Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

PRECIPITATION ACTIVITY AND THE ROLE OF CINE AND CAPE OVER NORTH INDIAN STATIONS DURING IOP GAME PERIOD, 1998

G.S. Prakasa Rao (1), U.R. Joshi (1), U.S. De (1)

Northwest Indian rainfall in the month of May is usually associated with the mid-latitudinal westerly systems in the form of western disturbances while other parts of the country receive rain due to convective activity in the form of thundershowers. With the onset of monsoon over NE India in the first week of June and its further advancement westwards changes the type of precipitation from convective showers to rain. "Convective Inhibition Energy" (CINE) play a major role for initiation of convective instability. This is the energy required to be given to the air parcel for its initial movement from surface to Lifting Condensation Level (LCL) at dry adiabatic lapse rate (DALR) and thereafter upto level of free convection (LFC) at pseudo adiabatic lapse rate. In mid-latitudes CINE is relatively less important as synoptic systems provide the trigger action for lifting the air and later convective available potential energy (CAPE) comes into play. In 1998, GAME intensive observing period (IOP) was implemented and India Meteorological Department (IMD) being a member of GAME collected intensive radiosonde data during this period by taking additional ascents. The upper air data were collected for nine stations viz. Patiala, Delhi, Mohanbari, Lucknow, Gorakhpur, Guwahati, Patna, Ranchi and Kolkata (Calcutta) for 00, 06, 12 and 18 UTC in two phases. The first phase of observations were taken from 15th May to 15th June and the second phase from 1st July to 31st July, 1998 covering the onset and active phases of the summer Indian monsoon. For rainy days and non rainy days the averages of CINE and CAPE are calculated separately and their role is discussed. The variation of CINE values with advance of monsoon from NE India to NW India are presented. Further, the diurnal variation of CINE and the variation of LCL and LFC heights stationwise and monthwise are discussed. OLR anomaly values for the same period in relation with the connective development activity are examined and the results are discussed.

Submittal Information

Name : Date :
    Dr. U.S. De
    31-May-01-11:22:40
Organization : Theme :
    India Meteorological Department
    Theme 2
Address : Presentation :
    Shivajinagar, Pune-411005, India
    Poster or oral
Country : Abstract ID :
    India
    T2DUD31May01112240
Phone : Fax :
    N.A.
    N.A.
E-mail :
    imdpune@pn3.vsnl.net.in