Studies of Two Important Stability Indices of Earth’s Atmosphere Determined by using the COSMIC GPS Radio Occultation Technique

Abstract

Objectives: To study the seasonal variations of two important atmosphere stability indices, i.e. Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN) for the selected years, i.e. from 2007 to 2012 using the COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) Radio occultation (RO) technique. Methods/Analysis: We used the COSMIC RO technique as we consider that it provides more accurate, all-weather, round the-clock and global coverage of the lower atmosphere and ionosphere constituents with unprecedented resolutions. Further, we used the lower atmosphere database provided by the COSMIC RO technique in order to study the above two parameters (CAPE & CIN). Findings: It was found that, for the very first time, the consistency of wavy nature in CAPE seasonal trends which are confined to northern and southern hemispheres alternatively. The wavelike nature in CAPE trends seems to be following Inter- Tropical Convergence Zone (ITCZ) movement and, in such case, the CAPE trends may be useful to ascertain the ITCZ movements during different seasons of a year and the CAPE magnitude shows higher values over land than oceanic regions, which confirms the consistency of their calculations. In this regard, the trends of both CAPE and CIN have shown a close bimodal distribution. Applications/Improvement: As a result, we find better correlations of both CAPE and CIN computed through the atmospheric data measured with the COSMIC RO and collocated Radiosonde technique when the profile data are reaching to the near-surface of the Earth.