Academic literature 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.