Global climate models

Fig. 4-13 Calculated and observed annual wet deposition of sulfur in mgS/m per year. (Reprinted from "Atmospheric Environment," Volume 30, Feichter, J., Kjellstrom, E., Rodhe, H., Dentener, F., Lelieveld, and Roelofs, G.-J., Simulation of the tropospheric sulfur cycle in a global climate model, pp. 1693-1707, Copyright 1996, with permission from Elsevier Science.)...

Fig. 4-14 Schematic diagram showing the components of a global climate model (GCM). (Reprinted from Hartmann (1994), with permission from Academic Press.)...

The complexities of land surface response and runoff generation have also presented a major obstacle to global climate modelers. Hydrologic response is linked to several important climate feedbacks (see Section 6.4.2), so imtil the hydro-logic cycle, and in particular its land surface component, can be accurately represented, there is little hope for accurate assessments of global change. 

Dickinson, R. E. (1984). Modeling evapotranspiration for three-dimensional global climate models. Geo-physical Monographs Q. E. Hansen and T. Takahashi, eds.) 29,58-72. American Geophysical Union. 

Holtslag, A. A. M. and Boville, B. A. (1993). Local versus nonlocal boundary-layer diffusion in a global climate model, /. Clim. 6,1825-1842. 

The table shows the originating institution (INST, where DM I Danish Meteorological Institute, SMHI Swedish Meteorological and Hydrological Institute), the driving global climate model (GCM) and the model s filename of the RCMs... 

But, two global climate models show that even if the concentrations of greenhouse gases in the atmosphere had been stabilized by the year 2000, we were already committed to further global warming. 

For example, Fig. 14.29 shows one calculation of direct radiative forcing using a global climate model, GCM (Penner et al., 1998). Due to the preponderance of anthropogenic S02 emissions in the Northern Hemisphere, the direct radiative forcing due to sulfate... 

Gaffney, J. S., and N. A. Marley, Uncertainties of Aerosol Effects in Global Climate Models, Atmos. Environ, 32, 2873-2874 (1998). 

The results presented here focus on the present and future effect on radiative forcing due to changes in the radiatively-important chemical species (03, water vapor and CHJ associated with aircraft emissions. To address this question, we conduct uncoupled model experiments using the University of Oslo (UiO) 3-D chemical transport models (CTMs) to calculate changes in atmospheric composition and the State University of New York at Albany (SUNYA) 3-D global climate model (GCM) to calculate the radiative forcing associated with these changes. Two case studies were conducted to... 

Atmospheric Research (NCAR) (U.S.A.) scientists. This development is a first step toward constructing a global climate model that takes into account the dynamics of biogeochemical cycles. To analyze the functioning of the CCSM model, two numerical experiments were carried out that took into account... 

Govindan R.B. Vyushin D. Bunde A. Brenner S. Havlin S. and Schellnhuber H.J. (2002). Global climate models violate scaling of the observed atmospheric variability. Physical Review Letters, 89(2), art. no. 028501. 

Abramopoulos, F., Rosensweig, C., and Choudhury, B. (1988) Improved ground hydrology calculations for global climate models (GCMs) soil water movement and evapotranspiration. J. Climate 1, 921-941. 

With even fewer runs relative to the number of input variables, Bettonvil and Kleijnen (1996) used a sequential bifurcation algorithm (see Chapter 13) to analyze a large deterministic global-climate model. The output is the worldwide CO2 circulation in the year 2100. The model has 281 input variables, 15 of which were identified as important after 154 runs. The sequential bifurcation algorithm makes several strong assumptions to enable an experiment with fewer runs than input variables (a supersaturated design—see Chapter 8). Each variable is considered at only two levels, and effects are assumed to be linear and additive. Moreover, the direction (sign) of each effect must be known a priori. The sequential bifurcation... 

The chemical composition fields from ACTMs may be used as a driver for Regional/Global Climate Models, including aerosol forcing on meteorological processes. This strategy could also be reahzed for NWP or MetMs. 

Europe) were driven by meteorological boundary conditions provided by a longterm simulation of the global climate model ECHAM4. Two time slices (representing 1990s and 2030s) of about 10 years each were compared. 

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