Comparison of CCI and GLEAM soil moisture products

We compare CCI and GLEAM soil moisture products over two regions which will help understanding the mechanisms of some systematic biases in the model simulations of soil moisture and evaporation. These regions are:

The overall aim of our study is to validate the soil moisture predicted by the LMDZOR model against the CCI soil moisture product (reference data set for the validation). LMDZOR  results from the coupling of the atmospheric model LMDZ and the land-surface model ORCHIDEE.

As other soil moisture products exist (e.g. GLEAM product), we wish to check if the different soil moisture products are in agreement, before validating our model.

Figure 1: Histograms of GLEAM and ESA CCI soil moisture data from 2001 to 2013 over Western Europe (no. 32, left) and the western part of the Mediterranean basin (no. 34, right).

According to the figure, there are some differences between the two products. The histogram of GLEAM data present a wider range of soil moisture values compared to the one of the CCI data. This is particularly true in dry context, i.e. during the dry season (boreal summer) and semi-arid regions. Thus we have to be careful when we validate climate models and we try to find a better method of validation.

About the author

This article was produced in 2016 by Paul Passy. Paul is a post-doctorate fellow at the Institut Pierre-Simon Laplace in Paris. Paul focuses on the study of the water cycle to understand better the links between this cycle and human activities. Paul leads this study by using modelling tools, GIS and remote sensing.