| Abstract |
Land Surface Temperature (LST) is the brightness temperature of the land surface, driven by solar radiation and related to air temperature, often used as an indicator for monitoring the state of crops and vege-tation and assessing plant stress. Land cover and the presence or absence of vegetation are factors that influence the land surface temperature.
The MODIS MOD11C3 Version 6.1 Monthly Daytime and Nighttime Land Surface Temperature (2000 to 2021) is used to derive the annual anomaly maps and the historic graphs. Incomplete records occur in the data derivation process of the MODIS product when the cloud-contaminated data is removed. Insufficient data particularly affects the central and northern parts of Angola and Zambia in the nighttime LST da-ta. Accordingly, for the spatial analysis, where annual data is compared to historic data, only historic records that are more than 80 % complete, were deemed sufficient to provide insight into the deviation from the average annual LST. For the graphs, only annual average LST records with 70% or higher data availability are shown.
The anomaly maps for southern Africa for daytime and nighttime LST suggest that on average, 2024 had normal or cooler daytime LST, while nights appeared to be, for most of southern Africa, warmer in 2024. Exceptions are found in sporadic areas, particularly those with bare soil, such as the Etosha salt pan and the Okavango floodplains, where daytime LST is warmer than normal.
Spatial analysis findings are reinforced by the historic graphs, that show that Angola, Botswana, Zambia and Zimbabwe had average annual daytime LST in 2024, but for Namibia and South Africa, the average annual daytime LST in 2024 was below average.
The historic graphs further show that for all countries analysed, the nighttime LST for 2024 was above average, and in fact the highest recorded since records begin in 2001. All countries suggest an increasing average annual nighttime LST. |
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