Climate Change 2001:
Working Group I: The Scientific Basis
  Other reports in this collection


Figure 8.14: Annual mean tropical cooling at the last glacial maximum: comparison between model results and palaeo-data. (Centre panel) simulated surface air temperature changes over land are displayed as a function of surface temperature changes over the oceans, both averaged in the 30°S to 30°N latitudinal band, for all the PMIP simulations: models with prescribed CLIMAP SSTs (circles) and coupled atmosphere-mixed layer ocean models (squares) (from Pinot et al., 1999). Numbers refer to different models: circles, 1: LMD4, 2-5: MRI2, ECHAM3, UGAMP, LMD5 (higher resolution), 6-7: CCSR/NIES1, LMD5, 8: GEN2. Squares : 1: LMD4,2: UGAMP, 3: GEN2, 4: GFDL, 5: HADAM2, 6: MRI2, 7: CCM1, 8: CCC2 (names refer to Tables 8.1 and 8.5). Results from two EMIC models including a dynamical ocean model have also been displayed (diamonds): 1-UVIC (Weaver et al., 1998), 2-CLIMBER-2 (Petoukhov et al., 2000).
The comparison with palaeo-data: (upper panel) over land is with estimates from various pollen data for altitudes below 1,500m (the label "nb data" refers to the number of data points in three different regions corresponding to the temperature change estimate plotted in the abscissa) from (Farrera, et al., 1999); (right panel) the distribution of SST changes estimated from alkenones in the tropics from the Sea Surface Temperature Evolution Mapping Project based on Alkenone Stratigraphy (TEMPUS) (Rosell-Melé, et al., 1998) (nb data: same as upper panel, number of data points for each temperature change). Caution: in this figure, model results are averaged over the whole tropical domain and not over proxy-data locations, which may bias the comparison (e.g., Broccoli and Marciniak, 1996). For example, for the pollen data, extreme values are obtained for specific regions: weakest values over the Indonesia-Pacific region and coldest values over South America.

Back to text


Table of contents
Other reports in this collection