bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring cumulus clouds by using global horizontal irradiance data
Authors: Zuev S V , Krasnenko N P 
Published: December 2020

Abstract
A previously proposed method for the detection of cumulus clouds by using time series of global horizontal irradiance from a pyranometer is developed. A characteristic feature of this method is the acceptance of short 21-minute moving analysis windows as stationary. This approach makes it possible not to construct a clear sky model for transforming a non-stationary daily time series of global horizontal irradiance to stationary time series.
Special aspects of snow cover formation in Western and Eastern Siberia
Authors: Martynova Yu V 
Published: December 2020

Abstract
Some features of snow cover onset in the autumn-winter season in Western and Eastern Siberia are presented. Snow cover extent data from NOAA historical satellite records are used in this study. The dates of onset and termination of snow cover, as well as the period of the most intense snow cover area increase during the season and its rate are revealed. The interannual variability of these parameters is estimated. The variation of the October snow cover area is also considered. A significant positive trend has been obtained, as well as a linear relationship with the date of the beginning of the week with the highest rate of snow cover increase during the season.
Long-term dynamics of snow cover in the Baikal region
Authors: Matyukhina A A , Voropay N N 
Published: December 2020

Abstract
An analysis of long-term changes in the depth (maximum, average), the dates of onset and destruction, and the duration of stable snow cover in the Baikal region is carried out according to data of observations at weather stations in 1959–2019, which makes it possible to reveal the differences of these characteristics on the eastern and western coasts of Lake Baikal. A maximum long-term snow cover depth of 39 -175 cm is recorded at weather stations in the eastern Baikal region with an average long-term depth of 9.1 -80.8 cm. At weather stations in the western Baikal region, the maximum long-term snow cover depth is 21-67 cm with average long-term values of 4.5-30.3 cm. A close dependence of the duration of snow cover on the dates of its onset and destruction has been found. At the end of the study period, a shift in the dates of onset and destruction of snow cover to earlier dates is observed in the absence of statistically significant trends. As a result of these changes, snow cover melts earlier and the duration of its occurrence is significantly reduced. The average long-term duration of stable snow cover on the territory of the Baikal region is 182 days: 186 days in the east, and 173 days in the west.
Characteristics of mesoscale eddies of Arctic marginal seas: results of numerical modeling
Authors: Platov Gennady , Golubeva Elena 
Published: December 2020

Abstract
A simple method is proposed for identifying mesoscale eddies in the results of numerical modeling. The method uses extrema in distributions of the sea level elevation as eddy markers. By using the method, we analyze statistics of mesoscale eddies resulting from SibPOM numerical simulations in the Eurasian sector of the Arctic marginal seas. The results of using this method show that the number of cyclonic eddies slightly exceeds the number of anticyclonic eddies, but the excess is only 2-3%. Also, we demonstrate that a significant number of eddies arise under the ice cover. The number of such eddies increases significantly in winter. This fact indicates that the convection caused by salt rejection during freezing plays an essential role in their formation. The numerical modeling results confirm the phenomenon of active eddy generation in the ice edge zone. Besides, the results show that in the near-edge zone, a more significant number of eddies are formed from the icy side adjacent to the edge, and not from the ice-free side. The periods of seawater freezing and ice melting, accompanied by corresponding displacements in the ice edge, produce eddies different in nature. The number of eddies in the marginal ice zone has two seasonal maxima corresponding to these two periods.
Numerical simulation of turbulent mixing and transport of biochemical substances in inland waters
Authors: Gladskikh D S , Mortikov E V , Stepanenko V M 
Published: December 2020

Abstract
Numerical modeling of inland water objects (lakes and reservoirs) and, in particular, mixing processes and transport of biochemical substances in these basins is considered. A three-dimensional hydrostatic model and a one-dimensional model LAKE based on averaging of three-dimensional equations over a horizontal section of a reservoir are used as tools for the calculations. In the LAKE model, seiche oscillations are taken into account by parameterizing the pressure gradient and horizontal eddy viscosity. A k-ε closure is used to describe the vertical exchange processes in both models. A parameterization of the Prandtl number is implemented in the 3D model which allows turbulence to persist at any values of the gradient Richardson number. The 3D model is also supplemented by equations for calculating biochemical substances by analogy with the one-dimensional biochemistry equations used in the LAKE model, which, in particular, allow us to study the transport of substances such as oxygen (O2) and methane (CH4). Numerical experiments aimed at studying turbulent mixing and transport of substances are carried out.
Assessment of the influence of various tree species and their parameters on the behaviour of wind flows in urban environments (on the example of the RUDN University campus, Moscow)
Authors: Bukin S S , Fadeeva I A , Yaroslavtsev A M , Konstantinov P I , Vasenev V I , Valentini R 
Published: December 2020

AbstractUrban environments are constantly growing, as a result of which natural surface covers are replaced by artificial materials. These changes have a strong impact on the wind fields in these urban environments, changing speeds and directions of wind flows. The aim of this study is to assess the effects of various tree parameters on the behaviour of wind flows in an urban environment. The EnviMet software package is used to model wind fields. The study is conducted in the city of Moscow on the RUDN University campus. Ten different kinds of trees are identified with characteristics such as tree height, crown width, trunk height, and the LAD (Leaf Area Density) index. For these species, a similar analysis is carried out to assess their impact on the wind field. The height of the trunk has a significant effect on the wind field at the pedestrian level; depending on the parameter, the wind speed and the area of wind gusts increase. Large crowns create a protective barrier, reducing wind activity. At the same time, a high LAD index creates low wind permeability, as a result of which the wind flows are refracted, and dangerous zones arise. On the other hand, a high LAD index reduces the area of wind gusts.
Microscale simulation of wind speed in urban areas during extreme weather events (case study of Moscow)
Authors: Nikolaeva E V , Kospanov A A , Bukin S S , Konstantinov P I 
Published: December 2020

Abstract
This study is primarily based on the goal to make a model of the MSU campus to investigate wind speed distribution. As a case study, a squall event on the 29th of May 2017 is chosen. The event caused human casualties, which required much research. To validate the results, they have to be tested for their stability. In this work this goal is met by varying wind directions. Later the wind maps were achieved as the results were overlaid to reflect the variability of the wind speed distribution. Moreover, the results of this work are possible dangerous areas of a campus which can be obtained as a result of simulating hazardous wind speeds. The wind directions are varied to match 4 primary directions. The heights of interest are chosen to be 1.5 m and 12.5 m, they represent the pedestrian level and the level of half the average tree height, respectively. The simulation software used is ENVI-met. This work shows whether this software is suitable for modeling hazardous events, how stable the results are, and whether the new user is able to successfully use the possibilities offered by ENVI-met to achieve the needed goals. With the results of simulations for stability tests and dangerous area outlining, spatial distributions of the wind speed are analyzed both quantitively and qualitatively.
Study of surface-based temperature inversions in the city of Nadym (Western Siberia) with direct measurements and numerical simulation
Authors: Vorotilova P G , Konstantinov P I , Varentsov M I , Timazhev A V , Baklanov A A 
Published: December 2020

Abstract
Frequent surface-based inversions are persistent features of climate in the Arctic and, in particular, in its Russian part. Most favourable conditions for temperature inversion formation during the winter period in this region are observed. Surface-based inversions formed in cities are most interesting for research, because of their impact on people’s health. Besides, “urban” surface-based inversions differ from “rural” ones, because of interactions with the urban heat island (UHI). Actually, urban surface-based inversions in the Arctic are weakly understood due to poor meteo monitoring equipment of most Arctic regions and because the reanalysis resolution is too low for the cities. To estimate the frequency of surface-based inversions and spatial distributions in the city of Nadym (Western Siberia), measurements with gradient complexes during the period from 18.12.2018 to 15.10.2019 have been conducted, and a numerical experiment with a model Advanced Research WRF (ARW) has been performed for the coldest days of the period. In the research, first statistic microclimatic data of vertical temperature distributions in the city of Nadym have been obtained. Such model experiments are realized for that region, and the results obtained for the rural area are compared with microwave temperature profiler MTP-5 measurements.
The influence of external parameters on river runoff in the INM RAS – MSU land surface model
Authors: Medvedev A I , Stepanenko V M 
Published: December 2020

Abstract
Estimation is made of the sensitivity of water balance in the land surface model INM RAS – MSU to changes in sources of external parameters: reanalysis for precipitation and a land surface map. The model shows a high degree of sensitivity to changes in the reanalysis. On the territory of Russia, all modern global reanalyses overestimate precipitation sums. It is less relevant to ERA5: its error in the monthly sums is close to random. The model shows a low degree of sensitivity to changes in the land cover map. The reason is that there is an excess in the stomatal resistance over the aerodynamic one by several orders of magnitude in most cases.
Analysis of surface wetness changes in the Maly Labysh mire in south of Western Siberia during the last two millennia
Authors: Kurina I V , Blyakharchuk T A 
Published: December 2020

Abstract
In this study we investigate peat deposits of a transitional sedge-Sphagnum mire by using a testate amoeba analysis to reconstruct the paleohydrology of the mire for the last two millennia. The Maly Labysh mire is located in a river floodplain in low mountains in the south of Western Siberia. The goal of our research is to evaluate the water table depth changes in the mire due to regional and continental climate changes in the late Holocene. Two short-term dryings of the mire surface in 2100-1900 and 1600-1400 yr BP have been revealed. Afterwards, an unusual shift in the oligotrophic conditions on the mire surface is documented between 1400-1100 yr BP. This indicates some weakening of the influence of the nearby river likely due to a decrease in the precipitation. Then, starting at ca. 900 yr BP the mire gradually came back to transitional conditions again, and its surface moisture remained moderately high without notable fluctuations. The close consistency of the thus revealed periods of short drying with similar events in the development of other lake and bog sediments in the south of Western Siberia indicates the fact of predominant influence of westerlies on the formation of the regional climate.
Dynamics of vegetation cover and quantitative palaeoclimatic reconstructions in the Western Sayan Mountains from the Late Glacial period to the present time according to a palynological study of the Yuzhno-Buybinskoe mire
Authors: Blyakharchuk T A 
Published: December 2020

Abstract
The aim of this research is an investigation of long-term palaeoclimatic changes. In this paper we present results of a palaeopalynological study of a high mountain peat-lake sediment core from the Yuzhno-Buibynskoe Mire in the Western Sayan Mountains covering the last 13000 cal yrs BP. In addition to qualitative palaeopalynological reconstructions we have performed quantitative reconstructions of T January, T July, and Annual precipitations using our own transfer functions constructed on 118 surface pollen spectra by a method developed by ter Braak and coauthors [16]. The results of the quantitative palaeclimatic reconstructions have demonstrated three types of climate changes in the study area from the Late Glacial period to the present time: cryo-arid climate in the Late Glacial period from 13000 cal yr BP to 11000 cal yr BP (I), humid moderate cool climate in the Middle Holocene (II) and humid cool climate in the Late Holocene after 5000 cal yr BP (III). The cold climate during the Late Glacial period was caused mostly by low winter temperatures combined with low annual precipitation, while the summer temperatures were equal or even higher than modern ones. This is characteristic for the anticyclone influenced areas. The winter temperatures and annual amount of precipitation considerably increased in all areas of the Altai-Sayan region during the early and middle Holocene times, when Atlantic cyclones reached this area. In the Late Holocene period we observe a gradual return to the climatic parameters of the pre-Holocene time.
Algorithms based on sensitivity operators for analyzing and solving inverse modeling problems of transport and transformation of atmospheric pollutants
Authors: Penenko Alexey , Gochakov Alexander , Penenko Vladimir 
Published: December 2020

Abstract
An application of sensitivity operator-based algorithms to an inverse modeling scenario of urban air quality is presented. A source identification problem and a concentration field continuation problem are solved and analyzed. The analysis of the sensitivity operator allows one to obtain a preliminary estimate of the source identification problem solution.
Mapping of changes in the stress-strain state of a landslide risk slope using an Earth’s natural pulsed electromagnetic field method
Authors: Malyshkov S Yu , Gordeev V F , Polivach V I 
Published: December 2020

Abstract
Among the wide range of hazardous natural processes and phenomena, the exogenic geodynamical processes stand aside. These events can either directly or indirectly provoke or amplify socio-economic or technogenic risks, and differ considerably in the time and space scales. The landslide processes can affect the environmental situation, decrease the durability of real estate objects, compromise the integrity of transportation and engineering infrastructure, and endanger the population safety. Among the reasons of soil plots destabilization are water cuts and technogenic stress on the geo-environment. As cities continue to grow, the environmental load increases. Global warming leads to an increase in precipitation and changes the regional hydrogeological conditions. Therefore, the problem of landslide research and forecasting becomes more urgent. This work presents results of a field research carried out on a site prone to intensive landslide process development, ravine erosion, and rain-wash by using an Earth’s natural pulsed electromagnetic field (ENPEMF) method. It has been demonstrated that the exogenic slope processes can develop rapidly and the occasional surveys alone are not enough to protect the infrastructure objects. It is necessary to establish an online ongoing monitoring of the stress-strain state (SSS) of the rocks. The ENPEMF method allows an instrumental real-time estimation of the soil stability and can be recommended for continuous monitoring of the SSS of the rocks.
Assessment of conditions of aridity and humidity in the growing season on the territory of Samara region
Authors: Mirsaeva N A 
Published: December 2020

Abstract
An analysis of the spatiotemporal variability of some agroclimatic characteristics shows that aridity is growing in the region, especially in the warm period. This is more evident in the south and southwest, where droughts are more intense than in the other areas of the region. A real-time analysis of the Ivanov-Vysotsky wetting coefficient and the BEI index has not revealed any significant changes. Currently, Samara region has satisfactory agroclimatic resources with moderate and low productivity. In Samara region, there are unfavorable moisture conditions due to droughts in 2010, 2011, 2015, and 2016 and extensive heat supply.
On long period trend estimates of upper-air extreme and sub-extreme temperatures by use of quantile regression
Authors: Sterin A M , Lavrov A S 
Published: December 2020

Abstract
The traditional studies of climate change are based on estimation of trends in average values of climate variables (such as monthly, seasonal, or annual average values of temperature, air pressure, precipitation, wind speed, etc.). However, these estimates do not provide detailed information on changes in the distributions and are not sufficient to answer questions about changes in extreme and sub-extreme values, as well as questions on left and right “tails” of the distributions and changes in the measures of variability. A mechanism called quantile regression (QR) is an instrument for performing such a study. Unlike the traditional regression methods that are based on the Ordinary Least Squares (OLS) methodology, QR can provide detailed information about the structure of climate trends for a whole range of values, i.e. including extremal and sub-extremal values. While the known climatological studies of QR trends in extremes and sub-extremes are related to surface meteorological variables, such as surface temperature, it is essential to make similar QR-based studies of trends for the upper-air (UA) temperature. This paper contains results of such an analysis for the UA temperature based on a collection of radiosonde data for more than 30 years of observation. We discuss typical patterns of a detailed structure of climate trends for the upper-air temperature in the troposphere and in the lower stratosphere for certain geographic sectors of the Northern Hemisphere. The existing difficulties to obtain realistic results in such a study are shown to be related to various kinds of gaps in the radiosonde data. Therefore, some data quality requirements are vital for such upper-air studies.
High-resolution wind speed modeling, and an assessment of mesoscale peculiarities caused by coastline parameters and relief of near-shore Kara Sea regions
Authors: Platonov Vladimir , Kislov Alexander 
Published: December 2020

Abstract
Complex shorelines and coastal relief strongly influence wind speeds. Since the Arctic is poorly covered by ground observations, one of the most reasonable approaches to investigating these events is hydrodynamical high-resolution modeling. In this work we apply a model COSMO-CLM to reproduce wind fields and characteristics in different rugged shore conditions. Some model experiments are designed with this regional climate non-hydrostatic atmospheric model COSMO-CLM to investigate the best configuration to reproduce the mesoscale circulations in the Arctic coastal zones considering different relief conditions on the example of the Kara Sea. Some mid-term experiments of a three-month timespan, Aug-Oct of 2012 and Jul-Sep of 2014, are conducted over the Arctic domain and specially over the Kara Sea region using a downscaling approach with ∼12 and ∼3 km horizontal grids. These periods are characterized by some storm events. The purpose of these experiments is to reproduce the surface wind and wave characteristics in the best way, especially near the shorelines during the storm events. Verification of these experiments has shown the best configuration of the COSMO-CLM with a “spectral nudging” technique and reducing the model time step. However, the verification and detailed investigation of the model runs raise a question about the quality of this verification, and how relevant are the wind station data in different coastline and relief conditions. Therefore, an additional analysis is carried out from a synoptic overview of the influence of the coastline configuration on different mesoscales and for different regions. Malye Karmakuly (Novaya Zemlya island), Belyi and Dikson Islands are considered as different examples to study the wind and wave regimes. Although the model cannot describe the dynamics on all scales using a 3-km resolution, it can realistically simulate the islands’ wind shadows, tip jets, downslope winds, vortex chains, etc. on different scales. It justifies further research to apply a finer resolution to learn detailed properties of mesoscale circulations and extreme winds. This analysis has shown a need to predict better these circulations by using numerical modelling.
Estimated influence of extreme climate events in the 21st century on the radial growth of pine trees in Povolzhie region (European Russia)
Authors: Matskovsky Vladimir , Kuznetsova Veronika , Morozova Polina , Semenyak Nadezhda , Solomina Olga 
Published: December 2020

Abstract
The projected climate change in the 21st century is expected to affect various forest ecosystems with corresponding ecological, economic, and social impact. Adaptation measures for forestry need to be planned well in advance, because the forests being regenerated today will have to cope with future climate conditions in long time periods. Here we use a process-based forward model of tree growth, VS-Lite, calibrated and independently validated on tree-ring data and forced by climate projections according to various greenhouse gas emission scenarios. We estimate the ensemble radial tree growth of pine in Povolzhie region in the future. Our projections show a constant tree growth throughout the 21st century. The increased temperature will slightly favour the tree growth, especially in the case of an extended growth season, while mostly constant precipitation will not lead to any soil moisture deficit. The results of this study are crucial for the development of Povolzhie region in the near or remote future.
Windthrows in the pine forests of the Tsagan-Daban ridge (the central part of the Selenga middle mountains)
Authors: Chernykh V N , Alymbaeva Zh B , Andreev S G , Ayurzhanaev A A , Tsydypov B Z 
Published: December 2020

Abstract
This paper presents results of an analysis of damage to cedars growing on the slopes of the Tsagan-Daban Ridge (the central part of the Selenga middle mountain) caused by storm winds in 2018-2019. Based on a study of Landsat satellite data, the main areas of windthrows are determined, and their morphometric characteristics are calculated. The damaged areas of cedar forests on key sites in the Kunaleyka River basin are surveyed with UAV. The causes and consequences of windthrows in the Tsagan-Daban Ridge taiga are identified.