The ocean , a heat reservoir (original) (raw)

The role of the oceans in climate

International Journal of Climatology, 2003

The ocean is increasingly seen as a vital component of the climate system. It exchanges with the atmosphere large quantities of heat, water, gases, particles and momentum. It is an important part of the global redistribution of heat from tropics to polar regions keeping our planet habitable, particularly equatorward of about 30°. In this article we review recent work examining the role of the oceans in climate, focusing on research in the Third Assessment Report of the IPCC and later. We discuss the general nature of oceanic climate variability and the large role played by stochastic variability in the interaction of the atmosphere and ocean. We consider the growing evidence for biogeochemical interaction of climatic significance between ocean and atmosphere. Air-sea exchange of several radiatively important gases, in particular CO 2 , is a major mechanism for altering their atmospheric concentrations. Some more reactive gases, such as dimethyl sulphide, can alter cloud formation and hence albedo. Particulates containing iron and originating over land can alter ocean primary productivity and hence feedbacks to other biogeochemical exchanges. We show that not only the tropical Pacific Ocean basin can exhibit coupled ocean-atmosphere interaction, but also the tropical Atlantic and Indian Oceans. Longer lived interactions in the North Pacific and Southern Ocean (the circumpolar wave) are also reviewed. The role of the thermohaline circulation in long-term and abrupt climatic change is examined, with the freshwater budget of the ocean being a key factor for the degree, and longevity, of change. The potential for the Mediterranean outflow to contribute to abrupt change is raised. We end by examining the probability of thermohaline changes in a future of global warming.

The role of ocean heat transport in climatic change

Earth-science Reviews, 1988

Covey, C. and Barron, E., 1988. The role of ocean heat transport in climatic change. Although heat transport by the oceans is comparable in magnitude to heat transport by the atmosphere and changes in oceanic heat transport have often been invoked to explain past climatic changes, there has been little explicit investigation of the sensitivity of climate to ocean heat transport. In fact, some theoretical studies employing general circulation models (GCMs) of Earth's atmosphere and oceans suggest that the climatic effect of a change in ocean heat transport may be moderated by a tendency of the atmosphere to compensate by changing its heat transport in the opposite sense. If this compensation effect exists, rethinking of the role of ocean heat transport in both paleoclimates and possible future climatic change is warranted.

Effects of the World’s Oceans on Global Climate Change

American Journal of Climate Change, 2013

The role of the World Ocean in Global Climate Change is considered from two points of view: 1) heat energy accumulation and distribution in the ocean and its discharge into the atmosphere as purely physical processes; 2) participation of living matter in the ocean in these processes. The oceanic organic matter, especially plankton and different organic compounds, absorbs solar energy and changes water transparency, controlling thickness of layers and amount of the energy accumulated. Having ability to react not only to fluctuations of solar heat energy supply, but also to extra weak fluctuations of electromagnetic and magnetic fields of terrestrial and extraterrestrial origin, phytoplankton and other organic matter should be considered as active forcing of global climate and ocean ecosystem fluctuations observed on different scales. Several mechanisms of solar activity effects on global climate-ocean ecosystem interactions are discussed.

What processes drive the ocean heat transport?

Ocean Modelling, 2011

The ocean contributes to regulating the Earth's climate through its ability to transport heat from the equator to the poles. In this study we use long simulations of an ocean model to investigate whether the heat transport is carried primarily by wind-driven gyres or whether it is dominated by deep circulations associated with abyssal mixing and high latitude convection. The heat transport is computed as a function of temperature classes. In the Pacific and Indian ocean, the bulk of the heat transport is associated with wind-driven gyres confined to the thermocline. In the Atlantic, the thermocline gyres account for only 40% of the total heat transport. The remaining 60% is associated with a circulation reaching down to cold waters below the thermocline. Using a series of sensitivity experiments, we show that this deep heat transport is primarily set by the strength and patterns of surface winds and only secondarily by diabatic processes at high latitudes in the North Atlantic. Abyssal mixing below 2000 m has hardly any impact on ocean heat transport. A major implication is that the role of the ocean in regulating Earth's climate strongly depends on how surface winds change across different climates in both hemispheres at low and high latitudes.

Why ocean heat transport warms the global mean climate

Tellus A, 2005

A B S T R A C T Observational and modelling evidence suggest that poleward ocean heat transport (OHT) can vary in response to both natural climate variability and greenhouse warming. Recent modelling studies have shown that increased OHT warms both the tropical and global mean climates. Using two different coupled climate models with mixed-layer oceans, with and without OHT, along with a coupled model with a fixed-current ocean component in which the currents are uniformly reduced and increased by 50%, an attempt is made to explain why this may happen.

Role of Ocean in Global Warming

Journal of the Meteorological Society of Japan, 2007

Based upon the results obtained from coupled ocean-atmosphere models of various complexities, this review explores the role of ocean in global warming. It shows that ocean can play a major role in delaying global warming and shaping its geographical distribution. It is very encouraging that many features of simulated change of the climate system have begun to agree with observation. However, it has been difficult to confirm the apparent agreement because the density and frequency of the observation are insufficient in many oceanic region of the world, in particular, in the Circumpolar Ocean of the Southern Hemisphere. It is therefore essential to intensify our effort to monitor not only at the surface but also in the subsurface layers of oceans.

Climate and the Oceans

Descriptive Physical Oceanography, 2011

Preface vii 1 Basics of climate 2 The oceans: A Descriptive overview 3 A Brief introduction to Dynamics 4 The ocean circulation 5 The ocean's overall role in climate 6 climate Variability from Weeks to years 7 Global Warming and the ocean Notes Further Reading Glossary References Index

Connecting Changing Ocean Circulation with Changing Climate

Journal of Climate, 2013

The influence of changing ocean currents on climate change is evaluated by comparing an earth system model's response to increased CO 2 with and without an ocean circulation response. Inhibiting the ocean circulation response, by specifying a seasonally varying preindustrial climatology of currents, has a much larger influence on the heat storage pattern than on the carbon storage pattern. The heat storage pattern without circulation changes resembles carbon storage (either with or without circulation changes) more than it resembles the heat storage when currents are allowed to respond. This is shown to be due to the larger magnitude of the redistribution transport-the change in transport due to circulation anomalies acting on control climate gradients-for heat than for carbon. The net ocean heat and carbon uptake are slightly reduced when currents are allowed to respond. Hence, ocean circulation changes potentially act to warm the surface climate. However, the impact of the reduced carbon uptake on radiative forcing is estimated to be small while the redistribution heat transport shifts ocean heat uptake from low to high latitudes, increasing its cooling power. Consequently, global surface warming is significantly reduced by circulation changes. Circulation changes also shift the pattern of warming from broad Northern Hemisphere amplification to a more structured pattern with reduced warming at subpolar latitudes in both hemispheres and enhanced warming near the equator.