Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron
Total-dissolvable iron has been measured in sections of three ice cores from Law Dome, East Antarctica, and the results used to calculate atmospheric iron deposition over this region during the late Holocene and to provide a preliminary est. of aerosol iron deposition during the Last Glacial Maximum...
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ftolddominionuni:oai:digitalcommons.odu.edu:oeas_fac_pubs-1112 2023-06-11T04:07:05+02:00 Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron Edwards, R. Sedwick, Peter N. Morgan, Vin Boutron, C. F. Hong, S. 1998-01-01T08:00:00Z application/pdf https://digitalcommons.odu.edu/oeas_fac_pubs/84 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1112/viewcontent/sedwick_Ironinice.pdf unknown ODU Digital Commons https://digitalcommons.odu.edu/oeas_fac_pubs/84 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1112/viewcontent/sedwick_Ironinice.pdf OES Faculty Publications Aerosol Iron influx Iron deposition Ice core Antarctica Biochemistry Biogeochemistry Oceanography Oceanography and Atmospheric Sciences and Meteorology article 1998 ftolddominionuni 2023-05-08T17:59:38Z Total-dissolvable iron has been measured in sections of three ice cores from Law Dome, East Antarctica, and the results used to calculate atmospheric iron deposition over this region during the late Holocene and to provide a preliminary est. of aerosol iron deposition during the Last Glacial Maximum (LGM). Ice-core sections dating from 56-2730 BP (late Holocene) and ∼18 000 BP (LGM) were decontaminated using trace-metal clean techniques, and total-dissolvable iron was determined in the acidified meltwaters by flow-injection analysis. Our results suggest that the atmospheric iron flux onto the Law Dome region has varied significantly over time-scales ranging from seasonal to glacial-interglacial. The iron concentrations in ice-core sections from the past century suggest (1) a 2-4-fold variation in the atmospheric iron flux over a single annual cycle, with the highest flux occurring during the spring and summer, and (2) a nearly 7-fold variation in the annual maximum atmospheric iron flux over a 14 yr period. The average estimated atmospheric iron flux calculated from our late-Holocene samples is 0.056-0.14 mg m-2 a-1, which agrees well with Holocene flux estimates derived from aluminum measurements in inland Antarctic ice cores and a recent order-of-magnitude estimate of present-day atmospheric iron deposition over the Southern Ocean. The iron concentration of an ice-core section dating from the LGM was more than 50 times higher than in the late-Holocene ice samples. Using a snow-accumulation rate est. of 130 kg m-2 a-1 for this period, we calculate 0.87 mg m-2 a-1 as a preliminary estimate of atmospheric iron deposition during the LGM, which is 6-16 times greater than our average Late-Holocene iron flux. Our data are consistent with the suggestion that there was a significantly greater flux of atmospheric iron onto the Southern Ocean during the LGM than during the Holocene. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica ice core Southern Ocean Old Dominion University: ODU Digital Commons Antarctic Southern Ocean East Antarctica Law Dome ENVELOPE(112.833,112.833,-66.733,-66.733) |
institution |
Open Polar |
collection |
Old Dominion University: ODU Digital Commons |
op_collection_id |
ftolddominionuni |
language |
unknown |
topic |
Aerosol Iron influx Iron deposition Ice core Antarctica Biochemistry Biogeochemistry Oceanography Oceanography and Atmospheric Sciences and Meteorology |
spellingShingle |
Aerosol Iron influx Iron deposition Ice core Antarctica Biochemistry Biogeochemistry Oceanography Oceanography and Atmospheric Sciences and Meteorology Edwards, R. Sedwick, Peter N. Morgan, Vin Boutron, C. F. Hong, S. Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron |
topic_facet |
Aerosol Iron influx Iron deposition Ice core Antarctica Biochemistry Biogeochemistry Oceanography Oceanography and Atmospheric Sciences and Meteorology |
description |
Total-dissolvable iron has been measured in sections of three ice cores from Law Dome, East Antarctica, and the results used to calculate atmospheric iron deposition over this region during the late Holocene and to provide a preliminary est. of aerosol iron deposition during the Last Glacial Maximum (LGM). Ice-core sections dating from 56-2730 BP (late Holocene) and ∼18 000 BP (LGM) were decontaminated using trace-metal clean techniques, and total-dissolvable iron was determined in the acidified meltwaters by flow-injection analysis. Our results suggest that the atmospheric iron flux onto the Law Dome region has varied significantly over time-scales ranging from seasonal to glacial-interglacial. The iron concentrations in ice-core sections from the past century suggest (1) a 2-4-fold variation in the atmospheric iron flux over a single annual cycle, with the highest flux occurring during the spring and summer, and (2) a nearly 7-fold variation in the annual maximum atmospheric iron flux over a 14 yr period. The average estimated atmospheric iron flux calculated from our late-Holocene samples is 0.056-0.14 mg m-2 a-1, which agrees well with Holocene flux estimates derived from aluminum measurements in inland Antarctic ice cores and a recent order-of-magnitude estimate of present-day atmospheric iron deposition over the Southern Ocean. The iron concentration of an ice-core section dating from the LGM was more than 50 times higher than in the late-Holocene ice samples. Using a snow-accumulation rate est. of 130 kg m-2 a-1 for this period, we calculate 0.87 mg m-2 a-1 as a preliminary estimate of atmospheric iron deposition during the LGM, which is 6-16 times greater than our average Late-Holocene iron flux. Our data are consistent with the suggestion that there was a significantly greater flux of atmospheric iron onto the Southern Ocean during the LGM than during the Holocene. |
format |
Article in Journal/Newspaper |
author |
Edwards, R. Sedwick, Peter N. Morgan, Vin Boutron, C. F. Hong, S. |
author_facet |
Edwards, R. Sedwick, Peter N. Morgan, Vin Boutron, C. F. Hong, S. |
author_sort |
Edwards, R. |
title |
Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron |
title_short |
Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron |
title_full |
Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron |
title_fullStr |
Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron |
title_full_unstemmed |
Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron |
title_sort |
iron in ice cores from law dome, east antarctica: implications for past deposition of aerosol iron |
publisher |
ODU Digital Commons |
publishDate |
1998 |
url |
https://digitalcommons.odu.edu/oeas_fac_pubs/84 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1112/viewcontent/sedwick_Ironinice.pdf |
long_lat |
ENVELOPE(112.833,112.833,-66.733,-66.733) |
geographic |
Antarctic Southern Ocean East Antarctica Law Dome |
geographic_facet |
Antarctic Southern Ocean East Antarctica Law Dome |
genre |
Antarc* Antarctic Antarctica East Antarctica ice core Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica ice core Southern Ocean |
op_source |
OES Faculty Publications |
op_relation |
https://digitalcommons.odu.edu/oeas_fac_pubs/84 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1112/viewcontent/sedwick_Ironinice.pdf |
_version_ |
1768379679062884352 |