Measurements of NOx emissions from the Antarctic snowpack
It has been shown that NOx is produced photochemically within the snowpack of polar regions. If emitted to the atmosphere, this process could be a major source of NOx in remote snowcovered regions. We report here on measurements made at the German Antarctic station, Neumayer, during austral summer 1999, aimed at detecting and quantifying emissions of NOx from the surface snow. Gradients of NOx measured, and fluxes calculated using local meteorology measurements. On the 2 days of flux measurements, the derived fluxes showed continual release from the snow surface, varying between ∼0 and 3 × 108 molecs/cm²/s. When not subject to turbulence, the variation was coincident with the uv diurnal cycle, suggesting rapid release once photochemically produced. Scaling the diurnal average of Feb. 7th (1.3 × 108 molecs/cm²/s) suggests an annual emission over Antarctica of the order 0.0076TgN.
Authors: Jones, A.E., Weller, R., Anderson, P.S., Jacobi, H.-W., Wolff, E.W., Schrems, O., Miller, H.