TY - JOUR
T1 - Linking global changes of snowfall and wet-bulb temperature
AU - Tamang, Sagar K.
AU - Ebtehaj, Ardeshir M.
AU - Prein, Andreas F.
AU - Heymsfield, Andrew J.
N1 - Publisher Copyright:
© 2019 American Meteorological Society.
PY - 2020/1
Y1 - 2020/1
N2 - Snowfall is one of the primary drivers of the global cryosphere and is declining in many regions of the world with widespread hydrological and ecological consequences. Previous studies have shown that the probability of snowfall occurrence is well described by wet-bulb temperatures below 1°C (1.1°C) over land (ocean). Using this relationship, wet-bulb temperatures from three reanalysis products as well as multisatellite and reanalysis precipitation data are analyzed from 1979 to 2017 to study changes in potential snowfall areas, snowfall-torainfall transition latitude, snowfall amount, and snowfall-to-precipitation ratio (SPR). Results are presented at hemispheric scales, as well as for three Köppen-Geiger climate classes and four major mountainous regions including the Alps, the western United States, High Mountain Asia (HMA), and the Andes. In all reanalysis products, while changes in the wet-bulb temperature over the Southern Hemisphere are mostly insignificant, significant positive trends are observed over the Northern Hemisphere (NH). Significant reductions are observed in annual-mean potential snowfall areas over NH land (ocean) by 0.52 (0.34) million km2 decade-1 due to an increase of 0.34°C (0.35°C) decade-1 in wet-bulb temperature. The fastest retreat in NH transition latitudes is observed over Europe and central Asia at 0.78 and 0.458 decade-1. Among mountainous regions, the largest decline in potential snowfall areas is observed over the Alps at 3.64% decade-1 followed by the western United States at 2.81% and HMA at 1.85% decade-1.
AB - Snowfall is one of the primary drivers of the global cryosphere and is declining in many regions of the world with widespread hydrological and ecological consequences. Previous studies have shown that the probability of snowfall occurrence is well described by wet-bulb temperatures below 1°C (1.1°C) over land (ocean). Using this relationship, wet-bulb temperatures from three reanalysis products as well as multisatellite and reanalysis precipitation data are analyzed from 1979 to 2017 to study changes in potential snowfall areas, snowfall-torainfall transition latitude, snowfall amount, and snowfall-to-precipitation ratio (SPR). Results are presented at hemispheric scales, as well as for three Köppen-Geiger climate classes and four major mountainous regions including the Alps, the western United States, High Mountain Asia (HMA), and the Andes. In all reanalysis products, while changes in the wet-bulb temperature over the Southern Hemisphere are mostly insignificant, significant positive trends are observed over the Northern Hemisphere (NH). Significant reductions are observed in annual-mean potential snowfall areas over NH land (ocean) by 0.52 (0.34) million km2 decade-1 due to an increase of 0.34°C (0.35°C) decade-1 in wet-bulb temperature. The fastest retreat in NH transition latitudes is observed over Europe and central Asia at 0.78 and 0.458 decade-1. Among mountainous regions, the largest decline in potential snowfall areas is observed over the Alps at 3.64% decade-1 followed by the western United States at 2.81% and HMA at 1.85% decade-1.
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U2 - 10.1175/JCLI-D-19-0254.1
DO - 10.1175/JCLI-D-19-0254.1
M3 - Article
AN - SCOPUS:85085274938
SN - 0894-8755
VL - 33
SP - 39
EP - 59
JO - Journal of Climate
JF - Journal of Climate
IS - 1
ER -