loading page

Impact of soil moisture updates on temperature forecast
  • Soyoung Ha,
  • Jenny Sun
Soyoung Ha
National Center for Atmospheric Research

Corresponding Author:[email protected]

Author Profile
Jenny Sun
National Center for Atmospheric Research (UCAR)
Author Profile


The impact of land variables on temperature forecasts in atmospheric cycling is often underestimated or overlooked. This oversight primarily occurs due to the abundance of meteorological measurements available for assimilation and partly because soil states are assumed to be quickly reset by atmospheric forcing, such as precipitation, justifying no spin-ups or no updates of soil states during cycling. In this study, by updating soil moisture every 6 hours using different analysis datasets for May 2019, considerable discrepancies were found, highlighting large uncertainties in soil moisture analysis. Different soil moisture analyses produced systematically different temperature forecasts, with errors growing over cycles to be comparable to a typical error magnitude of 2-m temperature observations (~2ºK). This study demonstrates that temperature forecasts are significantly influenced by whether and how soil moisture is updated, not only near the surface but also up to the low-mid troposphere and throughout the cycles.
20 May 2024Submitted to ESS Open Archive
20 May 2024Published in ESS Open Archive