Airborne Studies of Methane Emissions from Arctic Wetlands (AirMeth)

Polar 5 flying at low level over Arctic permafrost.
Fig.6: Polar5 flying at low lever over Arctic permafrost. (Photo: Alfred-Wegener-Institut)

The atmospheric concentration of methane, a potent greenhouse gas, has a significant maximum in the Arctic.

Estimates of the various sources and sinks of the global budget differ by a factor of 2 to 4 (McGuire et al., 2009), mainly due to the lack of reliable data from the vast remote areas.

Model simulations suggest that wetlands are the largest natural source of uncertainty and are the main contribution to the interannual variablity of the global budget of atmospheric methane (Bousquet et al., 2011).

The airborne campaigns AirMeth aim at contributing to close this knowledge gap by measurements of methane fluxes to the atmosphere from large areas of arctic wetlands.

In 2012 and 2013 flights have been conducted over the Arctic Coastal Plain in the North of Alaska (Fig.1) and over the Mackenzie Delta area in Canada (Fig.2).

A typical flight pattern is shown in Fig. 3. Starting from Barrow, long low level flight legs are flown over the permafrost wetland with ascents and descents interspersed for vertical soundings of the boundary layer structure (Fig. 4).

Fig. 5 shows a situation with an airflow from east to west during which the methane concentration accummulates in the boundary layer.

Permafrost wetland of Arctic Coastal Plain near Barrow, Alaska.
Fig.1: Permafrost wetland of the Arctic Coastal Plain near Barrow (Alaska) (Photo: Alfred-Wegener-Institut)
Northern part of Mackenzie Delta
Fig.2: Northern part of the Mackenzie Delta (Photo: Alfred-Wegener-Institut)
Fig.3: Flight pattern of Polar5 for measurements of methane fluxes in northern Alaska. (Graphic: Alfred-Wegener-Institut)
Fig.4: Vertical profiles of temperature (red) and methane concentration (blue) in the atmospheric boundary layer over Arctic permafrost wetland. (Graphic: Alfred-Wegener-Institut)
Fig.5: Atmospheric concentration of methane (colour coded) and wind vectors in the lower part of the boundary layer. (Graphic: Alfred-Wegener-Institut)

AirMeth is a significant contribution to the research programme PACES II and linked in the network theme Methane in the Arctic.

 

AirMeth is a cooperation with the GFZ-Potsdam.