A global dataset for lake physical variables from satellite measurements

The influence of climate change on freshwater ecosystems is becoming increasingly concerning worldwide. At the global level, lakes are facing rising temperatures, shifts in stratification phenology and precipitation patterns, and an increased frequency of extreme weather events. Understanding the long-term effects and the complex responses of lakes and inland waters in a changing environment is essential to managing water resources effectively and mitigating the effects of climate change. The preservation of freshwaters in good health status is a key issue for water potability, food and industry production, nature conservation, and recreation. To support the comprehension of this topic at a global scale, satellite technologies provide a unique source of data. Remote sensing can indeed enable long-term monitoring of freshwaters, supporting water managers' decisions providing data, and filling knowledge gaps to a better understanding of the regional and local areas most affected and threatened by health status degradation. With this aim, space agencies and the remote sensing community have joined the efforts to provide global, stable, consistent, and long-term products openly available and easily accessible to different kinds of users.

In this contribution, we present the latest release of the dataset from the Lakes_cci project (funded by the European Space Agency), which provides the most complete collection of the Essential Climate Variable LAKES consisting of six thematic products (lake water extent and level, lake ice cover and thickness, lake surface water temperature, lake water-leaving reflectance). The dataset spans the time range 1992 to 2022 and includes over 2000 relatively large lakes, which represent a small fraction of the number of lakes worldwide but a significant portion of the global freshwater surface. The dataset has been already adopted by 27 (to date) studies from several disciplines since 2019, including (but not limited to) limnology, hydrology, atmospheric physics and climatology, freshwater ecology, and biology. A WebGIS portal allows users to discover most of the variables and extract small sections of data for download or plotting. The portal has already been used as a resource for training and education. Products also come with example scripts to help new users familiarize themselves with data extraction as well as with basic analyses. 

With this contribution, we aim to discuss how this kind of product can be useful to the several research communities involved, their limits, potential improvements and chances to further joint research also respect to the research community's expectations and needs.