Search Results

You are looking at 31 - 36 of 36 items for :

  • Boundary currents x
  • CCSM4/CESM1 x
  • Refine by Access: All Content x
Clear All
A. Gettelman, J. E. Kay, and J. T. Fasullo

) . The results are spatially coherent, leading naturally to a discussion of particular physical regimes. The current analysis confirms that cloud feedbacks are a critical source of intermodel spread in climate sensitivity, and therefore we focus on parameters that are related to cloud radiative effects and explore how specific properties of clouds in the simulations are related to the climate sensitivity. Cloud radiative properties are evaluated, and then three areas are highlighted: 1) moisture in

Full access
Synte Peacock

of future climate from a model with a mean state that closely approximated present-day climate. However, without help from data assimilation techniques, freely evolving climate models have not yet reached this point. Therefore, the best that can be done with the current state-of-the-art global climate models is to make the assumption that present-day biases persist into the future, and thus that changes in model fields between the late twentieth and late twenty-first centuries will be in some way

Full access
David M. Lawrence, Keith W. Oleson, Mark G. Flanner, Christopher G. Fletcher, Peter J. Lawrence, Samuel Levis, Sean C. Swenson, and Gordon B. Bonan

feature is that BC and dust snow forcings are about equal in the present day. This is in contrast to an earlier study with CAM3 ( Flanner et al. 2009 ), where BC–snow forcing was more than double dust–snow forcing. The difference can be attributed mostly to much greater Asian dust emissions and deposition in the current study. Land-averaged BC–snow forcing decreased slightly from 0.040 to 0.037 W m −2 between these studies, due to application of new emissions ( Lamarque et al. 2010 ), whereas dust

Full access
Gerald A. Meehl, Julie M. Arblaster, Julie M. Caron, H. Annamalai, Markus Jochum, Arindam Chakraborty, and Raghu Murtugudde

developments and their impacts will be documented here. Fig . 16. SST (colors) and vertically integrated transport (contour interval 2 Sv for transports between −15 and +15 Sv, and 10 Sv beyond that) in CCSM4 for 1996–2005, based on six twentieth-century ensembles. The mostly North Pacific waters are carried through the Indonesian Seas in a multitude of currents, which are summarily referred to as the Indonesian Throughflow (ITF). They bring about 0.5 PW (10 15 watts) of heat from the tropical Pacific to

Full access
Gerald A. Meehl, Warren M. Washington, Julie M. Arblaster, Aixue Hu, Haiyan Teng, Jennifer E. Kay, Andrew Gettelman, David M. Lawrence, Benjamin M. Sanderson, and Warren G. Strand

given by Neale et al. (2010) and results for twentieth-century climate simulations are given by R. B. Neale et al. (2013, personal communication). The CAM5 is essentially a new atmospheric model with improved and more realistic formulations of radiation, boundary layer, and aerosols (R. B. Neale et al. 2013, personal communication). In particular, the aerosol scheme ( Liu et al. 2012 ) is prognostic, and the cloud microphysics ( Morrison and Gettelman 2008 ; Gettelman et al. 2010 ) includes both

Full access
Kirsten Zickfeld, Michael Eby, Andrew J. Weaver, Kaitlin Alexander, Elisabeth Crespin, Neil R. Edwards, Alexey V. Eliseev, Georg Feulner, Thierry Fichefet, Chris E. Forest, Pierre Friedlingstein, Hugues Goosse, Philip B. Holden, Fortunat Joos, Michio Kawamiya, David Kicklighter, Hendrik Kienert, Katsumi Matsumoto, Igor I. Mokhov, Erwan Monier, Steffen M. Olsen, Jens O. P. Pedersen, Mahe Perrette, Gwenaëlle Philippon-Berthier, Andy Ridgwell, Adam Schlosser, Thomas Schneider Von Deimling, Gary Shaffer, Andrei Sokolov, Renato Spahni, Marco Steinacher, Kaoru Tachiiri, Kathy S. Tokos, Masakazu Yoshimori, Ning Zeng, and Fang Zhao

. 2009 ). By 3000, the ensemble mean atmospheric CO 2 is 330 ppmv in RCP2.6, 440 ppmv in RCP4.5, 590 ppmv in RCP6.0, and 1560 ppmv in RCP8.5. Note that the upper boundary of the atmospheric CO 2 range spanned by models increases after 2300. The upper limit is set by the UMD model, which has slightly positive CO 2 emissions. Atmospheric CO 2 at 3000 in RCPs 4.5–8.5 is still at a high fraction (≥0.5) of the peak atmospheric CO 2 in all models ( Fig. 8 ). These results are consistent with previous

Full access