Open AccessBeryllium‐10 transport to Antarctica: Results from seasonally resolved observations and modeling
Author(s) -
Pedro J. B.,
Heikkilä U. E.,
Klekociuk A.,
Smith A. M.,
Ommen T. D.,
Curran M. A. J.
Publication year - 2011
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011jd016530
Subject(s) - stratosphere , ice core , troposphere , atmospheric sciences , climatology , environmental science , middle latitudes , polar night , cryosphere , geology , sea ice
Cosmogenic 10 Be measured in polar ice cores has important application in the reconstruction of past solar activity. However, the processes controlling its atmospheric transport and deposition to the ice sheets are not fully understood. Here we use the seasonal changes in 10 Be concentrations in a 10 year monthly resolved ice core record from the Law Dome site (East Antarctica) in conjunction with ECHAM5‐HAM general circulation model (GCM) simulations of 10 Be and 7 Be deposition as tools to examine this problem. Maximum 10 Be concentrations are observed in the ice core during the austral late summer to early autumn (summer‐autumn), while minimum concentrations are observed during the austral winter. The GCM simulations, corroborated by earlier observations of 10 Be: 7 Be ratios in Antarctica from the Georg von Neumayer air sampling station, suggest that the 10 Be concentration maximum is linked to direct input of stratospheric 10 Be from the Antarctic stratosphere to the lower levels of the Antarctic troposphere during the austral summer‐autumn. This result contrasts with the modeled transport of 10 Be to Greenland, where the seasonal maximum in stratospheric input is seen in the late winter to spring, synchronous with the timing of the seasonal maximum in midlatitude stratosphere to troposphere exchange. Our results suggest that a different combination of processes is responsible for the transport of 10 Be to the Antarctic and Greenland ice sheets.