Constraining oceanic dust deposition using surface

• Main Authors: Qin Han, J. Keith Moore, Charles Zender, Chris Measures, David Hydes
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Pacific; Southern Ocean
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.159.9790; http://dust.ess.uci.edu/ppr/ppr_HMZ08.pdf

[1] We use measurements of ocean surface dissolved Al, a global Biogeochemical Elemental Cycling (BEC) ocean model, and the global Dust Entrainment and Deposition (DEAD) model to constrain dust deposition to the oceans. Our Al database contains all available measurements with best coverage in the Atlantic. Vertical profiles and seasonal data exist in limited regions. Observations show that surface dissolved Al is distributed similarly to the dust deposition predicted by DEAD and other models. There is an equatorial Atlantic Al maximum that decreases toward higher latitudes. There are high Al concentrations in the Mediterranean Sea and the Arabian Sea and low concentrations in the Pacific and the Southern Ocean. The ocean basins maintain more distinct Al profiles than Fe profiles in the upper ocean, consistent with a weaker biological influence on Al than Fe. The BEC-predicted surface dissolved Al compares relatively well with observations. The Al distribution reflects the combined effects of Al input from dust and Al removal by particle scavenging and biological uptake by diatoms. Model-observed biases suggest a southward shift of maximum dust deposition compared to current dust model