On the Vertical Distribution of Mean Vertical Velocities in the Convective Regions during the Wet and Dry Spells of the Monsoon over Gadanki

Abstract

The Indian Mesosphere-Stratosphere-Troposphere (MST) radar observations of vertical distribution of mean vertical velocities w in convective regions during the wet and dry spells of the Indian summer monsoon over a tropical station at Gadanki, India (13.58N, 79.28E) are discussed. The composite w profile during the wet spell consistently shows a single peak at ;13 km whereas during the dry spell it shows two peaks, one at 5 km and another at 11-13 km. The characteristics of this altitudinal distribution in w are discussed in terms of background wind and thermal structure during both spells of the monsoon. Background w obtained from NCEP-NCAR reanalysis shows subsidence throughout the depth of the troposphere during the dry spell of the monsoon over Gadanki. Analysis of background wind and thermal structure clearly reveal that wind shear and temperature inversion in the midtroposphere are different in the dry spell compared to that of the wet spell, which may be the possible reason for the observed double-peak w structure during the dry spell of the monsoon. The present analysis for the first time brought out the distinct vertical distribution in w and the background meteorological conditions during the wet and dry spells of the monsoon over Gadanki, which may have implications in understanding the monsoon convective systems during the wet and dry spells of the Indian summer monsoon.

Possible climatic implications of high altitude emissions of black carbon

“…The monsoon season (June to September) appears to be the favorite period for the lifted layers in the stratosphere (fig.13a). This looks to be linked to the vertical lifting associated with severe convection (as seen in our model simulations fig.11 and Mov.1 in supplementary material) and thin tropopause layer as explained earlier (Fu et al, 2006;Randel et al, 2010;Vernier et al, 2011;Thampi et al, 2012;Uma et al, 2012). Additionally, these layers seem to be present during the other seasons (pre-monsoon and winter) as well.…”

Vertical motions of the tropical convective cloud spectrum over Darwin, Australia

“…Profiler retrievals from Darwin have further shown that non-precipitating anvil has potentially different vertical motion structure than precipitating stratiform cloud (Protat and Williams, 2011). Other profiler studies have been conducted over southern India and Indonesia (Kumar et al, 2005;Mori et al, 2006;Rao et al, 2009;Uma and Rao, 2009;Abhilash et al, 2010;Uma et al, 2012) and are generally consistent with the Darwin findings. In addition, Giangrande et al (2013) used profiler retrievals to analyse the statistics of deep convective vertical velocities over a midlatitude continental site and found updraught core maxima regularly exceed 10 m s −1 , although downdraught core maxima were skewed to lower values and found at lower heights.…”

“…Profiler retrievals from Darwin have further shown that non‐precipitating anvil has potentially different vertical motion structure than precipitating stratiform cloud (Protat and Williams, ). Other profiler studies have been conducted over southern India and Indonesia (Kumar et al ., ; Mori et al ., ; Rao et al ., ; Uma and Rao, ; Abhilash et al ., ; Uma et al ., ) and are generally consistent with the Darwin findings. In addition, Giangrande et al .…”

Possible climatic implications of high-altitude black carbon emissions

“…10 and Mov. 1 in the Supplement) and thin TTL as explained earlier (Fu et al, 2006;Randel et al, 2010;Vernier et al, 2011;Thampi et al, 2012;Uma et al, 2012). Additionally, these layers seem to be present during the other seasons (premonsoon and winter) as well.…”