New Approaches and Algorithms for the Analysis of Vertical Refractivity Profile Below 1 km in a Subtropical Region

In this communication, 17 years of high resolution surface and radiosonde meteorological data from 1997-2013 for the subtropical Gulf region are analysed. Relationships between the upper air refractivity, N_h, and vertical refractivity gradient, ΔN, in the low troposphere and the commonly available data of surface refractivity, N_s are investigated. A new approach is discussed to estimate N_h and ΔN from the analysis of the dry and wet components of N_s , which gives better results for certain cases. Results are compared with those obtained from existing linear and exponential models in the literature. The investigation focusses on three layer heights at 65 m, 100 m and 1 km above ground level. Correlation between the components of N_s with both N_h and ΔN are studied for each atmospheric layer. Where high correlations were found, empirical models are derived from best-fitting curves.