• Treffer 85 von 1448
Zurück zur Trefferliste

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

  • 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.

Volltext Dateien herunterladen

Metadaten exportieren

Weitere Dienste

Teilen auf Twitter Suche bei Google Scholar
Metadaten
Verfasserangaben:Günther HeinemannORCiD, Clemens DrüeORCiD, Alexander MakshtasORCiD
URN:urn:nbn:de:hbz:385-1-20148
DOI:https://doi.org/10.3390/atmos13060957
Titel des übergeordneten Werkes (Englisch):Atmosphere
Verlag:MDPI
Verlagsort:Basel
Dokumentart:Wissenschaftlicher Artikel
Sprache:Englisch
Datum der Fertigstellung:12.06.2022
Datum der Veröffentlichung:12.06.2022
Veröffentlichende Institution:Universität Trier
Beteiligte Körperschaft:The publication was funded by the Open Access Fund of Universität Trier and the German Research Foundation (DFG)
Datum der Freischaltung:12.05.2023
Freies Schlagwort / Tag:Laptev Sea; SODAR; atmospheric boundary layer; atmospheric modeling; low-level jets; topographic flow
GND-Schlagwort:Atmosphärische Grenzschicht; Laptewsee; Modellierung; Sewernaja Semlja; Sodar; Windfeld
Jahrgang:2022
Ausgabe / Heft:Band 13, Heft 6 (2022)
Seitenzahl:24
Institute:Fachbereich 6 / Raum- und Umweltwissenschaften
DDC-Klassifikation:9 Geschichte und Geografie / 90 Geschichte / 900 Geschichte und Geografie
Lizenz (Deutsch):License LogoCC BY: Creative-Commons-Lizenz 4.0 International

$Rev: 13581 $