Marine aerosol source regions to Prince of Wales Icefield, Ellesmere Island, and influence from the tropical Pacific, 1979–2001

Abstract

AbstractUsing a coastal ice core collected from Prince of Wales (POW) Icefield on Ellesmere Island, we investigate source regions of sea ice‐modulated chemical species (methanesulfonic acid (MSA) and chloride (Cl−)) to POW Icefield and the influence of large‐scale atmospheric variability on the transport of these marine aerosols (1979–2001). Our key findings are (1) MSA in the POW Icefield core is derived primarily from productivity in the sea ice zone of Baffin Bay and the Labrador Sea, with influence from waters within the North Water (NOW) polynya, (2) sea ice formation processes within the NOW polynya may be a significant source of sea‐salt aerosols to the POW core site, in addition to offshore open water source regions primarily in Hudson Bay, and (3) the tropical Pacific influences the source and transport of marine aerosols to POW Icefield through its remote control on regional winds and sea ice variability. Regression analyses during times of MSA deposition reveal sea level pressure (SLP) anomalies favorable for opening of the NOW polynya and subsequent oceanic dimethyl sulfide production. Regression analyses during times of Cl− deposition reveal SLP anomalies that indicate a broader oceanic region of sea‐salt sources to the core site. These results are supported by Scanning Multichannel Microwave Radiometer‐ and Special Sensor Microwave/Imager‐based sea ice reconstructions and air mass transport density analyses and suggest that the marine biogenic record may capture local polynya variability, while sea‐salt transport to the site from larger offshore source regions in Baffin Bay is likely. Regression analyses show a link to tropical dynamics via an atmospheric Rossby wave.