Cold and warm extreme temperatures in the subtropical Andes: evaluating convection-permitting simulations with in-situ observations.

BALMACEDA HUARTE, R; OLMO, M. E.; BETTOLLI MARIA LAURA

Bergen

Workshop; VII Convection Permitting Climate Modelling Workshop; 2023

NCAR-Universidad de Bergen

Temperature-related climate hazards directly affect human health and comfort, as well as energymanagement and mul+ple socio-economic ac+vi+es. The magnitude of their consequences oSendepends on the loca+on and suscep+bility of the affected popula+on, demanding regional-to-localclimate informa+on. Regional climate models can be used to address such problems, althoughmodel resolu+on can be a limita+on for their representa+on, especially in regions with complextopography. In this line, the Andes mountain range poses a par+cular challenge over the SouthAmerican con+nent. Thereby, the brand-new high-resolu+on models at convec+on-permiEng scales(CPM) arise as valuable tools that can provide tailored clima+c informa+on to carry out impactstudies over the Andes.In this work, we evaluate the state-of-the-art convec+on-permiEng WRF simula+on developed byNCAR at 4 km grid spacing over South America. The assessment is focused on the representa+on ofthe a) air temperature diurnal cycle in the CPM simula+ons; b) threshold-based indices of cold andwarm days (days with TMIN30 C, respec+vely) over selected meteorological sta+onslocated in the subtropical sec+on of the Andes. The simula+ons were compared against in-situobserva+ons and the MSWX dataset during 2000-2007 (the available simulated period at the +me ofsubmiEng this abstract). Also, the added value of the CPM resolu+on was explored by includingERA5.A first insight into the model runs shows that the diurnal cycle is well captured by WRF. In general,the reproduc+on of cold days is a more complex task than the warm days, for which largerdiscrepancies among the datasets are detected. The results that arise from these analyses indicatean overall good performance of the CPM simula+ons, with some added value represen+ng theindices in the meteorological sta+ons.