of predators and prey. Accounting for such effects will improve our capacity to predict the future dynamics of marine populations, especially in response to climate-driven changes in nocturnal cloud cover and intensification of artificial light, which could lead to population declines by reducing larval survival and growth.

Carbonaceous aerosol, one of the major components of atmospheric aerosols, significantly affects haze episodes, climate change, and human health. Northeastern China suffers severe air pollution, especially in some periods (e.g., the Spring Festival). However, studies on carbonaceous aerosols in typical northeast industrial cities (i.e., Changchun) are rare, limiting further comprehension of the atmospheric haze formation. In this study, we monitored the concentrations of carbonaceous aerosols (i.e., OC and EC) in Changchun during the Lunar New Year of 2018 (i.e., from Lunar 20 December to Lunar 20 January), and analyzed the temporal variation and source contributions via the HYbrid-Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model with the potential source contribution factor weights (PSCF) method. The daily concentrations of OC and EC were 9.00 ± 2.81 and 1.57 ± 0.46 µg m−3, respectively, and were significantly lower at nighttime than at the day during the Spring Festival. The concentrations during the major period (i.e., OC: 8.13 ± 2.93 µg m−3; EC: 1.47 ± 0.47 µg m−3 in festival days), including the Lunar Little New Year; the Lunar New Year’s Eve; New Year’s Day; Lunar 5 January, and the Spring Lantern Festival, were mainly from the northwestward with the wind speed of 4–6 m/s being lower than that of normal period (OC: 9.87 ± 2.46 µg m−3; EC: 1.67 ± 0.44 µg m−3) from the southeastward with a wind speed of 6–7 m/s. The direction of the airflow trajectory was mainly in local, northwestward, and northward, carrying particulate matter and gaseous pollutants. In major period, the daily concentration of atmospheric pollutants presented a bimodal trend, with peaks appearing regularly from 11:00 a.m. to 12:00 p.m. and 5:00 p.m. 10:00 p.m., which might be related to traffic, cooking, and firecrackers. The OC/EC was greater than 2 during the whole period, indicating the generation of secondary organic aerosols (i.e., SOC). This study was essential to understand the formation mechanisms of severe pollution episodes and develop control measures for the industrial cities of Northeast China during the Spring Festival.

Penentuan model empiris hari tenang variasi medan geomagnet dikonstruksi berdasarkan data geomagnet dari stasiun geomagnet (SG) Badan Meteorologi Klimatologi dan Geofisika (BMKG) Tondano, Manado. Hari tenang variasi medan geomagnet dinyatakan sebagai fungsi dari keempat komponen atau variabel yang mempengaruhinya yaitu: aktivitas matahari SA (solar activity), hari dalam setahun DOY (date of year), usia bulan LA (lunar age) dan waktu lokal LT (local time). Dalam bentuk matematis ditulis sebagai, EMQD ( SA, DOY, LA, LT ) = f(SA). g(DOY). h(LA). m(LT). Model empiris yang didasarkan pada fungsi kecocokan ini terdiri dari 270 bentuk ekspresi matematik. Sedangkan bentuk-bentuk ekspresi matematik ini juga mencakup proses-proses non-linier yang tak dapat diabaikan dalam model empiris hari tenang variasi medan geomagnet tersebut. Model empiris ini dapat ditiru atau dikonstruksi kembali pada suatu selang waktu yang relatif panjang (misalnya satu siklus matahari), asalkan kondisi geomagnet selalu berada dalam keadaan tenang. Kontribusi dari model empiris hari tenang ini akan memberikan informasi tentang gangguan geomagnet yang ada di stasiun geomagnet Tondano (Nilai Gangguan geomagnet = Nilai variasi medan geomagnet yang terukur – Nilai model empiris hari tenang). Dengan demikian model ini akan memberikan informasi gangguan geomagnet untuk operasi survey geomagnet disekitar stasiun geomagnet Tondano, Manado. Kata kunci : Model empiris, Hari tenang, Variasi medan geomagnet. The determination an empirical model of the quiet daily geomagnetic field variation that is constructed based on geomagnetic data from Tondano, Manado station geomagnetic This quiet daily of geomagnetic field variation was described as a function of four variables that its influence, these are solar activity (SA), day of year (DOY), lunar age (LA) and local time (LT). In the mathematically writes: EMQD ( SA, DOY, LA, LT ) = f(SA). g(DOY). h(LA). m(LT). The empirical model based on this fitting function consist of 270 coefficients which included in expression form of mathematic. While, expression form of this mathematic also comprise nonlinear processes which can not minimized in the empirical model of the quiet daily geomagnetic field variation. This empirical model can be reconstructed on the time interval that is long relative (for example one solar cycle). Provided that, under geomagnetic quiet conditions. Contribution of this empirical model of the quiet daily variation is can give information about the existence of geomagnetic disturbance at Tondano (value of geomagnetic disturbance equal value of measurable geomagnetic field variation minus value of empirical model of the quiet daily variation). Thus, information about the existence of this geomagnetic disturbance very useful for necessity geomagnetic survey at Tondano, Manado geomagnetic station. Keywords: Empirical model, the quiet daily variation, geomagnetic field variation.

We investigate the interrelation between the hydration of the lunar regolith and the mineral composition of the surface of the Moon with respect to the concentrations of plagioclase, TiO2 (highly correlated with the oxide mineral ilmenite), and Mg-spinel. The spectral properties of lunar regions with a low concentration of plagioclase or a high concentration of TiO2 or Mg-spinel show a significant reduction in hydration at lunar midday compared to other compositions. This suggests that these oxide minerals contain less of the strongly bound OH component, which is not removed at lunar midday. The time-of-day-dependent variation of the 3 μm band depth is greater in TiO2-rich areas compared to other mare regions. The TiO2-rich regions therefore appear to have a strong tendency to adsorb solar wind-induced hydrogen into binding states of low energy that can more readily desorb and readsorb OH/H2O on a daily basis.

This study describes the daily activity in a simulated high tide situation of four species of hermit crabs (Pagurus criniticornis, Clibanarius antillensis, C. sclopetarius, and C. vittatus) that coexist in an intertidal flat in southeastern Brazil. Observations were done in two-hour intervals during two subsequent days (48 h) in three replicate pools with thirty crabs each. Among species (between and within genera) there was an evident variation in activity patterns, of which three could be distinguished. The circadian activity patterns of C. antillensis and C. vittatus could be characterized as evening and nocturnal, with resting peaks during the morning and afternoon. The circadian activity pattern of C. sclopetarius was characterized by two marked peaks of inactivity, corresponding to dawn and evening, which could represent an intrinsic association with the semi-lunar tidal cycles of the study area. Pagurus criniticornis showed high activity not influenced by day/night conditions during the entire observed period. These activity pattern variations of the studied hermit crabs should be taken into account in designing further experiments. More precise and accurate interspecific behavioral comparisons among species could be achieved in nocturnal experiments, the high activity period of all species.

Abstract The relative influence of climatic and social factors on sex-specific variation in reproductive behaviour remains poorly understood. Here, we examine the influence of multiple climatic cues in combination with a social cue on the reproductive behaviours of males and females in a terrestrial breeding toadlet (Pseudophryne coriacea). Over a 115-day breeding season, arrival patterns of each sex, and male calling activity, were recorded daily, while climatic variables were logged continuously. Multivariate analysis showed that arrival of males at the breeding site, as well as male nightly calling activity, were most strongly influenced by a climatic variable (rainfall). By contrast, female arrival was strongly correlated with a social variable (male calling activity), with abiotic conditions having no influence, other than a moderate influence of lunar phase (lunar illumination). These results suggest that cues used for breeding are sex specific and provide new evidence that combinations of climatic and social cues can be integrated into breeding decisions.

Abstract A study of the activity patterns, time allocation for each activity and variations in activities due to environmental alterations are necessary for understanding the biology of any species. This study investigates the relationship of micro-habitat and environmental conditions with seasonal and temporal activities of Indian crested porcupines (ICP) around their burrows in Keoladeo National Park (KNP), India. This species is considered as a problem species, often ignoring its ecological importance as an ecosystem engineer. Of the 39 sampled burrows, 58.97%, 38.46% and 83.78% were occupied in winter, summer and monsoon, respectively. The estimated porcupine density was 3.21±1.32SD individuals/km2, accounting for a population size of 65.89±27.15SD individuals. A seasonal shift in rate of emergence was observed in monsoon and winter, when ICP emerged earlier, significantly correlating with the sunset timings. The daily activity records of adult ICP outside burrow significantly peaked in January–February when they prepare the burrows for the gestation period of 90–112 days, followed by rearing of the offspring. The temporal activity significantly reduced in the full moon nights, perhaps to avoid predators. The study affirms that environmental determinants including the timings of sunrise, sunset and lunar phase significantly affect the variations in temporal activity and burrow use patterns of ICP.

Abstract. Variations in the Polar Jet Stream directly affect weather across Europe and North America (Francis et al., 2012). Jet Stream dynamics are governed by the development of planetary Rossby waves (Dickinson, 1978) driven by variation of the Coriolis force with latitude. Here we show that increasing atmospheric tides induce the development of Rossby waves, especially during winter months. This changes the flow and direction of the Jet Stream, as measured by the Arctic Oscillation (AO). Although horizontal tidal forces are tiny (107 smaller than gravity), they act over huge areas dragging the Jet Stream flow southwards in regular pulses as the earth rotates. This induces a changing Coriolis torque, which then distorts the Jet Stream flow. The data from eight recent winters are studied indicating that the AO is anti-correlated to the horizontal "tractional" component of tides acting between latitude 45 and 60° N. The observed 28 day cycle in Jet Stream flow and extent has a statistical significance > 99 %. A cross-correlation between all daily AO data since 1950 and the tractional tidal strength shows a significant anti-correlation with a lag time of ~ 5 days. The strongest correlation and largest excursions of the AO are observed during winter 2005/2006 – a maximum lunar standstill year. This declination dependence of tidal forces at high latitudes is the proposed cause of many previous reports of an 18.6 year dependence of continental rainfall and drought.

Introduction: Variations of patient volumes in the ED according to days of the week and month of the year are well-established. Anecdotally, ED volumes follow ‘waves’ that correlate with previous days. Time-series models have traditionally been used in econometrics to develop financial models, but have been adapted in other fields, such as health informatics. This study uses a time-series approach to assess whether these impressions are valid. Methods: The daily volume of patients presenting to four emergency departments (ED) at the Nova Scotia Health Authority from Jan 2010 to May 2015 were analyzed to assess for the effect of previous volumes on future volumes. Parameters were selected using the auto-correlation (ACF) and partial auto-correlation functions (PACF) for a Seasonal Auto-regressive Integrated Moving Average (SARIMA) model. The Box-Jenkins statistic was assessed for model suitability. To assess for accuracy, a forecast of the model was evaluated with a year of volumes set aside for testing. Results: The EDs saw an average of 365.1 patients per day, with a minimum of 188 patients and a maximum of 479. The increasing trend in volumes consistent with the increasing number of ED presentations nation-wide was detrended using linear regression. There was a significant correlation in ACF with the previous day (ρ1 = 0.297). A seasonal, periodic trend was seen weekly. Significant correlations occurred annually (ρ365 = 0.279) and at 29 days (ρ29 = 0.339), consistent with the lunar cycle. A seasonal model was postulated incorporating an auto-regressive (AR) coefficient, and a moving average (MA) coefficient for the previous day’s volume. An AR and MA seasonal coefficient were each incorporated using the weekly period. When using the model on the test data, the model predicted 4 more patient presentations on average than the true value, with 90% of the values within 37 presentations of the true volume. The Box-Jenkins statistic was non-significant, indicating no problems with model specification. Conclusion: The volume of patients presenting to an ED system is correlated with that of the previous day. A weekly seasonal variation was confirmed. Auto-correlations also occur annually and possibly associated with the lunar cycle. Previous ED volumes may be useful in forecasting patient volumes. The time-series approach may discover further ways to predict ED volumes.

Abstract Spotted seatrout (Cynoscion nebulosus) exhibit various seasonal patterns of reproduction and juvenile recruitment in estuaries across their range. To explain this variability, data on the reproductive state of 1674 individual females from the Indian River Lagoon were used to develop a generalized additive model (GAM) describing the relationship between reproduction and local environmental conditions. The model predicted that optimum spawning conditions exist at a water temperature of 29°C, indicating that if this temperature was exceeded during the spawning season, spawning activity would be temporarily curtailed, which would lead to a bimodal recruitment curve. In contrast, daily mean water temperatures below the optimum condition would result in a single recruitment peak. The reproductive model was largely consistent with historical information on spotted seatrout spawning seasonality along the gulf and Atlantic coasts of the US. Factors other than temperature (i.e., hours after sunset, lunar period and size and condition factor of females) were also found to regulate reproductive activity. Model predictions of the number of recruits based on local temperature regimes during the spawning season were compared to actual catches of juvenile spotted seatrout in three Florida estuaries. The reproductive model was able to predict the timing and modality of recruitment, but the relative amplitude of the fluctuations in abundance was dampened considerably compared to the observed variation.

Abstract. SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) on-board the European Environmental Satellite (Envisat) provided spectrally resolved measurements in the wavelength range from 0.24 to 2.4 µm by looking into the Earth's atmosphere using different viewing geometries (limb, nadir, solar, and lunar occultation). These observations were used to derive a multitude of parameters, in particular atmospheric trace gas amounts. In addition to radiance measurements solar spectral irradiances (SSIs) were measured on a daily basis. The instrument was operating for nearly a decade, from August 2002 to April 2012. Due to the harsh space environment, it suffered from continuous optical degradation. As part of recent radiometric calibration activities an optical (physical) model was introduced that describes the behaviour of the scanner unit of SCIAMACHY with time (Krijger et al., 2014). This model approach accounts for optical degradation by assuming contamination layers on optical surfaces in the scanner unit. The variation in layer thicknesses of the various optical components is determined from the combination of solar measurements from different monitoring light paths available for SCIAMACHY. In this paper, we present an optimisation of this degradation correction approach, which in particular improves the solar spectral data. An essential part of the modification is the use of measurements from SCIAMACHY's internal white light source (WLS) in combination with direct solar measurements. The WLS, as an independent light source, therefore, gives an opportunity to better separate instrument variations and natural solar variability. However, the WLS emission depends on its burning time and changes with time as well. To use these measurements in the optimised degradation correction, the change in the WLS emission in space needs to be characterised first. The changes in the WLS with accumulated burning time are in good agreement with detailed laboratory lamp studies by Sperling et al. (1996). Although the optimised degradation-corrected SCIAMACHY SSIs still show some instrumental issues when compared to SSI measurements from other instruments and model reconstructions, our study demonstrates the potential for the use of an internal WLS for degradation monitoring.

This study assessed relationships between traffic accidents and variables of the physical environment. Daily data on traffic accidents over a 4-year period were compared with daily records of barometric pressure and synodic lunar cycle. No significant variations in the number of accidents were found related to barometric height but a significant lunar periodicity was observed for one of the years considered. The number of accidents occurring during the full moon day was lowest; the highest occurred two days before the full moon. Accidents occurred more frequently during crescent moon than during waning moon, but no significant differences were noted when the lunar month was divided into four intervals of new moon, first quarter, full moon, and second quarter.

The ground tracking support is a critical factor for the navigation performance of spacecraft orbiting around the Moon. Because of the tracking limit of antennas, only a small number of facilities can support lunar missions. Therefore, case studies for various ground tracking support conditions are needed for lunar missions on the stage of preliminary mission analysis. This study analyzes the ground supporting condition effect on orbit determination (OD) of Korea Pathfinder Lunar Orbiter (KPLO) in the lunar orbit. For the assumption of ground support conditions, daily tracking frequency, cut-off angle for low elevation, tracking measurement accuracy, and tracking failure situations were considered. Two antennas of deep space network (DSN) and Korea Deep Space Antenna (KDSA) are utilized for various tracking conditions configuration. For the investigation of the daily tracking frequency effect, three cases (full support, DSN 4 pass/day and KDSA 4 pass/day, and DSN 2 pass/day and KDSA 2 pass/day) are prepared. For the elevation cut-off angle effect, two situations, which are 5 deg and 10 deg, are assumed. Three cases (0%, 30%, and 50% of degradation) were considered for the tracking measurement accuracy effect. Three cases such as no missing, 1-day KDSA missing, and 2-day KDSA missing are assumed for tracking failure effect. For OD, a sequential estimation algorithm was used, and for the OD performance evaluation, position uncertainty, position differences between true and estimated orbits, and orbit overlap precision according to various ground supporting conditions were investigated. Orbit prediction accuracy variations due to ground tracking conditions were also demonstrated. This study provides a guideline for selecting ground tracking support levels and preparing a backup plan for the KPLO lunar mission phase.

In the context of chronobiological research on trees, a high-sensitivity device was developed to measure low-potential electric currents along the bole of two trees growing under open conditions. Rhythmic variations of the(bio-)electric potentials are found, linked on the one hand to daily photoperiods and on the other to lunar periodicities,depending on the physiological phase of the trees.

Abstract. The series of daily Ap-indices has been subdivided into pentades (1932–1936 etc.) and spectra with fine-frequency resolution have been calculated for the indices in each of these intervals. Daily sunspot numbers have been processed in the same way. The average spectrum from all spectra in the pentades, as well as the spectrum from the whole interval have been calculated, and significant peaks have been determined. There is a significant difference between the spectra in the pentades containing the solar activity minimum (1932–1936, 1942–1946 etc.) and those containing the solar activity maximum (1937–1941, 1947–1951 etc.). Most peaks can be interpreted as a response to solar rotation and to the structure of solar wind speed (two high-speed streams per solar rotation), both modulated by the 11-year, annual and semi-annual waves. No significant peak corresponding to the period of the synodic month, or its half has been found. This result suggests that the influence of lunar cycles on some natural phenomena (if any) is not mediated by geomagnetic activity.Key words. Geomagnetism and paleomagnetism · Time variations · Diurnal to secular · Magnetospheric physics · Solar wind-magnetosphere interactions

Abstract In Masbate, senatorial scallop Chlamys senatoria is one of the five commercially important species of scallop present in Asid Gulf, but its basic biology is poorly understood in the Philippines. To provide biological information for future conservation and management, the reproductive rhythm of senatorial scallop in relation to lunar phase was investigated from October 2016 to March 2017. Scallops were collected daily from the fishers’ catches and were measured, dissected, and processed for histological analysis; whereas, fecundity and size of eggs (diameter) were also determined. Ecological parameter such as bottom water temperature was monitored during the sampling period. Results showed that C. senatoria is a highly fecund species, which ranges from 8.3 X 105 to 2.1 X 106 oocytes per female and its sizes (oocytes) ranges from 53.8 µm to 72.5 µm while Gonado-somatic index (GSI) ranges from 3.2 to 7.1. Fecundity, egg diameter, and the GSI decreased during new moon (NM) and full moon (FM). GSI indicates that the onset of spawning activity commences during NM and FM. Environmental parameters that were monitored showed significant variations in relation to lunar phase. Spawning of scallop C. senatoria follows a lunar reproductive pattern, which was initiated and influenced by the variations of different factors such as temperature, water amplitude, and light as the effect of lunar/tidal cycles. These findings indicate that reproduction and necessarily spawning in the scallop are related to factors associated with lunar phases. Strategies for managing the resource can be formulated using the temporal dimension of lunar phases.

Abstract. High-quality ocean colour observations are increasingly accessible to support various monitoring and research activities for water quality measurements. In this paper, we present a newly developed regional total suspended solids (TSSs) empirical model using MODIS Aqua's Rrs(530) and Rrs(666) reflectance bands to investigate the spatial and temporal variation in TSS dynamics along the southwest coast of Sarawak, Borneo, with the application of the Open Data Cube (ODC) platform. The performance of this TSS retrieval model was evaluated using error metrics (bias = 1.0, MAE = 1.47, and RMSE = 0.22, in milligrams per litre) with a log10 transformation prior to calculation as well as using a k-fold cross-validation technique. The temporally averaged map of the TSS distribution, using daily MODIS Aqua satellite datasets from 2003 until 2019, revealed that large TSS plumes were detected – particularly in the Lupar and Rajang coastal areas – on a yearly basis. The average TSS concentration in these coastal waters was in the range of 15–20 mg L−1. Moreover, the spatial map of the TSS coefficient of variation (CV) indicated strong TSS variability (approximately 90 %) in the Samunsam–Sematan coastal areas, which could potentially impact nearby coral reef habitats in this region. Study of the temporal TSS variation provides further evidence that monsoonal patterns drive the TSS release in these tropical water systems, with distinct and widespread TSS plume variations observed between the northeast and southwest monsoon periods. A map of relative TSS distribution anomalies revealed strong spatial TSS variations in the Samunsam–Sematan coastal areas, while 2010 recorded a major increase (approximately 100 %) and widespread TSS distribution with respect to the long-term mean. Furthermore, study of the contribution of river discharge to the TSS distribution showed a weak correlation across time at both the Lupar and Rajang river mouth points. The variability in the TSS distribution across coastal river points was studied by investigating the variation in the TSS pixels at three transect points, stretching from the river mouth into territorial and open-water zones, for eight main rivers. The results showed a progressively decreasing pattern of nearly 50 % in relation to the distance from shore, with exceptions in the northeast regions of the study area. Essentially, our findings demonstrate that the TSS levels on the southwest coast of Sarawak are within local water quality standards, promoting various marine and socio-economic activities. This study presents the first observation of TSS distributions in Sarawak coastal systems with the application of remote sensing technologies and aims at enhancing coastal sediment management strategies for the sustainable use of coastal waters and their resources.

Accurate electricity load forecasting is an important prerequisite for stable electricity system operation. In this paper, it is found that daily and weekly variations are prominent by the power spectrum analysis of the historical loads collected hourly in Tai’an, Shandong Province, China. In addition, the influence of the extraneous variables is also very obvious. For example, the load dropped significantly for a long period of time during the Chinese Lunar Spring Festival. Therefore, an artificial neural network model is constructed with six periodic and three nonperiodic factors. The load from January 2016 to August 2018 was divided into two parts in the ratio of 9 : 1 as the training set and the test set, respectively. The experimental results indicate that the daily prediction model with selected factors can achieve higher forecasting accuracy.

Abstract. The effect of tidal triggering on earthquake occurrence has been controversial for many years. This study considered earthquakes that occurred near Taiwan between 1973 and 2008. Because earthquake data are nonlinear and non-stationary, we applied the empirical mode decomposition (EMD) method to analyze the temporal variations in the number of daily earthquakes to investigate the effect of tidal triggering. We compared the results obtained from the non-declustered catalog with those from two kinds of declustered catalogs and discuss the aftershock effect on the EMD-based analysis. We also investigated stacking the data based on in-phase phenomena of theoretical Earth tides with statistical significance tests. Our results show that the effects of tidal triggering, particularly the lunar tidal effect, can be extracted from the raw seismicity data using the approach proposed here. Our results suggest that the lunar tidal force is likely a factor in the triggering of earthquakes.

Locomotor activity patterns of laboratory mice are widely used to analyze circadian mechanisms, but most investigations have been performed under standardized laboratory conditions. Outdoors, animals are exposed to daily changes in photoperiod and other abiotic cues that might influence their circadian system. To investigate how the locomotor activity patterns under outdoor conditions compare to controlled laboratory conditions, we placed 2 laboratory mouse strains (melatonin-deficient C57Bl and melatonin-proficient C3H) in the garden of the Dr. Senckenbergische Anatomie in Frankfurt am Main. The mice were kept singly in cages equipped with an infrared locomotion detector, a hiding box, nesting material, and with food and water ad libitum. The locomotor activity of each mouse was recorded for 1 year, together with data on ambient temperature, light, and humidity. Chronotype, chronotype stability, total daily activity, duration of the activity period, and daily diurnality indices were determined from the actograms. C3H mice showed clear seasonal differences in the chronotype, its stability, the total daily activity, and the duration of the activity period. These pronounced seasonal differences were not observed in the C57Bl. In both strains, the onset of the main activity period was mainly determined by the evening dusk, whereas the offset was influenced by the ambient temperature. The actograms did not reveal infra-, ultradian, or lunar rhythms or a weekday/weekend pattern. Under outdoor conditions, the 2 strains retained their nocturnal locomotor identity as observed in the laboratory. Our results indicate that the chronotype displays a seasonal plasticity that may depend on the melatoninergic system. Photoperiod and ambient temperature are the most potent abiotic entraining cues. The timing of the evening dusk mainly affects the onset of the activity period; the ambient temperature during this period influences the latter’s duration. Humidity, overall light intensities, and human activities do not affect the locomotor behavior.

Understanding natural variations of Rn (222Rn) concentrations is the fundamental prerequisite of using this radioactive gas as a tracer, or even precursor, of natural processes, including earthquakes. In this work, Rn concentrations in groundwater were continuously measured over a seven-month period, during 2017, in the Giardino Spring, Italy, together with groundwater levels in a nearby well installed into a fractured regional aquifer. Data were processed to reduce noise, and then analyzed to produce the Fourier spectra of Rn concentrations and groundwater levels. These spectra were compared with the spectrum of tidal forces. Results showed that diurnal and semidiurnal cycles of Rn concentrations, and filtered oscillations of groundwater levels, in the nearby well, are correlated with solar and luni-solar components of tidal forces, and suggested no correlation with the principal lunar components. Therefore, influencing factors linked to solar cycles, such as daily oscillations of temperature and atmospheric pressure, and related rock deformations, may have played a role in Rn concentrations and groundwater levels. An open question remains regarding the correlation, which is documented elsewhere, of Rn concentrations and groundwater levels with the lunar components of the solid Earth tides.

Passive acoustic monitoring provides a method for studying grouper courtship associated sounds (CAS). For Red Hind (Epinephelus guttatus), this approach has documented spatio—temporal patterns in their spawning aggregations. This study described vocalizations produced by E. guttatus and their respective behavioral contexts in field and laboratory studies. Five sound types were identified, which included 4 calls recorded in captivity and one sound recorded in the wild, labeled as Chorus. Additionally, the Grunt call type recorded was presumed to be produced by a female. Call types consisted of variations and combinations of low frequency (50—450 Hz) pulses, grunts and tonal sounds in different combinations. Common call types exhibited diel and lunar oscillations during the spawning season, with both field and captive recordings peaking daily at 1800 AST and at 8 days after the full moon.

Passive acoustic monitoring provides a method for studying grouper courtship associated sounds (CAS). For Red Hind (Epinephelus guttatus), this approach has documented spatio—temporal patterns in their spawning aggregations. This study described vocalizations produced by E. guttatus and their respective behavioral contexts in field and laboratory studies. Five sound types were identified, which included 4 calls recorded in captivity and one sound recorded in the wild, labeled as Chorus. Additionally, the Grunt call type recorded was presumed to be produced by a female. Call types consisted of variations and combinations of low frequency (50—450 Hz) pulses, grunts and tonal sounds in different combinations. Common call types exhibited diel and lunar oscillations during the spawning season, with both field and captive recordings peaking daily at 1800 AST and at 8 days after the full moon.

Abstract. Gaseous pollutants at the ground level seriously threaten the urban air quality environment and public health. There are few estimates of gaseous pollutants that are spatially and temporally resolved and continuous across China. This study takes advantage of big data and artificial-intelligence technologies to generate seamless daily maps of three major ambient pollutant gases, i.e., NO2, SO2, and CO, across China from 2013 to 2020 at a uniform spatial resolution of 10 km. Cross-validation between our estimates and ground observations illustrated a high data quality on a daily basis for surface NO2, SO2, and CO concentrations, with mean coefficients of determination (root-mean-square errors) of 0.84 (7.99 µg m−3), 0.84 (10.7 µg m−3), and 0.80 (0.29 mg m−3), respectively. We found that the COVID-19 lockdown had sustained impacts on gaseous pollutants, where surface CO recovered to its normal level in China on around the 34th day after the Lunar New Year, while surface SO2 and NO2 rebounded more than 2 times slower due to more CO emissions from residents' increased indoor cooking and atmospheric oxidation capacity. Surface NO2, SO2, and CO reached their peak annual concentrations of 21.3 ± 8.8 µg m−3, 23.1 ± 13.3 µg m−3, and 1.01 ± 0.29 mg m−3 in 2013, then continuously declined over time by 12 %, 55 %, and 17 %, respectively, until 2020. The declining rates were more prominent from 2013 to 2017 due to the sharper reductions in anthropogenic emissions but have slowed down in recent years. Nevertheless, people still suffer from high-frequency risk exposure to surface NO2 in eastern China, while surface SO2 and CO have almost reached the World Health Organization (WHO) recommended short-term air quality guidelines (AQG) level since 2018, benefiting from the implemented stricter “ultra-low” emission standards. This reconstructed dataset of surface gaseous pollutants will benefit future (especially short-term) air pollution and environmental health-related studies.

Abstract. Carbon monoxide (CO) is a main pollutant in urban agglomerations. Quantifying the total burden of this pollutant in a megacity is challaging because not only its surface concentration but also its vertical dispersion present different behaviours and high variability. The diurnal trend of columnar CO in the boundary layer of Mexico City has been measured during various days with ground-based infrared absorption spectroscopy. Daytime CO total columns are retrieved from solar spectra and for the first time, nocturnal CO total columns using moonlight have been retrieved within a megacity. The measurements were taken at the Universidad Nacional Autónoma de México (UNAM) campus located in Mexico City (19.33° N, 99.18° W, 2260 m a.s.l.) from October 2007 until February 2008 with a Fourier-transform infrared spectrometer at 0.5 cm−1 resolution. The atmospheric CO background column was measured from the high altitude site Altzomoni (19.12° N, 98.65° W, 4010 m a.s.l.) located 60 km southeast of Mexico City. The total CO column within the city presents large variations that are caused mainly by fresh CO emissions at the surface, but also the transport of cleaner or more polluted air masses within the field-of-view of the instrument and other processes contribute to its variability. The mean background value above the boundary mixing layer was found to be around (1.2±0.2)×1018 molecules/cm2, while inside the city, the late morning mean on weekdays and Sundays was found to be (3.2±0.3)×1018 molecules/cm2 and (2.1±0.4)×1018 molecules/cm2, respectively. Continuous CO column retrieval during the day and night (when available), in conjunction with surface CO measurements, allow for a reconstruction of the effective mixing layer height. The limitations from this simplified approach, as well as the potential of using continuous column measurements in order to derive top-down CO emissions from a large urban area, are discussed. Also, further monitoring will provide more insight in daily and weekly emission patterns and a usable database for the quantitative validation of CO from satellite observations in a megacity.

Abstract. Carbon monoxide (CO) is an important pollutant in urban agglomerations. Quantifying the total burden of this pollutant in a megacity is challenging because not only its surface concentration but also its vertical dispersion present different behaviours and high variability. The diurnal trend of columnar CO in the boundary layer of Mexico City has been measured during various days with ground-based infrared absorption spectroscopy. Daytime CO total columns are retrieved from solar spectra and for the first time, nocturnal CO total columns using moonlight have been retrieved within a megacity. The measurements were taken at the Universidad Nacional Autónoma de México (UNAM) campus located in Mexico City (19.33° N, 99.18° W, 2260 m a.s.l.) from October 2007 until February 2008 with a Fourier-transform infrared spectrometer at 0.5 cm−1 resolution. The atmospheric CO background column was measured from the high altitude site Altzomoni (19.12° N, 98.65° W, 4010 m a.s.l.) located 60 km southeast of Mexico City. The total CO column within the city presents large variations. Fresh CO emissions at the surface, the transport of cleaner or more polluted air masses within the field-of-view of the instrument and other processes contribute to this variability. The mean background value above the boundary mixing layer was found to be (8.4±0.5)×1017 molecules/cm2, while inside the city, the late morning mean on weekdays and Sundays was found to be (2.73±0.41)×1018 molecules/cm2 and (2.04±0.57)×1018 molecules/cm2, respectively. Continuous CO column retrieval during the day and night (when available), in conjunction with surface CO measurements, allow for a reconstruction of the effective mixing layer height. The limitations from this simplified approach, as well as the potential of using continuous column measurements in order to derive top-down CO emissions from a large urban area, are discussed. Also, further monitoring will provide more insight in daily and weekly emission patterns and a usable database for the quantitative validation of CO from satellite observations in a megacity.

ABSTRAK. Penelitian ini bertujuan untuk menguji kontribusi faktor klimat di musim kemarau terhadap kondisi mikroklimat closed house periode brooder dengan panjang kandang berbeda. Unit kandang digunakan yaitu kandang ukuran panjang 60 m dan 120 m. Pengamatan dilakukan pagi hari (05.00 WIB), siang hari (13.00 WIB) dan malam hari (21.00 WIB). Parameter makroklimat yang diamati meliputi suhu, kelembaban udara, kecepatan angin dan radiasi matahari serta kondisi mikroklimat meliputi suhu, kelembaban udara, kecepatan angin dan THI. Besaran kontribusi diukur berdasarkan keeratan hubungan dengan analisis korelasi. Koefisien korelasi yang menunjukkan hubungan cukup kuat dengan nilai r0,3, digunakan untuk membentuk persamaan regresi. Hasil penelitian menunjukkan besaran kontribusi komponen makroklimat pada pagi hari, siang hari maupun malam hari terhadap kondisi mikroklimat berupa suhu, kecepatan angin dan THI lebih besar di kandang panjang 60 m, sedangkan kontribusi makroklimat terhadap kelembaban udara mikroklimat lebih besar di kandang 120 m (p0,05). Rentang nilai r pada korelasi yaitu cukup kuat hingga sangat kuat. Hasil persamaan regresi yang terbentuk memiliki nilai determinasi R2 sangat kuat, sehingga layak digunakan sebagai prediktor. Prediktor kelembaban udara di kandang 60 m berupa kecepatan angin, kelembaban udara dan radiasi matahari makroklimat, sementara prediktor kelembaban udara di kandang panjang 120 m berupa suhu, kelembaban udara dan radiasi matahari. Simpulan penelitian yaitu kontribusi faktor makroklimat terhadap variasi kondisi mikroklimat berupa suhu, kecepatan angin dan THI pada periode brooder lebih besar di kandang 60 m daripada 120 m, sedangkan kontribusi komponen makroklimat terhadap kelembaban udara di kandang 120 m lebih besar dari kandang 60 m. (Contribution of climatic factor outside the lengths to the change of microclimate closed house with different lengths in brooder period in the dry season) ABSTRACT. This study conducted to calculate macroclimate contribution during brooding period house to different closed house length in dry season. Two broiler closed house 60 m and 120 m length here used in this research. Observed data were daily at 05.00 a.m, 1.00 p.m. and 9.00 p.m to represented microclimate condition in the morning, afternoon and night. Macroclimate parameters observed included temperature, relative humidity, air velocity, sun radiation and microclimate parameters included temperature, relative humidity, air velocity, THI. Macroclimate contribution on the microclimate was calculates based on the strength of the relationship using correlation analysis. Subsequently, regression equation formed on parameters which has r value more than 0.3. Results showed that macroclimate contributes on variation of microclimate condition such as temperature, air velocity and THI which is larger in the 60 m length than 120 m length closed house(p0.05). Macroclimate factors contributes on microclimate humidity which is larger in the 120 m than 60 m closed house length. The range of correlation r value are strong enough to very strong. Regression equations confirmed to having strong determination R value, thus can be used as a predictor of microclimate variation. Predictor parameter of microclimate humidity in 60 m closed house consist of air velocity, relative humidity and sun radiation, whereas microclimate humidity in 120 m closed house predictors consist of temperature, relative humidity and sun radiation. In conclusion macroclimate that contributes to the microclimate variation consist of temperature, air velocity and THI, which is larger in 60 m than 120 m closed house. Meanwhile, macroclimate that contributes to the microclimate humidity is larger in 120 m than 60 m closed house.

The purpose of this study was to study the influence of the variability of weather and heliophysical factors on the appeal to the Ambulance service for different groups of nosologies in the population of the Russian North. Information about calls to the emergency medical service of Khanty-Mansiysk was obtained from the database of calls for the period from 2001 to 2021 by disease classes (ICD-10). To assess the dynamics of weather factors, data from the All-Russian Research Institute of Hydrometeorological Information and materials from the weather station of Khanty-Mansiysk were used. The dynamics of air temperature; barometric pressure; relative humidity; baric trend; maximum wind speed; weight oxygen content in the air are analyzed. Data on the relative daily number of sunspots are obtained from the materials of the Royal Observatory of Belgium. The average daily values of the level of planetary geomagnetic activity, expressed by the Ap index, are copied from the website of the National Center for Geophysical Data of the USA (Boulder). Mathematical processing was carried out using wavelet analysis. The graph of temperature fluctuations for the period from 2001 to 2021 shows a significant circadian cyclicity and a semi-annual rhythm with a high level of trend. Significant rhythms of barometric pressure with a period of 5 years, 1 year and rhythms close to semi-annual, seasonal and near-monthly are observed. Humidity changes significantly in the circadian and intra-annual rhythms. The baric tendency has significant rhythms: 3 years, 1 year, 6, 3, 2 months. Changes in the maximum wind speed do not have a circadian rhythm, but intra-annual monthly variations are observed. The value of the weight oxygen content has circadian; two-year, five-year; two- and near-monthly rhythms. The relative number of sunspots (W) for the period from 2001 to 2021 is characterized by a five-, two-year and circadian rhythm. When considering the variations of the number W for the period from 1818 to 2017, in addition to the classic eleven-year, annual and near-monthly, rhythms with a period of 42.5 years, 18.1 years and 2.1 years are found. The index of planetary geomagnetic activity (Ar) has a rhythm with a period of 4 years, two-year and near-annual. The significance of all rhythms is p=0.001. When analyzing fluctuations in geomagnetic activity from 1932 to 2016, long-term rhythms are added: 35.00 years; 16.06 years; 10.88 years; semi-annual and three-month rhythms. Despite numerous hypotheses of the search for cosmobiological harmony in the form of evolutionary synchronisms, rhythmic cascades, golden section, the problem of the interaction of exogenous natural rhythms and endogenous rhythms of the human body remains largely unresolved. Comparison of the results of various studies is difficult due to methodological and mathematical approaches. With observation periods of 100-200 years or more, a long-period component is monitored, and in clinical studies (from a day to a week), short-period components are detected. Changing the background in the form of helioclimatic and social variations also does not add accuracy. The use of various methods of time series analysis involves obtaining information of different resolution levels (Fourier transform, SWANN, wavelet analysis). Nevertheless, the results obtained track the classical rhythms of solar and geomagnetic activity with periods of about eleven years, a year and a month. There is also a 35-year-old rhythm, a 42.5-year-old rhythm close to the 44.16-year rhythm identified by Bezrukova A.Ya., at 18.1 years (long-period components of the lunar tide) and other intra-annual rhythms with periods from two weeks to 9 months. The effect of helioclimatic factors on human health indicates the absence of constant coherence (in our case, the consistency of these processes over time, manifested when they are combined), due to the presence of a large number of mega- and mesorhythms, which is manifested by amplitude and phase desynchronization of heliogeophysical indicators and health status.

"Semiotics of The Right To Dream: Mythical Dimensions of Time From The Romanian Fantastic Fairy Tale A fundamental concept of human existence as a species, Time has always been a defining landmark of the depth of thought of homo sapiens. With religious or scientific character, the ensemble of myths, beliefs, ideas, ideologies, representations and significances given to this concept led, …in time, to the birth of a rich, distinct and complex symbolic imaginary. Both a physical continuum (space-time in which biological, chemical, physical and mechanical processes occur that cause changes in Nature) and a philosophical one (events are perceived and cognitively systematized by man from the past to present towards future), Time it has always aroused peoples interest. We have deities of Time (Cronus, Zurvan, Maku). We have, also, the characteristic concepts that mark the fictional-mythical transfiguration and the triumph of the irreducible search for the truth of meaning. Such as the promise of a (possible) paradisiacal land of eternity, such as the Aion concept of the ancient Greeks (in the sense of cyclical time/eternity), or the existence of specialized divine beings (Moirs of ancient Greece, Roman Parce or Scandinavian Norns) who measure the profane time (past, present, future), and relates it to the celestial, relativistic, perpetual-eternal time. From the area of pure philosophy who approache the subject, inevitably passing through the field of quantum physics that tries to define as precisely as possible the notion of Time (definition, dimensions, units of measurement etc.), we have approaches to this concept at the level of music, literature, art. An true illud tempus, moving the content from metaphysics to myth, and viceversa, there are the many reflections of famous people about the concept of time. Approaching topics about the existence of ,,fashionable” references (billionaires, famous or just controversial politicians, footballers, actors, etc.), we have a post-modern mythological imaginary offered daily by Time Magazine, The New York Times, The Sunday Times etc. As well, being an important landmark in the editing policy, we have a font agreed by more and more magazines, periodicals, publishing houses - Times New Roman. The social life of the traditional Romanian communities, who generates and consumes fantastic fairy tales, tried to reconcile the human activities with the constant phenomena of the environment (terrestrial, cosmic). Starting from certain constants that counted human activity with the cosmic and terrestrial rhythms of Nature (day-night succession; the succession of seasons; the rhythmicity of some manifestations of the vegetal and animal kingdom), the calendars had appeared lunar, solar, solar-lunar, popular, Christian, civil). Their existence and use made that the passage of time to be more easily perceived and memorized. The calendar practices and habits, performed in a predetermined time and in a certain way (= ritual), did nothing but mark in the traditional symbolic thinking the specificity of that human time, to perform in that tradition, in Cosmic Time, trans-human time. This study deal with the valorizations and symbolism given to this concept by the popular imagination from Romanian fantastic fairy tale. The collections of fairy tales offered me some major directions that defines Time, sometimes the traditional imagination being a subtle game of physical constants and mythical-epic variations. Thus, I discovered metaphysical dimensions of time, the reason for linking Time, an optimal time of action, but also the exercise of distance (Time-Space) to be traveled by the hero or realms of eternity, where Time does not even exist as an abstraction… Everything followed, naturally, by a series of conclusions. Keywords: imaginary, phenomenology, hermeneutics, Romanian fairytale, Time "

AbstractThis paper describes solar and lunar daily variations of the geomagnetic field over low- and mid-latitude regions, using vector magnetometer data from Swarm satellites at altitudes of $$\sim$$ ∼ 500 km during the solar minimum years of 2017–2020. The average solar variation of the geomagnetic field is within the range of ±14 nT, while the lunar variation is within ±2 nT. The latter is comparable to the ocean tidal field. A spherical harmonic analysis is performed on the solar and lunar variations to evaluate their internal and external equivalent current systems. The results show that both the solar and lunar variations are mainly of internal origin, which can be attributed to combined effects of ionospheric dynamo currents and induced underground currents. Global patterns of the internal solar and lunar current systems are consistent with the corresponding external current systems previously reported based on ground observations. The Swarm external currents are mainly in the meridional direction, and are likely associated with interhemispheric field-aligned currents. Both the internal and external current systems depend on the season and longitude. Graphical Abstract

The geomagnetic field variation spectra for periods longer than 2 h are analysed using the data obtained at the Kandilli Observatory in Istanbul, Turkey. Among the deterministic components, only the harmonics of the solar daily variation (Si) and the second harmonic of the lunar daily variation (L2) were observed. The seasonal dependence of the D component is analysed; the first harmonic of the solar daily variation (S1) has maximum power in summer, decreasing symmetrically towards the winter; the second harmonic (S2) has equal power in spring, summer and fall, while the third harmonic (S3) has maximal power in spring and fall.

Abstract Background Many animals in coral reefs exhibit lunar cycles in their reproduction, showing synchronous gametogenesis and spawning at a particular moon phase. How these lunar reproductive cycles are endogenously regulated remains unknown, although changes in moonlight between the new moon and full moon are likely involved in this rhythmic event. Results This study evaluated the possible role of cryptochrome (cry1, cry2, cry3) in phase shifting and setting in the honeycomb grouper Epinephelus merra, which is a typical lunar spawner with full moon preference. qPCR analysis revealed that when fish were reared under alternating light-dark conditions, the transcript levels of cry1 and cry2, but not of cry3, in the diencephalon and pituitary gland showed daily variations. Weekly collection at midnight showed increases in the transcript levels of cry1 and cry2 in the diencephalon, but not the pituitary gland, from the first quarter moon through the last quarter moon. In comparison to the new moon, these transcript levels were significantly lower at all other sampling times. The artificial full moon conditions for 1 month resulted in increased cry transcript levels in both tissues at 2 (cry1) or 2 and 4 (cry2) weeks after the initiation of full moon conditions. Conclusions These results indicate the importance of transient changes in “brightness at night” in the response to moonlight for the phase shift and of “darkness at night” during the new moon for the phase set to the determined moon phase. We concluded that the moon phase-dependent oscillation of clock genes plays a role in lunar cycle-dependent behaviors in fish.

Abstract Background Spawning migrations are a widespread phenomenon among fishes, often occurring in response to environmental conditions prompting movement into reproductive habitats (migratory cues). However, for many species, individual fish may choose not to migrate, and research suggests that conditions preceding the spawning season (migratory primers) may influence this decision. Few studies have provided empirical descriptions of these prior conditions, partly due to a lack of long-term data allowing for robust multi-year comparisons. To investigate how primers and cues interact to shape the spawning migrations of coastal fishes, we use acoustic telemetry data from Common Snook (Centropomus undecimalis) in Everglades National Park, Florida, USA. A contingent of Snook migrate between rivers and coastal spawning sites, varying annually in both the proportion of the population that migrates and the timing of migration within the spawning season. However, the specific environmental factors that serve as migratory primers and cues remain unknown. Methods We used eight years of acoustic telemetry data (2012–2019) from 173 tagged Common Snook to investigate how primers and cues influence migratory patterns at different temporal scales. We hypothesize that (1) interannual differences in hydrologic conditions preceding the spawning season contribute to the number of individuals migrating each year, and (2) specific environmental cues trigger the timing of migrations during the spawning season. We used GLMMs to model both the annual and seasonal migratory response in relation to flow characteristics (water level, rate of change in water level), other hydrologic/abiotic conditions (temperature, salinity), fish size, and phenological cues independent of riverine conditions (photoperiod, lunar cycle). Results We found that the extent of minimum marsh water level prior to migration and fish size influence the proportion of Snook migrating each year, and that high river water level and daily rates of change serve as primary cues triggering migration timing. Conclusion Our findings illustrate how spawning migrations are shaped by environmental factors acting at different temporal scales and emphasize the importance of long-term movement data in understanding these patterns. Research providing mechanistic descriptions of conditions that promote migration and reproduction can help inform management decisions aimed at conserving ecologically and economically important species.

Abstract Objectives To study seasonal variation in minimum dietary diversity of women (MDD-W) and food group intake for women of reproductive age (WRA) living in rural Zambia and Malawi where the effect of seasonal agricultural production and seasonal food availability on dietary diversity is likely to be high. Methods 200 WRA living in Chitipa District, Malawi (n = 100) and Luwingu District, Zambia (n = 100) provided informed consent and were enrolled in a panel study. Households with at least one woman between age 15–49 were randomly selected. A dietary diversity questionnaire was administered every-other month for six rounds, from September 2017 to July 2018. MDD-W was calculated as the proportion of women consuming five or more out of ten food groups. Percent of women consuming each food group by round was also calculated. Chi square was used to test the difference in MDD-W across rounds. Results There was significant seasonal difference in the percentage of women achieving MDD-W. Lowest and highest proportion of WRA meeting MDD-W was 18% and 79% in Malawi (P < 0.05) and 28% and 70% in Zambia (P < 0.05). MDD-W followed expected variation, peaking in the season of greatest food abundance and lowering during the “lean” season. The food groups grains and tubers, dark green leafy vegetables and other vegetables dominate women's diets. Small fish species are the most commonly consumed flesh food, although availability and consumption decrease seasonally due to cold weather and annual fish bans. Vitamin-A rich fruits and vegetables, other fruit, and nuts and seeds are highly seasonal. Dairy and eggs are rarely consumed. Conclusions Significant seasonal fluctuations in the proportion of WRA achieving MDD-W exist. This has implications for project monitoring and evaluation. Periods of abundance and scarcity for nutritionally important food groups were demonstrated. Attention should be given to improved nutrition-sensitive processing, storage and access to nutrient dense food groups affected by seasonal fluctuations. Funding Sources Research was funded by the International Fund for Agricultural Development (IFAD) with project partners McGill University, WorldFish, Bioversity International, Self Help Africa, University of Zambia, SPRODETA and the LUANAR and by the CGIAR research program on Agriculture for Nutrition and Health.

Introduction This paper is based upon an investigation into the life of a street market in the city of Ha Noi in Vietnam, and experience of the street food served on Ha Noi’s pavements. It draws upon interviews with itinerant food vendors conducted by the researchers and upon accounts of their daily lives from a Vietnamese film subtitled in English and French, sourced from the Vietnamese Women’s Museum (Jensen). The research considers the lives of the people making and selling street food against the distilled versions of cultural experience accessible through the pages of two recent English language cookbooks focussing upon this cuisine. The data from the fieldwork is used as a point for critical comparison (Fram) with recipes and descriptions from Hanoi Street Food (Vandenberghe and Thys) and Vietnamese Street Food (Lister and Pohl), two recent relevant English language cookbooks. The research question addressed is “How are the everyday lives of Vietnamese street market cooks (mis)represented in cookery-related books published for an English-language readership?” The research team comprises an Australian Cultural Studies academic (Lelia Green) and a bi-lingual Vietnamese researcher (Nguyen Hong Van), who is Ha Noi born and bred, but who has lived overseas and whose first degree, in Sociology, is from a Canadian university. In each other’s company and over a period of some weeks, Lelia and Van spent more than 40 hours on ethnographic fieldwork in street markets, and interviewing street vendors. The purpose of the research was exploratory, but it was also undertaken as a means of making the labour and lives of marginalised women more visible, since most itinerant food vendors in Vietnam are women (Jensen). As Bhomik notes, male vendors “are engaged in motor cycle repair or sale of higher priced goods such as personal products, souvenirs etc. and their earnings are higher” (2261). Although the teamwork between Lelia and Van went some way to resolve the challenges posed by insider/outsider qualitative research (Corbin, Dwyer, and Buckle), Van has never lived or worked as a street vendor. First Take an Informal Street Market … Eating on the Street An informal Vietnamese street market is a multi-layered space, ordered according to the geography of the area in which the food is prepared and consumed. The informality of a street market indicates its status between legitimacy and repression. Informal street markets spring up in locales where there is significant demand—usually office workers nearby, and schools. The food they sell is cheap and flavourful, catering for the needs of people who have little time or money and want something hot and nourishing to start, punctuate, or end the day. As markets grow, so the vendors in the market constitute a secondary population in need of sustenance. Itinerant street vendors carry with them everything they need for their day’s work. Typically this includes a little oil or coal-based stove, their raw ingredients, dishes or trays for food preparation and serving, often a bowl for washing food or utensils, and a large bag to carry the dirty dishes used by their customers. Often these tools of their trade will be carried in two baskets balanced upon a pole that acts as a yoke across the vendor’s neck. Sometimes well-resourced vendors will also carry, (or push a bicycle or cart with), sets of small plastic stools and tables, so that their clients can sit and enjoy their food. In the semi-tropical climate of Ha Noi, carrying the raw materials to cook for and feed dozens of patrons is a tiring and difficult business. These street vendors’s lives are made more complex by the semi-legitimacy of the informal street market where itinerants are viewed as potential sources of income by a series of officials who extort small but frequent payments in the form of demanding bribes, or levying fines for illegal activity such as obstructing the pavement (Lincoln). Trung, who sells crab noodles, says the police are the most difficult aspect of her job: “they can come anytime and confiscate all my stuff and give me a fine. One time I was so panicked when I saw them approaching on a small truck that I took all my bowls and ran. The bowl slipped out of my hands and cut into my leg. I still have a deep scar from that accident” (Trung). Now add a smattering of street vendors. Bánh Mỳ: Bread Rolls “1 French baguette”, states the Vandenberghe and Thys recipe for bánh mỳ, implicitly acknowledging the hundred years of French colonisation which provides Vietnam with its excellent breads and pastries, “beat the eggs lightly in a mixing bowl, crumble the paté and combine the paté and the lightly beaten eggs. Put the oil in a small frying pan and cook the omelette […] fold the omelette double and put it on the [grilled, heated] bread […] the variations are endless” (71). The young Vietnamese woman, Anh, sells bánh mỳ trứng ngải cứu, bread rolls with egg cooked with mugwort, an aromatic leafy herb. She explains her initial motivation to sell food on the street: “some women in my village already came to the city to sell. I can’t earn much money at home and I need money to send my children to school, so I decided to follow them” (Anh). She shares rented accommodation in the city with other women—sometimes up to ten people in a room (Jensen)—and starts her day at 4.30am, washing vegetables and preparing her baskets. Although a street trader herself, she is networked into a complex set of supply and delivery connections. Her eggs and bread are delivered fresh each morning and she buys the mugwort from a market near her lodgings. “I leave home around 6am and start walking along the streets. […] I mostly sell to shop keepers. They have to stay in their shop so I bring breakfast to them. I walk through a lot of streets, whenever someone calls out I will stop and make bread for them” (Anh). Mid-morning, at around 10am, Anh goes back to her home to have lunch and prepare for the afternoon, with a fresh delivery of eggs around 1.00-1.30pm. Usually, she leaves again around 2.00pm “but if it’s too hot outside, I will stay until 3pm, because it is very tiring to walk in the heat, and people don’t eat that early either. I go home whenever I sell out […], sometimes as early as 4pm, or as late as 7pm” (Anh). Like many street vendors, Anh has sought out points of contact with the local community to punctuate her walking with episodes of rest. Her customers are mainly other Vietnamese people, “shop keepers and residents of the streets I walk along every day. There is an old lady. I sit in front of her shop every afternoon from 3pm to 5pm. She eats one egg every day” (Anh). Anh has been selling Bánh mỳ on the streets for three years, but this is not her only source of income: “At home I grow rice, but I can only harvest it at the end of the season. It only takes a storm or hail to destroy the whole effort I spend for months […] This [food] is very easy to make, and I make a little profit everyday” (Anh). She has never worked from a recipe book: “I think only people in hotels, like a big chef who makes complicated dishes need recipes, this one is very easy, just a common everyday food” (Anh). As for the problems posed by the policing of informal markets, Anh says: “if I am not careful, the ward police will give me a fine for selling on the street.” Such a calamity can write off the profit of many hours’ or days’ work. Xôi: Sticky Rice Xôi is a popular street food dish, and Lister and Pohl provide two recipes, one for xôi lạc (sticky rice with peanuts)(68), and one for xôi xéo (sticky rice with turmeric and mung beans, and fried shallots) (80). Nga, the xôi seller interviewed for this research, sells both types of sticky rice along with xôi gậc (a festive red sticky rice cooked with and coloured by spiny bitter gourd, and typically eaten at Tết, the celebration for the Lunar New Year) and xôi đỗ đen, sticky rice with black bean. She used to specialise in only one kind of sticky rice but, as she says, “business was slow so I added other types of sticky rice. I sit here in the morning everyday anyway, so I sell different types, a small quantity for each” (Nga). The biggest complication for street vendors selling sticky rice is the requirement that it is still being steamed just before being sold, so that it is hot, soft, and sticky, and not dried out. The cooked sticky rice is usually packed in banana leaves under a plastic cover and put in a bamboo basket. The basket helps with ventilation while banana leaves keep the rice moist and the plastic cover keeps in heat. Traditionally, xôi is also sold in banana leaves. Nga uses first a layer of banana leaf, then one of plastic, and finally newspaper. Nga is a grandmother and constructs her street vending as a retirement job, which puts food on the table for her husband and herself. In Vietnam, there is a tradition that the younger generations look after their elders, but her work as a street vendor means that Nga and her husband can retain their autonomy and help their own family, for longer. Nga starts cooking at 4.00am, but her street food is only one element of her income: “In addition to selling here, I also deliver to restaurants. Actually most of my income comes from them. I deliver at around 5 to 5.30am, and start selling here at 6” (Nga). Both of Lister and Pohl’s recipes start with soaking the sticky rice overnight in water, just as Nga does. She says, “I wash the rice and soak them before I go to bed the night before. I get up, start the stove which uses black coal. I sell out all the rice everyday, otherwise it won’t taste good […] usually I sell out at 8 or 8.30am, 9am at the latest. I don’t work in the afternoon. I pick up my grandchildren at 4pm and take care of them until the end of the day.” Nga has strong views about the place of recipes in cooking, especially in cooking as a business: I don’t need to learn from a book. Written recipes or informal teaching from relatives is the same, they are just the starting point. What matters is you learn from your own experience. For example, you soak your rice for 6 hours today, but your customers complain that the rice is not soft, so you soak it for 8 hours next time. Or maybe you sell to a poorer community, you will adjust your ingredients to cheaper type, so you can reduce your price but still make profit; but if you sell in a richer neighbourhood, you make sure you have good quality, even with higher price, or else they will not buy from you (Nga). Lister and Pohl dedicate a two-page spread (70-1) to Ðặng Thị Sáu and her Xôi shopfront stall, noting that she learned her business from her mother-in-law who was “an itinerant sticky rice peddler for most of her life, walking the city streets, selling from bamboo baskets. It was a hard and uncertain life and not one Sáu wanted to follow” (70). Sáu’s compromise, ultimately, was to sell sticky rice from the comparative security and stability of a fixed location. Lister and Pohl’s focus upon Sáu and her food, along with the pictures of everyday life featured in Vietnamese Street Food, mean that this is more than an inspirational cookbook. It is a vivid introduction to the vernacular foodways of Vietnam “a set of social, economic and cultural practices around the production and consumption of food that are normatively distinctive to an ethnocultural group” (Jonas 119). Bún Riêu Cua: Crab Meat Noodle Crab meat noodle is a complicated recipe and a reminder that many people who eat street food do so because these are favourite Vietnamese dishes which may require considerable effort to prepare. The specialisation of street food vendors, making a complicated dish for the relish of dozens of customers, allows busy Vietnamese workers to enjoy their authentic cuisine at an affordable cost without the time constraints of buying multiple ingredients and making the dish themselves. The recipe in Hanoi Street Food involves several steps: preparation of the sauce using sautéing, frying and reducing (Jones); cooking of the crab in boiling water (not including separately bought crabmeat used in the sauce); creation of a chicken stock, to which the sauce is added; along with the washing and chopping a range of vegetables including soya bean sprouts, spring onions, lettuce, fresh herbs, lime etc., some of which is used as garnish (Vandenberghe, and Thys 90). Trung and her husband have been selling their bún riêu cua for five years. For nine years prior to working as a street food vendor, Trung was a recyclables collector. She began working in the city when she “followed a cousin to Ha Noi so I could earn money to support my family of six people. At first I collected materials such as plastic bottles, metal, papers, etc, but because I carried too much on my shoulders, I developed severe back pain and shoulder pain” (Trung). Now she and her husband use a bicycle to help carry the various necessities for her bún riêu cua street stall, using the vehicle to reduce some of the physical burden of the work. Trung learned how to make bún riêu cua from an aunt in Hai Phong, “I just observed her and other people”. The dish remains time consuming, however:I get up at 3am to start preparing the crab and cook the soup. My husband washes vegetables. It often takes us about 2 hours. By 5am, we leave the house, and we are here by 5.30, ready to sell breakfast […] I am most busy during lunchtime, from 10am to 1-2pm. Breakfast time can last from 6am to 9am. When I am not selling to customers I often get tired and easily fall asleep because I always crave sleep. In between, my husband and I wash dishes. He also delivers to people too. We get lots of phone calls from patients of the hospitals nearby. They say my food is more delicious than food in the hospital’s canteen […] Usually I go home around 4pm in the summer and 5 to 6pm in the winter. But I also stop by different shops to buy ingredients for the next day on my way home. Once I get home, I wash the bowls, re-supply and re-arrange my stuffs, and do some preparation. I work until I go to bed at 9pm (Trung). The illustration for this recipe in Hanoi Street Food is not of the dish itself, but of young Vietnamese men enjoying the dish. As is the case with Lister and Pohl, Vandenberghe and Thys’s book is about more than recipes, it is a rich evocation of daily life on the streets of Vietnam. Serve with a Side-dish of Conclusions Authentic street food is cooked, sold and consumed on the street. However, street food cookbooks tend to recommended shopfront eateries, partly because they are easier to find, and are more convenient, in that neither the tourist nor the vendor is at risk of police intervention. Another reason for featuring the more established vendors with their own premises concerns food hygiene: In 1989 the Vietnamese government adopted a law on the protection of people’s health. A survey on food samples in Hanoi showed that 47 per cent were microbiologically unsafe. [This has now changed.] The government has adopted two practices for ensuring safer street food, namely, monitoring street food vendors through a licensing system, and educating and training them on hygiene (Bhowmik 2260). Such licensing, training and the maintenance of hygiene standards are more difficult to police with itinerant food vendors. In the two cookbooks featured, ingredients tend to be measured as to specific amounts, with the idea that the result should be predictable. Street vendors, however, learn to cook their signature dishes from friends, relatives, and experience. They do not measure their ingredients while cooking, and their products vary from one vendor to another, and also to some extent from day to day, even given the same cook. This creates a special characteristic of street food and means that regular customers gravitate to particular vendors whose choice of seasoning and cooking techniques culminates in the most attractive results according to their personal taste. While there are lots of stalls captioned as bánh mỳ, regular customers will find that there are significant differences between stalls. One reason for this is offered in Lister and Pohl: small quantities of special ingredients that are difficult to get in Vietnam and impossible elsewhere. The cook in a featured Bánh cuốn stall (selling rice pancakes) adds a drop of giant water bug juice to season her dipping broth: “ ‘It’s the real thing! One drop off the top of a chopstick is enough’ she explains” (Lister, and Pohl 33). As is clear from the interviews with vendors, itinerant sellers of street food don’t use recipe books, and have generally learned how to cook their dishes through women’s networks of family and friends. The two cookbooks discussed are designed for consumption by people who engage in or aspire to “food and drink tourism” (Boniface vii) in Vietnam, whether the readers have visited in person or become aware of the cuisine through popular culture, such as Luke Nguyen’s SBS cooking shows (Nguyen). They are as much coffee table books as collections of recipes, and are written by westerners for a western readership. The recipes focus on ingredients that can be sourced in everyday western contexts but the beautiful and evocative photographs of daily life in Vietnam, supplemented by written commentary on people and place, clearly locate the recipes in their Vietnamese cultural context. Culinary tourism allows people unfamiliar with a cuisine and culture to use “food to explore new cultures and ways of being” (Long 21). Street food vendors are part of many communities. They require knowledge, skill, and personal networks to acquire the quality ingredients at the best possible price for the daily routine of food preparation and selling. Whereas recipe books deal with domestic-scale food production, a vendor may cook for a hundred or more people in a single day. Many itinerant street food sellers work in the city to support absent husbands and children in rural locations, taking money home on a regular basis ($20 profit a fortnight makes their labour worthwhile), and spending 10 days in 14 on the streets (Jensen). As women help each other to begin a career as a vendor through oral teaching, observation, and first-hand experience, they do away with the invisible, authoritative voice of cookbooks. Itinerant food sellers are also a part of the larger communities in which they work, including customers, their suppliers, and other actors such as the authorities and the media. This larger community sets the tone for their food, and their lives. The vast majority of vendors of street food are women, prepared to work hard and with passion and pride to make enough money to make a difference to their families. Books about street food might help recreate some of the dishes that can be bought on the streets of Vietnam. After participating in street life, however, as an observer or customer, it becomes clear that recipe cookbooks intended for English readers only capture part of the complexity and beauty of street food, and the lives of those who make it. References Anh. Personal communication. Trans. Nguyen Hong Van. 2013. Boniface, Priscilla. Tasting Tourism: Travelling for Food and Drink. Aldershot: Ashgate, 2003. 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