Special issue  

Leaching of dissolved organic carbon (DOC) from soils to the river network is an important component of the land carbon (C) budget but its spatio-temporal variation is not yet fully constrained. We use a land surface model to simulate at the European scale the present-day land C budget including leaching of DOC from the soil. We found an average leaching of 14.3 TgC/yr (0.6 % of the terrestrial net primary production) with seasonal variations. We determine runoff and temperature as main drivers.

The effect of inland waters on the climate is commonly parameterized as a function of surface water temperature that is estimated by 1D models that run coupled with climate models. These models often neglect advection due to inflows. Analyzing the trade-off between the complexity and requirements of different modeling approaches and the accuracy of their results, this study highlights the need to accurately model reservoir dynamics and selects an efficient way of doing so.

Wind blowing over the ocean creates waves, which by increasing the level of turbulence, promote gas exchange at the air-water interface. In this study we measured for the first time enhanced gas exchanges by wind-induced waves at the surface of a large lake. We adapted an ocean-based model to account for surface waves on gas exchange in lakes. We finally show that intense wind events with surface waves contribute disproportionately to the annual CO₂ gas flux in a large lake.

An operational lake forecast system was developed and tested for a large lake. The system predicted storm-surge and up-/down-welling events that are important for flood water and drinking water/fishery management. This study provides an example of the successful development of an operational forecast system, driven by open-access meteorological forecast, validated by online real-time observations, that can be adapted to simulate aquatic systems as required for management and public safety.

We developed the T-CHOIR, a hydrologic simulation framework, to solve fluvial- and thermo- dynamics of river-lake continuum. This provides an algorithm for upscaling high-resolution topography as well, which enables the representation of those interactions at the global scale. Validation against in-situ and satellite observations shows that the coupled mode outperforms river or lake only modes. T-CHOIR will contribute to elucidate the role of surface hydrology in Earth’s energy and water cycle.