$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

                        森羅万象セミナー  第 42 回
                 http://www.ep.sci.hokudai.ac.jp/~sinra/

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

                  時 ： 11 月 14 日 (火) 15：30-17:00
                 場所： 理 5 号館 201 号室
               
         Dr. Richard J. Doviak (National Sevear Storms Laboratory)

               『Measurements of Doppler Spectrum Width』
          (Measurement Problems, Classification by Weather, 
           New Approaches to Measurements and Relation to 
           Weather  Phenomena)

                                 Abstract

  This presentation will discuss measurements of Doppler
  spectrum width, the least used of the three Doppler moments available
  from many research radars and the operational weather radar network in
  the USA.  We will present reasons why there is interest in the spectrum
  width measurements and why relatively little use is made of these data. 
  Examples will be presented illustrating some of the problems with
  spectrum width measurements and it will be shown that when these
  problems are solved there is a wealth of information in the spectrum
  width data fields. Statistical analysis of the spectrum width field is
  made in volumes of space occupied by various weather types.  We classify
  spectrum width statistics, in particular its mean value in a volume of
  weather, by weather type.  We will show that, surprisingly, spectrum
  width data in a severe tornadic storm, one that destroyed thousands of
  homes and killed over 40 people in Moore Oklahoma, had values expected
  from fair weather. The data suggests that this storm has quasi-laminar,
  but strong flow.  We introduce another estimator of spectrum width that
  has less problems with estimation than the Pulse Pair algorithms
  currently used on the USA's network of WSR-88D radars. This new
  algorithm has been used on a Russian weather radar and we shall show
  examples of the spectrum width filed that reveals interesting features
  in various types of weather.


世話人：上田 博

# 諸事情により、変更や追加のある場合があります。
# 話題希望要望サポーター、大募集中です


セミナー幹事：倉本　圭