BIPOMAC
Short Title: BIPOMAC Project URL: http://www.polarjahr.de/BIPOMAC.100+M52087573ab0.0.html Proposal URL: http://classic.ipy.org/development/eoi/proposal-details.php?id=130 Paleoclimatic research indicates that processes and conditions in polar regions play a large role in driving and amplifying global climate variability at centennial to millenial time scales. The outstanding role of polar regions in the global climate system is currently evidenced by the distinct warming of polar regions (e.g. Arctic realm, Antarctic Peninsula) that exceed modern warming on a global scale. Polar processes and conditions include biological cycling and physical circulation in the polar oceans, the formation and distribution of sea ice, the behavior of permafrost areas, atmospheric circulation and transport of water vapor, and the volume and stability of continental ice. Polar and subpolar High-Nutrient-Low-Chlorophyll (HNLC) areas may act as CO2 sinks during glacial periods when the increased input of the micronutrient, iron, stimulates primary production. The extent and the seasonal variability of sea ice influences the Earth's albedo, water mass production, heat and gas exchange between the ocean and atmosphere, and biological productivity. Melt water pulses, which alter surface ocean density gradients, may induce rapid climate change. The impact of such environmental events in the Arctic Ocean, North Atlantic, and Southern Ocean may propagate globally via ocean circulation, through the operation of the "bipolar seesaw". New data suggest a less stable Antarctic ice volume than generally presumed, even during cold periods, and shed new light on the vulnerability of the Antarctic ice sheets and their effect on global ocean circulation and sea level change. What is needed now is determined investigation of these diverse processes so a sophisticated picture of the power of polar regions to drive climate change can be assembled. The international and multidisciplinary effort within the proposed BIPOMAC network will generate the coordinated, broad-ranging influx of knowledge necessary to clarify the intertwined roles of bipolar ice, ocean, and atmospheric processes in climate evolution and sea level change at different operational modes of the bipolar climate machinery. This wave of knowledge will come from carefully selected marine and terrestrial records covering the Pliocene to Holocene from both polar regions. This will also include records from areas that have to date been sparsely investigated, if at all (central Arctic Ocean, Arctic Pacific, NE Siberia, Antarctic Pacific, Antarctic ice shelf). The better understanding of the polar systems will substantially increase our ability to forecast future climate and sea level change, and help us focus our responses to the environmental challenges that we will be facing. The BIPOMAC network combines: (1) Process studies to clarify mechanisms of polar sediment deposition and alteration and quantify the impacts on paleoenvironmental proxies. These studies include that of polar land to ocean sediment transfer, sediment and particle fluxes in the polar seas and lakes, and the paleoecological implications of an experiment in the Scotia Sea to test iron addition as a means for CO2 sequestration. (2) Paleoenvironmental reconstruction based on well-dated northern and southern polar paleoceanographic, paleolimnological, terrestrial fossil, and continental ice volume/extent records. Study intervals and areas include: (a) warmer-than-present Pliocene and Pleistocene intervals from the Canadian Arctic (Beaver Pond, Bylot Island), the Atlantic, Indian and Pacific sectors of the Southern Ocean and expected from NE Siberia (El' gygytgyn) and Antarctic near-shore drillsites (ANDRILL); (b) Pleistocene glacial/interglacial cycles from shelf/coastal lowland permafrost and lake deposits of NE Siberia (e.g. Lake El´gygytgyn), North Greenland terrestrial records and from Patagonian/South American lake sediments; and marine deposits from the continental margin and deep Arctic Ocean, the Arctic and Subarctic Pacific, Bering Sea and Sea of Okhotsk, North Atlantic, the Indian, Atlantic (Scotia Sea) and Pacific sectors of the Southern Ocean including near-shore studies in the areas of Prydz Bay, the Antarctic Peninsula and the Ross Sea (e.g. McMurdo Sound); (c) the Late Glacial and Holocene documented in terrestrial, permafrost and/or lake deposits from a large variety of locations in the Canadian and Russian Arctic, NE Siberia and Kamtchatka, on Svalbard, Southern Ocean islands and in Antarctic coastal areas (e.g. Prydz Bay) together with marine deposits from the Arctic continental shelf and margin, the Arctic Pacific, Bering Sea and Sea of Okchotsk, the Indian, Atlantic (Scotia Sea) and Pacific sectors of the Southern Ocean. (3) Numerical modeling of ice-atmosphere-ocean processes to decipher the complex pathway and timing of climate development, its internal amplification and propagation mechanisms (ice/ocean/atmosphere), and the effect of external forcing (insolation/solar activity). The BIPOMAC network also includes projects for the development of innovative methods for the enhancement of paleoenvironmental reconstructions based on diatom biomarkers and stable isotopes of biogenic opal and associated organic matter, and the increase in the accuracy of dating with the radiocarbon method in polar, low-carbonate sediments.
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