Spatial and Temporal Characteristics of Summer Precipitation over Central Europe in a Suite of High-Resolution Climate Models

Abstract

Spatial and temporal characteristics of summer precipitation over Central Europe in a suite of high-resolution climate models. Journal of Climatehttp://dx.doi.org/10.1175/JCLI-D-15-0463.1Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. Permanent link to this version:http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-128380 Journal of Climate EARLY ONLINE RELEASEThis is a preliminary PDF of the author-produced manuscript that has been peer-reviewed and accepted for publication. Since it is being posted so soon after acceptance, it has not yet been copyedited, formatted, or processed by AMS Publications. This preliminary version of the manuscript may be downloaded, distributed, and cited, but please be aware that there will be visual differences and possibly some content differences between this version and the final published version. High-impact, localized intense rainfall episodes represent a major socioeconomic problem for societies worldwide, and at the same time these events are notoriously difficult to simulate properly in climate models. Here, the authors investigate how horizontal resolution and model formulation influence this issue by applying the HARMONIE regional climate model (HCLIM) with three different setups; two using convection parameterization at 15 and 6.25 km horizontal resolution (the latter within the "grey-zone" scale), with lateral boundary conditions provided by ERA-Interim reanalysis and integrated over a pan-European domain, and one with explicit convection at 2 km resolution (HCLIM2) over the Alpine region driven by the 15 km model. Seven summer seasons were sampled and validated against two high-resolution observational data sets. All HCLIM versions underestimate the number of dry days and hours by 20-40%, and overestimate precipitation over the Alpine ridge. Also, only modest added value were found of "grey-zone" resolution.However, the single most important outcome is the substantial added value in HCLIM2 compared to the coarser model versions at sub-daily time scales. It better captures the local-to-regional spatial patterns of precipitation reflecting a more realistic representation of the local and meso-scale dynamics. Further, the duration and spatial frequency of precipitation events, as well as extremes, are closer to observations. These characteristics are key ingredients in heavy rainfall events and associated flash floods, and the outstanding results using HCLIM in convection-permitting setting are convincing and encourage further use of the model to study changes in such events in changing climates.

The HARMONIE–AROME Model Configuration in the ALADIN–HIRLAM NWP System

“…FLake is already used operationally in NWP by, for example, COSMO (Mironov et al 2010) and ECMWF (ECMWF 2015b), and in climate applications of the ALADIN-HIRLAM system using the HARMONIE Climate configuration (Lind et al 2016). The most important physiography information for lakes is the lake depth.…”

Scale dependency of regional climate modeling of current and future climate extremes in Germany

“…in the Rothaar and Harz Mountains, or in the Thuringian Forest. It is a well-known problem that RCMs produce too much precipitation over mountainous areas (e.g., Ban et al 2014;Lind et al 2016). With higher spatial resolution, the orography is more pronounced.…”

“…To date, the application of convection-permitting models in climate studies is limited, and is typically restricted to relatively small domains (Knote et al 2010;Prein et al 2013;Tölle et al 2014;Gutjahr et al 2016). Often, only a few summer seasons (Hohenegger et al 2008;Prein et al 2013;Lind et al 2016) are investigated because of computational constraints. The immense computational costs are inherent with climate simulations at convection-permitting scale.…”

Strong Dependence of Extreme Convective Precipitation Intensities on Gauge Network Density

“…Precipitation at very small scales below 1 km can be studied in confined, campaign-type study settings (Goodrich et al, 1995;Pedersen et al, 2010;Peleg et al, 2013), and at large scales, uncertainties generally decrease. But on the 1 to 10 km scale, just below most operational rain gauge network densities and in the gray zone of climate models, extreme convective surface area precipitation is still subject to large uncertainties (Lind et al, 2016). This restrains evaluation of climate model skill to represent precipitation intensities, particularly for rare extreme events relevant to society (Prein & Gobiet, 2017;Sunyer et al, 2013).…”