Compositing of MODIS Products Stephanie L Haines and Frank LaFontaine June 12, 2007
Introduction • Coastal NWS offices wanted high resolution SST product to address forecast problems • Weather associated with land/sea breezes • Off shore weather such as clouds, precipitation, temperatures etc. • Single pass of MODIS provides limited coverage • Simple composite generated from multiple passes of MODIS data provides spatially continuous cloud free coverage • Main assumption is that SST does not change significantly from one day to the next • High resolution (1 km), full coverage on a regional scale • Small scale features in SST gradients retained • Alternative to the Real-Time Global (RTG) SST analysis and/or the OSTIA analysis for model assimilation • Can also composite additional MODIS ocean color products such as chlorophyll
Methodology • Use the 1km SST MODIS product to produce a detailed and spatially continuous SST field while minimizing cloud contamination and latency effects • Obtain SST in real-time from University of South Florida (USF) • Generate a SPoRT MODIS cloud mask for the same pass • Retain 5 clear (as determined by the cloud mask) SST values for each pixel separately for day and night • Average some of clear values to obtain a more consistent field • Evaluating the use of AMSR-E SST to reduce latency
SST Comparisons Terra 04 UTC Aqua 07 UTC Terra 16 UTC Aqua 19 UTC • MODIS SST composites generated 4 times daily at 1 km resolution • RTG-SST once daily 0.5 degree or 1/12 degree resolution • OSTIA once daily 5 km resolution • Loops available online at http://weather.msfc.nasa.gov/sport/sstAnimation/ RTG SST 0.5 degree OSTIA SST 5 km
Work Performed Since Last SAC • Operational domain expanded to include Central America and composites being provided to the SERVIR group • SST composites provided in near real time in GRIB (gridded binary) format for ease of use by modelers and additional users, used in several WRF modeling studies • Composites also provided to Mobile and Miami NWS offices within AWIPS • Journal article describing the method and validation for the May 2004 case, written and accepted for publication in the IEEE journal “Transactions on Geoscience and Remote Sensing” • SST composites provided to WorldWinds Inc. • Ocean color products obtained from USF and compositing work begun
NASA Products Support Marine Weather MERGED ATLANTIC MODIS AND AVHRR SST PRODUCT MODIS composite SST serves as a data source for hybrid marine products. Proprietary • SPoRT provides WorldWinds Inc. MODIS SST composites for their analysis system • WorldWinds packages SST with other marine products for distribution by WxWorx Inc. (an affiliate of Baron Services) • In conjunction with XM Satellite Radio Inc., WxWorx provides up to date weather information for boat owners • PC based display software • hand-held applications WxWorx, Inc. products available to marine customers MODIS SST data reaches over 8000 users in the marine community!
Ocean Color Composites • Obtaining in real time from University of South Florida the following products • Chlorophyll • Total suspended matter • Fluorescence line height • Started work on compositing these products • Of the two most recent values for each pixel, use the largest value in the composite • Composites and single passes put on web http://weather.msfc.nasa.gov/sport/oceancolor/ Single Pass of Aqua CHL Aqua CHL Composite
Future Work • Continue to improve MODIS SST composites by • Improving latency by including AMSR-E SST in cloudy, non-coastal regions • Improve the SPoRT MODIS cloud mask for ocean applications • Improve the ocean color composites • Learn about the products from USF experts • Adjust the compositing techniques • Looking at generating West Coast composites (requested by WorldWinds). Requires near real time source of MODIS data – both SST and cloud mask • Provide ocean color composites to NWS offices, WorldWinds Inc. • Support field programs (ex. TCSP (summer 06), TC4 (summer 07)). • Proposals • WRF linked with coastal ocean model into the North Carolina Forecast System - NASA provide SST data and other remote sensing expertise. ROSES 2007 – Disaster Management. PI: Adel Hanna (UNC-Chapel Hill), Jedlovec and Haines Co-PIs • Daily Chlorophyll Products for Ecosystem and Fishery Applications, Co-PIs: Elizabeth Valenti (WorldWinds, Inc.) and Gary Jedlovec (NASA/MSFC) – RPC Council, May 2007.