How ice age climate got the shakes
Records in Greenland ice, ocean mud, and ancient corals are revealing abrupt climate shifts during the last ice age. The climate at the end of the last ice age apparently jumped from cold to warmer conditions, jumped back to cold, and then jumped into the present warm weather conditions. The mechanism for this erratic behavior is unknown, but appears to be an interaction of North Atlantic ocean currents and the ice sheets themselves. Warm water from the tropics would evaporate and become more saline and dense as it moved north. The colder, denser water would then sink and flow back to the tropics. The melting of ice caused by the warm water would decrease the salinity of the North Atlantic current, the water would not sink, the return current would be shut down, and the waters surrounding the ice sheets would become colder, slowing melting of the sheets. The cycle could be started again by collapse of the ice sheets from their internal heat. There may be other switches that could cause sudden climate change, as may be evidenced by links between changes in the Pacific and a decade of erratic weather in North America. Researcher would like to identify these switches to prevent them from being activated by human activity.
- OSTI ID:
- 6338793
- Journal Information:
- Science (Washington, D.C.); (United States), Vol. 260:5110; ISSN 0036-8075
- Country of Publication:
- United States
- Language:
- English
Similar Records
High-resolution climate simulation of the last glacial maximum
Evolution of the deep Atlantic water masses since the last glacial maximum based on a transient run of NCAR-CCSM3
Related Subjects
ATLANTIC OCEAN
CURRENTS
CLIMATIC CHANGE
PALEOCLIMATOLOGY
ICE CAPS
MELTING
CORALS
GREENLAND
ICEBERGS
LITTLE ICE AGE
SEDIMENTS
ANIMALS
CNIDARIA
COELENTERATA
ICE
INVERTEBRATES
PALEONTOLOGY
PHASE TRANSFORMATIONS
SEAS
SURFACE WATERS
540110*
540310 - Environment
Aquatic- Basic Studies- (1990-)