Academic literature on the topic 'Northern Diurnal variations'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Northern Diurnal variations.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Northern Diurnal variations"
1
He, Huizhong, and Fuqing Zhang. "Diurnal Variations of Warm-Season Precipitation over Northern China." Monthly Weather Review 138, no. 4 (April 1, 2010): 1017–25. http://dx.doi.org/10.1175/2010mwr3356.1.
Full textAbstract:
Abstract This study examines the diurnal variations of the warm-season precipitation over northern China using the high-resolution precipitation products obtained from the Climate Prediction Center’s morphing technique (CMORPH) during May–August of 2003–09. The areas of focus are the Yanshan–Taihangshan Mountain ranges along the east peripheries of the Loess and Inner Mongolian Plateaus and the adjacent North China Plains. It is found that the averaged peak in local precipitation begins early in the afternoon near the top of the mountain ranges and propagates downslope and southeastward at a speed of ∼13 m s−1. The peak reaches the central North China Plains around midnight and the early morning hours resulting in a broad area of nocturnal precipitation maxima over the plains. The diurnal precipitation peak (minimum) is closely collocated with the upward (downward) branch of a mountain–plains solenoid (MPS) circulation. Both the MPS and a low-level southwesterly nocturnal jet are likely to be jointly responsible for the nighttime precipitation maxima over the plains.
2
Huang, Fangfang, and Weiqiang Ma. "Analysis of Long-Term Meteorological Observation for Weather and Climate Fundamental Data over the Northern Tibetan Plateau." Advances in Meteorology 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/4878353.
Full textAbstract:
Meteorological observation plays a critical role in climatic study, and in situ measurements are the foundation of meteorological observation, especially in the Tibetan Plateau, the surface of which is fairly complex. Several field stations in the Northern Tibetan Plateau, which features relatively homogeneous surface, were selected as the study area. A detailed description on the significance of site observation for climate prediction was given in this paper. Data from weather stations can be used to verify satellite data and provide parameters for initial mode field in the study of weather and climate changes. The field observation data in the Northern Tibetan Plateau from 2001 to 2013 is analyzed. The results show that in El Nino year, values of land surface temperature (Ts), air temperature (Ta) and wind speed are all greater than their mean values and that soil moisture values are lower than the averaged, while the opposite is the case in La Nina year. The warming rate in the Northern Tibetan Plateau is greater than that in global areas. The diurnal variations ofTsandTaare various in different seasons and underlying surfaces, with the diurnal variations greater in spring, and less in summer and autumn. Furthermore, the diurnal variation in the area with drier underlying surface is more obvious than that in area with moist surface.
3
Cheng, Yueming, Tie Dai, Jiming Li, and Guangyu Shi. "Measurement Report: Determination of aerosol vertical features on different timescales over East Asia based on CATS aerosol products." Atmospheric Chemistry and Physics 20, no. 23 (December 10, 2020): 15307–22. http://dx.doi.org/10.5194/acp-20-15307-2020.
Full textAbstract:
Abstract. The Cloud-Aerosol Transport System (CATS) lidar, on board the International Space Station (ISS), provides a new opportunity for studying aerosol vertical distributions, especially the diurnal variations, from space observations. In this study, we investigate the seasonal variations and diurnal cycles in the vertical aerosol extinction coefficients (AECs) over East Asia by taking advantage of 32 months of continuous and uniform aerosol measurements from the CATS lidar. Over the Tibetan Plateau, a belt of AECs at approximately 6 km between 30 and 38∘ N persistently exists in all seasons with an obvious seasonal variation. In summer, the aerosols at 6 km are identified as a mixture of both anthropogenic aerosols transported from India and coarse dust particles from Asian dust sources. In addition, the high AECs up to 8 km in summer over the Tibetan Plateau are caused by smoke aerosols from thermal dynamic processes. In fall and winter, the northern slope of the plateau is continuously influenced by both dust aerosols and polluted aerosols transported upslope from cities located at lower elevations in northwestern Asia. The diurnal variation in AECs in North China is mainly related to the diurnal variations in the transported dust and local polluted aerosols. Below 2 km, the AEC profiles in North China at 06:00 and 12:00 CST (China standard time) are significantly higher than those at 00:00 and 18:00 CST, reaching a maximum at midday. The aerosol vertical profiles over the Tarim Desert region in summer have obvious diurnal variations, and the AECs at 12:00 and 18:00 CST are significantly higher than those at 00:00 and 06:00 CST, which are induced by the strong diurnal variations in near-surface wind speeds. In addition, the peak in the AEC profiles has a significant seasonal variation, which is mainly determined by the boundary layer height.
4
Zhang, X., K. R. Gurney, P. Rayner, D. Baker, and Y. P. Liu. "Sensitivity of simulated CO2 concentration to sub-annual variations in fossil fuel CO2 emissions." Atmospheric Chemistry and Physics Discussions 15, no. 14 (July 31, 2015): 20679–708. http://dx.doi.org/10.5194/acpd-15-20679-2015.
Full textAbstract:
Abstract. Recent advances in fossil fuel CO2 (FFCO2) emission inventories enable sensitivity tests of simulated atmospheric CO2 concentrations to sub-annual variations in FFCO2 emissions and what this implies for the interpretation of observed CO2. Six experiments are conducted to investigate the potential impact of three cycles of FFCO2 emission variability (diurnal, weekly and monthly) using a global tracer transport model. Results show an annual FFCO2 rectification varying from −1.35 to +0.13 ppm from the combination of all three cycles. This rectification is driven by a large negative diurnal FFCO2 rectification due to the covariation of diurnal FFCO2 emissions and diurnal vertical mixing, and a smaller positive seasonal FFCO2 rectification driven by the covariation of monthly FFCO2 emissions and monthly atmospheric transport. The diurnal FFCO2 emissions are responsible for a diurnal FFCO2 concentration amplitude of up to 9.12 ppm at the grid cell scale. Similarly, the monthly FFCO2 emissions are responsible for a simulated seasonal CO2 amplitude of up to 6.11 ppm at the grid cell scale. The impact of the diurnal FFCO2 emissions, when only sampled in the local afternoon is also important, causing an increase of +1.13 ppmv at the grid cell scale. The simulated CO2 concentration impacts from the diurnally and seasonally-varying FFCO2 emissions are centered over large source regions in the Northern Hemisphere, extending to downwind regions. This study demonstrates the influence of sub-annual variations in FFCO2 emissions on simulated CO2 concentration and suggests that inversion studies must take account of these variations in the affected regions.
5
Zhang, Xia, Kevin R. Gurney, Peter Rayner, David Baker, and Yu-ping Liu. "Sensitivity of simulated CO<sub>2</sub> concentration to sub-annual variations in fossil fuel CO<sub>2</sub> emissions." Atmospheric Chemistry and Physics 16, no. 4 (February 19, 2016): 1907–18. http://dx.doi.org/10.5194/acp-16-1907-2016.
Full textAbstract:
Abstract. Recent advances in fossil fuel CO2 (FFCO2) emission inventories enable sensitivity tests of simulated atmospheric CO2 concentrations to sub-annual variations in FFCO2 emissions and what this implies for the interpretation of observed CO2. Six experiments are conducted to investigate the potential impact of three cycles of FFCO2 emission variability (diurnal, weekly and monthly) using a global tracer transport model. Results show an annual FFCO2 rectification varying from −1.35 to +0.13 ppm from the combination of all three cycles. This rectification is driven by a large negative diurnal FFCO2 rectification due to the covariation of diurnal FFCO2 emissions and diurnal vertical mixing, as well as a smaller positive seasonal FFCO2 rectification driven by the covariation of monthly FFCO2 emissions and monthly atmospheric transport. The diurnal FFCO2 emissions are responsible for a diurnal FFCO2 concentration amplitude of up to 9.12 ppm at the grid cell scale. Similarly, the monthly FFCO2 emissions are responsible for a simulated seasonal CO2 amplitude of up to 6.11 ppm at the grid cell scale. The impact of the diurnal FFCO2 emissions, when only sampled in the local afternoon, is also important, causing an increase of +1.13 ppmv at the grid cell scale. The simulated CO2 concentration impacts from the diurnally and seasonally varying FFCO2 emissions are centered over large source regions in the Northern Hemisphere, extending to downwind regions. This study demonstrates the influence of sub-annual variations in FFCO2 emissions on simulated CO2 concentration and suggests that inversion studies must take account of these variations in the affected regions.
6
Pham Thi Thu, H., C. Amory-Mazaudier, and M. Le Huy. "Time variations of the ionosphere at the northern tropical crest of ionization at Phu Thuy, Vietnam." Annales Geophysicae 29, no. 1 (January 26, 2011): 197–207. http://dx.doi.org/10.5194/angeo-29-197-2011.
Full textAbstract:
Abstract. This study is the first which gives the climatology of the ionosphere at the northern tropical crest of ionization in the Asian sector. We use the data from Phu Thuy station, in Vietnam, through three solar cycles (20, 21 and 22), showing the complete morphology of ionosphere parameters by analyzing long term variation, solar cycle variation and geomagnetic activity effects, seasonal evolution and diurnal development. Ionospheric critical frequencies, foF2, foF1 and foE, evolve according to the 11-year sunspot cycle. Seasonal variations show that foF2 exhibits a semiannual pattern with maxima at equinox, and winter and equinoctial anomalies depending on the phases of the sunspot solar cycle. ΔfoF2 exhibits a semiannual variation during the minimum phase of the sunspot solar cycle 20 and the increasing and decreasing phases of solar cycle 20, 21 and 22. ΔfoF1 exhibits an annual variation during the maximum phase of solar cycles 20, 21 and 22. Δh'F2 shows a regular seasonal variation for the different solar cycles while Δh'F1 exhibits a large magnitude dispersion from one sunspot cycle to another. The long term variations consist in an increase of 1.0 MHz for foF2 and of 0.36 MHz for foF1. foE increases 0.53 MHz from solar cycle 20 to solar cycle 21 and then decreases −0.23 MHz during the decreasing phase of cycle 21. The diurnal variation of the critical frequency foF2 shows minima at 05:00 LT and maxima around 14:00 LT. foF1 and foE have a maximum around noon. The diurnal variation of h'F2 exhibits a maximum around noon. The main features of h'F1 are a minimum near noon and the maximum near midnight. Other minima and maxima occur in the morning, at about 04:00 or 05:00 LT and in the afternoon, at about 18:00 or 19:00 LT but they are markedly smaller. Only during the maximum phase of all sunspot solar cycles the maximum near 19:00 LT is more pronounced.
7
Meng, Z. Y., X. B. Xu, P. Yan, G. A. Ding, J. Tang, W. L. Lin, X. D. Xu, and S. F. Wang. "Characteristics of trace gaseous pollutants at a regional background station in Northern China." Atmospheric Chemistry and Physics 9, no. 3 (February 5, 2009): 927–36. http://dx.doi.org/10.5194/acp-9-927-2009.
Full textAbstract:
Abstract. Measurements of trace gaseous pollutants were taken at the Shangdianzi site, a WMO Global Atmosphere Watch (GAW) background station in Northern China. The results are presented for the period from September 2003 to December 2006. Seasonal and diurnal variations of the O3, NOx, SO2, and CO concentration are characterized and possible causes for them are discussed. The observed levels of the trace gases are comparable to those at some other background sites in polluted regions inside and outside of China. It was shown that the seasonal variation of O3 can change slightly from year to year due to the year-to-year alternation in the meteorological conditions. Higher CO concentrations were observed in some warmer months, particularly in June and July, 2006. Intensive biomass burning in the North China Plain region, in combination with the transport of regional pollution by more frequent southwesterly winds, is believed to be responsible for the elevated CO concentrations. The diurnal variation of O3, with delayed peaking times, suggests that the transport of photochemical aged plume is an important source for O3 at Shangdianzi. The diurnal variations of SO2 in all seasons show higher values during daytime, contradicting the common view. An explanation for this unusual phenomenon is hypothesized. To gain an insight into the impact of transport on the trace gases levels at Shangdianzi, air mass backward trajectories were calculated and analyzed in combination with corresponding pollutant concentrations. The results indicate that the transport of air masses from the North China Plain region and from the major coal mining regions west of Shangdianzi is responsible for the high concentrations of the gaseous pollutants.
8
Verma, Santosh Kumar, Kimitaka Kawamura, Fei Yang, Pingqing Fu, Yugo Kanaya, and Zifa Wang. "Measurement report: Diurnal and temporal variations of sugar compounds in suburban aerosols from the northern vicinity of Beijing, China – an influence of biogenic and anthropogenic sources." Atmospheric Chemistry and Physics 21, no. 6 (March 30, 2021): 4959–78. http://dx.doi.org/10.5194/acp-21-4959-2021.
Full textAbstract:
Abstract. Sugar compounds (SCs) are major water-soluble constituents in atmospheric aerosols. In this study, we investigated their molecular compositions and abundances in the northern receptor site (Mangshan) of Beijing, China, to better understand the contributions from biogenic and anthropogenic sources using a gas chromatography–mass spectrometry technique. The sampling site receives anthropogenic air mass transported from Beijing by southerly winds, while northerly winds transport relatively clean air mass from the forest areas. Day- and nighttime variations were analyzed for anhydrosugars, primary sugars, and sugar alcohols in autumn 2007. We found that biomass burning (BB) tracers were more abundant at nighttime than daytime, while other SCs showed different diurnal variations. Levoglucosan was found to be dominant sugar among the SCs observed, indicating an intense influence of local BB for cooking and space heating at the surroundings of the Mangshan site. The high levels of arabitol and mannitol in daytime suggest a significant contribution of locally emitted fungal spores and long-range-transported bioaerosols from the Beijing area. The plant emissions from Mangshan forest park significantly control the diurnal variations of glucose, fructose, and mannitol. The meteorological parameters (relative humidity, temperature, and rainfall) significantly affect the concentrations and diurnal variations of SCs. Sucrose (pollen tracer) showed a clear diurnal variation, peaking in the daytime due to higher ambient temperature and wind speed, which influences the pollen release from the forest plants. We found the contribution of trehalose from soil dust in daytime, while microbial and fungal spores were responsible for nighttime. Anhydrosugar and primary sugars are prime carbon sources of the Mangshan aerosols. The high ratios of levoglucosan in organic carbon and water-soluble organic carbon at nighttime suggest a significant contribution of BB to organic aerosols at night. Levoglucosan / mannosan ratios demonstrate that low-temperature burning of hardwood is dominant in Mangshan. The positive matrix factorization analysis concluded that forest vegetation, fungal species, and local BB are the significant sources of SCs.
9
Lu, Zhongming, Jianping Gan, and Minhan Dai. "Modeling seasonal and diurnal pCO2 variations in the northern South China Sea." Journal of Marine Systems 92, no. 1 (April 2012): 30–41. http://dx.doi.org/10.1016/j.jmarsys.2011.10.003.
Full text
10
Tu, Qianguang, Yun Zhao, Jing Guo, Chunmei Cheng, Liangliang Shi, Yunwei Yan, and Zengzhou Hao. "Spatial and Temporal Variations of Aerosol Optical Thickness over the China Seas from Himawari-8." Remote Sensing 13, no. 24 (December 14, 2021): 5082. http://dx.doi.org/10.3390/rs13245082.
Full textAbstract:
Six years of hourly aerosol optical thickness (AOT) data retrieved from Himawari-8 were used to investigate the spatial and temporal variations, especially diurnal variations, of aerosols over the China Seas. First, the Himawari-8 AOT data were consistent with the AERONET measurements over most of the China Seas, except for some coastal regions. The spatial feature showed that AOT over high latitude seas was generally larger than over low latitude seas, and it is distributed in strips along the coastline and decreases gradually with increasing distance from the coastline. AOT undergoes diurnal variation as it decreases from 9:00 a.m. local time, reaching a minimum at noon, and then begins to increase in the afternoon. The percentage daily departure of AOT over the East China Seas generally ranged ±20%, increasing sharply in the afternoon; however, over the northern part of the South China Sea, daily departure reached a maximum of >40% at 4:00 p.m. The monthly variation in AOT showed a pronounced annual cycle. Seasonal variations of the spatial pattern showed that the largest AOT was usually observed in spring and varies in other seasons for different seas.
Dissertations / Theses on the topic "Northern Diurnal variations"
1
Jiminez, Greg M. "Diurnal variation over the tropical monsoon regions during northern summer 1991." Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/8273.
Full textAbstract:
Approved for public release; distribution is unlimited.This study examines diurnal variation of convection over western India, the Bay of Bengal, Indochina and the northern South China Sea during the 1991 northern summer monsoon using combined Japanese (GMS) and Indian (INSAT) geostationary satellite data, ECMWF 850 hPa wind data, and NCEP sea surface temperature analyses. The diurnal cycle is examined in terms of spatial and temporal structure prior to onset and during the monsoon. The northern South China Sea is examined to determine how different periods of synoptic influences resulted in an anomalously strong diurnal signal during June. The wind and SST data are used to examine the relationship between the diurnal variation of convection and both low level convergence and vertical latent heat fluxes. Convection over west India is most common during May and June and starts as a diurnal system over land that becomes organized and propagates westward over the east Arabian Sea. The Bay of Bengal follows the classic land-sea breeze model and convection is modulated by convergence between the land breeze and large- scale monsoon flow. The diurnal cycle is generally enhanced over the ocean during active phases of convective activity. The maximum latent heat fluxes generally occurs prior to maximum convection due to strong monsoon flow enhancing evaporation
2
Long, Kevin D., and Thesis (University of Lethbridge Faculty of Arts and Science). "Methane fluxes from a northern peatland : mechanisms controlling diurnal and seasonal variation and the magnitude of aerobic methanogenesis." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2008, 2008. http://hdl.handle.net/10133/744.
Full textAbstract:
Continuous eddy covariance measurements were conducted for a 125 day period, throughout the 2007 growing season, in a northern Alberta peatland. Significant diurnal and seasonal variation in methane fluxes were observed. Diurnal variation in methane flux was suggested to be due to variation in soil temperature and methane convective flow through vegetation to the atmosphere. Seasonal variation in methane flux was associated with a variety of factors, most notably seasonal variation in the capacity for methane emission at 10 ºC (R10). The R10 values varied as a function of soil temperature and were an important control of seasonal variation in methane flux. Also, a greenhouse gas budget was calculated comparing net methane emission and net CO2 sequestration. This analysis indicated that the peatland was acting as a net sink of radiative forcing agents for the 2007 growing season.xiii, 100 leaves ; 29 cm. --
Books on the topic "Northern Diurnal variations"
1
Jiminez, Greg M. Diurnal variation over the tropical monsoon regions during northern summer 1991. Monterey, Calif: Naval Postgraduate School, 1997.
Find full text
2
Diurnal Variation over the Tropical Monsoon Regions During Northern Summer 1991. Storming Media, 1997.
Find full textBook chapters on the topic "Northern Diurnal variations"
1
Whiteman, C. David. "Four Factors That Determine Climate." In Mountain Meteorology. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195132717.003.0007.
Full textAbstract:
Climate differs from one location to another because of differences in • latitude, the angular distance north or south from the equator • altitude, the height above sea level • continentality, the distance from the sea • exposure to regional circulations, including winds and ocean currents. The latitude of a given site determines the length of the day and the angle of incoming sunlight and therefore the amount of solar radiation received at that site. Seasonal and diurnal (day—night) variations in the amount of solar radiation received cause seasonal and diurnal variations in the weather. Near the equator, the days of the year are all about the same length, and the noon sun is nearly overhead year-round. Because day length and solar angle change little with the season, there is little seasonal variability in the weather. In the polar regions, on the other hand, the sun does not rise at all in the winter, and in the summer it never sets, although it remains low in the sky. Thus, polar weather has a high seasonal variability, but a low diurnal variability. In the midlatitudes, the climate is characterized by both seasonal and diurnal changes. Except at the equator, day length varies throughout the year. In the Northern Hemisphere, the longest day of the year is at the summer solstice (June 21), the shortest day of the year is at the winter solstice (December 21), and the day is 12 hours long on the vernal and autumnal equinoxes (March 20 and September 22). The altitude angle of the sun also varies throughout the year, with an increase of about 47° from winter to summer. The more direct summer sunlight produces more heating than the slanted rays of the winter sun. The latitude of a given site affects its climate not only because it determines the angle of solar radiation and the length of a day, but also because it determines the site’s exposure to latitudinal belts of surface high and low pressure that encircle the earth.
2
"Grenadiers of the World Oceans: Biology, Stock Assessment, and Fisheries." In Grenadiers of the World Oceans: Biology, Stock Assessment, and Fisheries, edited by Alexei M. Orlov and Alexei M. Tokranov. American Fisheries Society, 2008. http://dx.doi.org/10.47886/9781934874004.ch16.
Full textAbstract:
<em>Abstract</em>.—The giant grenadier <em>Albatrossia pectoralis </em>and popeye grenadier <em>Coryphaenoides cinereus </em>are among the most abundant continental slope fish species of the North Pacific. Their high biomass constitutes about 2 million metric tons and they comprise a large portion of by-catch in deepwater bottom trawl and longline fisheries. However, these species are mostly discarded and their specialized fisheries are currently only in the initial stage. The ecology and biology of giant and popeye grenadiers in the Pacific off the northern Kuril Islands and southeastern Kamchatka are still poorly understood. This paper is based on results of studies conducted in 1992–2002 aboard Japanese trawlers in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka. It describes seasonal changes of spatial and vertical distributions and bottom temperature preferences, provides data on their lengths and weights, length-weight relationships, sex ratios, and multi-annual, seasonal, and diurnal variations of catch rates. Relationships between mean body weight and capture depth are presented for different seasons. Data on composition of species co-occurring in catches are given for both grenadiers in respect to different times of year.
3
"Grenadiers of the World Oceans: Biology, Stock Assessment, and Fisheries." In Grenadiers of the World Oceans: Biology, Stock Assessment, and Fisheries, edited by Alexei M. Orlov and Alexei M. Tokranov. American Fisheries Society, 2008. http://dx.doi.org/10.47886/9781934874004.ch16.
Full textAbstract:
<em>Abstract</em>.—The giant grenadier <em>Albatrossia pectoralis </em>and popeye grenadier <em>Coryphaenoides cinereus </em>are among the most abundant continental slope fish species of the North Pacific. Their high biomass constitutes about 2 million metric tons and they comprise a large portion of by-catch in deepwater bottom trawl and longline fisheries. However, these species are mostly discarded and their specialized fisheries are currently only in the initial stage. The ecology and biology of giant and popeye grenadiers in the Pacific off the northern Kuril Islands and southeastern Kamchatka are still poorly understood. This paper is based on results of studies conducted in 1992–2002 aboard Japanese trawlers in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka. It describes seasonal changes of spatial and vertical distributions and bottom temperature preferences, provides data on their lengths and weights, length-weight relationships, sex ratios, and multi-annual, seasonal, and diurnal variations of catch rates. Relationships between mean body weight and capture depth are presented for different seasons. Data on composition of species co-occurring in catches are given for both grenadiers in respect to different times of year.
4
McHugh, Maurice J., and Douglas G. Goodin. "Interdecadal-Scale Variability: An Assessment of LTER Climate Data." In Climate Variability and Ecosystem Response in Long-Term Ecological Research Sites. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195150599.003.0023.
Full textAbstract:
Interdecadal-scale climate variability must be considered when interpreting climatic trends at local, regional, or global scales. Significant amounts of variance are found at interdecadal timescales in many climate parameters of both “direct” data (e.g., precipitation and sea surface temperatures at specific locations) and “indirect” data through which the climate system operates (e.g., circulation indices such as the Pacific North American index [PNA] or the North Atlantic Oscillation index [NAO]). The aim of this study is to evaluate LTER climate data for evidence of interdecadal-scale variability, which may in turn be associated with interdecadal-scale fluctuations evident in ecological or biophysical data measured throughout the LTER site network. In their conceptualization of climatic variability, Marcus and Brazel (1984) describe four types of interannual climate variations: (1) Periodic variations around a stationary mean are well known to occur at short timescales, such as diurnal temperature changes or the annual cycle, but are difficult to resolve at decadal or longer timescales. (2) Discontinuities generated by sudden changes in the overall state of the climate system can reveal nonstationarity in the mean about which data vary in a periodic or quasi-periodic manner. These sudden alterations can result in periods perhaps characterized by prolonged drought or colder than normal temperatures. (3) The climate system may undergo trends such as periods of slowly increasing or decreasing precipitation or of warming or cooling until some new mean “steady” state is reached. (4) Climate data may exhibit increasing or decreasing variability about a specific mean value or steady state. Interdecadal contributions to climate variability can be described in terms of types 2 and 3 of Marcus and Brazel’s conceptual classification—discontinuities in the mean and trends in the data. Records of the Northern Hemisphere’s average land surface temperature show discontinuities in the mean state of the hemispheric temperature record in conjunction with obvious trends. Conceptually, it is hard to distinguish between these aspects of climate variability. Trends are an essential component of an alteration in the mean state of the temperature series, as they serve as a temporal linkage between the different mean states.
5
"Proceedings of the First International Snakehead Symposium." In Proceedings of the First International Snakehead Symposium, edited by Nicolas W. R. Lapointe, Ryan K. Saylor, and Paul L. Angermeier. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874585.ch6.
Full textAbstract:
<em>Abstract.</em>—Understanding the diel activity of a species can shed light on potential interactions with other species and inform management practices. To understand the diel activity of Northern Snakehead <em>Channa argus</em>, feeding habits and movement patterns were observed. Two hundred seventy-three Northern Snakehead were captured by boat electrofishing during May and June of 2007 and 2008. Their gut contents were extracted and preserved. The level of digestion of each prey item was estimated from fresh (1) to >50% digested (4) or empty (5). Random forest models were used to predict feeding activity based on time of day, tide level, date, water temperature, fish total length, and sex. Diel movement patterns were assessed by implanting Northern Snakehead with radio transmitters and monitoring them every 1.5 h for 24 h in both March and July 2007. Movement rates were compared between March and July and among four daily time periods. Independent variables accounted for only 6% of the variation in feeding activity; however, temporal feeding patterns were apparent. No fresh items were observed in guts between 12:30 and 7:30 am, and the proportion of empty stomachs increased at the end of May coinciding with the onset of spawning. Overall, fish moved greater distances during the July tracking period compared to March. Fish showed a greater propensity to move during daylight hours than at night during the March tracking period. A similar but nonsignificant (<EM>P </EM>> 0.05) pattern was observed in July. Movement and feeding data both indicated greater activity during daylight hours than at night, suggesting that Northern Snakehead is a diurnal species. Based on our preliminary findings, we hypothesize that a) diurnal species are more susceptible than nocturnal species to predation by Northern Snakehead and b) Northern Snakehead are more likely to compete for food with diurnal than nocturnal predators.
Conference papers on the topic "Northern Diurnal variations"
1
Duong, Ninh T., and Michael Wegener. "SensorVision validation: diurnal temperature variations in northern Australia." In AeroSense 2000, edited by Robert Lee Murrer, Jr. SPIE, 2000. http://dx.doi.org/10.1117/12.391702.
Full text
2
Sepehri, Amin, and Brent Nelson. "Analysis of Round Trip Efficiency of Thermal Energy Storage in Northern Arizona." In ASME 2019 Power Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/power2019-1860.
Full textAbstract:
Abstract Energy storage systems provide a variety of benefits, including taking better advantage of renewable electricity when available and smoothing demand by shifting demand peaks to times when electricity prices and demand are lower. When low electricity demand occurs during the nighttime, system wide advantages also occur. These lower nighttime ambient temperatures lead to efficiency improvements throughout the grid, including power generators, transmission and distribution systems, chillers, etc. An analysis of ice thermal energy storage carried out by T. Deetjen et al. in 2018 analyzed fuel consumption of the power generation fleet for meeting cooling demand in buildings as a function of ambient temperature, relative humidity, transmission and distribution current, and baseline power plant efficiency. Their results showed that the effective round trip efficiency for ice thermal energy storage could exceed 100% due to the efficiency gains of nighttime operation. However, their analysis was performed on a case study in Dallas, where relatively high humidities lead to a relatively small diurnal temperature variation during the cooling season. In order to expand on this limitation, our study extends this analysis to a mountain west climate, using northern Arizona as a case study. The climate of the mountain west has several key differences from that of the Dallas case study in the previous work, including lower relative humidity, higher diurnal temperature variation, and near- and below-freezing nighttime temperatures during shoulder seasons that also exhibit cooling demand in buildings. To address these differences, this paper updates the models of Deetjen et al. to consider generator fleet efficiency and chiller/icemaking COP for local weather characteristics relevant to the mountain west, as well as considering the differences between fuel mixes of the generator fleet in nighttime and daytime. Compared to Dallas, the larger temperature variation of northern Arizona leads to higher round trip efficiencies (RTE) over the course of the year in most days of the year (e.g. 313 days of the year in northern Arizona in comparison with 182 days in Dallas), demonstrating frequent achievement of over 100% effective round trip efficiency. The presence of a mature commercial market and the possibility of gaining over 100% effective round trip efficiency create a strong case for cooling thermal energy storage as an energy storage approach. Future work will investigate emissions impacts as well as extend the analysis to additional western climates, including the hot dry and marine climates.