A Three-Year Climatology of the Wind Field Structure at Cape Baranova (Severnaya Zemlya, Siberia) from SODAR Observations and High-Resolution Regional Climate Model Simulations during YOPP

Abstract

Measurements of the atmospheric boundary layer (ABL) structure were performed for three years (October 2017–August 2020) at the Russian observatory “Ice Base Cape Baranova” (79.280° N, 101.620° E) using SODAR (Sound Detection And Ranging). These measurements were part of the YOPP (Year of Polar Prediction) project “Boundary layer measurements in the high Arctic” (CATS_BL) within the scope of a joint German–Russian project. In addition to SODAR-derived vertical profiles of wind speed and direction, a suite of complementary measurements at the observatory was available. ABL measurements were used for verification of the regional climate model COSMO-CLM (CCLM) with a 5 km resolution for 2017–2020. The CCLM was run with nesting in ERA5 data in a forecast mode for the measurement period. SODAR measurements were mostly limited to wind speeds <12 m/s since the signal was often lost for higher winds. The SODAR data showed a topographical channeling effect for the wind field in the lowest 100 m and some low-level jets (LLJs). The verification of the CCLM with near-surface data of the observatory showed good agreement for the wind and a negative bias for the 2 m temperature. The comparison with SODAR data showed a positive bias for the wind speed of about 1 m/s below 100 m, which increased to 1.5 m/s for higher levels. In contrast to the SODAR data, the CCLM data showed the frequent presence of LLJs associated with the topographic channeling in Shokalsky Strait. Although SODAR wind profiles are limited in range and have a lot of gaps, they represent a valuable data set for model verification. However, a full picture of the ABL structure and the climatology of channeling events could be obtained only with the model data. The climatological evaluation showed that the wind field at Cape Baranova was not only influenced by direct topographic channeling under conditions of southerly winds through the Shokalsky Strait but also by channeling through a mountain gap for westerly winds. LLJs were detected in 37% of all profiles and most LLJs were associated with channeling, particularly LLJs with a jet speed ≥15 m/s (which were 29% of all LLJs). The analysis of the simulated 10 m wind field showed that the 99%-tile of the wind speed reached 18 m/s and clearly showed a dipole structure of channeled wind at both exits of Shokalsky Strait. The climatology of channeling events showed that this dipole structure was caused by the frequent occurrence of channeling at both exits. Channeling events lasting at least 12 h occurred on about 62 days per year at both exits of Shokalsky Strait.

Future projections of wind energy potentials in the arctic for the 21st century under the RCP8.5 scenario from regional climate models (Arctic-CORDEX)

“…For the surface condition classification we use the land-sea and sea-ice masks of the respective RCMs. It should be noted that this empirical extrapolation does not account for effects of atmospheric stability or local topography, such as low-level jets, which may play also a role for WPD, since the wind maximum is typically at 100-300m height (Tuononen et al, 2015;Heinemann et al, 2022).…”

“…Investigating the spatial and temporal variability of near-surface wind speed is critical to assess the current wind energy potential and evaluate its future changes as the world continues to warm (Pryor et al, 2005;Moemken et al, 2018). The local near-surface wind speed variability is determined by large-scale, synoptic, and meso-scale circulations (storms, polar lows) as well as local conditions (Jakobson et al, 2019;Fabiano et al, 2021;Heinemann et al, 2022;Rapella et al, 2023). Large-scale atmospheric circulation patterns such as NAO/AO affect the cyclone activity in the Arctic (Akperov et al, 2019) and impact on local wind characteristics (Laurila et al, 2021).…”

Evaluation of Vertical Profiles and Atmospheric Boundary Layer Structure Using the Regional Climate Model CCLM during MOSAiC

“…This study showed that the representations of the wind, temperature, and moisture structure by the simulations were very good for the ABL and the troposphere. A comparison of wind profiles from SODAR measurements and RCM simulations for a three-year period in the area of Severnaya Zemlya (Siberia) showed a positive bias for a wind speed of about 1 m/s below 100 m, which increased to 1.5 m/s for higher levels [11].…”