The climatic trends of temperature and salinity in the Bering straight in the last decades

2021 ◽  
pp. 101-104
Author(s):  
Т.Р. Кильматов ◽  
А.С. Попов
Keyword(s):  
Chukchi Sea ◽  
Winter Season ◽  
Warm Season ◽  
Cold Season ◽  
Winter Period ◽  
Bering Strait ◽  
Time Data ◽  
Climatic Trend ◽  
Time Period ◽  
Flux Increase

Представлены результаты расчетов линейных климатических трендов температуры и солености поверхностных вод Берингова пролива и прилегающих акваторий за временной период 1950 – 2020 гг., отдельно за август и февраль месяцы. Отмечается нагрев поступающей тихоокеанской воды в Чукотское море в летний период на +0,120С/10лет, в зимний период +0,140С/10лет. Одновременно происходит временной тренд в сторону уменьшения солености поступающих вод, это ‒0,060/00/10лет в летний сезон и ‒0,03 S0/00/10лет в зимний сезон. Таким образом в случае инерционного изменения климата через 100 лет вода в Беринговом проливе будет на 1,30С теплее и на 0,450/00 менее соленой. Сделаны оценки роста потока тепла через Берингов пролив в Чукотское море вследствие климатического тренда, который составляет +2,4*1019Дж/10лет. Отмечено, что направления трендов температуры и солености в Беринговом море и Беринговом проливе в сторону нагрева и уменьшения солености совпадают, а в Чукотском море климатические тенденции противоположные. The calculation of the climatic linear trends of the surface waters temperature and salinity in the Bering Strait and nearby water areas are presented. The time period is 1950 – 2020 years. The Time data for the warm season - August and the cold season - February series are shown separately. The heating of the incoming Pacific water into the Chukchi Sea is note. There is the summer period +0.120C/decade, in the winter period +0.140C/decade. At the same time, there is some trend towards decrease in salinity the straight water, this is ‒0.06psu/decade in the summer season and this is ‒0.03psu/decade in the winter season. Following of an inertial climate change in 100 years there is the Bering Strait water will be +1.30Cwarmer and ‒0.45psu/decade salty less. The estimate of the heat flux increase through the Bering Strait to the Chukchi Sea due to the climatic trend is +2.4*1019J/decade. There is a peculiarity that the time trends of temperature and salinity in the Bering Sea and the Bering Strait have the same direction to the heating and the salinity decrease, but at the same time the Chukchi Sea has the opposite tendency. An explanation of this discrepancy is given.

Monitoring the Variability of the Stratospheric Aerosol Layer over Tomsk in 2016–2018 Based on Lidar Data

2021 ◽  
pp. 61-72
Author(s):  
V. N. Marichev ◽  
◽  
D. A. Bochkovskiia ◽  
Keyword(s):  
Volcanic Eruptions ◽  
Temperature Inversion ◽  
Cold Season ◽  
Stratospheric Aerosol ◽  
Single Frequency ◽  
Winter Period ◽  
Lidar Data ◽  
Aerosol Layer ◽  
Time Data ◽  
Academy Of Sciences

The results of observations of the features of intraannual variability for the vertical structure of background aerosol in the stratosphere over Western Siberia in 2016–2018 are presented and analyzed. Experimental data were obtained at the lidar complex of Zuev Institute of Atmospheric Optics (Siberian Branch, Russian Academy of Sciences) with a receiving mirror diameter of 1 m. The objective of the study is to investigate the dynamics of background stratospheric aerosol, since during this period there were no volcanic eruptions leading to the transport of eruptive aerosol into the stratosphere. The results of the study confirm a stable intraannual cycle of maximum aerosol filling of the stratosphere in winter, a decrease in spring to the minimum, practical absence in summer, and an increase in autumn. At the same time, the variability of stratification and aerosol filling is observed for different years. It was found that aerosol is concentrated in the layer up to 30 km all year round, except for the winter period. It is shown that the vertical aerosol stratification is largely determined by the thermal regime of the tropo- sphere–stratosphere boundary layer. The absence of a pronounced temperature inversion at the tropopause contributes to an increase in the stratosphere–troposphere exchange and, as a result, to the aerosol transport to the stratosphere. This situation is typical of the cold season. For the first time, data on the quantitative content of stratospheric aerosol (its mass concentration) were obtained from single- frequency lidar data.

scholarly journals The Future of Drought in the Southeastern U.S.: Projections from Downscaled CMIP5 Models

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 259 ◽  
Author(s):  
David Keellings ◽  
Johanna Engström
Keyword(s):  
Climate Models ◽  
Warm Season ◽  
Cold Season ◽  
Cmip5 Models ◽  
Time Period ◽  
Dry Spells ◽  
Future Time Period ◽  
Dry Spell ◽  
The Future ◽  
Southern Half

After being repeatedly struck by droughts in the last few decades, water managers and stakeholders in the Southeast U.S. dread the future extremes that climate change might cause. In this study, the length of future dry periods is assessed using a sub-ensemble of downscaled CMIP5 climate models, which are proven to perform well in precipitation estimations. The length of a dry spell with a twenty-year return period is estimated for the cold and warm seasons for two time periods; 2020–2059 and 2060–2099, and considering two emission scenarios: RCP 4.5 and 8.5. The estimates are then compared with historical dry spells and differences in length and geospatial distribution analyzed. Based on the findings of this paper, little change can be expected in dry spell length during the warm season. Greater changes are to be expected in the cold season in the southern half of Florida, where dry spells are expected to be up to twenty days shorter, while dry spells in Alabama, Mississippi and Tennessee are predicted to be up to twenty days longer. The changes predicted by the models are positively associated with emission trajectory and future time period.

scholarly journals Possible Changes of Bioclimatic Conditions of Winter Period in Ukraine

2018 ◽  
Keyword(s):  
Winter Season ◽  
Weather Conditions ◽  
Cold Season ◽  
Winter Period ◽  
Mean Values ◽  
Wind Chill ◽  
Bioclimatic Conditions ◽  
The Given ◽  
Second Period ◽  
Different Levels

Purpose. Assessment of bioclimatic conditions of cold season on the basis of weather severeness indices and analysis of their dynamics on the territory of Ukraine. Methods. Estimation of possible values of some cold stress indices and their changes in different regions of the country is based on two scenarios А1В and А2. Results. Possible consequences of climate change on human health in Ukraine are considered. On the base of Bodman index and wind chill factor of Siple-Passel, there are given forecast parameters of uncomfortable climate within three periods: 1986-2005, 2011-2030 and 2031-2050 years. According to both scenarios, mean values of Bodman index during the given periods on the major part of Ukraine reach to 2-3 points and this means that during certain winter months and whole winter moderate severe conditions will prevail, though in western and southern areas will dominate slightly severe ones. According to both scenarios, during December-January within first and second periods in some areas of the country even high risk of hypothermia is possible, as well as frostbite of open parts of the skin in 5-10 minutes can occur. The most severe conditions are expected in January-February in Sumy (A1B) and Lugansk (A2), the least severe – in Kropyvnytsky (A1B) and Ternopil (A2). The trend of hypothermia and frostbite conditions change during the winter season in different regions of the country has been analyzed. Conclusions. The trend of decrease of Bodman index prevails on the whole territory of the country during all winter months. Weather conditions in February are the harshest in first and third periods and weather conditions in January-February are the most severe in the second period (А1В), according to another scenario for the whole researched time the harshest conditions are observed in January. In all analyzed time periods, in December winter weather conditions were the most comfortable according to both scenarios. But mostly repeatability of wind chill factor of Siple-Passel prevailed in the interval of 0 ÷ -9 ºC, thus a slight risk of frostbite, some discomfort will be observed. So, in winter expected compounds of low air temperature and wind in certain days in future might cause frostbite of different levels, they will influence on spreading of infections epidemics and «cold» diseases.

Temperature and Flow Conditions in a Reservoir with a Submerged Outlet Tunnel During the Winter Period

1986 ◽  
Vol 17 (4-5) ◽  
pp. 399-406
Author(s):  
Arve M. Tvede
Keyword(s):  
Strong Influence ◽  
Winter Season ◽  
Circulation Pattern ◽  
Electricity Production ◽  
Winter Period ◽  
Flow Conditions ◽  
Power Station ◽  
Reservoir Water ◽  
Southern Norway ◽  
Tunnel Depth

The reservoir Sundsbarmvatn, in Southern Norway, is used for electricity production from November to May. Sundsbarmvatn has two main basins. Water from the upper basin, Mannerosfjorden, flows into the lower basin, Gullnesfjorden. The two basins are separated by a narrow sound with a sill. The regulation interval for Sundsbarmvatn is 612-574 m a.s.l., but the sill prevents Mannerosfjorden from being lowered below 580 m a.s.l. The water intake in Gullnesfjorden is 571 m a.s.l. The water temperature conditions has been studied during two winters when the reservoir water was released. This study shows that a marked thermocline was gradually developed at the depth of withdrawal in Gullnesfjorden. In the epilimnion layer the temperature is gradually lowered through the winter, but in the hypolimnion layer the temperature seems to stay constant through the winter. In Mannerosfjorden, however, we find no clear thermocline at the end of the winter. The remaining water was relatively warm with temperatures mainly above 3 °C. The sill between the two basins seems to have a strong influence on which depth the water is flowing out of Mannerosfjorden and hence on the temperature and circulation pattern in Gullnesfjorden. At the end of the winter season this flow is strengthening and initiates a homogeneous flow layer in Gullnesfjorden. This layer is dipping downwards towards the outlet tunnel. For this reason the temperature of the water leaving the power station is 0.4-1.2 °C colder than the hypolimnion temperature in the reservoir at the tunnel depth.

scholarly journals Temperature and Relative Humidity Profile Retrieval from Fengyun-3D/HIRAS in the Arctic Region

2021 ◽  
Vol 13 (10) ◽  
pp. 1884
Author(s):  
Jingjing Hu ◽  
Yansong Bao ◽  
Jian Liu ◽  
Hui Liu ◽  
George P. Petropoulos ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Real Time ◽  
Wide Spectrum ◽  
Warm Season ◽  
Arctic Region ◽  
Cold Season ◽  
The Arctic ◽  
Practical Applications ◽  
A New Technique ◽  
The Arctic Region

The acquisition of real-time temperature and relative humidity (RH) profiles in the Arctic is of great significance for the study of the Arctic’s climate and Arctic scientific research. However, the operational algorithm of Fengyun-3D only takes into account areas within 60°N, the innovation of this work is that a new technique based on Neural Network (NN) algorithm was proposed, which can retrieve these parameters in real time from the Fengyun-3D Hyperspectral Infrared Radiation Atmospheric Sounding (HIRAS) observations in the Arctic region. Considering the difficulty of obtaining a large amount of actual observation (such as radiosonde) in the Arctic region, collocated ERA5 data from European Centre for Medium-Range Weather Forecasts (ECMWF) and HIRAS observations were used to train the neural networks (NNs). Brightness temperature and training targets were classified using two variables: season (warm season and cold season) and surface type (ocean and land). NNs-based retrievals were compared with ERA5 data and radiosonde observations (RAOBs) independent of the NN training sets. Results showed that (1) the NNs retrievals accuracy is generally higher on warm season and ocean; (2) the root-mean-square error (RMSE) of retrieved profiles is generally slightly higher in the RAOB comparisons than in the ERA5 comparisons, but the variation trend of errors with height is consistent; (3) the retrieved profiles by the NN method are closer to ERA5, comparing with the AIRS products. All the results demonstrated the potential value in time and space of NN algorithm in retrieving temperature and relative humidity profiles of the Arctic region from HIRAS observations under clear-sky conditions. As such, the proposed NN algorithm provides a valuable pathway for retrieving reliably temperature and RH profiles from HIRAS observations in the Arctic region, providing information of practical value in a wide spectrum of practical applications and research investigations alike.All in all, our work has important implications in broadening Fengyun-3D’s operational implementation range from within 60°N to the Arctic region.

scholarly journals Late Dorset architecture on Little Cornwallis Island, Nunavut

2005 ◽  
Vol 27 (1-2) ◽  
pp. 255-280 ◽  
Author(s):  
Genevieve LeMoine ◽  
James Helmer ◽  
Bjarne Grønnow
Keyword(s):  
Warm Season ◽  
Cold Season ◽  
Nuclear Families ◽  
Construction Techniques ◽  
Architectural Features ◽  
Size Number ◽  
Cornwallis Island

Abstract Late Dorset dwellings from two sites on Little Cornwallis Island (Nunavut) illustrate the diversity of architectural forms from this period. Ten architectural features are described. They include five tent rings, ascribed to warm season occupations, and five rectangular semi-subterranean houses with axial features, including one exceptionally well-preserved example, ascribed to cold season occupations. Variations in size, number of hearths, and construction techniques are examined and the use of both types of structures to house multiple nuclear families is suggested.

scholarly journals Protozooplankton characterization of two contrasting sites in a tropical coastal ecosystem (Guanabara Bay, RJ)

2007 ◽  
Vol 55 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Eli Ana Traversim Gomes ◽  
Viviane Severiano dos Santos ◽  
Denise Rivera Tenenbaum ◽  
Maria Célia Villac
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Food Web ◽  
Warm Season ◽  
Descriptive Study ◽  
Cold Season ◽  
Guanabara Bay ◽  
Trophic Conditions ◽  
Plankton Dynamics

Much time and resources have been invested in understanding plankton dynamics in Guanabara Bay (Brazil), but no attention has been devoted to the protozooplankton. To fulfill this lacuna, abundance and composition of protozooplankton were investigated from January to December - 2000 in fortnightly surface water samplings at two distinct water quality sites (Urca - closer to the bay entrance, more saline and cleaner waters; Ramos - inner reaches, hypereutrophic waters). The density at Urca (10³ - 10(5) cell.l-1) was one to three orders of magnitude lower than at Ramos (10(4) - 10(5) cell.l-1). A seasonal trend for nanoplankton and protozooplankton was more evident at Urca, but both sites had lower densities during the colder period. Small heterotrophic dinoflagellates (20-30 mm) were dominant in over 50% of the samples. The protozooplankton abundance and composition reflected the distinct trophic conditions states found at the bay. During the wet-warm season, non-oligotrich ciliates were representative of Ramos site with Gymnodiniaceae dinoflagellates, while tintinnids and heterotrophic dinoflagellates were predominantly found at Urca mainly during the dry-cold season. This first descriptive study towards the understanding of the intricate relationships among the microbial food web components reveals that protozooplankton can be a good indicator of water quality conditions at the bay.

scholarly journals Diet composition and feeding habits of the eyespot skate, Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae), off Uruguay and northern Argentina

2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora
Keyword(s):  
Body Size ◽  
Diet Composition ◽  
Prey Size ◽  
Prey Availability ◽  
Feeding Habits ◽  
Warm Season ◽  
Cold Season ◽  
The North ◽  
Multiple Hypothesis ◽  
Modelling Approach

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.

scholarly journals Annual cycles of organochlorine pesticide enantiomers in Arctic air suggest changing sources and pathways

2015 ◽  
Vol 15 (3) ◽  
pp. 1411-1420 ◽  
Author(s):  
T. F. Bidleman ◽  
L. M. Jantunen ◽  
H. Hung ◽  
J. Ma ◽  
G. A. Stern ◽  
...  
Keyword(s):  
Warm Season ◽  
Open Water ◽  
Cold Season ◽  
Secondary Emission ◽  
Air Monitoring ◽  
The Arctic ◽  
Gas Chromatography Mass Spectrometry ◽  
Annual Cycles ◽  
Digital Filtration ◽  
Peak Areas

Abstract. Air samples collected during 1994–2000 at the Canadian Arctic air monitoring station Alert (82°30' N, 62°20' W) were analysed by enantiospecific gas chromatography–mass spectrometry for α-hexachlorocyclohexane (α-HCH), trans-chlordane (TC) and cis-chlordane (CC). Results were expressed as enantiomer fractions (EF = peak areas of (+)/[(+) + (−)] enantiomers), where EFs = 0.5, < 0.5 and > 0.5 indicate racemic composition, and preferential depletion of (+) and (−) enantiomers, respectively. Long-term average EFs were close to racemic values for α -HCH (0.504 ± 0.004, n = 197) and CC (0.505 ± 0.004, n = 162), and deviated farther from racemic for TC (0.470 ± 0.013, n = 165). Digital filtration analysis revealed annual cycles of lower α-HCH EFs in summer–fall and higher EFs in winter–spring. These cycles suggest volatilization of partially degraded α-HCH with EF < 0.5 from open water and advection to Alert during the warm season, and background transport of α-HCH with EF > 0.5 during the cold season. The contribution of sea-volatilized α-HCH was only 11% at Alert, vs. 32% at Resolute Bay (74.68° N, 94.90° W) in 1999. EFs of TC also followed annual cycles of lower and higher values in the warm and cold seasons. These were in phase with low and high cycles of the TC/CC ratio (expressed as FTC = TC/(TC+CC)), which suggests greater contribution of microbially "weathered" TC in summer–fall versus winter–spring. CC was closer to racemic than TC and displayed seasonal cycles only in 1997–1998. EF profiles are likely to change with rising contribution of secondary emission sources, weathering of residues in the environment, and loss of ice cover in the Arctic. Enantiomer-specific analysis could provide added forensic capability to air monitoring programs.

Establishment Stage Competition between Exotic Crimson Fountaingrass (Pennisetum setaceum, C4) and Native Purple Needlegrass (Stipa pulchra, C3)

2015 ◽  
Vol 8 (2) ◽  
pp. 139-150 ◽  
Author(s):  
Lynn C. Sweet ◽  
Jodie S. Holt
Keyword(s):  
Southern California ◽  
Niche Partitioning ◽  
Winter Season ◽  
Warm Season ◽  
Summer Rainfall ◽  
Summer Season ◽  
Initial Growth ◽  
Cool Season ◽  
California Grasslands ◽  
Pennisetum Setaceum

Southern California grasslands have largely been type-converted to dominance by exotic annual grasses, leading to displacement of many native grass and forb species. Crimson fountaingrass, Pennisetum setaceum, an exotic perennial C4 species and a relatively new invader to California, is expanding to areas currently occupied by purple needlegrass, Stipa pulchra, a C3 native. We predicted that fountaingrass seedlings might withstand cool season competition in California's Mediterranean-type climate and establish in Stipa pulchra grasslands due to less competition during the warm, dry summer season, and that interactions might be influenced by density. A field experiment was conducted to examine competitive interactions of the two species from the cool winter season to the warm summer season. As predicted, Stipa produced greater aboveground biomass in the cool season and showed strong intraspecific competition, as well as interspecific suppression of Pennisetum growth, whereas Pennisetum showed no suppression of Stipa. In the warm season, Stipa showed relatively less suppression of Pennisetum, erasing significant differences, and Pennisetum showed increased growth. Results of this study show that C3Stipa can suppress initial growth of C4Pennisetum in the cool season, but in warmer months, Pennisetum can overcome this initial suppression at both low and high densities, even within a Mediterranean-type climate with little to no summer rainfall. Thus, in southern California, temporal niche partitioning due to photosynthetic pathway in these two species can allow Pennisetum invasion. Given the similarity in life history and growth form of Stipa and Pennisetum, few options exist for controlling Pennisetum in habitats where Stipa occurs. In these cases, restoration plantings of desirable species are essential in order to reestablish competitive vegetation that will be more resistant to invasion.

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