A physically-based soil temperature retrieval model, which utilizes remotely sensed inputs is being developed. The approach uses satellite remotely sensed observations of net radiation and microwave- based surface temperature to drive the model. The retrieval algorithm uses: Standard soil heat transfer equations to calculate soil temperature at various depths in the profile. Model corrections to the near-surface soil temperature estimating near-surface temperatures from deeper temperature observations, near-surface observations to calculate deeper temperatures in the profile, during daytime. Furthermore, errors were found to be the greatest in locations with bare soils or limited vegetation cover, mostly in arid and semi-arid regions. The errors are due to high net radiation that causes excessive heat build-up at the surface and results in unusual ground heat flux patterns near the surface. There are also upward radiation fluxes (latent and sensible heat) near the surface that are not accounted for in the standard soil heat flow equations. The addition of a ground heat flux model based on remotely sensed net radiation to the standard soil heat flow model has resulted in significant improvements in model behavior. Initially, the model will be used to derive surface temperatures from large data fields of sub-surface temperature observations, such as the Oklahoma Mesonet. These results will then be used to calibrate satellite observations of high frequency vertically polarized microwave brightness temperatures, that have been shown to possess a strong physically-based relationship with the thermodynamic temperature of the surface. A Physically-Based Soil Temperature Retrieval Model with Remote Sensing Inputs Manfred Owe Hydrological Sciences Branch, NASA/GSFC, Greenbelt, MD, Thomas Holmes and Richard de Jeu Dept. of Geo-Environmental Sciences, Vrije Universiteit, NL.

Figure 1. Time series of soil temperature simulations using a soil heat flow model without adequate ground heat flux parameterization. The left panel depicts estimated temperatures at 5 cm based on 2 cm observations as input. The right panel depicts estimated temperatures at 5 cm based on 0.5 cm observations as input. Simulations based on the deeper 2 cm input are less sensitive to the ground heat flux, and result in excellent simulations at 5 cm. However, simulations based on 0.5 cm input are highly sensitive to the ground heat flux, and greatly overestimate temperatures 5 cm. Remote Sensing-Based Soil Temperature Model M. Owe / 614.3

Figure 2. Time series of soil temperature simulations using the soil heat flow model with ground heat flux parameterization. The left panel depicts estimated temperatures at 0.5 cm based on 5 cm observations as input. The right panel depicts estimated temperatures at 5 cm based on 0.5 cm observations as input. Simulations that either use near-surface observations as input or estimate near-surface temperatures from deeper input are highly sensitive to the ground heat flux parameterization. Highly improved estimates are observed. Remote Sensing-Based Soil Temperature Model M. Owe / 614.3

Hurricane Katrina Waves (1) Katrina track and intensity ( (2) NOAA aircraft flight track (black line) extending from black circle indicating radius of maximum wind (RMW). (3) Some of the wave topography (gray-scale-coded) measured by the SRA. The dominant waves were swell generated near the RMW. A secondary wind- driven wave system can be seen propagating across the swath. The NASA Scanning Radar Altimeter, mounted onboard a NOAA hurricane research aircraft, measured waves of 12 m significant wave height and 320 m wavelength on 28 August (1) (2) (1) (3) along-track distance (km) Estimates from these measurements suggest the significant wave height in the right forward quadrant would have been 15 m with individual waves occasionally approaching 30 m height.

Researchers from the Ocean Sciences Branch at GSFC (Code 614.2; Drs. Antonio Mannino, Tiffany Moisan, and Stan Hooker) recently completed an oceanographic expedition aboard the R/V Cape Henlopen, traversing nearly 500 miles of Mid-Atlantic continental shelf waters (from nearshore to 100 miles offshore) along the Delmarva peninsula and southern Virginia coast (see map) to study coastal ocean carbon and ecosystems by linking in situ biological, chemical, optical and other physical measurements with ocean color remote sensing observations from MODIS. The cruise science team consisted of:  3 GSFC scientists,  Post-docs  Graduate student  NASA Marine Technicians  Biospherical Instruments engineer Measurements included: dissolved and particulate organic carbon inorganic carbon colored dissolved and detrital organic matter Chlorophyll and pigment concentrations optical properties nutrients primary productivity bacterial productivity phytoplankton taxonomy salinity temperature fluorescence current velocity profiles

Seawater was collected at multiple depths with Niskin bottles attached to a CTD-Rosette John Morrow, an engineer from Biospherical Instruments, participated on the cruise and is shown holding the spectroradiometer