Geophysical Fluid Dynamics Laboratory

About: Geophysical Fluid Dynamics Laboratory is a facility organization based out in Princeton, New Jersey, United States. It is known for research contribution in the topics: Climate model & Climate change. The organization has 525 authors who have published 2432 publications receiving 264545 citations. The organization is also known as: GFDL.

A multitrophic model to quantify the effects of marine viruses on microbial food webs and ecosystem processes

Abstract: Viral lysis of microbial hosts releases organic matter that can then be assimilated by nontargeted microorganisms Quantitative estimates of virus-mediated recycling of carbon in marine waters, first established in the late 1990s, were originally extrapolated from marine host and virus densities, host carbon content and inferred viral lysis rates Yet, these estimates did not explicitly incorporate the cascade of complex feedbacks associated with virus-mediated lysis To evaluate the role of viruses in shaping community structure and ecosystem functioning, we extend dynamic multitrophic ecosystem models to include a virus component, specifically parameterized for processes taking place in the ocean euphotic zone Crucially, we are able to solve this model analytically, facilitating evaluation of model behavior under many alternative parameterizations Analyses reveal that the addition of a virus component promotes the emergence of complex communities In addition, biomass partitioning of the emergent multitrophic community is consistent with well-established empirical norms in the surface oceans At steady state, ecosystem fluxes can be probed to characterize the effects that viruses have when compared with putative marine surface ecosystems without viruses The model suggests that ecosystems with viruses will have (1) increased organic matter recycling, (2) reduced transfer to higher trophic levels and (3) increased net primary productivity These model findings support hypotheses that viruses can have significant stimulatory effects across whole-ecosystem scales We suggest that existing efforts to predict carbon and nutrient cycling without considering virus effects are likely to miss essential features of marine food webs that regulate global biogeochemical cycles

Transient response of a global ocean-atmosphere model to a doubling of atmospheric carbon dioxide

Abstract: The transient response of climate to an instantaneous increase in the atmospheric concentration of carbon dioxide has been investigated by a general circulation model of the coupled ocean-atmosphere-land system with global geography and annual mean insulation. An equilibrium climate of the coupled model is perturbed by an abrupt doubling of the atmospheric carbon dioxide. The evolution of the model climate during the 60-year period after the doubling is compared with the result from a control integration of the model without the doubling. The increase of surface air temperature in middle and high latitudes is slower in the Southern Hemisphere than the Northern Hemisphere The large thermal inertia of the ocean-dominated hemisphere is partly responsible for this difference. The effective thermal inertia of the oceans becomes particularly large in high southern latitudes. Owing to the absence of meridional barriers at the latitudes of the Drake Passage. a wind-driven. deep cell meridional circulatio...

Variability of the Baroclinic and Barotropic Transient Eddy Forcing Associated with Monthly Changes in the Midlatitude Storm Tracks

Abstract: The heat and vorticity transports by synoptic-scale eddies at various levels between 1000 and 100 mb have been compiled for each winter month of the 1966–84 period using time-filtered daily analyses produced by the U.S. National Meteorological Center. These circulation statistics were used to compute the three-dimensional distributions of the quasigeostrophic geopotential tendency and vertical motion induced by baroclinic and barotropic eddy processes in individual months. The latter fields serve as the basis for describing the synoptic-scale eddy forcing associated with the leading modes of month-to-month variability of the storm tracks over the North Pacific and North Atlantic. These modes are associated with the meridional displacements of the storm-track axes from their climatological positions. The placement of a storm track at a certain latitude ϕ in a certain month is accompanied by enhanced convergence of eddy heat fluxes poleward of ϕ. In the tropospheric column poleward of the storm tra...

Simulation of the Seasonal Cycle of the Tropical Pacific Ocean

Abstract: In a general circulation model of the tropical Pacific Ocean forced with climatological seasonally varying winds, equatorial upwelling and downwelling in adjacent latitudes play central roles in closing the oceanic circulation. The transport of the eastward North Equatorial Countercurrent decreases in a downstream direction because fluid is lost to downwelling into the thermocline where there is equatorward motion. Although this fluid converges onto the Equatorial Undercurrent, the latter's transport decreases because of equatorial upwelling. The upwelling, on the other hand, enhances the transport of the westward South Equatorial Current. Seasonally, the Countercurrent and South Equatorial Current are intense during the Northern Hemisphere summer and fall, at which time the thermocline has a pronounced trough near 3°N and a ridge near 10°N, and are weak in the spring when latitudinal thermal gradients are small and when the southeast trades are relatively weak. These variations are out of phase ...

Whither Hurricane Activity

Abstract: Alternative interpretations of the relationship between sea surface temperature and hurricane activity imply vastly different future Atlantic hurricane activity.