The ionization in the lower atmosphere which is relevant here is produced by galactic cosmic rays and close to the surface by radio-activity from the ground. The ionization profile is maintained irrespective of seasons (solar X rays and EUV radiation play a role in the ionization process only above 60 km). Immediately after winter, land warms up quickly whereas different layers of atmosphere gradually warm up. This process results in temperature gradients that are unstable to convection (lighter and warmer air masses rising against denser and colder air masses higher above). Strong convection, during the pre-monsoon period, is the reason for cumulo-nimbus clouds (thunderclouds) appearing frequently then. There are instruments that capture the large electric fields associated with a charge cloud in the vicinity and so they can be used to alert people in an area couple of hours in advance.

Most of the lightning strikes occur within the cumulonimbus clouds, called Intra-cloud discharges. Their formation results from the distribution of charges among the different parts of the cloud, thus the distribution of charged ice and graupel particles. There is also a strong correlation between strong vertical wind velocities and lightning activity, so you cannot assume how the clouds will be charged before their formation. 

Thank you Mr.subrmanian Gurubaran for your elaborated explanation of the theory  behind lightening.I would also like to express my sincere thanks  to  Mr.stavros for giving technical answer to the the question.thank you very much scholers.

with regards 

vasanth

 Dear  Victor Lorenzo,

May i know availability of such sensors in indian market or do I need to import from global market? Any way thank you very much for your useful information.

with best regards

vasanth