A Software Toolkit for Advancing our Understanding of Land Surface Interactions: Recent developments to the SimSphere SVAT model

Mathematical models are widely used today to study the intricate physical processes and interactions among the different components of the Earth’s system. Such models are often used synergistically with Earth Observation (EO) data allowing to derive spatiotemporal estimates of key parameters characterising land surface interactions. This synergy allows combining the horizontal coverage and spectral resolution of EO data with the vertical coverage and fine temporal continuity of those models. SimSphere is a mathematical model belonging to the Soil Vegetation Atmosphere Transfer (SVAT) models. As a software toolkit, it has been developed in Java and it is used either as a stand-alone application or synergistically with EO data. The model use is constantly expanding worldwide both as an educational and as a research tool. Herein we present recent advancements introduced to SimSphere. We have comprehensively tested and updated the model code and added new functionalities which are illustrated herein using a variety of case studies. For example, it presents herein the new functionality that allows it to be applied over complex/heterogeneous landscapes, and this new model capability is demonstrated in experimental settings in various European ecosystems. The present study contributes towards efforts ongoing nowadays by the users' community of the model and is also very timely, given the increasing interest in SimSphere particularly towards the development of EO-based operational products characterising the Earth’s water cycle.  The research presented herein has been conducted in the framework of the project LISTEN-EO (DeveLoping new awareness and Innovative toolS to support efficient waTer rEsources man-agement Exploiting geoinformatiOn technologies), funded by the Hellenic Foundation for Research and Innovation programme (ID 015898). 

Keywords: SVAT, SimSphere, Earth Observation, land surface interactions, LISTEN-EO