Saturday, February 25, 2012

The Value of Airborne Surveys is Indisputable in Climate Science

A new paper in Eos Transactions of the American Geophysical Union ('Regular Airborne Surveys of Arctic Sea Ice and Atmosphere', Vol. 93, No. 4, 24 January, p. 41) really highlights the importance of aerial and satellite surveys in determining how the ocean, atmosphere and cryosphere are intertwined and especially how they impact global atmospheric and oceanic circulations in the climate cycle.

Of pre-eminent import has been the 'Polar Airborne Measurements and Arctic Regional Climate Model Simulation Project' (PMARCMiP) which featured precise measurements made over April, 2009 and 2011. Measurements were primarily made from the Alfred Wegener Institute's Polar 5 aircraft. Meanwhile, an existing network of Arctic meteorological sites served the logistical requirements of the missions.

The reason for investment of resources for such surveys is well known: The Arctic region is undergoing rapid climatic and environmental change most dramatically manifested in sea ice reduction - extent and thickness. As EOS report notes: "These changes are attributed to anthropogenic effects related to greenhouse warming."

One of the primary findings of the two surveys was that the modal thickness of old ice changed little between 2007 and 2009, but "in 2011 was significantly less". The latter campaign was also highlighted by coordination of observations with the European Space Agency's CryoSat-2 satellite mission. The latter included flyovers of several in situ sea ice "validation" sites. Readers who are interested can learn more here:

In the graphic appended, readers can see the blue (2009) and red (2011) flight tracks of the Polar 5 aircraft as well as an insert image of the plane. Also, pay particular attention to the legend at the lower right for ice concentration and the gradation of levels. This can be used to infer estimates of the sea ice concentration over the region, from Barrow, AK to Longyearbyen.

Based on the 2 successful survey missions, future plans are to include regular April missions over successive years to monitor inter-annual changes at the time of sea ice maximum extent. The ultimate goal is to obtain a better grasp of how the ice surface energy budget varies and in turn affects the distribution of sea ice cover.

Let us sincerely hope no budget cuts are in the offing, because these aerial flyovers are simply too important to place at the whim of the austerity hawks!

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