1. NASA Jet Propulsion Laboratory, California Institute of Technology
Highlights of sensitivity experiments
Tony Lee
NASA Jet Propulsion Laboratory, California Institute of Technology
IGST-XII meeting, St. John’s, Newfoundland, Aug. 7-9, 2007
Sensitivity of ocean state to wind forcing measured by one vs. two satellite scatterometers.
Sensitivity of heat content & transport in the tropical Indian Ocean to remote temperature field – implications to in-situ observing systems (XBT, Argo).

2. NASA scatterometer tandem mission (QuikSCAT & SeaWind) during 2003 (days ) provides an opportunity to evaluate the impact of high-frequency wind sampling on estimated oceanic state.
One (two) scatterometers samples 90% of the ocean at daily (twice-daily) intervals.

3. Difference in spring-summer SST of 2003 using twice-daily and daily wind obtained from QuikSCAT and SeaWind tandem mission (in °C)
The difference would be even larger if relaxation of model SST to Reynolds is turned off

4. Cause for the SST difference with twice-daily vs
Cause for the SST difference with twice-daily vs. daily SCAT winds away from ACC (similar to Lee and Liu 2005 based on NCEP wind experiments) Z
Twice-daily wind: stronger vertical mixing, deeper mixed layer, colder SST
Daily wind: weaker vertical mixing, shallower mixed layer, warmer SST
T profiles

5. Significance of difference in SST, mixed-layer depth, & vertical mixing
Air-sea heat flux estimates (e.g., in 4D-VAR assimilation or bulk-formula estimates).
Re-emergence of water mass formed in previous winter.
Biogeochemical simulations