Four‐decadal climatological intercomparison of rocketsonde and radiosonde with different reanalysis data: results from Thumba Equatorial Station

Abstract

Four decades of climatological data on winds from 0 to 65 km measured over the Thumba Equatorial Rocket Launching Station (TERLS) (8.53°N, 76.87°E), a low‐latitude equatorial station in India, are compared with four global reanalysis datasets. The observations are made using balloon‐borne experiments (0–35 km) and rocket soundings (20–65 km) from 1970 to 2013. Reanalysis data compared well with the real‐time observations below the tropopause and less well above it in both the wind components (zonal and meridional). The average correlation coefficient between observations and reanalysis is found to be 0.9 for zonal wind from the surface to 30 km and 0.6 for meridional wind from the surface to 15 km. The amplitude of the semi‐annual oscillation (SAO), annual oscillation (AO), and Quasi‐Biennial Oscillation (QBO) are reproduced well in the four reanalysis datasets. The QBO amplitude maximum around 20–30 km altitude is systematically underestimated by all the reanalyses compared to the observations.