TY - JOUR AU - James E Hansen AU - Makiko Sato AU - Reto Ruedy AU - Pushker A Kharecha AU - Andrew A Lacis AU - Ronald L Miller AU - Larissa Nazarenko AU - Kwok-Wai Ken Lo AU - Gavin A Schmidt AU - Gary L Russell AU - Igor D Aleinov AU - Susanne E Bauer AU - Ellen Baum AU - Brian Cairns AU - Vittorio M Canuto AU - Mark Chandler AU - Ye Cheng AU - Armond Cohen AU - Anthony Del Genio AU - Gregory S Faluvegi AU - Eric L Fleming AU - Andrew D Friend AU - Timothy M Hall AU - Charles H Jackman AU - Jeffrey Jonas AU - Maxwell Kelley AU - Nancy Y Kiang AU - Dorothy M Koch AU - Gordon J Labow AU - J Lerner AU - Surabi Menon AU - Tihomir Novakov AU - Valdar Oinas AU - Jan Perlwitz AU - Judith Perlwitz AU - David H Rind AU - Anastasia Romanou AU - Robert B Schmunk AU - Drew T Shindell AU - Peter H Stone AU - S Sun AU - David G Streets AU - Nicholas Tausnev AU - D Thresher AU - Nadine Unger AU - Mao-Sung Yao AU - S Zhang AB -

We carry out climate simulations for 1880-2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880-2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds.

BT - Climate Dynamics DA - 12/2007 DO - 10.1007/s00382-007-0255-8 IS - 7-8 N2 -

We carry out climate simulations for 1880-2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880-2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds.

PY - 2007 SP - 661 EP - 696 T2 - Climate Dynamics TI - Climate simulations for 1880–2003 with GISS modelE VL - 29 SN - 1432-0894 ER -