Atmospheric Investigations on the Russian North Pole Drifting Ice Station NP-35
Arctic Climate change has a large impact on ecosystems and societies on the global scale. The region north of 82 ° is still a blanc spot in the observational network of atmospheric measurements. In the frame of the International Polar Year 2007/2008 (IPY), the section Atmospheric Circulations at the Research Unit Potsdam initiated a research project to fill this gap. The close cooperation with the Arctic and Antarctic Research Institute (AARI), St. Petersburg, made it possible to participate in the 35th Russian North Pole Ice Drifting Station (NP-35) with own experiments.
Track of the drifting ice station NP-35 until April 2008.
A suitable ice floe was chosen based on many years experience, satellite data and local investigations. Once implemented, NP-35 drifted during winter within the ice from its initial position at 81º N und 103º E, north of Severnaya Zemlya in the Arctic ocean (see map). From end of September 2007 to April 2008, the AWI technician Jürgen Graeser participated as only international member of the 21-headed overwintering team on the roughly three by five kilometre large ice floe. During the drifting period, several measurements took place at the station. The Russian colleagues operated the standard meteorological observations on ground and by radiosounding, as well as surface energy fluxes and carbon dioxide measurements. They also focussed on upper ocean observations and sea-ice thickness measurements. Their expertise goes back to 1952 for regular drifting stations in the Arctic ocean
The AWI technician Jürgen Graeser performed tethered balloon measurements and ozone soundings to provide information on different parts of the atmosphere.
One focus aimed at the state and variability of the planetary boundary layer (PBL), and its connection with mesoscale cyclones and storm tracks. During the drift of NP-35, the dynamics and structure of the PBL was detected by tethered balloon measurements. As the analyses focus on the spatial and temporal characterization of the arctic PBL, up to 6 tethersondes were mounted along the tether, measuring a meteorological profile over several hours. Data interpretation is supported by model simulations with the regional climate model HIRHAM. Mesoscale pressure, temperature, and wind fields are generated to identify cyclones and storm tracks. Special emphasis is put on the connection of cyclogenesis and different surface conditions (e.g. sea ice cover).
The ozone soundings were the first systematic ozone sonde measurements in the central Arctic. They allow the study of dynamical processes and ozone transport processes during the formation of the Arctic polar vortex, and contribute to the quantification of chemical ozone loss in the Arctic stratosphere. The NP-35 ozone soundings are part of a so-called Match campaign that allows distinguishing chemical ozone loss from dynamical changes and to precisely quantify chemical ozone loss rates. So far, the region north of 82° N, the central Arctic a key region for the variability of Arctic ozone is a blank spot in the observational network. The observations of NP-35 have closed this essential gap in the vertically highly resolved global maps of the ozone layer.
Jürgen Graeser launching an ozone sonde on a helium-filled (white) balloon, with the red tethered balloon in stand-by position.
