Are Atmospheric Models Too Cold in the Mountains? The State of Science and Insights from the SAIL Field Campaign

• DOI: 10.1175/bams-d-23-0082.1
• Publication Date: 2024-04-09T11:21:11Z
• Authors: William Rudisill; Alan Rhoades; Zexuan Xu; Daniel R. Feldman
• Keywords: Atmospheric sciences; Model evaluation/ performance; 550; Climate change science; Climate; Temperature; 0207 environmental engineering; Mountain meteorology; 02 engineering and technology; Physical Geography and Environmental Geoscience; Atmospheric Sciences; Climate Action; Earth Sciences; Meteorology & Atmospheric Sciences; Astronomical and Space Sciences

Abstract Mountains play an outsized role in water resource availability, and the amount timing of they provide depend strongly on temperature. To that end, we ask question: How well are atmospheric models capturing mountain temperatures? We synthesize results showing high-resolution, regionally relevant climate produce 2-m air temperature (T2m) measurements colder than what is observed (a “cold bias”), particularly snow-covered midlatitude ranges during winter. find common cold biases 44 studies across global ranges, including single-model multimodel ensembles. explore factors driving these examine physical mechanisms, data limitations, observational uncertainties behind T2m. Our analysis suggests genuine not due to observation sparsity or resolution mismatches. Cold occur primarily peaks ridges, whereas valleys often warm biased. literature review increasing model does clearly mitigate bias. By analyzing from Surface Atmosphere Integrated Field Laboratory (SAIL) field campaign Colorado Rocky Mountains, test various hypotheses related local wind circulations, longwave (LW) radiation, surface-layer parameterizations contribute T2m this particular location. conclude by emphasizing value coordinated evaluation development efforts heavily instrumented locations for addressing root cause(s) improving predictive understanding climates.