Dynamical downscaling of medium- and short-term climate series for assessing climate impacts on a world heritage site

The present work utilizes two non-hydrostatic, mesoscale numerical weather forecast models, namely the Weather Research and Forecasting – Advanced Research WRF (WRF) model and the Mesoscale Model (MEMO), to dynamically downscale climatic series by performing high-resolution atmospheric simulations for the area of Dion in Pieria (Greece). The study area was selected due to the presence of an outdoors world heritage site that is exposed in hazards connected to extreme weather events and climate change. The site is situated in a coastal area and therefore is strongly influenced by wind flows originating from the sea. Local wind circulation can carry sea salt and other suspended particles that inevitably cause damage to the surface of monuments while convective precipitation exacerbates corrosion by enhancing the wet deposition of reactive species. Meteorological factors such as wind, condensation, fog, frost, and solar radiation can also cause fading and deterioration on stone monuments. Climate data used in the frame of the present analysis originated from the EURO-CORDEX initiative with a 3-hourly temporal resolution which were then downscaled from a resolution of approximately 12 km down to a fine grid of 500 m, adequate to resolve local topography-induced flow and thermal phenomena. For assessing the influence of local effects on shorter time scales, selected periods of extreme weather conditions were simulated through short-term hindcasts. This approach aimed to validate and intercompare the performance of the two mesoscale models in simulating local flow and thermal effects at a very high resolution. While both models appear able to capture the local structures directly caused by the overlying synoptic circulation, notable differences are expected in the simulation of thermally-induced flows, including sea- and land-breeze as well as cloud effects under strongly convective conditions.