Enhancing Tropical Cyclone Monitoring with Synthetic Aperture Radar: Addressing the Decline in Space-Based Environmental Monitoring Sensors at the Joint Typhoon Warning Center

The Joint Typhoon Warning Center (JTWC), located at Pearl Harbor, HI, provides tropical cyclone monitoring, warning, and forecast support for the U.S. Department of Defense and other U.S. Government agencies across the Pacific and Indian Ocean basins – spanning from the east coast of Africa to the west coast of the Americas, an area encompassing over 85% of the world’s tropical cyclone activity. JTWC extensively utilizes space-based environmental monitoring (SBEM) sensors to conduct tropical cyclone reconnaissance, compensating for the absence of routine manned aerial reconnaissance which ceased in 1987. The presence of low-latency, high-resolution polar orbiting microwave SBEM sensors significantly influences the accuracy and reliability of initial analyses, consequently affecting nearly all forecast products of JTWC. However, the number of operational SBEM sensors crucial for the tropical cyclone mission has been steadily declining as these platforms reach their end of life (EOL).

A growing influence at JTWC in mitigating the decline of SBEM is the incorporation of extra-wide swath, co-polarity Synthetic Aperture Radar (SAR), notably provided by the European Sentinel-1A and the Canadian RADARSAT constellation. This presentation aims to provide a concise overview of SBEM requirements and the consequences of dwindling operational satellites, followed by an examination of the application of SAR in JTWC operations. The objective of this presentation is to offer new insights into tropical cyclone characterization from space in regions with scarce in-situ measurements, and to assess the potential of this emerging application in supplementing the limited availability of traditional sensors.