CloudSat–CALIPSO characterizations of cloud during the active and the break periods of Indian summer monsoon

Here we report cloud macrophysical (cloud top height (CTH), cloud base height (CBH), cloud geometrical depth), microphysical (liquid and ice water contents, water paths, effective radii and number concentration) and radiative (heating rate) properties over the North Central India (18–28°N, 65–88°E) region (core monsoon zone) during the active and the break periods (2006–2010) of the Indian summer monsoon (ISM). Synergetic data from the CloudSat radar and the CALIPSO lidar are used. Analysis shows that the CTH and CBH have bimodal distributions during both the phases of monsoon. We have classified clouds into four type's viz., high-, mid-, low- and vertically extended deep clouds. The low-level clouds and optically thick cirrus are more dominant of the total observations and they occur more frequently during the active period compared to that of the break period. In contrast, the high-level clouds and optically thin cirrus are more frequent during the break phase of monsoon. The integrated depolarization ratio of high-level cloud exhibits bimodal distribution. It is observed that there is a significant variation in macrophysical, microphysical, optical and radiative properties of all the four types of clouds during the active and the break periods. As little observational evidence exists in the vertical structure of clouds during the active and the break periods of the ISM, the current results would be useful in understanding the characteristics of monsoon clouds, which have implications in the Earth's radiation budget and global climate models.

► Characterization of vertical structure of clouds over the core monsoon region.
► Variability in cloud properties during the active and break periods of ISM.
► Low level clouds are more in active than break periods of ISM.