Duration of the influence of snowmelt on land surface temperature and humidity after snowmelt on the Mongolian Plateau

Abstract

The impact of snowmelt on surface hydrothermal conditions is a research hot spot given the background of global warming. However, existing remote sensing-based studies have mostly focused on demonstrating the impacts of snow and are based on large time scales. How to measure the duration of snowmelt impact on surface hydrothermal conditions more accurately is a problem that needs to be addressed. We used a method to quantify the impact duration of snowmelt based on the characteristics of the phase change in land surface temperature (LST) and land surface water index (LSWI) after melting. We analyzed the snow factors that have caused the difference in impact duration and the interaction on the impact duration. The results are described as follows: (1) The LST and LSWI changes after snow melting are characterized by distinct phases. (2) The duration of the snowmelt impact on LST ranged from 4.61 days in the south to 21.23 days in the north; the effect of snow on the LSWI ranged from 8.06 days in the south to 25.38 days in the north. (3) The two durations have a significant positive correlation with snow depth and snow melt date. The combination of several snow parameters and other meteorological factors has a significant interaction effect on the duration of snowmelt influence. In most combinations where there is no interaction, the duration is significantly affected only by snow elements. The interaction can change the direction and extent of the effect of a single snow or meteorological element on the duration of snow impact. This research can supplement the theoretical basis for solving ecological problems and production in the study area, such as spring drought, forage mowing, and cold protection of livestock.