Simulation of orographic precipitation’s component on the Mount Elbrus example

• Published in: Global and Planetary Change
• Main Authors: P. Toropov A., A. Shestakova A., J. Yarynich I., S. Kutuzov S., П. Торопов А., А. Шестакова А., Ю. Ярынич И., С. Кутузов С.
• Other Authors: The main part of this study was funded by the Russian Foundation for Basic Research (project № 20–05–00176). The ice cores’s data was analyzed and interpreted in the framework of Megagrant № 075–15–2021–599, 08.06.2021, Большая часть работы выполнена при поддержке РФФИ (проект № 20–05– 00176), анализ и интерпретация данных по ледяному керну проведена в рамках Мегагранта № 075–15–2021–599 от 08.06.2021 г.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2023
• Subjects: orographic precipitation;the mountains precipitation modeling;reanalysis data;reconstruction of accumulation on glaciers;ice cores; орографические осадки;моделирование осадков в горах;данные реанализа;реконструкция аккумуляции на ледниках;ледовые керны; ice core; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/1082; https://doi.org/10.31857/S2076673422040146

A model of the orthographic component of precipitation based on the calculation of the condensation rate of water vapor in the air stream uplifting onto the mountain slope is proposed. The main assumptions of the model are: the cooling of the rising air is determined only by the adiabatic process; the orographic component of the vertical component of wind speed is generated by the relief, and its weakening with elevation is determined only by the atmospheric stratification; the proportion of precipitation from the total mass of the condensed moisture depends only on the air temperature. ERA5 reanalysis, which was previously compared with observational data, is used as initial data. The proposed model adequately reproduces the spatial and temporal variability of precipitation on the Elbrus slopes both for short episodes and on the climatic time scale (1985–2018). Comparison of the modeling results with the reconstruction of the annual accumulation of precipitation from the ice core obtained on the Western Elbrus Plateau in 2018 showed a statistically significant positive correlation. However, similar comparison with the data from the core extracted in 2009 did not give a statistically significant result. This means that the proposed model can be used as a tool for conformity between methods of accumulation reconstruction and for substantiation of their physical justification (correctness). In addition, this algorithm can be used to calculate monthly and annual sums of precipitation on mountain slopes of various exposures and to estimate annual accumulation on mountain glaciers. Предложена модель орографической компоненты осадков, основанная на алгоритме расчёта скорости конденсации водяного пара в воздухе, вынужденно поднимающемся вдоль горного склона. В модели учтены затухание вертикальной компоненты скорости ветра, инициированной рельефом, в зависимости от стратификации, а также доля влаги, выпадающей в виде осадков, от общей массы конденсата. В качестве начальных данных применяется информация реанализа ERA5 ...