[A-AS02] Evolution of Global Environmental Research based on Atmospheric Vertical Motions

[AAS02-05] Vertical wind statistics observed by the WINDAS

*Yuichi Ohno¹, Hiroaki Horie¹, Seiji Kawamura¹, Masayuki Yamamoto¹ (1.National Institute of Information and Communications Technology)

Keywords:Vertical wind, wind profiler

WINDAS is a wind profiler network of Japan Meteorological Agency. 31 of wind profilers have been operated since 2003 from north to south of Japan. (33 of wind profilers are operated now.) High altitude wind data observed by the WINDAS are used for numerical weather prediction as complemental usage of radiosonde. Since its frequency is rather high (1.357 GHz), not only atmospheric turbulent echoes but also cloud and precipitation echoes are available in WINDAS as targets for wind estimation. Although horizontal wind data of WINDAS are broadly used for operational aim, vertical wind data are not so used because they include information of both atmospheric vertical motion and fall velocity of cloud and rain particles. Here, we made a rough method to separate atmospheric echoes and cloud and precipitation echoes using vertical velocity and echo intensity observed by the WINDAS along with its height and temperature information. Statistics of vertical wind obtained only from atmospheric echoes are studied here. WINSDAS data from 2003 to 2005, which have 10 minutes in time interval and 0.3 km in vertical interval are used in this analysis. Figure 1 shows all echo appearance frequency with vertical velocity and height (left), atmospheric echo appearance frequency (middle), and averaged vertical velocity and its standard deviation of atmospheric echo (right). This figure is obtained using the WINDAS data at Sakata site (Yamagata) in summer season from 2003 to 2005. In the right figure, both atmospheric echoes and precipitation echoes are included, but in the middles figure, precipitation echoes are removed and atmospheric echoes remain. Then in the right figure, averaged vertical velocity profile is calculated using velocity of remaining atmospheric echo. Figure 2 shows monthly averaged vertical wind at Sakata WINDAS in 2003-2005 using similar method above. These results should be carefully checked considering contamination of remained precipitation echoes or excess removal of atmospheric echoes.
Acknowledgements
WINDAS data is provided from Japan Meteorological Agency. This work was supported by the 'Promotion of observation and analysis of radio wave propagation' fund of the Ministry of Internal Affairs and Communications, Japan.