The measurements onboard the Polarstern have been performed using the mobile Bruker IFS 120 M interferometer. The instrument is installed in a thermostated container, mounted on the observation deck of the ship, 20 m above see level. Most trace gases could be detected during the ship cruises. For a few compounds the interfering water, caused by the high humidity, prevented the detection of the molecules (e.g. NO).
- measure the interhemispheric differences of tropospheric and stratospheric trace gases which helps to study (i) inter
hemispheric transport time scales, (ii) anthropogenic emissions strengths and (iii) atmospheric lifetimes of the trace gases. For the troposphere it is of interest to study the impact of the biomass burning compared to the anthropogenic emissions in the northern hemisphere. In the stratosphere an investigation of the meridional circulation, like the subtropical transport barrier or the polar vortex in the stratosphere are of interest. - to validate satellite sensors by the ground based observations. The cruise observations allow to obtain data in remote areas not covered by other measurements. The use of one instrument for a validation over a braod latitudinal range eliminates possible instrumental effects.
- to study the oxidation capacity (OH concentrations) in the free troposphere. The knowledge of the total tropospheric columns of several trace gases together with model simulations allow to calculate the OH concentrations.
- to create data sets to be used in model simulations. Our knowledge on the atmospheric chemistry and physics needs to be tested by comparing measured data sets with simulated ones.
