Search Results

You are looking at 1 - 10 of 28 items for :

  • Waves, oceanic x
  • CCSM4/CESM1 x
  • All content x
Clear All
Richard B. Neale, Jadwiga Richter, Sungsu Park, Peter H. Lauritzen, Stephen J. Vavrus, Philip J. Rasch, and Minghua Zhang

pair of cyclones to the west of the maximum divergence. Both CAM3 and CAM4 overestimate the upper-tropospheric divergent flow with local velocity potential maxima near the Arabian Peninsula. Since the excess is slightly larger in CAM3 because of large precipitation biases (see Fig. 11 ) it generates a larger anomalous Rossby wave response, particularly over the Indian subcontinent and in the southern Indian Ocean. In the fully coupled equivalent analysis the divergent anomalies are much lower

Full access
Stephen J. Vavrus, Marika M. Holland, Alexandra Jahn, David A. Bailey, and Benjamin A. Blazey

of temperature, sea ice, precipitation, cloud amount, sea level pressure, and the upper ocean, while leaving most of the assessment of CCSM4’s simulated present-day Arctic climate for two related papers ( de Boer et al. 2012 ; Jahn et al. 2012 ). We also only consider the model response to the strongest greenhouse forcing among the representative concentration pathways (RCPs) being used in the new Coupled Model Intercomparison Project, version 5 (CMIP5). This high-end scenario is called RCP8

Full access
Gerald A. Meehl, Warren M. Washington, Julie M. Arblaster, Aixue Hu, Haiyan Teng, Claudia Tebaldi, Benjamin N. Sanderson, Jean-Francois Lamarque, Andrew Conley, Warren G. Strand, and James B. White III

(CAM4) with improved components of ocean, land, and sea ice compared to CCSM3 ( Gent et al. 2011 ). The ocean is a version of the Parallel Ocean Program (POP) with a nominal latitude–longitude resolution of 1° (down to ¼° in latitude in the equatorial tropics) and 60 levels in the vertical. Specifically, grid points in the ocean have a uniform 1.11° spacing in the zonal direction and 0.27° near the equator, extending to 0.54° poleward of 35°N and S. No flux adjustments are used in CCSM4

Full access
Gokhan Danabasoglu, Susan C. Bates, Bruce P. Briegleb, Steven R. Jayne, Markus Jochum, William G. Large, Synte Peacock, and Steve G. Yeager

bias that was present in CCSM3. This improvement is likely due to the lower horizontal viscosities that allow for more vigorous tropical instability waves ( Jochum et al. 2008 ) whose meridional heat transports remove the cold bias of the equatorial cold tongue ( Hansen and Paul 1984 ; Jochum et al. 2005 ). As particularly evident at 110°W, the CCSM4 thermocline remains nearly as sharp as in observations, in contrast with a more diffuse thermocline in CCSM3. Three main changes to the ocean model

Full access
Semyon A. Grodsky, James A. Carton, Sumant Nigam, and Yuko M. Okumura

shading effect reducing the net surface radiative forcing. The erroneously warm coastal SSTs in turn could be the result of coastal downwelling Kelvin waves (e.g., Lübbecke et al. 2010 ) generated by erroneously weak equatorial zonal winds (see March–May in Fig. 4 ). We note that the spurious warming of the eastern ocean expands coincident with the spurious decline of MSLP, both over the erroneously warm water in the southeastern tropical Atlantic ( Fig. 4 ) and along the equator ( Fig. 5 ). Fig . 5

Full access
Matthew C. Long, Keith Lindsay, Synte Peacock, J. Keith Moore, and Scott C. Doney

1. Introduction Over the last 200 years the ocean has absorbed 118 ± 19 Pg carbon (1 Pg = 10 15 g), an amount equivalent to 25%–30% of the total CO 2 emitted by fossil-fuel burning, cement production, and land-use change over this period ( Sabine et al. 2004 ; Le Quéré et al. 2009 ). The ocean carbon sink has partially mitigated CO 2 -induced warming by slowing the rise of atmospheric CO 2 during the anthropocene ( Crutzen 2006 ). However, the mechanisms regulating the ocean carbon sink are

Full access
Alicia R. Karspeck, Steve Yeager, Gokhan Danabasoglu, Tim Hoar, Nancy Collins, Kevin Raeder, Jeffrey Anderson, and Joseph Tribbia

1. Introduction In this paper, we document the development of an ensemble adjustment Kalman filter (EAKF) ( Anderson et al. 2009 ) data assimilation system for the ocean component of the Community Climate System Model, version 4 (CCSM4). The ocean assimilation system described here was developed to support the eventual generation of historical ocean-state estimates and ocean-initialized climate predictions with the CCSM4 and its next generation, the Community Earth System Model (CESM). 1 This

Full access
Wilbert Weijer, Bernadette M. Sloyan, Mathew E. Maltrud, Nicole Jeffery, Matthew W. Hecht, Corinne A. Hartin, Erik van Sebille, Ilana Wainer, and Laura Landrum

1. Introduction The Southern Ocean is a region of extremes: it is exposed to the most severe winds on the earth ( Wunsch 1998 ), the largest ice shelves ( Scambos et al. 2007 ), and the most extensive seasonal sea ice cover ( Thomas and Dieckmann 2003 ). These interactions among the atmosphere, ocean, and cryosphere greatly influence the dynamics of the entire climate system through the formation of water masses and the sequestration of heat, freshwater, carbon, and other properties ( Rintoul

Full access
Aneesh C. Subramanian, Markus Jochum, Arthur J. Miller, Raghu Murtugudde, Richard B. Neale, and Duane E. Waliser

oscillations that travel at speeds of 10–22 m s −1 , which are faster than the typical observed MJO phase speed of 5 m s −1 . This weakly energetic and fast propagation at wavenumbers 2 and 3 in CCSM4 may be associated with a lack of coupling between MJO and oceanic Kelvin waves in the central equatorial Pacific, which Roundy and Kravitz (2009) identified as an important mechanism for slowing and amplifying higher-wavenumber-observed MJO in this region. The faster phase speed of MJO in CCSM is also

Full access
Laura Landrum, Marika M. Holland, David P. Schneider, and Elizabeth Hunke

patterns and the eastward propagation of observations in the Antarctic circumpolar wave ( White and Simmonds 2006 ). This suggests that the sea ice anomalies are in effect advected with the mean ocean circulation. Although the regions of high SIC variability are in areas where the seasonal ice melts and is gone during austral summer, the ice anomaly is seen again in following years because of the corresponding anomalies in ocean SST—essentially a “memory” of the ice anomaly maintained in the surface

Full access