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Land surface impacts on subseasonal and seasonal predictability
Author(s) -
Guo Zhichang,
Dirmeyer Paul A.,
DelSole Tim
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl049945
Subject(s) - predictability , environmental science , climatology , atmosphere (unit) , evapotranspiration , atmospheric sciences , precipitation , boreal , meteorology , geology , geography , ecology , paleontology , physics , quantum mechanics , biology
This paper shows that realistically initialized land surface states enhance atmospheric predictability significantly out to two‐to‐three months during summer. The spatial structure of the impact of land initialization on atmospheric predictability can be explained by the simultaneous influence of soil moisture memory time and land surface‐evapotranspiration coupling strength. A proxy for this impact based on soil moisture and evaporation anomalies is proposed. The results also show that the impact of the land surface on atmospheric predictability varies with season: enhancement of predictability is relatively small during boreal spring and autumn, and reaches a maximum during boreal summer. Remarkably, the predictability of atmospheric temperature and precipitation increases with lead time from spring to summer. This increase is diagnosed as a “transfer” of predictability from land to atmosphere: during spring, the soil moisture predictability is high, but this predictability does not impact the atmosphere due to lack of land‐atmosphere coupling; during summer, the coupling increases, thereby transferring the predictability from land to atmosphere.