Accession Number : ADA292567

Title :   Typhoon Monitoring Using Passive Microwave Observations.

Descriptive Note : Final rept. Sep 92-Oct 94,

Corporate Author : WISCONSIN UNIV-MADISON SPACE SCIENCE AND ENGINEERING CENTER

Personal Author(s) : Merrill, Robert T.

PDF Url : ADA292567

Report Date : OCT 1994

Pagination or Media Count : 27

Abstract : Because tropical cyclones have deep warm cores they are amenable to monitoring using passive microwave radiometers in the 55 GHz (Oxygen) band. However, such radiometers currently have horizontal resolution of 100 km or more, which is significantly larger than the eye of most tropical cyclones. The warm anomaly directly observable in the brightness temperature distribution is therefore an underestimate of the actual warm anomaly strength. The subject of this contract is an algorithm to correct for this underestimate. Passive microwave observations are modeled as an interaction between the radiometer antenna pattern and an analytic function approximating the thermal structure of a tropical cyclone. Solution of the inverse of this model using a maximum likelihood method yields an estimate of the amplitude of the warm anomaly. Application of this technique to observations from two different radiometers (MSU and SSM/T) indicates that it is relatively successful at correcting for horizontal resolution differences. However, the warm anomalies so obtained are little better than the raw observations themselves as estimators of tropical cyclone intensity. Reasons for this are examined and some potential avenues of research are suggested. (MM)

Descriptors :   *METEOROLOGICAL SATELLITES, *MICROWAVE OPTICS, *TROPICAL CYCLONES, *TYPHOONS, COMPUTER PROGRAMS, MONITORING, MAXIMUM LIKELIHOOD ESTIMATION, WIND, OPTICAL IMAGES, RADIOMETERS, BAROMETRIC PRESSURE, RAINFALL, REMOTE DETECTION, ATMOSPHERIC SOUNDING.

Subject Categories : Meteorology
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE