Morphological analysis of snow deposit distribution in Eurasian mountain land during 2001–2019

Author(s): A.G. Terekhov 1 , N.G. Makarenko 2

Published by: 1 Republican State Enterprise Kazhydromet, Almaty 050022, Kazakhstan 2. Central Astronomical Observatory RAS, Saint Petersburg 196140, Russia

Published in: 19700101

Format: article

Region: Eurasia

Link: Visit this Publication

Abstract: This paper is dedicated to the morphological analysis of the spatio-temporal features of snow deposit in Eurasian mountain land that includes: Jungar Alatau, Tien Shan, Pamir, Karakorum, Hindu Kush, Himalaya and Kun-Lun. Data were provided by the Snow Water Equivalent Anomaly (SWEA) USGS FEWS NET product for April 30, 2001–2019. The descriptor of patterns of seasonal distribution of the snow deposit was the Euler characteristic, which measures the topology of SWEA outliers (as set of territorial clusters) at a given level. For six SWEA levels (0, 10, 25, 50, 100, and 200 mm) for the period from 2001 to 2019, significant variations in the Euler characteristic values were found. Coefficients of determination in exponential regression models varied from 0,63 to 0,90. Morphological analysis of the SWEA values normalized by the area showed that the average area of separate clusters of the positive anomaly decreased by a factor of 10 over 19 years from ~10,000 km2 to ~1,000 km2 . Large area anomalies typical of the beginning of the 21th century became groups of relatively small, isolated zones (clusters), especially specific after 2015. Such significant changes in the SWEA spatial patterns practically did not affect their mean values, Pearson correlation coefficient was 0,02. However, the stability of the average level of moisture of the studied mountain territories was accompanied by significant local changes. For example, the zone of positive SWEA anomalies (more 100 mm) for 2019 in the period 2001–2019 was characterized by an increase in average SWEA at a rate of 182 mm per 10 years with Pearson correlation coefficient of 0.63. Thus, the dynamics of the spatial snow regime of the Eurasian mountain land in the past 19 years was accompanied by a local redistribution of snow, with a change in the long-term norms of snow deposit of the cold period of some mountain zones by competition with the others.

Topics: Mountain snow cover,  

Keywords: Climate Change,  Euler characteristic,  Eurasian snow cover,  snow deposit,  snow water equivalent anomaly,  SWEA FEWS NET,  trends over years,  weather variability,