Specific updates to the Naval Research Laboratory’s (NRL) tropical cyclone web page will be highlighted in terms of both new remote sensing products and modified graphical user interface (GUI) features. The Marine Meteorology Division has created an Internet web site dedicated to providing a capability to produce storm centered satellite imagery for any “active” system (e.g., suspect areas, tropical depressions, and tropical cyclones) on the globe. “Active” system information is gathered from the Joint Typhoon Warning Center (JTWC, Pearl Harbor, HI), the National Hurricane Center (Miami, FL) and the Naval Atlantic Meteorology and Oceanography Center (NLMOC, Norfolk, VA), whose combined area of responsibility covers the globe.

The NRL TC web page includes passive microwave imagery products which permit the user to “see through” non-raining clouds and thus greatly enhance our knowledge of storm positions and structure/intensity. Temporal sampling issues have accompanied this unique data set since all these sensors are on polar orbiting platforms and thus view TCs no more than twice/day/satellite. The Special Sensor Microwave/Imager (SSM/I) and Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) have been supplemented with the Advanced Microwave Sounding Unit (AMSU-B) and more recently the Advanced Microwave Scanning Radiometer (AMSR-E).

AMSU-B was designed to provide temperature and humidity vertical profiles, but can also be used as a generic imager by mapping the pixels for each channel appropriately. The spatial resolution is moderate (16 km at nadir) and degrades at the swath edges, but the large swath (2343 km) and multiple satellites (N-15, 16 and shortly Aqua) greatly augment the SSM/I and TMI data sets. AMSU-B 89 GHz and 150 GHz are combined to create a “false color composite” product similar to the earlier SSM/I and TMI efforts using 85 GHz data. The 89 GHz and false color composite product have readily displayed TC structure, including concentric eyewalls when these features are strong and are not on the sensor swath edges.

The Advanced Microwave Scanning Radiometer (AMSR-E) on the National Aeronautics & Space Administration (NASA) Earth Observation System (EOS) Aqua spacecraft has added significant benefits. The relatively large 1600 km swath and constant high 5-km spatial resolution at 89 GHz (conical scan) provide TMI-like resolution with a much larger swath. Comparisons between nearly coincident AMSR-E, TMI, SSM/I and AMSU-B data clearly highlight the superb AMSR-E sensor capabilities. The AMSR-E data is provided by the NASA Near Real Time (NRT) data team (headed by Jim O’Neal and Joy Henegar). As with all other passive microwave data sets, the digital data arrives at NRL within 1-3 hours of the image scan. Examples will be illustrated with multiple hurricanes and typhoons.

These upgrades are being phased into the Navy’s operational TC web page hosted by the Fleet Numerical Meteorology and Oceanography Center (FNMOC), collocated with NRL in Monterey, CA.