How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic


Holocene Climatic Oscillations of the USA's Mid-Atlantic Region
Reference
Li, Y.-X., Yu, Z. and Kodama, K.P. 2007. Sensitive moisture response to Holocene millennial-scale climate variations in the Mid-Atlantic region, USA. The Holocene 17: 3-8.

What was done
The authors developed a lake-level record based on lithologic and mineral magnetic data from the Holocene sediments of White Lake, New Jersey, northeastern USA (41N, 74.8W), the characteristics of which they compared with a host of other paleoclimatic reconstructions from this region and beyond.

What was learned
Li et al.'s lake-level history reveals low lake levels at ~1.3, 3.0, 4.4 and 6.1 thousand years before present; and they say that comparison of their results with drift-ice records from the North Atlantic Ocean "indicates a striking [our italics] correspondence," as they "correlate well with cold events 1, 2, 3 and 4 of Bond et al. (2001)." They also report that a comparison of their results with those of other land-based studies suggests "a temporally coherent pattern of climate variations at a quasi-1500-year periodicity at least in the Mid-Atlantic region, if not the entire northeastern USA." In addition, and with respect to the other node of the climatic cycle, they note that "the Mid-Atlantic region was dominated by wet conditions, while most parts of the conterminous USA experienced droughts, when the North Atlantic Ocean was warm."

What it means
In discussing their findings, the three researchers say the dry-cold correlation they found "resembles the modern observed relationship between moisture conditions in eastern North America and the North Atlantic Oscillation (NAO), but operates at millennial timescales, possibly through modulation of atmospheric dynamics by solar forcing," and in this regard they write that the sun-climate link on millennial timescales has "been demonstrated in several records (eg, Bond et al., 2001; Hu et al., 2003; Niggemann et al., 2003), supporting solar forcing as a plausible mechanism for modulating the AO [Arctic Oscillation]/NAO at millennial timescales."

References
Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M.N., Showers, W., Hoffmann, S., Lotti-Bond, R., Hajdas, I. and Bonani, G. 2001. Persistent solar influence on North Atlantic climate during the Holocene. Science 294: 2130-2136.

Hu, F.S., Kaufman, D., Yoneji, S., Nelson, D., Shemesh, A., Huang, Y., Tian, J., Bond, G., Clegg, B. and Brown, T. 2003. Cyclic variation and solar forcing of Holocene climate in the Alaskan subarctic. Science 301: 1890-1893.

Niggemann, S., Mangini, A., Mudelsee, M., Richter, D.K., and Wurth, G. 2003. Sub-Milankovitch climatic cycles in Holocene stalagmites from Sauerland, Germany. Earth and Planetary Science Letters 216: 539-547.

Reviewed 21 November 2007