Study of the intensity of super cyclonic storm GONU using satellite observations

Satellite microwave measurements show sea surface temperature (SST) increase in advance of significant cyclone intensification. Moreover, cyclone intensification may also be related to the location of high SST. In the present study results indicate pre-existing high sea surface temperature anomaly (SSTA) located at the right side of the storm track for Cyclone GONU. I emphasize that high SST which occurred at the right time and right place was conducive to the cyclone intensification. In particular, high SST in the northeastern quadrant of the storm track induced significant increases in surface latent heat fluxes contributing to the rapid intensification of GONU. The present study also focuses on the air-sea interactions associated with cyclone GONU. Surface latent heat flux (SLHF) and precipitation rate (PR) increase anomalously prior to landfall as compared to when the GONU was at its maximum intensity (category 5). Wind speed and rain-rate data from satellite observations show breakup of the eye-wall and asymmetric structure leading to increased precipitation prior to landfall.     

Satellite microwave detected SST anomalies and hurricane intensification

Sea surface temperature (SST) from the remotely sensed infrared measurements, like the GOES, AVHRR, and MODIS, etc., show missing values of SST over the cloudy regions associated with hurricanes. While satellite microwave measurements, like the Tropical Rainfall Measuring Mission (TRMM) microwave imager (TMI), can provide SST even under cloudy conditions. Both satellite microwave measurements and buoy observations show SST increase in advance of significant hurricane intensification. Moreover, hurricane intensification may also be related to the location of high SST. Our results indicate pre-existing high SST anomaly (SSTA) located at the right side of the storm track for Hurricane Katrina. Numerical simulations also confirm the important impacts of SSTA location on hurricane intensification. Similar situations are also found for Hurricanes Rita and Wilma. In contrast, if there is no high SSTA at the right location, hurricane may not undergo further intensification. This may explain why not all tropical cyclones associated with warm waters can attain peak intensity (categories 4 and 5) during their life cycle, and partially explains why hurricanes do not reach the maximum potential intensity as calculated only according to the magnitude of SST.     

EVACUATION BEHAVIOR IN RESPONSE TO NUCLEAR POWER PLANT ACCIDENTS*

A telephone survey of 2,595 households on Long Island, NY provides a data base for analyzing potential spatial behaviors in response to an accident at the Shoreham Nuclear Power Station in Suffolk County. These intended behaviors approximated the actual behaviors of Three Mile Island area residents during the general emergency at that plant in 1979. Using evacuations from natural and other technological hazards as a basis for comparison, we conclude that evacuations in response to nuclear power plant accidents are likely to be characterized by an extreme over-response to limited protective action advisories; this phenomenon needs to be considered in behaviorally-based radiological emergency response planning.     

用TRMM卫星微波成像仪资料遥感地面洪涝的研究

文中阐述了用热带降雨测量卫星 (TRMM )微波成像仪 (TMI)监测地面洪涝灾害的能力 ,并利用动态聚类、土壤湿度指数、极化亮温差指数、极化亮温比指数等 4种基于TMI亮温资料的方法遥感了 1998年夏季中国江淮流域的洪涝灾害。通过与机载雷达图像、星载雷达图像以及基于地面日降雨量资料的Z 指数方法确定的地面洪涝情况的对比 ,结果表明用TMI亮温资料监测地面洪涝灾害是可行的 ,遥感结果也是比较满意的     

TRMM测雨雷达和微波成像仪对两个中尺度特大暴雨降水结构的观测分析研究

文中利用TRMM卫星的测雨雷达和微波成像仪探测结果,研究了1998年7月20日21时(世界时)和1999年6月9日21时发生在武汉地区附近和皖南地区的两个中尺度强降水系统的水平结构和垂直结构,以及TMI微波亮温对降水强弱和分布的响应。研究结果表明:这两个中尺度强降水系统中对流降水所占面积比层云降水面积小,但对流降水具有很强的降水率,它对总降水量的贡献超过了层云降水。降水水平结构表明,两个中尺度强降水系统由多个强雨团或雨带组成,它们均属于对流性降水;降水垂直结构分析表明,强对流降水的雨顶高度可达15km,强对流降水主体中存在垂直方向和水平方向非均匀降水率分布区,层云降水有清晰的亮度带,层云降水的上方存在多层云系结构。降水廓线分布表明:对流降水廓线与层云降水廓线有明显的区别,并且降水廓线清晰地反映了降水微物理过程的垂直分布。整个中尺度强降水系统中对流降水与层云降水的区别还反映在标准化的总降水率随高度的分布。微波信号分析表明:TMI85 GHz极化修正亮温,19.4与37.0,19.4与85.5,37.0与85.5 GHz的垂直极化亮温差均能较好地指示陆面附近的降水分布。