Climate Adjustment of Photosynthetically Active Radiation Estimates Using Site Adaptation Technique
Abstract
In this work, a local adjustment is proposed for photosynthetically active radiation (PAR) estimates at several locations around the world with different Köppen-Geiger climate classes, resulting in a climate adjustment for PAR estimates. For adjustment, a site adaptation technique was used for each of the climates (hemiboreal, semi-arid, mediterranean, oceanic, and tropical) represented in this study. Remote sensing PAR data from thirteen locations were collected from the Copernicus CAMS global greenhouse gas reanalysis (EGG4) dataset to be used as initial PAR estimates, while observed PAR data from the same locations were also collected to perform the local adjustment. The results evidenced good fitting for four out of five climates; conversely, the semi-arid climate had to be divided into two subclimates (hot and cold semi-arid) to obtain good results. After division, the best results were obtained for the cold semi-arid and mediterranean climates. In the hot semi-arid climate, the results were contradictory, since it had the worst determination coefficient and the second-best MBE and RMSE among all climates. These results suggest that PAR is affected by local climatic and atmospheric conditions.