Project: Investigating climate change related impacts on the urban winter climate of Hamburg - Influences of climate change on urban climate are often investigated in the context of increased values for high temperatures or precipitation extremes. As a consequence, many studies concentrate on the climate change impacts that happen during summer. When looking at projected temperature and precipitation changes, mean changes are larger in winter than in summer, at least for northern Germany. At the same time, the distribution of temperature is broadened, which implies that winters with temperatures below freezing point or snowfall will still happen in the future. The aim of this project is to quantify climate change related impacts on the winter climate of Hamburg in detail. For this purpose, an existing canopy resolving model (MITRAS) will be expanded to allow a detailed analysis of precipitation including snow and of frost distribution at the local scale. The model will be forced by regional climate model results using a here to be newly developed statistical-dynamical downscaling approach. With this tool the impact on the local winter climate, as well as of adaption measures developed for a changed summer climate are investigated. To ensure model results occur in time a code optimisation and parallelisation is part of this project (https://www.hicss-hamburg.de/projects/urban_winter_hamburg/). Summary: This experiment contains sensitivity test results (Ferner et al. 2023) of 11 simulations with the microscale, obstacle-resolving model MITRAS v 3.1 (Salim et al., 2018; Schluenzen et al., 2018) for a domain of 1.6 x 1.8 km² around Hamburg City Hall in Hamburg. The domain contains various street configurations, open spaces, water surfaces, orography and building heights. The simulations were performed with different initial wind speeds, rain amounts, wind directions, and domain configurations. The simulations cover 1:40 hours, starting at 7:30 LST (LST refers to Local Solar Time), with a temporal resolution of 10, 1 or 5 minutes. This experiment contains a selection of output variables, control variables are not included. The file names of the data sets are composed as follows. {precipitation}_{intensity}_{windspeed}_ {intensity}_{winddirection}_{value}_{case ID}.nc There are 3 intensities: low, medium, high Associated values are these: pr_low = 0.5 mm, pr_medium =0.9 mm, pr_high = 1.7 mm (after 10 minutes) ff_low = 2 m/s, ff_medium = 4 m/s, ff_high = 4 m/s Example: pr_medium_ff_low_dd_270_ML27.nc
