The GISP2, central Greealand, glaciochemical series (sodium, potassium, ammonium,calcium, magnesium, sulfate, nitrate and chloride) provides a unique view of the chemistry of the atmosphere and the history of atmosphe...The GISP2, central Greealand, glaciochemical series (sodium, potassium, ammonium,calcium, magnesium, sulfate, nitrate and chloride) provides a unique view of the chemistry of the atmosphere and the history of atmospheric circulation over much of the Northern Hemisphere. Interpretation of this record reveals the controls on both high and low frequency climate events of the last 110 000 years.Changes in insolation on the order of the major orbital cycles control the long-term behavior of atmospheric circulation patterns through changes in ice volume (sea level) and related positive feedbacks.Events such as the Heinrich events (massive discharges of icebergs first identified in the marine record)are found to operate on a 6 100 year cycle due largely to the lagged response of ice sheets to changes in insolation and consequent glacier dynamics Rapid climate change events (massive reorganizations of atmospheric circulation) are demonstrated to operate on 1 450 year cycle possibly in response to internal oscillations in the ocean-atmosphere system or due to changes in solar output. Changes in insolation and associated positive feedbacks related to ice sheets assist in explaining favorable time periods and controls on the amplitude of these massive rapid climate change events.Comparison of the GISP2 glaciochemical series with an ice record from Taylor Dome in Antarctica indicates considerable similarity suggesting that both polar regions experience marked changes in climate. While preliminary evidence points to similar phasing of several major climate events in the two polar regions exact phasing cannot as yet be determined, because dating of Antarctic ice core records is not as well-established as the dating for Greenland ice cores.展开更多
This study employed proxy data to investigate the phase relationship between the North Atlantic deep-level temperature and the Qinghai-Tibet Plateau(TP)surface air temperature(TP temperature)and its evolution at the m...This study employed proxy data to investigate the phase relationship between the North Atlantic deep-level temperature and the Qinghai-Tibet Plateau(TP)surface air temperature(TP temperature)and its evolution at the millennial scale since the Last Interglaciation.The results indicate the alternation of in-phase and anti-phase relationships since the Last Interglaciation,with the in-phase relationships showing a shorter duration than the anti-phase relationships.Alternations between the in-phase and antiphase relationships occurred more frequently during the Last Interglaciation than during the Last Glaciation.The phase relationship between the North Atlantic deep-level temperature and the TP temperature was broadly illustrated by that between the North Atlantic temperature(based on oxygen isotope data from the Greenland ice core)and TP temperature.Furthermore,the North Atlantic deep-level temperature and the TP temperature may be connected through the North Atlantic sea surface temperature.展开更多
文摘The GISP2, central Greealand, glaciochemical series (sodium, potassium, ammonium,calcium, magnesium, sulfate, nitrate and chloride) provides a unique view of the chemistry of the atmosphere and the history of atmospheric circulation over much of the Northern Hemisphere. Interpretation of this record reveals the controls on both high and low frequency climate events of the last 110 000 years.Changes in insolation on the order of the major orbital cycles control the long-term behavior of atmospheric circulation patterns through changes in ice volume (sea level) and related positive feedbacks.Events such as the Heinrich events (massive discharges of icebergs first identified in the marine record)are found to operate on a 6 100 year cycle due largely to the lagged response of ice sheets to changes in insolation and consequent glacier dynamics Rapid climate change events (massive reorganizations of atmospheric circulation) are demonstrated to operate on 1 450 year cycle possibly in response to internal oscillations in the ocean-atmosphere system or due to changes in solar output. Changes in insolation and associated positive feedbacks related to ice sheets assist in explaining favorable time periods and controls on the amplitude of these massive rapid climate change events.Comparison of the GISP2 glaciochemical series with an ice record from Taylor Dome in Antarctica indicates considerable similarity suggesting that both polar regions experience marked changes in climate. While preliminary evidence points to similar phasing of several major climate events in the two polar regions exact phasing cannot as yet be determined, because dating of Antarctic ice core records is not as well-established as the dating for Greenland ice cores.
基金supported by the Special Foundation for the National Science and Technology Major Project of China(2011FY120300)the National Natural Science Foundation of China(41001058)
文摘This study employed proxy data to investigate the phase relationship between the North Atlantic deep-level temperature and the Qinghai-Tibet Plateau(TP)surface air temperature(TP temperature)and its evolution at the millennial scale since the Last Interglaciation.The results indicate the alternation of in-phase and anti-phase relationships since the Last Interglaciation,with the in-phase relationships showing a shorter duration than the anti-phase relationships.Alternations between the in-phase and antiphase relationships occurred more frequently during the Last Interglaciation than during the Last Glaciation.The phase relationship between the North Atlantic deep-level temperature and the TP temperature was broadly illustrated by that between the North Atlantic temperature(based on oxygen isotope data from the Greenland ice core)and TP temperature.Furthermore,the North Atlantic deep-level temperature and the TP temperature may be connected through the North Atlantic sea surface temperature.
