The Spring-Time Boundary Layer in the Central Arctic Observed during PAMARCMiP 2009

Autor: Andreas Herber, Maria Stock, Ralf Brauner, Vladimir Sokolov, Thomas Orgis, Gerit Birnbaum, Klaus Dethloff, Roland Neuber, Johannes Kässbohrer, P. S. K. Liu, Alexander Makshtas, Christian Haas, Anne Hoffmann, Marion Maturilli, Robert S. Stone, Christoph Ritter, Astrid Lampert
Rok vydání: 2012
Předmět:
Zdroj: EPIC3Atmosphere, MDPI, 3(3), pp. 320-351, ISSN: 2073-4433
Atmosphere, Vol 3, Iss 3, Pp 320-351 (2012)
Atmosphere; Volume 3; Issue 3; Pages: 320-351
Popis: The Arctic atmospheric boundary layer (AABL) in the central Arctic was characterized by dropsonde, lidar, ice thickness and airborne in situ measurements during the international Polar Airborne Measurements and Arctic Regional Climate Model Simulation Project (PAMARCMiP) in April 2009. We discuss AABL observations in the lowermost 500 m above (A) open water, (B) sea ice with many open/refrozen leads (C) sea ice with few leads, and (D) closed sea ice with a front modifying the AABL. Above water, the AABL had near-neutral stratification and contained a high water vapor concentration. Above sea ice, a low AABL top, low near-surface temperatures, strong surface-based temperature inversions and an increase of moisture with altitude were observed. AABL properties and particle concentrations were modified by a frontal system, allowing vertical mixing with the free atmosphere. Above areas with many leads, the potential temperature decreased with height in the lowest 50 m and was nearly constant above, up to an altitude of 100–200 m, indicating vertical mixing. The increase of the backscatter coefficient towards the surface was high. Above sea ice with few refrozen leads, the stably stratified boundary layer extended up to 200–300 m altitude. It was characterized by low specific humidity and a smaller increase of the backscatter coefficient towards the surface.
Databáze: OpenAIRE