Release of the new EPS Ten-Day Surface Albedo Data Record (ETAL-R LSA-152)
Consistent with the operational near-real-time generated EPS Ten-Day Surface Albedo product, this data record covers 2008 to 2021
- Oct. 17, 2024
The EUMETSAT Satellite Application Facility for Land Surface Analysis (LSA SAF) has announced a significant enhancement to its operational near-real-time (NRT) generated EPS Ten-Day Albedo product (ETAL LSA-103). Previously, the ETAL archive only extended back to 2015 when NRT production started. Now, by back-processing the full catalogue of EPS-Metop/AVHRR radiance data, the new ETAL-R dataset (LSA-152) extends the temporal coverage of the global land surface albedo archive back to January 2008. From this date to June 2021, ETAL-R provides more consistent and reliable surface albedo by performing improved atmospheric correction. The reprocessing also mitigates issues associated with missing data in the EPS-Metop/AVHRR NRT radiance inputs.
Key Improvements
- Extended Coverage: ETAL-R now includes data from 2008 to 2021, significantly extending the temporal coverage of the EPS-Metop surface albedo data archive.
- Accuracy and Quality: By using reanalysed atmospheric constituents data instead of forecasts and improved radiometric calibration of EPS-Metop/AVHRR sensors, ETAL-R offers increased stability and homogeneity compared to the NRT-generated archive. Global and local comparisons with ground stations and additional satellite reference data confirm its reliable long-term stability and satisfactory accuracy.
- Consistency with NRT Data: Despite the improvements, ETAL-R remains consistent with the operational NRT-generated ETAL product, which keeps being produced nowadays, allowing users to combine both datasets for long-term environmental analysis.
Fig.1: Left – ETAL-R surface albedo differences between 2020 and 2009, averaged over August to September. Right – mean precipitation anomalies from 2005 to 2020, corresponding to the black box region, averaged over June to October.
Applications and Showcase Study
The enhanced ETAL-R data record is valuable for several applications, including climate-related studies of the surface radiative budget or the analysis of environmental changes (e.g. deforestation, desertification, ice melt) over long time periods.
An illustrative case study in the Sahel region in Africa demonstrates the correlation between surface albedo evolution in ETAL-R and episodes of drought or intense rainfall. Fig. 1 shows that the surface albedo in the black box is lower in 2020 than in 2009. As the precipitation in 2020 was significantly higher than in 2009 in this area, the mechanism for the change in albedo may be related to an increase in vegetation growth in years with higher precipitation. In addition, the lower reflectance of wet soil compared to dry soil may also contribute to the observed change in surface albedo.
This update marks a significant step forward in providing more accurate and comprehensive surface albedo data to users, supporting a wide range of environmental and climate research initiatives.