Publications

Export 4 results:
Sort by: Author [ Title  (Asc)] Type Year
A B C D E F [G] H I J K L M N O P Q R S T U V W X Y Z   [Show ALL]
G
Shell, KM, Somerville RCJ.  2005.  A generalized energy balance climate model with parameterized dynamics and diabatic heating. Journal of Climate. 18:1753-1772.   10.1175/jcli3373.1   AbstractWebsite

Energy balance models have proven useful in understanding mechanisms and feedbacks in the climate system. An original global energy balance model is presented here. The model is solved numerically for equilibrium climate states defined by zonal average temperature as a function of latitude for both a surface and an atmospheric layer. The effects of radiative, latent, and sensible heating are parameterized. The model includes a variable lapse rate and parameterizations of the major dynamical mechanisms responsible for meridional heat transport: the Hadley cell, midlatitude baroclinic eddies, and ocean circulation. The model reproduces both the mean variation of temperature with latitude and the global average heat budget within the uncertainty of observations. The utility of the model is demonstrated through examination of various climate feedbacks. One important feedback is the effect of the lapse rate on climate. When the planet warms as a result of an increase in the solar constant, the lapse rate acts as a negative feedback, effectively enhancing the longwave emission efficiency of the atmosphere. The lapse rate is also responsible for an increase in global average temperature when the meridional heat transport effectiveness is increased. The water vapor feedback enhances temperature changes, while the latent and sensible heating feedback reduces surface temperature changes.

Somervil.Rc, Stone PH, Halem M, Hansen JE, Hogan JS, Druyan LM, Russell G, Lacis AA, Quirk WJ, Tenenbau.J.  1974.  GISS Model of Global Atmosphere. Journal of the Atmospheric Sciences. 31:84-117.   10.1175/1520-0469(1974)031<0084:tgmotg>2.0.co;2   AbstractWebsite

A model description and numerical results are presented for a global atmospheric circulation model developed at the Goddard Institute for Space Studies (GISS). The model version described is a 9-level primitive-equation model in sigma coordinates. It includes a realistic distribution of continents, oceans and topography. Detailed calculations of energy transfer by solar and terrestrial radiation make use of cloud and water vapor fields calculated by the model. The model hydrologic cycle includes two precipitation mechanisms: large-scale supersaturation and a parameterization of subgrid-scale cumulus convection.Results are presented both from a comparison of the 13th to the 43rd days (January) of one integration with climatological statistics, and from five short-range forecasting experiments. In the extended integration, the near-equilibrium January-mean model atmosphere exhibits an energy cycle in good agreement with observational estimates, together with generally realistic zonal mean fields of winds, temperature, humidity, transports, diabatic heating, evaporation, precipitation, and cloud cover. In the five forecasting experiments, after 48 hr, the average rms error in temperature is 3.9K, and the average rms error in 500-mb height is 62 m. The model is successful in simulating the 2-day evolution of the major features of the observed sea level pressure and 500-mb height fields in a region surrounding North America.

Jouzel, J, Somerville RCJ.  2008.  The global consensus and Intergovernmental Panel on Climate Change. Facing climate change together. ( Gautier C, Fellous JL, Eds.).:12-29., Cambridge, UK; New York: Cambridge University Press Abstract

"This volume brings together scientists from the US and Europe to review the state-of-the-art in climate change science; all of them have extensive experience with climate research and international collaboration. scientific jargon has been minimized for readers from different backgrounds.""This book is written for scientists and students in a wide range of fields, such as atmospheric science, physics, chemistry, biology, geography, geology, and socioeconomics, who are not necessarily specialists in climatology, but are seeking an accessible and broad review of climate change issues."--BOOK JACKET.

Chertock, B, Frouin R, Somerville RCJ.  1991.  Global Monitoring of Net Solar Irradiance at the Ocean Surface - Climatological Variability and the 1982-1983 Elnino. Journal of Climate. 4:639-650.   10.1175/1520-0442(1991)004<0639:gmonsi>2.0.co;2   AbstractWebsite

A new method has been used to generate the first satellite-based long-term climatology of surface solar irradiance over the world oceans. These monthly mean data cover the period November 1978 through October 1985 on a global, 9-degrees latitude-longitude spatial grid. The large-scale variability of surface solar irradiance is assessed over the world oceans for the entire (84-month) record. The results demonstrate the ability of the method to reveal large-scale seasonal and interannual phenomena. The reduction in surface solar irradiance due to clouds is evaluated globally both on monthly and long-term climatological scales. Monthly cloud forcing anomalies are found to display eastward propagation over the course of the 1982-1983 El Nino event. The mean January climatology is found to be consistent with the climatology obtained from a general circulation model run in perpetual January mode. This study marks the first large-scale observation-based examination of cloud solar forcing at the ocean surface. In addition, empirical orthogonal function (EOF) analysis is employed to investigate modes of seasonal and nonseasonal variability. Nonseasonal EOF modes of surface solar irradiance are related to nonseasonal EOF modes of outgoing longwave radiation (OLR). The dominant modes during the 1982-1983 El Nino are associated with eastward propagation in both the shortwave and longwave fields. These dominant nonseasonal EOF modes of surface solar irradiance are found to display features and amplitude variations that are identical to those of the corresponding nonseasonal EOF modes of OLR. The association of these modes with EL Nino is quantified using the correlation of the mode amplitudes with the Southern Oscillation index (SOI). In each case modes 1 and 2 are positively correlated with the SOI, and mode 1 has a strong correlation of 0.75 for the shortwave and 0.76 for the longwave field. Finally, a study of the regionally averaged behavior of surface solar irradiance and sea surface temperature (SST) in a section of the tropical Pacific (9-degrees-N-9-degrees-S, 117-degrees-144-degrees-W) during this same period indicates that fluctuations of surface solar irradiance in the tropical Pacific are sometimes a regional response to underlying changes in SST (and associated changes in cloudiness), rather than a driving mechanism responsible for variations in SST.