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Iron in East Antarctic snow: Implications for atmospheric iron deposition and algal production in Antarctic waters
Author(s) -
Edwards Ross,
Sedwick Peter
Publication year - 2001
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl012867
Subject(s) - snow , deposition (geology) , bay , oceanography , environmental science , mineral dust , aerosol , sea spray , atmosphere (unit) , firn , atmospheric sciences , geology , sediment , meteorology , geography , geomorphology
To evaluate the deposition and solubility of aerosol iron in the Antarctic seasonal sea ice zone (SSIZ), iron was measured in snow samples collected from three areas in the SSIZ (Prydz Bay, Dumont d'Urville Sea and Ross Sea) and one continental area (Princess Elizabeth Land) of East Antarctica. Concentrations of total‐dissolvable iron (that soluble at pH ∼2) ranged from 20–2950 pg g −1 , with the lowest concentrations measured in snow from the Dumont d'Urville Sea. Using estimates of snow accumulation rates, we calculate atmospheric iron deposition fluxes of 0.017–0.11 mg m −2 yr −1 (0.30–2.0 µmol m −2 yr −1 ), which are generally lower than previously published estimates. Measurements of iron in filtered meltwaters of snow samples from Prydz Bay and Princess Elizabeth Land suggest that ∼10–90% of the total atmospheric iron is readily soluble. Assuming our results to be broadly representative of atmospheric deposition over seasonally ice‐covered, high‐nutrient Antarctic waters, we use our mean estimates of atmospheric iron deposition (1.1 µmol m −2 yr −1 ) and solubility (32%) to calculate that atmospheric iron potentially supports annual phytoplankton production of 1.1 × 10 12 mole C in the Antarctic SSIZ, which is less than 5% of the estimated total annual primary production in this ocean region.