DFG Research Group: Virtual Neckar River meant to improve weather forecasts
27 November 2013, by Markus Dressel
A new DFG research group wants to create a virtual river landscape with the aid of a super computer. Researchers of the German Centre for Earth System Research and Sustainability (Centrum für Erdsystemforschung und Nachhaltigkeit, CEN) at Universität Hamburg are also participating. It is the goal of the simulation to better understand the physical processes in a catchment basin, making it for example easier to give more precise...
The German Federal Society for the Advancement of Scientific Research (Deutsche Forschungsgemeinschaft) has supported the project "Data Assimilation for Improved Characterisation of Fluxes Across Compartmental Interfaces" with an amount of more than two million euros since April. To simplify matters, the researchers are asking the following questions: What do we have to measure in order to trace the course of the water in a precise manner? And how can we integrate this information into models? At the research centre of Jülich, one of the most powerful computers in Europe simulates a so-called catchment basin from the source to the mouth. The area also comprises deeper soil layers and uses the catchment basin of the Neckar River as orientation, which covers an area of approx. 150 x 200 kilometres.
In practice, it takes immense efforts to measure all water transports in such a vast area. That is why the research group uses a trick: The model creates virtual reality from which you can take any number of artificial measured data. In the next step, the scientists return to actual reality and treat the model like a real catchment basin. There is only a limited number of measuring stations and, consequently, of data. The group specifies a selection of artificial measured data and uses them to reconstruct the water fluxes and the weather, aiming to approach virtual reality with the forecast as close as possible.
Professor Felix Ament, meteorologist at the CEN and KlimaCampus, heads the Hamburg sub-project. He is challenged by the prospect of forecasting the weather in a more reliable way with measurements in the soil. "What is so exciting about soil is the fact that slow and fast processes happen at the same time," explains Professor Ament, giving an example: A cloud obscures the sun. Within seconds, the temperature at the earth's surface cools down. In contrast, the temperature at a depth of two metres changes only slowly.
The meteorologist wants to make use of this knowledge: "If we discover, for example, that the forecast for a particular place is generally too warm, the reason for this lies probably deep in the soil. We also call this the specific time fingerprint of a mistake. However, if the estimations of meteorologists are alternately above or below the real temperature, we have to look for the cause of the mistake preferably in the upper layers of the soil," says Professor Ament.
The results from basic research promise many different possible applications. Forecasts regarding precipitation could contribute to securing water supplies and serve as prognosis for possible floodings. Further, the knowledge about soil moisture helps farmers increase their yields. Speaker of the group is meteorologist Professor Clemens Simmer of the University of Bonn. Apart from the University of Hamburg, also the universities of Augsburg, Bonn, Hanover and Tübingen, the European Space Agency (ESA) and the institutes of the Helmholtz-Gemeinschaft in Jülich and Leipzig are also taking part. Including the newly-established group, the University of Hamburg boasts a total number of 19 DFG research groups.
More information
www3.uni-bonn.de/Pressemitteilungen/242-2013
Webpage of Prof. Felix Ament:
https://www.clisap.de/clisap/people/felix_ament-8/
https://www.mi.uni-hamburg.de/arbeitsgruppen/atmosphaerenmessungen/personen/ament-felix.html