Characteristics of intermittent turbulence in the upper stable boundary layer over Greenland

• Main Authors: Clemens Drüe (druee(at)muk. Uni-hannover. De, Günther Heinemann (heinemann(at)uni-trier. De
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2006
• Subjects: intermittent turbulence; stable boundary layer; Greenland summit; aircraft; Greenland; Summit Camp
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.454.2114; http://www2.meteo.uni-bonn.de/staff/alte_seiten/GHeinemann/pub/repints/polar/Druee_Heinemann_iglos_blm2007.pdf

land inland ice. The German research aircraft Polar2, equipped with the turbulence measurment system Meteopod, was used to investigate turbulence and radiation flux profiles near research station “Summit Camp”. Aircraft measurements are com-bined with measurements of radiation fluxes and turbulent quantities made by a 50m tower at Summit Camp operated by Eidgenössische Technische Hochschule (ETH) Zürich. During all six flight missions, well-developed stable boundary layers were found. Even in high-wind conditions, the surface inversion thickness did not exceed roughly 100 m. The turbulent height of the SBL was found to be much smaller than the surface inversion thickness. Above 3m height, significant turbulent fluxes occurred only intermittently in intervals on the order of a few kilometres. Turbulent event fraction in the upper SBL shows the same dependence on gradient Richardson number as reported for near-surface measurements. Clear-air longwave radiation divergence was always found to contribute significantly to the SBL heat budget. In low-wind cases, radiative cooling even turned out to be dominant.