New Cloud Detection Index (CDI) for Forecasting the Extreme Rain Events

Niket Shastri,Kamlesh Kamlesh Pathak

doi:10.4236/ars.2019.81002

Abstract

The water vapor content and clouds play a very significant role in atmospheric conditions. This paper is derived from the new cloud detection index (CDI) which is useful to forecast extreme weather events like heavy or extreme rain. The CDI is retrieved using two crucial elements of cloud formation, the critical humidity and critical water vapor. The cloud thickness is determined by using CDI for a radiosonde site (VABB) located in Mumbai, the western part of India. The obtained results are compared with the cloud thickness required for extreme rain. The outcome of the comparison is discussed in this paper. The cloud detection index is also useful in establishing the atmospheric stability along with another four atmospheric stability indices.

Highlights

Clouds play a significant role in both the Earth’s climate system and the ground-to-space radio communication system [1] [2]
The cloud thickness determined from the Cloud Detection Index (CDI) for months of June, July and August are shown in Figure 4, Figure 5 and Figure 6 respectively
Such thick cloud and low value of Convection Inhibition Energy (CINE) are observed during each event of extreme rain at VABB

Summary

Introduction

Clouds play a significant role in both the Earth’s climate system and the ground-to-space radio communication system [1] [2]. The use of relative humidity as a constant threshold to sense the cloud base height and cloud thickness were developed in 1978. To determine the water vapor at different atmospheric levels, relative humidity and temperature data from radiosonde observations are used for calculating the spatial pressure of water vapor [11]. The approaches to detect the cloud base height and thickness using relative humidity or water vapor are quite successful. We utilized both crucial parameters of cloud formation i.e. relative humidity and perceptible water vapor to detect cloud presence conditions. The cloud detection index is given by Equation (2.1)

Data and Methodology

Results

25 July 2002

Conclusions