Verification of the regional atmospheric model CCLM v5.0 with conventional data and Lidar measurements in Antarctica

Abstract

Abstract. The non-hydrostatic regional climate model CCLM was used for a long-term hindcast run (2002–2016) for the Weddell Sea region with resolutions of 15 and 5 km and two different turbulence parametrizations. CCLM was nested in ERA-Interim data. We prescribed sea-ice concentration from satellite data, and used a thermodynamic sea-ice model. The performance of the model was evaluated in terms of temperature and wind using data from Antarctic stations, AWS over land and sea ice, operational forecast model and reanalyses data, and lidar wind profiles. For the reference run we found a warm bias for the near-surface temperature over the Antarctic plateau. This bias was removed in the second run by adjusting the turbulence parametrization, which results in a more realistic representation of the surface inversion over the plateau. Differences in other regions were small. A comparison with measurements over the sea ice of the Weddell Sea by three AWS buoys for one year showed small biases for temperature around 1 K and for wind speed of 1 m s−1. Comparisons of radio soundings showed a model bias around zero and a RMSE of 1–2 K for temperature and of 3–4 m s−1 for wind speed. The comparison of CCLM simulations at resolutions down to 1 km with wind data from Doppler Lidar measurements during December 2015 and January 2016 yielded almost no bias in wind speed and RMSE of ca. 2 m s−1. Overall CCLM shows a good representation of temperature and wind for the Weddell Sea region. These results encourage for further studies using CCLM data for the regional climate in the Antarctic at high resolutions and the study of atmosphere-ice-ocean interactions processes.

PARASO, a circum-Antarctic fully-coupled ice-sheet - ocean - sea-ice - atmosphere - land model involving f.ETISh1.7, NEMO3.6, LIM3.6, COSMO5.0 and CLM4.5

“…This coupling combination, which is hereinafter named CCLM 2 , forms the land-atmosphere basis for PARASO and is described in Davin et al (2011). More recently, at least two CCLM 2 Antarctic configurations have been developed (e.g., Souverijns et al, 2019;Zentek and Heinemann, 2020). In the following, we will use AEROCLOUD, the circum-Antarctic configuration described in Souverijns et al (2019), as a comparison reference.…”

Comparison of kilometre and sub‐kilometre scale simulations of a foehn wind event over the Larsen C Ice Shelf, Antarctic Peninsula using the Met Office Unified Model (MetUM)

“…However, as well as this aspect, an additional challenge for the atmospheric models is the turbulent erosion/removal of cold‐air pools due to the complex interplay between dynamics and thermodynamics (Mahrt, 1998; Holtslag et al ., 2013; Zardi and Whiteman, 2013; Steeneveld, 2014). Moreover, to meet the requirements of the extremely cold and demanding conditions that characterise the Antarctic Peninsula (and Antarctica in general), polar‐optimised versions of some atmospheric models such as the Weather Research and Forecasting (WRF: Turton et al ., 2017), MAR (Modèle Atmosphérique Régionale: Datta et al ., 2019), RACMO2 (Regional Atmospheric Climate Model: van Wessem et al ., 2016), and the Consortium for Small‐Scaled Modelling (COSMO) model in Climate Mode (CCLM: Zentek and Heinemann, 2020) have been developed. By comparison, the kilometre‐scale limited‐area configuration of the UK Met Office Unified Model (MetUM) numerical weather prediction system has been used to conduct many studies of the Antarctic Peninsula despite having little or no polar‐optimisation (e.g.…”