Dust storm in Asia continent and its bio-environmental effects in the North Pacific： A case study of the strongest dust event in April, 2001 in central Asia

The iron hypothesis, first proposed by John Martin in 19901], suggests that some surface oceans such as North and Equatorial Pacific Oceans have high nutrient but low chlorophyll (HNLC). Thus iron coming from terrestrial dusts is the primary factor limit…

Dust storm in Asia continent and its bio-environmental effects in the North Pacific: A case study of the strongest dust event in April, 2001 in central Asia

Testing the effects of iron fertilization in booming metabolism of microbes in North Pacific Ocean has become an important hot topic in current global climate change study. The first supportive evidence with natural iron inputs to ocean was obtained by Bishop and his colleagues at the PAPA region in North Pacific Ocean. They found a rapid increase of marine phytoplankton over North Pacific Ocean after a strong dust storm in April 2001. We demonstrate that the dust deposition flux during this dust storm period decreases exponentially with increasing distance from the dust source regions along the dust transport pathway, through integration of synoptic dynamics, changes of TOMS-Al (aerosol index) and surface PM10 values along the dust pathway and changes of particulate organic carbon and chlorophyll in surface oceans. This strong dust storm may result in deposition of about 3.1–5.8 μg/m³ eolian iron into the PAPA region in North Pacific Ocean, thus causing a rapid increase of marine phytoplankton productivity observed by Bishop and his colleagues. This work supplies more direct and detailed evidence, from continental dust process, to support the iron hypothesis with natural iron inputs to the surface oceans through dust storms.