Next-Generation Land Surface Albedo Products from Metop-SG: Towards a Synergetic Use of METimage and 3MI Observations

Land surface albedo, the ratio of reflected to incoming solar radiation at the Earth’s surface, is a fundamental parameter in the global energy budget. As an essential climate variable, it plays a key role in climate monitoring, environmental studies, and operational numerical weather prediction. Accurate, high-resolution albedo products are therefore critical for capturing land surface processes and their rapid changes, which in turn influence atmospheric dynamics and climate feedbacks.

Satellite remote sensing from Low Earth Orbit (LEO) provides a consistent means of estimating land surface albedo in the visible and near-infrared globally across the planet. The recent launch of the first platform of the EUMETSAT Polar System - Second Generation A series (Metop-SG-A1) marks a significant leap in satellite observation capabilities in comparison to the previous generation. In particular, Metop-SG-A payload includes two advanced multi-spectral imaging radiometers: METimage, offering enhanced spatial resolution down to 500 meters across a wide range of spectral channels, and the Multi-viewing, Multi-channel, Multi-polarisation Imager (3MI), which provides unique multi-angular information for characterising clouds, aerosols properties and surface directional reflectance.

Within the EUMETSAT Satellite Application Facility for Land Surface Analysis (LSA SAF), led by the Portuguese Institute for Sea and Atmosphere (IPMA), efforts are currently underway to develop, validate, and operationally and freely distribute surface albedo products derived from METimage and 3MI observations separately. These will ensure continuity with existing LSA SAF albedo products based on previous-generation sensors (Metop/AVHRR). The next step will be to exploit the complementarity between Metop-SG-A instruments, by combining METimage’s high spatial and spectral detail with 3MI’s angular diversity and related aerosol retrievals (e.g. from future EUMETSAT operational aerosol products). This joint retrieval is expected to mitigate existing atmospheric correction biases and enhance the overall accuracy of the current LSA SAF albedo products, as well as their temporal responsiveness in front of sudden land surface changes. All these aspects will be discussed in our presentation.