Future Changes of Subseasonal Precipitation Variability in North America During Winter Under Global Warming

TitleFuture Changes of Subseasonal Precipitation Variability in North America During Winter Under Global Warming
Publication TypeJournal Article
Year of Publication2018
AuthorsDong, Lu, L. Leung Ruby., and Song Fengfei
JournalGeophysical Research Letters
Volume45
Number22
Pages12,467-12,476
Date Published11/2018
Abstract / Summary

Changes in subseasonal precipitation variability have important implications for predictability of weather and climate extreme. Here we explore the mechanisms that lead to future changes in subseasonal precipitation variability in North America during winter based on 20 state‐of‐the‐art climate models. Modeling evidences indicate that in a warmer climate, the subseasonal precipitation variability consistently increases over most of North America, with intensified swing between the wet and dry extremes, but declines over Mexico. Using a moisture budget decomposition framework, two opposing mechanisms are established: the thermodynamic component from increasing moisture due to global warming intensifies the subseasonal precipitation variability, while the dynamic component from the projected reduction in subseasonal rainfall‐related circulation variability has an opposite effect. Overall, the thermodynamic effect wins the tug of war at the mid‐to‐high latitudes over most of North America, while the dynamic effect overwhelms the thermodynamic effect in Mexico, creating distinct changes in subseasonal precipitation variability.

URLhttp://doi.org/10.1029/2018gl079900
DOI10.1029/2018gl079900
Journal: Geophysical Research Letters
Year of Publication: 2018
Volume: 45
Number: 22
Pages: 12,467-12,476
Date Published: 11/2018

Changes in subseasonal precipitation variability have important implications for predictability of weather and climate extreme. Here we explore the mechanisms that lead to future changes in subseasonal precipitation variability in North America during winter based on 20 state‐of‐the‐art climate models. Modeling evidences indicate that in a warmer climate, the subseasonal precipitation variability consistently increases over most of North America, with intensified swing between the wet and dry extremes, but declines over Mexico. Using a moisture budget decomposition framework, two opposing mechanisms are established: the thermodynamic component from increasing moisture due to global warming intensifies the subseasonal precipitation variability, while the dynamic component from the projected reduction in subseasonal rainfall‐related circulation variability has an opposite effect. Overall, the thermodynamic effect wins the tug of war at the mid‐to‐high latitudes over most of North America, while the dynamic effect overwhelms the thermodynamic effect in Mexico, creating distinct changes in subseasonal precipitation variability.

DOI: 10.1029/2018gl079900
Citation:
Dong, L, LR Leung, and F Song.  2018.  "Future Changes of Subseasonal Precipitation Variability in North America During Winter Under Global Warming."  Geophysical Research Letters 45(22): 12467-12476.  https://doi.org/10.1029/2018gl079900.