Sensitivity of precipitation in the highlands and lowlands of Peru to physics parameterization options in WRFV3.8.1

Abstract. The performance of the Weather Research and Forecasting (WRF) model version 3.8.1 at convection-permitting scale is evaluated by means several sensitivity simulations over southern Peru down to a grid resolution 1 km, whereby main focus on domain with 5 km horizontal resolution. Different configurations microphysics, cumulus, longwave radiation, planetary boundary layer schemes are tested. For year 2008, simulated precipitation amounts patterns compared gridded observational data sets weather station gathered from Peru, Bolivia, Brazil. temporal correlation monthly accumulated against in situ show that most challenging regions for WRF slopes along both sides Andes, i.e. elevations between 1000 3000 m above sea level. pattern analysis suggests all tested setups perform rather poorly northeastern Andes during entire year. In southwestern region better except driest period (May–September). results reasonably well dry season. reveal typical setup used Europe too throughout year, experiment combination single-moment 6-class microphysics scheme Grell–Freitas cumulus parameterization domains resolutions larger than suitable East Africa, does not perfectly apply other equatorial such as Amazon basin southeastern Peru. Stony Brook University Grell-Freitas tends overestimate but enforces positive feedback soil moisture, air temperature, relative humidity, mid-level cloud cover and, finally, precipitation. Hence, this provides accurate Peruvian Amazon, particularly department Madre de Dios, which interest because it considered biodiversity hotspot robustness particular configuration backed up similar obtained wet climate conditions observed 2012.