R Script to Extract Monthly and Yearly CO2 from GOSAT L4 Datasets

These R scripts are designed to extract carbon dioxide (CO₂) concentration values from the GOSAT Level 4 (L4) satellite datasets. The extracted data are then processed to generate monthly and yearly average CO₂ values, as well as to calculate changes over time in the form of absolute differences (delta) and relative changes expressed as percentages. The unit of spatial analysis in this study is based on the official administrative boundaries of the Common Market for Eastern and Southern Africa (COMESA) member countries, which currently include 21 nations primarily located in the eastern region of Africa. The GOSAT data used in this analysis can be accessed through the official portal at: https://data2.gosat.nies.go.jp/index_ja.html. However, please note that users are required to complete a registration process and obtain a user account before they are able to download any datasets from the site.