ESRL Director's Office Seminar
A New Technique for Remote Measurement of the Intensities of Tropical Cyclones
Introduction (Duane Ratliff)
The Center for the Advancement of Science in Space (CASIS), a no-profit research organization, is the sole manager of the portion of the International Space Station that operates as a U.S. National Laboratory. CASIS develops and manages a varied research and development portfolio based on U.S. national needs for basic and applied research; establishes a marketplace to facilitate matching research pathways with qualified funding sources; and stimulates interest in using the National Lab for research and technology demonstrations to offer a platform for science, technology, engineering and mathematics education. The goal is to support, promote and accelerate innovations and new discoveries in science, engineering and technology that will improve life on Earth.
Abstract (Paul Joss)
Cyclone Intensity Measurements from the International Space Station (CIMISS) is an approved CASIS project whose purpose is to demonstrate a unique method for measuring the intensity of strong (category 3 and higher) tropical cyclones from space. These storms are nature's most destructive phenomenon in terms of loss of human life and property. The need for accurate real-time measurements of tropical cyclone intensities was yet again demonstrated in just the past few months, in the cases of Tropical Cyclone Phailin and Super Typhoon Haiyan. The strength of Phailin, which struck the northwest coast of India on October 13, 2013, was overestimated prior to landfall. This resulted in excessive, costly preparations and may lead to complacency by the local populace when the next intense storm strikes the region. In contrast, the intensity of Haiyan was underestimated prior to its landfall in the Philippines on November 7, 2013, resulting in inadequate preparations and adding to the loss of life and property.
Our technique is based on the well established theory of the thermodynamics of tropical cyclones and requires the simultaneous measurement of the altitudes (to an accuracy of ~100 meters) and temperatures (to within ~1 K) of the tops of the cirriform clouds comprising the eyewall of the storm. In our proof-of-concept experiment, long wavelength infrared sensors (e.g., two LWIR cameras with selected passbands) will be mounted on the exterior of the ISS to measure the cloud temperatures. The altitudes of the clouds will be measured with a pseudo-stereoscopic technique that will utilize a unique "in-scene" approach to avoid the need for highly accurate knowledge of the orientation of the cameras with respect to inertial space. These simultaneous measurements will permit the retrieval of the central sea-level pressure and peak surface winds of the most intense tropical cyclones, where other remote sensing techniques fail. I will discuss the underlying theory behind our technique, the engineering required for deployment of our instruments on the ISS, and our new approach for accurate altitude determination of the eyewall cloud tops.