Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Subseasonal Prediction With and Without a Well-Represented Stratosphere in CESM1

TitleSubseasonal Prediction With and Without a Well-Represented Stratosphere in CESM1
Publication TypeJournal Article
Year of Publication2020
JournalWeather and Forecasting
Volume35
Number6
Pages2589-2602
Abstract / Summary

There is a growing demand for understanding sources of predictability on subseasonal to seasonal (S2S) time scales. Predictability at subseasonal time scales is believed to come from processes varying slower than the atmosphere such as soil moisture, snowpack, sea ice, and ocean heat content. The stratosphere as well as tropospheric modes of variability can also provide predictability at subseasonal time scales. However, the contributions of the above sources to S2S predictability are not well quantified. Here we evaluate the subseasonal prediction skill of the Community Earth System Model, version 1 (CESM1), in the default version of the model as well as a version with the improved representation of stratospheric variability to assess the role of an improved stratosphere on prediction skill. We demonstrate that the subseasonal skill of CESM1 for surface temperature and precipitation is comparable to that of operational models. We find that a better-resolved stratosphere improves stratospheric but not surface prediction skill for weeks 3–4.

URLhttp://dx.doi.org/10.1175/waf-d-20-0029.1
DOI10.1175/waf-d-20-0029.1
Journal: Weather and Forecasting
Year of Publication: 2020
Volume: 35
Number: 6
Pages: 2589-2602
Publication Date: 12/2020

There is a growing demand for understanding sources of predictability on subseasonal to seasonal (S2S) time scales. Predictability at subseasonal time scales is believed to come from processes varying slower than the atmosphere such as soil moisture, snowpack, sea ice, and ocean heat content. The stratosphere as well as tropospheric modes of variability can also provide predictability at subseasonal time scales. However, the contributions of the above sources to S2S predictability are not well quantified. Here we evaluate the subseasonal prediction skill of the Community Earth System Model, version 1 (CESM1), in the default version of the model as well as a version with the improved representation of stratospheric variability to assess the role of an improved stratosphere on prediction skill. We demonstrate that the subseasonal skill of CESM1 for surface temperature and precipitation is comparable to that of operational models. We find that a better-resolved stratosphere improves stratospheric but not surface prediction skill for weeks 3–4.

DOI: 10.1175/waf-d-20-0029.1
Citation:
Richter, J, K Pegion, L Sun, H Kim, J Caron, A Glanville, E LaJoie, et al.  2020.  "Subseasonal Prediction With and Without a Well-Represented Stratosphere in CESM1."  Weather and Forecasting 35(6): 2589-2602.  https://doi.org/10.1175/waf-d-20-0029.1.