scholarly journals IMPACT OF LOW LATITUDES ON THE CLIMATIC CONDITIONS IN THE MAIN SIBERIAN RIVERS CATCHMENT AREA

2020 ◽  
Vol 4 ◽  
pp. 54-67
Author(s):  
G.V. Alekseev ◽  
◽  
A.E. Vyazilova ◽  
N.E. Kharlanenkova ◽  
◽  
...  
Keyword(s):  
Air Temperature ◽  
General Circulation ◽  
Climatic Conditions ◽  
The Arctic ◽  
Climatic Parameters ◽  
Meridional Transport ◽  
Cold Part ◽  
Cross Correlation Analysis ◽  
Catchment Areas ◽  
Low Latitudes

It was previously shown that atmospheric and oceanic transports of heat and moisture play an important role in the development of Arctic warming, and sea surface temperature anomalies at low latitudes have a significant effect on the formation of these transports. Atmospheric circulation, transferring heat, moisture and precipitation, also affects the climatic conditions in the catchment areas of 3 main Siberian rivers Ob, Yenisei and Lena with runoff that it about half of the average annual inflow of river waters into the Arctic Ocean. According to the reanalyses and data arrays for the period 1979-2019 air temperature and precipitation in the catchment areas of Ob, Lena and Yenisei are rising. The greatest increase in precipitation was noted in the spring months. The spring months (March and April) also have a maximum positive air temperature trend. To assess the effect of low latitudes on changes in climatic conditions in the catchment areas reanalysis data ERA5, HadISST, precipitation gridded data of the GPCC project were used. The indexes of zonal, meridional and general circulation were calculated based on the mean monthly surface air temperature at the nodes of the geographic grid in the Northern Hemisphere. To determine the connections between the indexes and climatic parameters the methods of multivariate cross-correlation analysis were used. It was defined that zonal atmospheric transports have a significant impact on climatic conditions most of all in the cold part of the year, especially in November and March. In summer amplification of zonal circulation is accompanied by a decrease in air temperature in the catchment areas, but meridional transports enhance the air temperature. The greatest influence of meridional transport was observed in spring and summer. The climatic change in low latitudes has the greatest impact in autumn on meridional transport in spring and on zonal transport in the cold part of the year, especially in March, with time lag of 2 years. The influence of low latitudes on the climatic conditions in the catchment areas is presented in the form of correlation graphs between climatic parameters and indexes of circulation on the generalizing diagram.

Impact of global warming on the conditions of the Siberian rivers discharge formation

2020 ◽  
Author(s):  
Anastasia Vyazilova ◽  
Alekseev Genrikh ◽  
Kharlanenkova Natalya ◽  
Glok Natalya
Keyword(s):  
Global Warming ◽  
Water Vapor ◽  
Moisture Content ◽  
Arctic Ocean ◽  
Air Temperature ◽  
The Arctic ◽  
Wave Radiation ◽  
Catchment Areas ◽  
Low Latitudes ◽  
The Arctic Ocean

<p> <span>The modern Arctic is becoming warmer and more humid, and the Arctic Ocean is increasingly free of ice in summer. One of the feedbacks of global warming in the arctic part of the climate system is an increase of downward long-wave radiation inflow to the surface of snow and ice due to an increase of the content of water vapor in the atmosphere of the Arctic. The source of the increase of the water vapor content in the arctic atmosphere is the atmospheric branch of the freshwater cycle, including moisture transport from low latitudes and inflow from the ocean surface. Moisture from low latitudes is transferred not only to the Arctic, but also to the adjacent continent of Eurasia, from where its excess is transferred by river flow to the Arctic Ocean. Strengthening of zonal transports of heat and moisture from oceanic regions to continents and meridional transports from low latitudes of the World Ocean to temperate and high latitudes is shown using the proposed indices of the zonal and meridional circulation. The indices were calculated according to the NCEP, ERA-Interim reanalysis data. It has been established that the increase in transports is manifested, in particular, in an increase of air temperature, in an increase of the total moisture content in the atmosphere over the area of Siberian rivers flow formation, in an increase of precipitation and, as a result, in an increase of the run-off of rivers flowing into the Arctic Ocean. <span>The </span><span>connection</span><span> between the indices and surface air temperature, precipitation, atmospheric moisture content in the regions of catchment areas </span><span>of three main Siberian rivers, Ob, Lena and Yenisei,</span><span> confirmed the influence of atmospheric transport</span><span>s</span><span> in the cold part of the year. Assessment of the relationship between changes of climatic conditions in the catchment areas and interannual changes of river runoff parameters indicated that annual runoff increases and mostly is affected by increase of average annual precipitation. </span>The study was carried out with the support of the Russian Foundation for Basic Research (Project 18-05-60107).</span></p>

scholarly journals Remote Sensing of Snow Cover Variability and Its Influence on the Runoff of Sápmi’s Rivers

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 130
Author(s):  
Sebastian Rößler ◽  
Marius S. Witt ◽  
Jaakko Ikonen ◽  
Ian A. Brown ◽  
Andreas J. Dietz
Keyword(s):  
Remote Sensing ◽  
Snow Cover ◽  
Air Temperature ◽  
Kendall Test ◽  
The Arctic ◽  
Boreal Winter ◽  
Snowmelt Runoff ◽  
River Catchment ◽  
Catchment Areas ◽  
Runoff Model

The boreal winter 2019/2020 was very irregular in Europe. While there was very little snow in Central Europe, the opposite was the case in northern Fenno-Scandia, particularly in the Arctic. The snow cover was more persistent here and its rapid melting led to flooding in many places. Since the last severe spring floods occurred in the region in 2018, this raises the question of whether more frequent occurrences can be expected in the future. To assess the variability of snowmelt related flooding we used snow cover maps (derived from the DLR’s Global SnowPack MODIS snow product) and freely available data on runoff, precipitation, and air temperature in eight unregulated river catchment areas. A trend analysis (Mann-Kendall test) was carried out to assess the development of the parameters, and the interdependencies of the parameters were examined with a correlation analysis. Finally, a simple snowmelt runoff model was tested for its applicability to this region. We noticed an extraordinary variability in the duration of snow cover. If this extends well into spring, rapid air temperature increases leads to enhanced thawing. According to the last flood years 2005, 2010, 2018, and 2020, we were able to differentiate between four synoptic flood types based on their special hydrometeorological and snow situation and simulate them with the snowmelt runoff model (SRM).

scholarly journals Projected Changes in Daily Variability and Seasonal Cycle of Near-Surface Air Temperature over the Globe during the Twenty-First Century

2019 ◽  
Vol 32 (24) ◽  
pp. 8537-8561 ◽  
Author(s):  
Jiao Chen ◽  
Aiguo Dai ◽  
Yaocun Zhang
Keyword(s):  
Sea Ice ◽  
Air Temperature ◽  
Seasonal Cycle ◽  
Surface Air Temperature ◽  
First Century ◽  
The Arctic ◽  
Boreal Summer ◽  
High Latitudes ◽  
Low Latitudes ◽  
Twenty First Century

Abstract Increases in atmospheric greenhouse gases will not only raise Earth’s temperature but may also change its variability and seasonal cycle. Here CMIP5 model data are analyzed to quantify these changes in surface air temperature (Tas) and investigate the underlying processes. The models capture well the mean Tas seasonal cycle and variability and their changes in reanalysis, which shows decreasing Tas seasonal amplitudes and variability over the Arctic and Southern Ocean from 1979 to 2017. Daily Tas variability and seasonal amplitude are projected to decrease in the twenty-first century at high latitudes (except for boreal summer when Tas variability increases) but increase at low latitudes. The day of the maximum or minimum Tas shows large delays over high-latitude oceans, while it changes little at low latitudes. These Tas changes at high latitudes are linked to the polar amplification of warming and sea ice loss, which cause larger warming in winter than summer due to extra heating from the ocean during the cold season. Reduced sea ice cover also decreases its ability to cause Tas variations, contributing to the decreased Tas variability at high latitudes. Over low–midlatitude oceans, larger increases in surface evaporation in winter than summer (due to strong winter winds, strengthened winter winds in the Southern Hemisphere, and increased winter surface humidity gradients over the Northern Hemisphere low latitudes), coupled with strong ocean mixing in winter, lead to smaller surface warming in winter than summer and thus increased seasonal amplitudes there. These changes result in narrower (wider) Tas distributions over the high (low) latitudes, which may have important implications for other related fields.

Seasonal variation in nocturnal calling activity of a savanna anuran community in central Brazil

1997 ◽  
Vol 18 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Glória Moreira ◽  
Larissa Barreto
Keyword(s):  
Species Richness ◽  
Seasonal Variation ◽  
Air Temperature ◽  
Reproductive Period ◽  
Climatic Conditions ◽  
Activity Period ◽  
Climatic Parameters ◽  
Central Brazil ◽  
Calling Activity ◽  
Permanent Pond

AbstractWe studied the calling activity of a savanna anuran assemblage and correlated two climatic parameters, rainfall and air temperature, with anuran calling. We made observations from September 1991 until March 1993 and quantified nocturnal calling activity by counting the number of calling males for each species present in a permanent pond. Bufo paracnemis had the shortest calling activity period and Physalaemus cuvieri had a seasonal calling period, lasting a maximum of four months. Diversity of calling males and species richness reached a peak in the first three months of the rainy season. Comparisons with other populations indicate that the reproductive period of P cuvieri varies along its geographical distribution in a manner related to regional climatic conditions.

scholarly journals Hydrological Conditions Of Drained Lake Basins Of The Anadyr Lowland Under Changing Climatic Conditions

2021 ◽  
Vol 14 (4) ◽  
pp. 41-54 ◽  
Author(s):  
Оleg D. Tregubov ◽  
Vladimir E. Glotov ◽  
Pavel Ya. Konstantinov ◽  
Vladimir V. Shamov
Keyword(s):  
Coastal Zone ◽  
Active Layer ◽  
Air Temperature ◽  
Field Measurements ◽  
Climatic Conditions ◽  
Surface Flow ◽  
The Arctic ◽  
Mean Annual Precipitation ◽  
Lake Area ◽  
Lake Basins

The lakes of the Arctic lowlands are both the unique indicator and the result of climatic and permafrost changes. Remote sensing methods and field measurements were used to consider the patterns and features of the morphometric indicators dynamics of the Anadyr lowland lakes over 65 years. We analyzed the parameters of 36 lakes with an area of 0.02–0.3 km2 located in the bottoms of drained lake basins, in river floodplains, on sea-shore terraces. Field studies were conducted on 22 typical lakes. The considered dynamics of seasonal thawing are based on the monitoring of the active layer for 1994–2020. Due to an increase of mean annual air temperature by 1.8 °C, as well as an increase and then a decrease in the mean annual precipitation by 135 mm, the average share of a lake area in the study area decreased by 24%. It is shown for the first time that cryogenic processes of the lacustrine coastal zone affect the change in the area of lakes simultaneously with the influence of precipitation and air temperature. Based on field observations, we considered two causes of natural drainage: discharge of the lakes through newly formed thermokarst and thermoerosional surface flow channels and decrease in suprapermafrost groundwater recharge as a result of changing depth of seasonally thawed active layer in the coastal zone.

scholarly journals Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 319
Author(s):  
Cristian Pérez-Granados ◽  
Karl-L. Schuchmann
Keyword(s):  
Air Temperature ◽  
Daily Rainfall ◽  
Climatic Conditions ◽  
Dry Season ◽  
Climate Impacts ◽  
Calling Behavior ◽  
Wet Season ◽  
Focal Species ◽  
Calling Activity ◽  
Vocal Activity

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, air temperature was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.

Modeling soil temperature using air temperature features in diverse climatic conditions with complementary machine learning models

2021 ◽  
Vol 185 ◽  
pp. 106158
Author(s):  
Maryam Bayatvarkeshi ◽  
Suraj Kumar Bhagat ◽  
Kourosh Mohammadi ◽  
Ozgur Kisi ◽  
M. Farahani ◽  
...  
Keyword(s):  
Machine Learning ◽  
Soil Temperature ◽  
Air Temperature ◽  
Climatic Conditions ◽  
Learning Models ◽  
Machine Learning Models

scholarly journals Changes in Air Temperature and Snow Cover in Winter in Poland

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Arkadiusz M. Tomczyk ◽  
Ewa Bednorz ◽  
Katarzyna Szyga-Pluta
Keyword(s):  
Snow Cover ◽  
Air Temperature ◽  
Winter Season ◽  
Primary Objective ◽  
Climatic Conditions ◽  
Cover Depth ◽  
North Eastern ◽  
Northern Regions ◽  
Maximum Air Temperature ◽  
Snow Cover Depth

The primary objective of the paper was to characterize the climatic conditions in the winter season in Poland in the years 1966/67–2019/20. The study was based on daily values of minimum (Tmin) and maximum air temperature (Tmax), and daily values of snow cover depth. The study showed an increase in both Tmin and Tmax in winter. The most intensive changes were recorded in north-eastern and northern regions. The coldest winters were recorded in the first half of the analyzed multiannual period, exceptionally cold being winters 1969/70 and 1984/85. The warmest winters occurred in the second half of the analyzed period and among seasons with the highest mean Tmax, particularly winters 2019/20 and 1989/90 stood out. In the study period, a decrease in snow cover depth statistically significant in the majority of stations in Poland was determined, as well as its variability both within the winter season and multiannual.

scholarly journals Contributors to linkage between Arctic warming and East Asian winter climate

2021 ◽  
Author(s):  
Xinping Xu ◽  
Shengping He ◽  
Yongqi Gao ◽  
Botao Zhou ◽  
Huijun Wang
Keyword(s):  
Sea Ice ◽  
General Circulation ◽  
Initial Conditions ◽  
Wave Train ◽  
East Asian ◽  
Surface Air Temperature ◽  
General Circulation Models ◽  
The Arctic ◽  
Winter Climate ◽  
Arctic Warming

AbstractPrevious modelling and observational studies have shown discrepancies in the interannual relationship of winter surface air temperature (SAT) between Arctic and East Asia, stimulating the debate about whether Arctic change can influence midlatitude climate. This study uses two sets of coordinated experiments (EXP1 and EXP2) from six different atmospheric general circulation models. Both EXP1 and EXP2 consist of 130 ensemble members, each of which in EXP1 (EXP2) was forced by the same observed daily varying sea ice and daily varying (daily climatological) sea surface temperature (SST) for 1982–2014 but with different atmospheric initial conditions. Large spread exists among ensemble members in simulating the Arctic–East Asian SAT relationship. Only a fraction of ensemble members can reproduce the observed deep Arctic warming–cold continent pattern which extends from surface to upper troposphere, implying the important role of atmospheric internal variability. The mechanisms of deep Arctic warming and shallow Arctic warming are further distinguished. Arctic warming aloft is caused primarily by poleward moisture transport, which in conjunction with the surface warming coupled with sea ice melting constitutes the surface-amplified deep Arctic warming throughout the troposphere. These processes associated with the deep Arctic warming may be related to the forcing of remote SST when there is favorable atmospheric circulation such as Rossby wave train propagating from the North Atlantic into the Arctic.

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