Spatial Variation of the Rain–Snow Temperature Threshold across the Northern Hemisphere Public Deposited

Downloadable Content

Download PDF
  • Despite the importance of precipitation phase to global hydroclimate simulations, many land surface models use spatially uniform air temperature thresholds to partition rain and snow. Here we show, through the analysis of a 29-year observational dataset (n = 17.8 million), that the air temperature at which rain and snow fall in equal frequency varies significantly across the Northern Hemisphere, averaging 1.0°C and ranging from –0.4 to 2.4°C for 95% of the stations. Continental climates generally exhibit the warmest rain–snow thresholds and maritime the coolest. Simulations show precipitation phase methods incorporating humidity perform better than air temperature-only methods, particularly at relative humidity values below saturation and air temperatures between 0.6 and 3.4°C. We also present the first continuous Northern Hemisphere map of rain–snow thresholds, underlining the spatial variability of precipitation phase partitioning. These results suggest precipitation phase could be better predicted using humidity and air temperature in large-scale land surface model runs.

Date Issued
  • 2018-03-20
Academic Affiliation
Journal Title
Journal Volume
  • 9
Last Modified
  • 2020-01-09
Resource Type
Rights Statement
  • doi:10.1038/s41467-018-03629-7


In Collection: