Significant advances in Earth system understanding will only be achieved through better integration of data and knowledge from the different Earth science disciplines and Earth compartments. Improvement in this field strongly depends on our capabilities of dealing with fast growing multi-parameter data and on our effort employing Data Science methods, adapting new algorithms and developing digital workflows tailored to specific scientific needs.

Digital Earth has been strategically initiated by all eight centres of the Helmholtz research field Earth and Environment (E&E). The project is coordinated by GEOMAR Helmholtz Centre for Ocean Research Kiel and is directly linked to two other HGF initiatives MOSES 'Modular Observation Solutions for Earth Systems' and ESM 'Earth System Modelling'.

Although the atmospheric abundance of methane (CH4) is about 200 times smaller compared to that of carbon dioxide (CO2), it is a far more potent warming agent as its greenhouse warming potential (GWP) is 25-30 times larger (depending on the considered time frame) than that of CO2 (IPCC 2013). Today anthropogenic sources of agriculture/waste and biomass burning are the dominating methane fluxes into the atmosphere, followed by natural sources e.g. from wetlands in tropical and Arctic regions or other geological sources (e.g. Kirschke et al. 2013). However, also leakage of methane and volatile organic compounds (VOCs) from oil, gas and coal exploration on land and at sea leads to in detail yet not quantified emissions, which manifests in huge discrepancies in top-down and bottom-up estimates of the methane emissions (IPCC 2013). To overcome this discrepancy and to distinguish natural from anthropogenic sources, an evaluation of individual, local sources (e.g. leaking oil and gas wells) by detailed field studies accompanied by high resolution modelling is needed to assess the impact of local CH4 and VOC sources on atmospheric concentrations.

At IMK-ASF we are investigating the emission flux of disused and active offshore platforms. Explorations of the sea floor in the North Sea showed a release of methane near the boreholes of both, oil and gas producing platforms. The basis of our work is the established emission data base EDGAR (Emission Database for Global Atmospheric Research), an inventory that includes methane emission fluxes in the North Sea region. While methane emission fluxes in the EDGAR inventory and platform locations are matching for most of the oil platforms almost all of the gas platform sources are missing in the database. We develop a method for estimating the missing sources based on the EDGAR emission inventory. In this study the global model ICON-ART (ICOsahedral Nonhydrostatic model - Aerosols and Reactive Trace gases) will be used. ART is an online-coupled model extension for ICON that includes chemical gases and aerosols. One aim of the model is the simulation of interactions between the trace substances and the state of the atmosphere by coupling the spatiotemporal evolution of tracers with atmospheric processes. ICON-ART sensitivity simulations are performed with inserted and adjusted sources to access their influence on the methane and OH-radical distribution on regional (North Sea) and global scales.