Rainfall on the Greenland Ice Sheet: Present‐Day Climatology From a High‐Resolution Non‐Hydrostatic Polar Regional Climate Model
Masashi Niwano, Jason E. Box, Adrien Wehrlé, B. Vandecrux, William Colgan, John Cappelen
Abstract
Abstract Greenland ice sheet rainfall is expected to increase under a warming climate. Yet, there have been no active long‐term in‐situ rainfall records on the ice sheet due to observational difficulties. Here, we utilize the state‐of‐the‐art 5 km polar non‐hydrostatic regional climate model NHM‐SMAP to evaluate the ice sheet’s rainfall over 40 years (1980–2019). The largest trends include a fourfold increase in annual rainfall for the northwestern ice sheet; 3.1 Gt year −1 or 12 mm m −2 year −1 . September ice‐sheet‐wide rainfall amount and intensity increase by 7.5 Gt month −1 and 20.8 mm h −1 year −1 . In the last two decades, the increasing September maximum hourly rainfall rate exceeded 50 mm h −1 six times. The increased surface water delivery has numerous implications, including for snow metamorphism and ice flow dynamics.