The relevance of air-instability indices in assessing the thermoconvective phenomena within the operation area of the “Traian Vuia” airport in Timisoara, on 10 july 2021

At present, we are witnessing progressive changes in the global climate, caused by both natural and anthropogenic factors. According to a 2019 IPCC (Intergovernmental Panel on Climate Change) report, ocean levels will rise drastically, storms will be more frequent, summers will be warmer, with frequent air-temperatures of 35°C. These high temperatures will lead to much more frequent manifestations of convective phenomena. The correlation between convective phenomena and airplane flights is important for identifying the conditions having a negative impact on aviation. In order to observe the factors that influence the occurrence and development of convective phenomena in the operation area of the "Traian Vuia" International Airport, Timi?oara, an analysis of atmospheric instability was conducted based of some air-instability indices: CAPE (Convective Available Potential Energy), SWEAT index (Severe Weather Threat Index), LI (Lifted Index), K-index (KI), TT (Total Totals Index), SI (Showalter Index), CIN (Convective Inhibition), for July 10, 2021, a representative day in terms of the severity of convective processes. The analysis of the above-mentioned indices was further developed by means of the radar images from the WSR Doppler radar in Timi?oara (source: the SMIN network of the Romanian National Meteorological Administration - NMA) and by the number of cases with convective phenomena recorded at the Timi?oara meteorological station. This day (10 July 2021) was associated with high values of all air-instability indices, and with estimated hail sizes of 5.71 cm inside the clouds. The analyzed instability indices were extracted both from maps (including the CAPE and LI index), as well as through radiosonde data, measuring values of - 2...-7 K for the LI index (strong severity level), between 1,200 – 1,300 J/kg for CAPE (Szeged meteorological station and from GFS data from zyGrib program) and 1,900 J/kg based on ERA5 dataset (moderate instability), values lower than +1 K for SI (increased atmospheric instability), values indicating the occurrence of convective storms in the area for SWEAT index and values that indicate high probability of scattered convective storms for KI and TT indices.