Speaker: Dr. David Lund (University of Connecticut - Avery Point)
Abstract:
The deep Pacific Ocean is the largest reservoir of readily exchangeable carbon on Earth. Reconstructions of deep Pacific ventilation rate are therefore key to understanding the ocean's role in glacial-interglacial CO2 cycles. High resolution radiocarbon data spanning 5 to 25 kyr BP will be presented and different ventilation age methods will be discussed...
Graduate student Marena Lin will lead the discussion of Foster and Rahmstorf (2011), summarized below:
"Following the work of Lean and Rind (2008), Foster and Rahmstorf (2011) use lagged multiple linear regression to determine the influences of ENSO, aerosols, and solar variability on variability of global mean temperature from 1979-2010, applying their analysis to 5 different temperature data-sets. They find that, upon adjusting for these...
Earth history is punctuated by a huge variety of transitions and perturbations in climate and global biogeochemical cycling. These may be linked to major extinctions or evolutionary innovations, and may exhibit evidence for greenhouse warming and CO2 release and hence potentially hold direct future-relevant information. However, in...
Millennial-scale variability associated with Dansgaard Oeschger (DO) and Heinrich events (HE) is one of the most puzzling glacial climate features found in...
Please join us for our weekly ClimaTea seminar. Graduate student, Lauren Kuntz, will lead a discussion of a recent paper by Carslaw et al. (2013), summarized below:
"Carslaw et al. investigate the main sources of uncertainty in indirect aerosol radiative forcing over the industrial period. A variance-based sensitivity analysis is conducted on a global...
Observations of δ13C and Cd/Ca from benthic foraminifera have been interpreted to reflect a shoaling of northern source waters by about 1000 m during the Last Glacial Maximum, with the degree of shoaling being significant enough for the water mass to be renamed Glacial North Atlantic Intermediate Water. These nutrient tracers, however, may not solely...
"The distribution of tropical precipitation and the atmospheric heat transport in the deep tropics are both primarily controlled by the strength and location of the Hadley cell with the atmosphere transporting heat away from the precipitation maximum. We...
"In the present climate, the ocean below 2~km is mainly filled by waters sinking into the abyss around Antarctica and in the North Atlantic. Paleo proxies indicate that waters of North Atlantic origin were instead absent below 2~km at the Last Glacial Maximum (LGM), resulting in an expansion of the volume occupied by Antarctic origin waters. In my presentation I will...
"The Northern Hemisphere exhibits an abrupt regime transition between winter in summer involving the organization of the flow into subtropical anticyclones and monsoons. The transition provides a useful example of how moisture and momentum transports by planetary-scale waves are coordinated to dominate the large-scale circulation. The mechanisms of the abrupt transition are explored in idealized aquaplanet...