Naval Research Laboratory Tropical Cyclone Demonstration Web Page: Plans and Upgrades

The Naval Research Laboratory's (NRL) tropical cyclone (TC) web page has enabled the global TC community to benefit from access to near real-time microwave imager/sounder imagery and derived products that assist in monitoring TC storm structure since 1997. Microwave sensors have the inherent advantage of seeing through non-raining clouds, thus mitigating a common problem associated with visible/Infrared (vis/IR) imagery that forms the bulk of the temporal sampling due to 30 minute or more rapid refresh afforded by geostationary sensors. NRL's Marine Meteorology Division in Monterey, CA (NRL-MRY) recognized the potential to use the SSM/I to map TC location, structure, and infer intensity, resulting in a public web page that contained near real-time SSM/I products focused on existing TCs as monitored by the National Hurricane Center (NHC, Miami, FL), the Joint Typhoon Warning Center (JTWC, Pearl Harbor, HI) and the Central Pacific Hurricane Center (CPHC, Honolulu, HI). This effort was only possible due to our close collaboration with the Fleet Numerical Meteorology and Oceanography Center (FNMOC) collocated in Monterey, CA with NRL-MRY and coordination with the Automated Tropical Cyclone Forecasting (ATCF) system. With time, a range of other satellite sensors was added to near real-time operations, including SSMIS, TMI, AMSR-E, and QuikSCAT.

More recently, we have brought online the DMSP F-19 SSMIS and the NASA Global Precipitation Mission (GPM) Microwave Imager (GMI) via NASA/GSFC. Data latencies for F-19 SSMIS data is ~ 1-2 hours, while GMI is < 30 minutes with 5-6 km spatial resolution at 89 GHz providing advantages in mapping inner core structure. Additional microwave sensors capable of retrieving ocean surface wind vectors have been hosted using scatterometers (ASCAT) and NASA's RapidSCAT wind vectors are now included. The 900 km swath and 51.6 deg orbital inclination onboard the host International Space Station (ISS) complement the ASCAT data sets and thus increase the spatial and temporal sampling used by the various WMO and TC warning centers around the globe.

Efforts have begun on creating Himawari-8 AHI sensor products and making them available on the TC web page. Other current efforts and future plans include recalibration of the ice scattering channels to 89 GHz to reduce bias between sensors, remapping (cubic spline interpolation) of SSM/I and SSMIS data (the sensors with the coarsest spatial resolution) to a common oversampled grid with AMSR2 and GMI, and use of CIMSS ARCHER for recentering. A standardized database of both digital data and image products will be generated and made available to the TC community to compliment the near-realtime data. A study and application of a more sophisticated parallax correction scheme will be performed to provide increased confidence in the initialization of the TC center. Finally, the color tables used to visualize a TC were subjectively developed based on a small sample of cases observed by the SSM/I. Resolution and frequency changes since that time necessitate an expanded and quantitative revisiting of this visualization. Examples of these new research areas and visualization strategies will be shown.