Regional dynamical downscaling with CCLM over East Asia

Inspired by the framework of the Coordinated Regional Climate Downscaling Experiment (CORDEX), the hindcast (1971–2000) and projection (2021–2050) simulations based on a resolution of $0.44^\circ$ over the East Asia domain are performed with the regional climate model COSMO-CLM (CCLM). The simulations are driven by ERA-40 reanalysis data and output of the global climate model ECHAM5. This is the first time that the CCLM is adapted and evaluated for the East Asia Monsoon region; the setup is considered a starting point for further improvements in this region by the CCLM community. The evaluation results show that the CCLM is able to reasonably capture the climate features in this region, especially the monsoon dynamics on small scales. However, total precipitation in the northern part of the domain, over the Tibetan Plateau, and over east Indonesia has a pronounced wet bias. The projected climate change under the A1B scenario indicates an overall annual surface temperature increase of 1–2 K, but no significant precipitation changes.     

On correcting precipitation as simulated by the regional climate model COSMO-CLM with daily rain gauge observations

Precipitation amounts simulated by the regional climate model COSMO-CLM are compared with observations from rain gauges at German precipitation stations for the period 1960–2000. The model overestimates precipitation by about 26 %. This bias is accompanied with a shift of the frequency distribution of rain intensities. The model overestimation varies regionally. A correction function is derived which adjusts rain intensities at every model grid point to the observations.     

Thermo-optical parameter acquisition and characterization of geologic properties: a 400-m deep BHE in a karstic alpine marble aquifer

To dimension a geothermal array, it is necessary to explore the geophysical and geologic qualities of the subsoil. At the following example the project engineering of a prospective geothermal array is shown from the investigation up to the execution planning. For the geothermic investigation a 400 m (1312 ft.) deep drilling was established and equipped with 50 mm (1.97 in.) duplex BHE. With the mounting of the BHE a fiberglass hybrid cable was inserted as a loop parallel to the shanks of the BHE. By means of optical frequency domain reflectometry (OFDR) an enhanced geothermal response test has been executed. Due the high local resolution of the resulting profile of conductivities the geological profile can be differentiated in areas with mainly conductive and areas of convective influenced heat transfer. By knowledge of these both parts and its parameters the incident of groundwater flow on the BHE can be calculated (Peclet number analysis/ Darcy velocity). With the help of the ascertained geophysical and hydraulic rock parameters solid rock, cleavages and karst cavity could be identified. Also the undisturbed ground temperature, the effective thermal conductivity and areas with different geothermal gradients and the groundwater velocity in cleaved and caveated rocks could be determined.     

Numerical simulation of colour equations for the uvby system

The results of numerical simulation of colour equations of uvby photometry for filter-defined bandpasses are presented. It is shown that linear transformation equations to the standard system are valid for instrumental systems deviating by no more than 2.5 nm in peak transmission wavelengths. The comparison with the results of observations is satisfying. Im Ergebnis einer numerischen Farbgleichungssimulation im uvby-System wird nachgewiesen, daß für Instrumentensysteme mit Abweichungen der Wellenlängen maximaler Transmission bis zu 2.5 nm gegenüber den Standardwerten eine lineare Transformation möglich ist. Der Vergleich mit Beobachtungsresultaten zeigt eine gute Übereinstimmung.