FEATURES OF SNOW COVER OF SEMI-DESERTS AND DRY STEPPES OF THE CASPIAN SEA ACCORDING TO SATELLITE DATA FOR THE PERIOD 2001...2020

2021 ◽  
Vol 101 (2) ◽  
pp. 80-87
Author(s):  
A.G Terekhov ◽  
◽  
N.I. Ivkina ◽  
N.N. Abayev ◽  
A.V. Galayeva ◽  
...  

The Snow Depth FEWS NET daily product was used to analyze snowy regime of the upper part of the River Emba basin from January 1 to April 30 for the period of 2001...2020. The Emba River basin is situated in Kazakhstan at the Eastern coast of the Caspian Sea. The area is characterized by the arid and extreme continental climate with dry-steppe and semi-desert landscapes. The population is small and the anthropogenic impact on the snow cover is minimal there. These conditions give an opportunity to identify the natural tendency in long-term changes of snow covering in semidesert zone of Kazakhstan. This paper describes the characteristics of the formation and destruction of the snow cover in the last 20 years. It was indicated that snowy regime has a trigger structure including two states; low-snowy regime and others years. It was shown that the snowy conditions are triggered. There are two modes, the first, as a low-snowy regime (up to 50 % of the entire sample) and the second mode includes other years. Significant variations of snow depth in various years masked many years’ tendencies of snow cover characteristics. But low-snowy regime was observed four times during five last years that can relate with modern decreasing snow covering in semi-desert zone of Kazakhstan.

2020 ◽  
Vol 324 (2) ◽  
pp. 262-272
Author(s):  
I.V. Doronin ◽  
T.N. Dujsebayeva ◽  
K.M. Akhmedenov ◽  
A.G. Bakiev ◽  
K.N. Plakhov

The article specifies the type locality of the Steppe Ribbon Racer. The holotype Coluber (Taphrometopon) lineolatus Brandt, 1838 is stored in the reptile collection of the Zoological Institute of the Russian Academy of Sciences (ZISP No 2042). Literature sources provide different information about the type locality. A mistake has been made in the title of the work with the original species description: the western coast of the sea was indicated instead of the eastern one. The place of capture was indicated as “M. Caspium” (Caspian Sea) on the label and in the reptile inventory book of the Zoological Museum of the Academy of Sciences. The specimen was sent to the museum by G.S. Karelin. The “1842” indicated on the labels and in the inventory book cannot be the year of capture of the type specimen, just as the “1837” indicated by A.M. Nikolsky. In 1837, Karelin was in Saint Petersburg and in 1842 in Siberia. Most likely, 1837 is the year when the collection arrived at the Museum, and 1842 is the year when the information about the specimen was recorded in the inventory book (catalog) of the Zoological Museum of the Academy of Sciences. In our opinion, the holotype was caught in 1932. From Karelin’s travel notes of the expedition to the Caspian Sea in 1832, follows that the snake was recorded in two regions adjacent to the eastern coast of the Caspian Sea – Ungoza Mountain (“Mangyshlak Mountains”) and site of the Western Chink of Ustyurt between Zhamanairakty and Kyzyltas Mountains (inclusive) on the northeast coast of Kaydak Sor (“Misty Mountains”). In our article, Karelin’s route to the northeastern coast of the Caspian Sea in 1832 and photographs of these localities are given. The type locality of Psammophis lineolatus (Brandt, 1838) should be restricted to the Mangystau Region of the Kazakhstan: Ungoza Mountain south of Sarytash Gulf, Mangystau (Mangyshlak) Penninsula (44°26´ N, 51°12´ E).


2016 ◽  
Author(s):  
Martin Wegmann ◽  
Yvan Orsolini ◽  
Emanuel Dutra ◽  
Olga Bulygina ◽  
Alexander Sterin ◽  
...  

Abstract. Snow cover variability has significant effects on local and global climate evolution. By changing surface energy fluxes and hydrological conditions, changes in snow cover can alter atmospheric circulation and lead to remote climate effects. To analyze such multi-scale climate effects, atmospheric reanalysis and derived products offer the opportunity to analyze snow variability in great detail far back in time. So far only little is know about their quality. Comparing four long-term reanalysis datasets with Russian in situ snow depth data, a good representation of daily to sub-decadal snow variability was found. However, the representation of pre-1950 inter-decadal snow variability is questionable, since datasets divert towards different base states. Limited availability of independent long-term snow data hinders investigating this bifurcation of snow states in great detail, but initial investigations reveal a non-stationary performance of snow evolution representation. This study demonstrates the ability of long-term reanalysis to reproduce snow variability accordingly.


2019 ◽  
Author(s):  
Xiongxin Xiao ◽  
Tingjun Zhang ◽  
Xinyue Zhong ◽  
Xiaodong Li ◽  
Yuxing Li

Abstract. Snow cover is an effective best indicator of climate change due to its effect on regional and global surface energy, water balance, hydrology, climate, and ecosystem function. We developed a long term Northern Hemisphere daily snow depth and snow water equivalent product (NHSnow) by the application of the support vector regression (SVR) snow depth retrieval algorithm to historical passive microwave sensors from 1992 to 2016. The accuracies of the snow depth product were evaluated against observed snow depth at meteorological stations along with the other two snow cover products (GlobSnow and ERA-Interim/Land) across the Northern Hemisphere. The evaluation results showed that NHSnow performs generally well with relatively high accuracy. Further analysis were performed across the Northern Hemisphere during 1992–2016, which used snow depth, total snow water equivalent (snow mass) and, snow cover days as indexes. Analysis showed the total snow water equivalent has a significant declining trends (~ 5794 km3 yr−1, 12.5 % reduction). Although spatial variation pattern of snow depth and snow cover days exhibited slight regional differences, it generally reveals a decreasing trend over most of the Northern Hemisphere. Our work provides evidence that rapid changes in snow depth and total snow water equivalent are occurring beginning at the turn of the 21st century with dramatic, surface-based warming.


2020 ◽  
pp. 269-305
Author(s):  
V.N. Malinin ◽  
S.M. Gordeeva ◽  
Yu.V. Mitina ◽  
O.I. Shevchuk

Study of sea level is being developed at RSHU in several directions: global, regional and local. The global one includes the study of the patterns of interannual fluctuations of the global sea level (GLS), identification of their genesis and development of a set of methods for its long-term forecast. Two approaches to the genesis of GLS are considered. In foreign studies, changes in GLS are determined by changes in the water mass of various cryosphere components, land water reserves and steric level fluctuations. Another approach, implemented at RSHU, is to assess contributions of various factors using the equation of the freshwater balance of the World Ocean as the sum of eustatic and steric factors. A physical-statistical method for two-decade GLS forecasting, based on delay in the GLS response to air temperature over the ocean, has been developed, as well as the GLS projections at the end of the century for climatic scenarios according to the CMIP5 project have been provided. In the regional context, the main attention is paid to identifying the genesis of the interannual variability of the Caspian Sea level with the aim of its long-term forecasting. The entire chain of cause-and-effect relationships in the North Atlantic-atmosphere-Volga basin-Caspian level system is discussed. It has been established that, as a result of the intensification of cyclonic activity in the North Atlantic, especially in the Norwegian Sea, caused by the processes of large-scale interaction between the ocean and the atmosphere, there is an increase in evaporation and in the zonal transfer of water vapour to Europe and then to the Volga basin. Therefore, more precipitation falls in the runoff-forming zone of the basin, the annual runoff of the Volga and the level of the Caspian Sea increasing. The reverse is observed with weakening of cyclonic activity in the North Atlantic. In view of this, the level of the Caspian Sea is an integral indicator of largescale moisture exchange in the ocean-atmosphere-land system. The article discusses the features of interannual sea level fluctuations in Kronstadt since 1836. A simple two-parameter model for forecasting sea level by the end of the 21st century is proposed for major climate scenarios, the predictors being the GSL and the North Atlantic Oscillation. According to the most realistic forecast, the level in Kronstadt may rise to 34-59 cm (Baltic system) by the end of the century, while according to the “pessimistic” one — to 80-90 cm (Baltic system). The estimates of the extreme storm surge at which the level rise north of the Gorskaya can reach 600 cm (Baltic system) are given. The effect of flooding from storm surges is especially strong near Sestroretsk. The total area of possible flooding of the Kurortny district at a 4-m high surge wave exceeds 1260 hectares, all the beaches being completely lost. The trajectories of flood cyclones and their role for periods of climate warming and cooling are considered


2018 ◽  
Author(s):  
Gleb S. Dyakonov ◽  
Rashit A. Ibrayev

Abstract. The decadal variability of the Caspian Sea thermohaline properties is investigated by means of a high-resolution ocean general circulation model including sea ice thermodynamics and air-sea interaction, forced by prescribed realistic atmospheric conditions and riverine runoff. The model describes synoptic, seasonal and climatic variations of the sea thermohaline structure, water balance and level height. A reconstruction experiment was conducted for the period of 1961–2001, covering a major regime shift in the global climate of 1976–1978, which allows to investigate the Caspian Sea response to such significant episodes of climate change. The long-term trends in the sea circulation patterns are considered with an assessment of the influence of model error accumulation.


Fisheries ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 52-56
Author(s):  
Tatiana Vetlugina

Rudd is one of the most abundant species in the large group of minnow in the Volga-Caspian and Northern-Caspian fishery subareas of the Volga–Caspian fishery basin south. The article contains the data on its catches and usable stocks during ХХ – ХХI centuries. A long term analysis of the rudd catches and the runoff volume during the spring high water showed no substantial connection between these processes due to the rudd’s ecological peculiarities. The dynamics of the rudd catches and the level of the Caspian Sea are connected in inverse ratio. Inverse correlations with high determination coefficients between the rudd catches, the usable stocks, and the sea level were obtained.


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