HR: 09:45h
AN: PP51G-08    [Abstracts]
TI: Solar Forcing of Southern Hemisphere Climate Change During the Maunder Minimum
AU: * Cullather, R I
EM: cullat@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory at Columbia University, 61 Route 9w, Palisades, NY 10964 United States
AU: Shindell, D T
EM: dshindell@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 United States
AB: The Little Ice Age (LIA) is a term used to describe a period of glacier advance over the approximate time period 1450 until 1890. In many regions the maximum advance coincided with a decrease in solar activity known as the Maunder Minimum. Recent literature has emphasized the regional character of the LIA as seen in proxy records and modeling studies. From the analysis of multiproxy records, it has become clear that the LIA was manifest as a complex spatial and temporal pattern in the Northern Hemisphere. Analysis of the Southern Hemisphere is limited by the small amount of terrestrial surface from which proxy records may be retrieved. Given the strongly zonal circulation and the predominantly zonal character of variability found in the recent instrumental record, one may speculate that the patterns may be more uniform and widespread in the Southern Hemisphere. In this study climate model simulations of the Maunder Minimum are investigated for the purpose of advancing the understanding of LIA patterns in the Southern Hemisphere. Similarities and differences of the climate response to reduced solar irradiance in the Southern Hemisphere as compared to the Northern Hemisphere are examined. The Goddard Institute for Space Studies general circulation model (GISS GCM) includes a detailed representation of the stratosphere and a mixed-layer ocean model. The model has been run to equilibrium for spectrally discriminated irradiances in 1680 and 1780. This experiment has now also been conducted with the state-of-the-art GISS ModelE coupled to both a thermodynamic "slab" ocean simulation and to the fully dynamic HYCOM ocean model. Comparisons of the local model response at proxy data locations in the Southern Hemisphere are assessed. Some questions to be answered by this study are as follows: Evaluated against proxy data, how well does the model simulate the regional response of the irradiance forcing in the Southern Hemisphere, as compared with the Northern Hemisphere? What are the spatial and temporal patterns of response? What is the influence of solar output on modes of variability in the Southern Hemisphere? What is the role of the dynamic ocean in producing the spatial and temporal patterns of response?
DE: 1650 Solar variability (7537)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3337 Global climate models (1626, 4928)
DE: 3344 Paleoclimatology (0473, 4900)
DE: 9310 Antarctica (4207)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005