Search Results

You are looking at 1 - 10 of 24 items for :

  • Water budget/balance x
  • CCSM4/CESM1 x
  • All content x
Clear All
A. Gettelman, J. E. Kay, and K. M. Shell

at cooler temperatures, causing warming. Low clouds cool and high clouds warm, with the balance of effects being a net cooling ( Stephens 2005 ). Changes to cloud amount, location, and radiative properties (e.g., optical depth) can exert feedbacks on the system. Any of these feedbacks may significantly alter the magnitude of the response to radiative forcing. The water vapor feedback, for example, is large and positive ( Held and Soden 2000 ). While it is straightforward to calculate the direct

Full access
William H. Lipscomb, Jeremy G. Fyke, Miren Vizcaíno, William J. Sacks, Jon Wolfe, Mariana Vertenstein, Anthony Craig, Erik Kluzek, and David M. Lawrence

varies rapidly on small scales, and 3) more realistic treatment of physical processes such as basal sliding, subglacial water transport, and iceberg calving ( Little et al. 2007 ; Lipscomb et al. 2009 ). These improvements are beginning to be incorporated in a new generation of ice sheet models ( Gagliardini and Zwinger 2008 ; Pattyn et al. 2008 ; Price et al. 2011 ; Larour et al. 2012 ; Cornford et al. 2013 ). The new models are providing improved estimates of ice sheet mass loss and resulting

Full access
S. J. Ghan, X. Liu, R. C. Easter, R. Zaveri, P. J. Rasch, J.-H. Yoon, and B. Eaton

influence of anthropogenic aerosol on the optical properties of clouds by serving as the nuclei for droplets and ice crystals and thereby changing droplet and ice crystal number concentration, which changes cloud particle surface area, influences droplet collisions, and changes the accumulation of liquid water and ice in clouds, all of which affect the reflectivity and emissivity of clouds. Semi-direct effects are changes in the planetary energy balance as clouds respond to radiative heating by

Full access
Gijs de Boer, William Chapman, Jennifer E. Kay, Brian Medeiros, Matthew D. Shupe, Steve Vavrus, and John Walsh

Model, version 4 (CCSM4) to simulate various components of the present-day Arctic atmosphere. Six major atmospheric characteristics are evaluated because of their significant implications on regional and global climate. Properties are chosen based in part upon guidance from Walsh et al. (2005) and include surface air temperature ( T sfc ), sea level pressure (SLP), cloud distribution and phase, precipitation and evaporation ( P − E ), the Arctic atmospheric energy budget, and lower

Full access
Keith Oleson

were applied to studies of the urban energy balance ( Myrup 1969 ) and urban-induced circulation patterns ( Bornstein 1975 ). Over the next 30 years, increasingly sophisticated urban parameterizations were used (see reviews by Bornstein 1986 ; Brown 2000 ; Masson 2006 ). Most recently, explicit representations of the effects of individual urban components (e.g., roofs, walls, and roads) on the urban energy budget have been implemented ( Mills 1997 ; Masson 2000 ; Martilli et al. 2002 ; Chen

Full access
Markus Jochum, Alexandra Jahn, Synte Peacock, David A. Bailey, John T. Fasullo, Jennifer Kay, Samuel Levis, and Bette Otto-Bliesner

Dave Lawrence and Keith Oleson for explaining the intricacies of the snow budget, and trout fishing in America for inspiration. REFERENCES Aagaard , K. , and E. C. Carmack , 1989 : The role of sea ice and other fresh water in the Arctic circulation . J. Geophys. Res. , 94 , 14 485 – 14 498 . Andrews , J. T. , and M. A. W. Mahaffy , 1976 : Growth-rate of Laurentide ice sheet and sea-level lowering (with emphasis on 115,000 BP sea-level low) . Quat. Res. , 6 , 167 – 183 . Berger

Full access
Samuel Levis, Gordon B. Bonan, Erik Kluzek, Peter E. Thornton, Andrew Jones, William J. Sacks, and Christopher J. Kucharik

components: Sap-flow, soil water budget, eddy covariance and catchment water balance . Agric. For. Meteor. , 106 , 153 – 168 , doi:10.1016/S0168-1923(00)00199-4 . Xue , Y. , M. J. Fennessy , and P. J. Sellers , 1996 : Impact of vegetation properties on U.S. summer weather prediction . J. Geophys. Res. , 101D , 7419 – 7430 . 1 C3 and C4 refer to different photosynthetic pathways of plants.

Full access
A. Gettelman, J. E. Kay, and J. T. Fasullo

.9° × 2.5° (-SOM2). Results are not sensitive to these different resolutions ( Gettelman et al. 2012 ). There are three different parameter adjustment experiments of CAM5-SOM2 with interim versions of the model, but with a host of different changes to the physics suite, labeled α 1– α 3. These represent different experiments altering ice nucleation, ice autoconversion, and convective cloud water partitioning along with adjustment of the energy balance with changes to the relative humidity threshold

Full access
Christine A. Shields, David A. Bailey, Gokhan Danabasoglu, Markus Jochum, Jeffrey T. Kiehl, Samuel Levis, and Sungsu Park

-century temperature anomalies are higher than both observations and other resolutions. Precipitation patterns for T31x3 across the globe are similar to that of FV2x1 and FV1x1 in that major biases, such as the double ITCZ, exist in all resolutions. Analysis of river transport as a metric to approximate the accuracy of the model water balance, in particular precipitation and river runoff, show the T31x3 model to approximate the FV2x1 in the Pacific basin and perform better in the Atlantic and Indian Ocean basins

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

biases near Congo and Amazon outflows, respectively, reflect some persistent river discharge biases in coupled CCSM simulations associated with excessive Congo and weak Amazon runoffs. Precipitation and Amazon runoff errors as well as the oceanic freshwater loss to the land model to balance the water budget over wetlands and lakes in the Eastern Caribbean are likely contributors to the saline bias in this region in CCSM4. In contrast with CCSM3, the Mediterranean in CCSM4 has now a saline bias of >3

Full access