Preliminary evaluation of the long-term GLASS albedo product

TLDR

Land surface albedo is a key climate forcing parameter, and a long‑time series of global albedo products is required to understand climate‑change mechanisms. The study aims to provide and evaluate the GLASS long‑term global land surface albedo product (1981‑2010) to support Earth‑system research and to assess its quality upon release. GLASS derives albedo from multisource remote‑sensing data using newly developed algorithms, and the paper evaluates its integrity, accuracy, and robustness. The GLASS product is gapless, continuous, self‑consistent, and as accurate as MODIS MCD43, with a quality flag that indicates expected uncertainty.

Abstract

Land surface albedo is an important parameter to describe the radiant forcing in the climate system. A long-time series of global albedo products is needed to understand the mechanism of climate change. Aiming to support global change and Earth system studies, GLASS (Global LAnd Surface Satellites) provides long-term global land surface albedo product from 1981 to 2010, which are generated from multisource remote sensing data and newly developed algorithms. It is critical to assess the quality of the GLASS product when it is released to the public. This paper first introduced the algorithms and then analyzed the integrity, accuracy, and robustness of the GLASS albedo product. The results show that the GLASS albedo product is a gapless, long-term continuous, and self-consistent data-set with an accuracy similar to that of the widely acknowledged MODIS MCD43 product. The quality flag, which is provided along with the black-sky and white-sky albedo, gives a pertinent indication of the expected uncertainty in the product.