Current status of atmospheric studies at Summit (Greenland) and implications for future research
Résumé
The present paper is an overview of the some of the basic questions raised by the recent experiments in Greenland, in the field of air-snow transfer of gases and particles. After an introduction that indicates the frame of the ATM programme, we successively present results of studies concerning the transport of chemical species from source regions to the atmosphere of the Greenland Ice Sheet, their deposition processes, and the post deposition effects that can modify the chemical signal recorded in the snow layers. It shows that a comprehensive approach of all of these questions calls for complementary investigations in research areas covering several scales of space and time, from large scale meteorology to microscale physics. In many cases, the field studies performed during DGASP and ATM increased significantly our knowledge of the processes involved in the transfer of chemical species from source regions to the deep ice, and allowed the determination of the most important parameters controlling these processes. But many areas are still poorly understood, that we try to point out.