Progress in Satellite Tropical Cyclone Monitoring: Katrina and Beyond

Satellite sensors (imagers, sounders, and radars) play a crucial role in the operational satellite reconnaissance of tropical cyclones (TC). Multiple key changes have occurred since Hurricane Katrina that directly impact our global ability to nowcast TC location, structure, and intensity: 1) the fly out and health of the microwave imagers and sounders on the Defense Meteorological Satellite Program (DMSP), NOAA, and EUMETSAT low earth orbiting (LEO) satellites, 2) the launch and near real-time access to new research and development (R&D) sensors, 3) launch and near real-time access to foreign sensors and joint mission collaboration, and 4) the upgrade of the global geostationary (GEO) platforms with critical advances in temporal, spatial, and spectral sensing capabilities.

Since Katrina, a combination of factors has led to a relative abundance of microwave imagers/sounders, with a primary factor being the long-lived nature of sensors originally built to operate for 3-5 years. The current “golden age” of microwave remote sensing has been a boon to operational center fixing, since they mitigate inherent limitations of VIS/IR sensors and have benefited from the stability offered by US and foreign operational platforms. However, the current enhanced temporal sampling will shortly decline considerably due to multiple factors: a) old operational SSM/I and SSMIS sensors and/or channels becoming nonoperational, b) old R&D sensors failing, c) uncertain future for the DMSP F-20 and Weather System Follow on (WSF), and d) uncertain project funding for multiple foreign efforts. A major unknown is the fidelity of foreign microwave sensors where data access and latency issues are unresolved.

In contrast, GEO sensor improvements with Meteosat Second Generation, Himawari-8, and in the near future GOES-R/S, are ushering in a new era of TC remote sensing. The enhanced temporal sampling (2-10 minutes routinely), higher spatial resolution, and more than doubling of spectral channels has already demonstrated an ability to view near real-time aspects of TC monitoring only briefly captured during some earlier rapid scan experiments. The ability to observe rapid changes in convective bursts near the TC core are now common place and provide more complementary measurements to the less frequent LEO microwave imager/sounders. Objective methods to extract storm position, eye size, structure, and intensity from satellites are now in various stages of operations and demonstrations, as data fusion moves center stage to enable key steps forward in extracting new accuracy levels.

This presentation will highlight advances in satellite remote sensing since Katrina and include a best guess timeline for imagers, sounders, and scatterometers likely to soon become accessible for operational and scientific study. Comparisons in our satellite TC sensor network will be made from Katrina to the present and then into the near future.