Space-Based Remote Sensing for Tropical Cyclone Diagnostics and Forecasting
Born over the warm, moist, tropical oceans, packing winds over 33 m/s (74 mph), and reaching diameters of over 1000 km, the tropical cyclone is the most powerful weather system on Earth. For many societies, they are the lifeblood, bringing much needed precipitation to tropical nations. Yet, tropical cyclones are a mixed blessing, bringing copious rains to rugged terrain, producing waterlogged landscapes and triggering dangerous mudslides. And, along with the rains come the winds, and the storm surges. Although tropical cyclones have been studied extensively throughout the twentieth century, there is surprisingly little quantitative knowledge as to how they develop and progress through their life cycle. The major problems that inhibit progress in this area are the chronically sparse traditional sources of data over the tropical oceans and the difficulties in separating cause and effect in these complex systems with important nonlinear processes interacting on several time and spatial scales. Geostationary and polar-orbiting satellites provide a unique opportunity to observe aspects of the tropical cyclone structure continuously and at high temporal frequency These instruments do not provide direct measurement of parameters such as surface wind speed, wind field structure, or 3-D temperature and humidity. Thus, a grand challenge in tropical cyclones is to develop strategies using satellite-based observations to: 1) accurately estimate current TC parameters such as intensity and wind field size; 2) develop techniques to project their development into the future including estimate likelihood of development; and 3) develop techniques to project their likely impacts upon landfall. In this research program satellite-based observations and techniques are merged with statistical, statistical-dynamical, and dynamically-based numerical weather models to better understand, and forecast tropical cyclone behavior.