Investigation of Katabatic winds and Polynyas during Summer - IKAPOS : field phase report

• Main Authors: Heinemann, Günther, Ernsdorf, Thomas, Drüe, Clemens
• Format: Report
• Language: English
• Published: 2011
• Subjects: Arctic; Greenland; Nares; Smith Sound; Qaanaaq; Alfred Wegener Institute; Berichte zur Polar- und Meeresforschung; glacier; Ice Sheet; Nares strait; Sea ice; Smith sound
• Online Access: https://oceanrep.geomar.de/id/eprint/26209/; https://oceanrep.geomar.de/id/eprint/26209/1/Hei2011c_BPMf_633.pdf; http://epic.awi.de/29945/1/Hei2011c.pdf

Processes of the exchange of energy and momentum at the sea-ice/ocean/atmosphere interface are key processes for the polar climate system. The experiment IKAPOS (Investigation of Katabatic winds and Polynyas during Summer) was performed in June 2010. The investigations comprised studies of the summertime katabatic wind system in the coastal area of north and northwest Greenland, and of atmosphere/sea-ice/ocean exchange processes over the North Water Polynya (NOW). The main tool of the experimental study was the polar aircraft POLAR 5 of the Alfred Wegener Institute (AWI), which was based at Qaanaaq (Northwest Greenland). The aircraft was instrumented with turbulence sensors, basic meteorological equipment, radiation and surface temperature sensors, laser altimeters, and video and digital cameras. A total of six research flights have been performed, two of them were katabatic wind flights (over the Humboldt and Steenstrup glacier, respectively). Katabatic wind flights capture conditions of weak and strong synoptically forced katabatic wind. During the NOW flights a fully turbulent stable boundary layer with strong winds of 15 to 20 m s-1 was measured, and channeling effects caused by Smith Sound and Nares Strait were documented. The data of IKAPOS are valuable for the validation of numerical models (including climate models) and will contribute to the understanding of the exchange processes over summertime Arctic polynyas and the Greenland ice sheet.