A database of deep convective systems derived from the intercalibrated meteorological geostationary satellite fleet and the TOOCAN algorithm (2012–2020)

Abstract

Abstract. We introduce two databases, TOOCAN (Tracking Of Organized Convection Algorithm using a 3D segmentatioN) and CACATOES, aimed at facilitating the study of deep convective systems (DCSs) and their morphological characteristics over the intertropical belt during the period spanning from 2012 to 2020. The TOOCAN database is constructed using a tracking algorithm called TOOCAN applied on a homogenized GEOring infrared (IR) archive and enables the documentation of the morphological parameters of each DCS throughout their life cycles. The homogenized GEOring IR database has been built from level-1 data of a fleet of geostationary platforms originating from various sources and has been intercalibrated; spectrally adjusted; and limb-darkening corrected, specifically for high cold clouds, based on a common reference, the IR channel of the Scanner for Radiation Budget (ScaRaB) radiometer on board the Megha-Tropiques. The resulting infrared observations are then homogeneous for brightness temperatures (BT) <240 K, with a standard deviation lower than 1.5 K, throughout the GEOring. A systematic uncertainty analysis is carried out. First, the radiometric errors are shown to have little impact on the DCS characteristics and occurrences. We further evaluate the impact of missing data and demonstrate that a maximum of 3 h of consecutive missing images represents a favorable compromise for maintaining tracking continuity while minimizing the impact on the DCS morphological parameters. However, beyond this temporal threshold, the segmentation of DCS is significantly compromised, necessitating the interruption of the tracking process. The CACATOES database is derived from the TOOCAN database through a post-processing procedure, which involves projecting the morphological parameters of each deep convective system (DCS) onto a daily 1° × 1° grid. The resultant dataset provides a broader perspective, allowing for an Eulerian analysis of the DCS and facilitating comparisons with auxiliary gridded datasets on the same daily 1° × 1° grid box. Both the TOOCAN and CACATOES databases are provided in a common netCDF format that is compliant with the standards of Climate and Forecast (CF) conventions and the Attribute Convention for Dataset Discovery (ACDD). A total of 15×106 DCSs have been identified over the tropical regions and the 9-year period. The analysis of DCSs over the tropical oceans and continents reveals a large variety of DCS characteristics and organizations. They can last from few hours up to several days, and their cloud shield ranges from 1000 km2 to a few millions of squared kilometers. Oceanic DCSs are characterized by a longer lifetime duration and larger shields. Finally, the DCS geographical distribution is in line with previous DCS climatologies built from other algorithms and satellite observations. All datasets can be accessed via the repository under the following data DOIs: TOOCAN database: https://doi.org/10.14768/1be7fd53-8b81-416e-90d5-002b36b30cf8 (Fiolleau and Roca, 2023a) CACATOES database: https://doi.org/10.14768/98569eea-d056-412d-9f52-73ea07b9cdca (Fiolleau and Roca, 2023b).