HR: 1400h
AN: H33B-11    [Abstracts]
TI: Soil Moisture Memory and Predictability of Seasonal Streamflow in Sri Lanka
AU: Mahanama, S
EM: sarith@gmao.gsfc.nasa.gov
AF: Goddard Earth Sciences and Technology Center (GEST/UMBC), NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: Mahanama, S
EM: sarith@gmao.gsfc.nasa.gov
AF: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center Code 610.1, Greenbelt, MD 20771, United States
AU: * Reichle, R H
EM: reichle@gmao.gsfc.nasa.gov
AF: Goddard Earth Sciences and Technology Center (GEST/UMBC), NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: * Reichle, R H
EM: reichle@gmao.gsfc.nasa.gov
AF: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center Code 610.1, Greenbelt, MD 20771, United States
AU: Zubair, L
EM: lareef@iri.columbia.edu
AF: International Research Institute for Climate and Society, The Earth Institute at Columbia University PO Box 1000, Palisades, NY 10964, United States
AU: Koster, R D
EM: koster@gmao.gsfc.nasa.gov
AF: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center Code 610.1, Greenbelt, MD 20771, United States
AB: Global water and energy budget studies as well as long term soil moisture observation records have shown that the time scales of soil moisture anomaly dissipation are about 2-3 months. This implies that the baseflow component of streamflow should, in principle, be partly predictable at seasonal time scales. Here we investigate the hypothesis of seasonal streamflow predictability for Sri Lanka. Gridded 0.25 degree monthly precipitation observations for Sri Lanka were merged with 0.5 degree 6-hourly bias-corrected global reanalysis data for the period 1979-1993 and used to force the NASA Catchment Land Surface Model (CLSM) over Sri Lanka. CLSM simulations of monthly minimum and maximum surface temperatures and streamflow compared well with station observations. One-month lagged autocorrelation of simulated soil moisture was high (spatial average was about 0.75), with anomaly dissipation time scales of about 3-5 months. The lagged cross-correlation between simulated total runoff efficiency and soil moisture showed predictability of streamflow up to 3 months in advance in the drier seasons (April to June and July to September).
DE: 1816 Estimation and forecasting
DE: 1833 Hydroclimatology
DE: 1840 Hydrometeorology
DE: 1866 Soil moisture
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
SC: Hydrology [H]
MN: 2007 Joint Assembly