Estimates of recent changes in snow storage in the river Northern Dvina basin from observations and modeling

• Published in: Ice and Snow
• Main Authors: V. V. Popova, D. V. Turkov, O. N. Nasonova
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: Nauka 2021
• Subjects: бассейн северной двины; водный эквивалент снега; наблюдения; модели тепло- и влагообмена; тренды; изменчивость; спектральная плотность; весенний сток; Science; Q; Spring River; dvina
• Online Access: https://doi.org/10.31857/S2076673421020082; https://doaj.org/article/fb931d4307994100872e93f94f9eacbf

The variability of snow accumulation in the Northern Dvina River basin at the end of March 1980-2016 was studied using data on the snow water equivalent of (SWE) obtained from archives of the Russian Institute of HydroMeteorological Information-World Data Center (RIHMI-WCD) as well as calculated by models of the local heat and moisture exchange SWAP and SPONSOR using the WATCH reanalysis (WFDEI) as input data. A possibility to use the SWE data from these sources to describe long-term variability of the SWE values, including trend, high-frequency component, quasi-decadal fluctuations, and spatial distribution, is evaluated. When describing the structure of the SWE variability, in particular, the contribution of trend and quasi-decadal fluctuations, as well as spatial characteristics, uncertainty remains associated with both the capabilities of the models under consideration and the imperfection of the observation network (insufficient density, measurement errors, etc.). Taking into account these uncertainties, the following conclusions can be made: the SWE variability in the Northern Dvina basin at the end of March has a low-frequency component (trend), as well as high-frequency, two- and five-year quasi-periodicities and quasi-decadal fluctuations. Long-lasting SWE anomalies in 1989–1995 and 1999–2005 and the absolute minimum in 1996 associated with quasi-decadal fluctuations are almost synchronously reflected in spring runoff anomalies. The informativeness of the considered data was also investigated from the point of view of the influence of SWE on the anomalies of the spring runoff of the Northern Dvina. The results of regression estimates and calculations of predictive values point to the advantage of the model SWE data for describing anomalies of spring river discharge compared to observations, which is primarily due to the high resolution of the model data. All the considered data sources indicate a long period of SWE deficits, starting from 2005 – 15-20%. Estimates of trend parameters are in a wide range. ...