The Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX): overview and preliminary results

Kulkarni, J. R. ; Maheskumar, R. S. ; Morwal, S. B. ; Padma Kumari, B. ; Konwar, M. ; Deshpande, C. G. ; Joshi, R. R. ; Bhalwankar, R. V. ; Pandithurai, G. ; Safai, P. D. ; Narkhedkar, S. G. ; Dani, K. K. ; Nath, A. ; Nair, Sathy ; Sapre, V. V. ; Puranik, P. V. ; Kandalgaonkar, S. S. ; Mujumdar, V. R. ; Khaladkar, R. M. ; Vijayakumar, R. ; Prabha, T. V. ; Goswami, B. N. (2012) The Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX): overview and preliminary results Current Science, 102 (3). pp. 413-425. ISSN 0011-3891

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While the demand for enhancing rainfall through cloud seeding is strong and persistent in the country, considerable uncertainty exists on the success of such an endeavour at a given location. To understand the pathways of aerosol-cloud interaction through which this might be achieved, a national experiment named Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX) in two phases, was carried out. The rationale of CAIPEEX, the strategy for conducting the experiment, data quality and potential for path-breaking science are described in this article. Pending completion of quality control and calibration of the CAIPEEX phase-II data, here we present some initial results of CAIPEEX phase-I aimed at documenting the prevailing microphysical characteristics of aerosols and clouds and associated environmental conditions over different regions of the country and under different monsoon conditions with the help of an instrumented research aircraft. First-time simultaneous observations of aerosol, cloud condensation nuclei (CCN) and cloud droplet number concentration (CDNC) over the Ganges Valley during monsoon season show very high concentrations (> 1000 cm-3) of CCN at elevated layers. Observations of elevated layers with high aerosol concentration over the Gangetic valley extending up to 6 km and relatively less aerosol concentration in the boundary layer are also documented. We also present evidence of strong cloud- aerosol interaction in the moist environments with an increase in the cloud droplet effective radius. Our observations also show that pollution increases CDNC and the warm rain depth, and delays its initiation. The critical effective radius for warm rain initiation is found to be between 10 and 12 µm in the polluted clouds and it is between 12 and 14 µm in cleaner monsoon clouds.

Item Type:Article
Source:Copyright of this article belongs to Current Science Assosciation.
Keywords:Aircraft Observation; Caipeex; Cloud Seeding; Cloud-aerosol Interaction; Cloud Condensation Nuclei
ID Code:93580
Deposited On:20 Jun 2012 14:18
Last Modified:19 May 2016 06:38

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