TRACKING HURRICANES

October 2003
		In recent years, scientists have made leaps and bounds in improving our ability to predict and track hurricanes, mitigating their destructive power. Two scientists, Dr. Naomi Surgi of the National Hurricane Center and Dr. William Gray of Colorado State University's Tropical Meteorology Project, answer your questions about the latest developments in predicting and tracking the devastating storms.

Online NewsHour Special Report: Tracking Hurricanes Forum Introduction How does your field approach view the work being done in chaos theory? Is lack of temperature soundings in the sea the main problem in track prediction? What are the flights through the hurricane like for the observers on board? Are you concerned that such warming might cause not continued warming but a total irreversible change in realities? I was wondering what role Linux and computer clustering have in NOAA's hurricane modeling efforts? Are there any hurricane models that treat a storm as an electrical model where temperature is represented as resistance?	Herschel Goldstein of Cherry Hill, N.J., asks: I was wondering what role Linux and computer clustering have in NOAA's hurricane modeling efforts? Since the mid-70s I've used Unix (or various cousins) to model how the brain moves the eye around, which so far, has not required a supercomputer to get fairly accurate results in one dimension. Dr. Naomi Surgi responds: Linux and computer clustering have no role in NOAA's operational hurricane modeling efforts. NOAA's National Weather Service operations require sustained teraflops (trillions) for operational applications with 99.9 percent reliability. This can not be obtained with clusters. Some NOAA folks however may use clusters for conducting some hurricane modeling research but research modeling is much less rigorous and demanding than running a modeling system for operational application. Ruben of San Antonio, Texas, asks: Are there any hurricane models that treat a storm as an electrical model where temperature is represented as resistance? Also, can numerical models determine if hurricanes are the weather's version of an oscillation? Dr. Naomi Surgi responds: No. Hurricane models treat temperature explicitly, along with other atmospheric variables such as wind and air pressure. The models can do this because temperatures are represented explicitly in the equations that govern our atmosphere, which include the laws of thermodynamics, equations for heat flux from the ocean surface, and the Perfect Gas Law. A hurricane is a phenomenon, or an atmospheric process if you like. It is not an oscillation. Having said this, variations in Atlantic hurricane activity from one season to the next are strongly controlled by climate fluctuations (rather than perfect oscillations) occurring on both yearly and decadal time scales. These climate fluctuations are referred to as the El Niņo/ Southern Oscillation (ENSO, which includes El Niņo and La Niņa), and the Tropical Multi-Decadal Mode (TMM), respectively. The TMM reflects fluctuations in the main tropical convective rainfall areas of the Indian Ocean, the Amazon Basin, and the West African monsoon region. The TMM strongly controls decadal fluctuations in Atlantic hurricane activity.