Publications

Saha, U.; Maitra, A. (2014). Effects on stratospheric moistening by rates of change of aerosol optical depth and ozone due to solar activity in extra-tropics. INDIAN JOURNAL OF PHYSICS, 88(11), 1117-1126.

Abstract
The solar-induced changes in ozone and aerosol optical depth have relative effects on stratospheric moistening at upper troposphere/ lower stratosphere region. Wavelet-based multi-scale principal component analysis technique has been applied to de-noise component of quasi-biennial oscillation and El Nino-Southern Oscillation from ozone and aerosol optical depth variations. Rate of change of aerosol optical depth sharply increases indicating a positive gradient whereas rate of change of ozone sharply decreases indicating a negative gradient with solar activity during the years 2004-2010. It is also observed that with increase of rate of change of aerosol optical depth, there is a sharp increase of stratospheric moistening caused by enhanced deep convection. On the contrary, with the increase of stratospheric moistening, there is a sharp decrease of rate of change of ozone resulting in a cross-over between the two parameters. An increase in aerosol optical depth may cause a significant increase in the gradient of vertical temperature profile, as well as formation of cloud condensation nuclei, clouds and hence rainfall. This may lead to formation of strong convective system in the atmosphere that is essential for vertical transfer of water vapour in the tropics percolating tropical tropopause layer and depleting stratospheric ozone in the extra-tropics.

DOI:
10.1007/s12648-014-0563-x

ISSN:
0973-1458