The latitudinal dependence in the trend of snow event to precipitation event ratio

Abstract

Precipitation phase is expected to shift from solid to liquid with temperature rising, which would in turn bring challenges to regional water resource management. Although in recent decades, consistent decreasing trends in the ratio of snowfall to precipitation rate in a warming climate have been found across multiple regions, a global view of the trends in the precipitation partitioning has not been established. In this study, we investigated the global trends of annual rain and snow frequency of occurrences and the ratio of number of snow events to number of precipitation events (SE/PE ratio) using land station and shipboard synoptic present weather reports from 1978 to 2019. Results show that when averaged over all qualified land stations and over the shipboard reports, both the annual rain frequency and snow frequency decrease over the 42 years. Over both land and ocean, the averaged SE/PE ratio has a significant decreasing trend. Moreover, the trend of SE/PE ratio shows a strong latitudinal dependence. At the mid- and low latitudes in the Northern Hemisphere, the SE/PE ratio has a decreasing trend. In contrast, at high latitudes, the SE/PE ratio has an increasing trend.

Era5 Reproduces Key Features of Global Precipitation Change in a Warming Climate

“…Canada (Han et al, 2018); Tibetan Plateau (Wang et al, 2016); Europe (Blöschl et al, 2019;Matiu et al, 2021;Rixen & Rolando, 2013); and the whole world (Shi & Liu, 2021). Although not examined in this study, a seasonality in precipitation type shift has been reported by Wrzesien et al (2022).…”

“…Decreases in the proportion of precipitation falling as snow have been reported in almost every part of the mid-and high latitudes: the Arctic (Screen & Simmonds, 2012), western and contiguous US (Feng & Hu, 2007;Huntington et al, 2004;Knowles et al, 2006;Shi & Liu, 2021);…”

“…Furthermore, changes to precipitation frequency, precipitation type, and wet and dry spells are expected to accompany a warming climate and may likely carry a different signal of change than precipitation totals. With respect to precipitation type, decreases in the proportion of precipitation falling as snow have been reported in almost every part of the mid-and high manuscript submitted to replace this text with name of AGU journal latitudes (Matiu et al, 2021;Screen & Simmonds, 2012;Shi & Liu, 2021). Over the Arctic, there is growing consensus that precipitation is increasing, consistent with an amplified warming climate (Bintanja & Selten, 2014;McCrystall et al, 2021;Serreze & Barry, 2011), but most of these studies involve precipitation totals.…”

A Novel Approach to Validate Satellite Snowfall Retrievals by Ground-Based Point Measurements

“…The change in snowfall to total precipitation ratio can serve as a useful indicator on how global warming impacts on hydrological cycle. In a recent study using present weather reports, Shi and Liu found that the ratio of snowfall to precipitation occurrence has been decreasing globally in the past 40 years while at high latitudes shows an increasing trend [50]. The ratio of snowfall to precipitation amount cannot be examined in their study because of the lack of snowfall data.…”

Improvements on Phase Classification Using Atmospheric Melting and Refreezing Energy Based on Soundings

“…We used the National Centers for Environmental Prediction (NCEP) Automated Data Processing (ADP) operational global surface observations to obtain near-surface atmospheric variables and precipitation phase. Two data sets, ds464.0 from January 1978 to February 2007 (https://rda.ucar.edu/ datasets/ds464.0/) and ds461.0 from February 2007 to December 2019 (https://rda.ucar.edu/datasets/ds461.0/), were merged to create a longer series following Shi and Liu (2021). Variables used include near-surface temperature, dew point temperature, surface pressure, and the present weather codes ("ww" codes).…”