ISAM 4, Kunming, China, 24 -29 May, 2004 Land Surface Memory & Hydrological Cycle Over Asia and Its Impacts on Summer Monsoon System Yun Fan & Huug van den Dool CPC/NCEP/NWS/NOAA
Outline – Motivations – Asian Monsoon & Soil Moisture – Land Surface Hydrological cycle & long term variation – Land Memory – Local & non-local impacts – Summary
Motivations Soil moisture often has a longer memory • Drought & flood monitoring • Land surface processes • Coupled atmosphere-land-ocean modeling • land memory & predictability studies • ……
CPC Leaky Bucket Soil Moisture Model The soil moisture budget over an area A: Where W(t) is soil water content R(t) net streamflow divergence P(t) precipitation E(t) evaportranspiration G(t) net groundwater loss Forcing Data: -CPC Monthly Global Precipitation Over Land -Monthly Global Reanalysis/CDAS Temperature Data Coverage: 56+ years (1948 -present)
Summary & Future work • Soil moisture – an important factor for climate monitoring & prediction • Land surface hydrological cycles • LSMs can simulate some realistic land features • Need more detailed analysis & studies – Data validation, model comparisons & improvements – Modeling & Prediction experiments • Global Retrospective LDAS Run