Variability of Arctic climate and sea ice over the past millennium: implications for ice cap mass balance

Meteorological measurements and NCEP and ERA-40 climate reanalysis data can be used to calculate wind fields and thus back trajectories of air parcels. This essentially involves running climate models in reverse to determine the wind fields resulting from synoptic conditions, and hence the general source of, and path taken by, an air mass that crossed the ice cap. Similarly these datasets can be used to derive regional pressure anomalies from which generalized source areas can be derived. Certain pollutants can also be useful tracers of atmospheric circulation over recent decades (Patris et. al., 2002), and pollen samples from ice chips exhumed during the drilling process can also be used to identify air source regions.

Using these techniques we will be able to identify characteristic chemical compositions from different source areas and, hence, identify shifts between different aerosol source areas under the influence of changing circulation patterns. Snow samples collected from across the PoW icefield will be used to understand the spatial variation in chemical composition under the infleunce ofdifferent air source areas.