scholarly journals Detection of the Earth rotation response to a rapid fluctuation of Southern Ocean circulation in November 2009

2012 ◽  
Vol 39 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. L. Marcus ◽  
J. O. Dickey ◽  
I. Fukumori ◽  
O. de Viron
Keyword(s):  
Southern Ocean ◽  
Ocean Circulation ◽  
Earth Rotation ◽  
The Earth ◽  
Rapid Fluctuation

On the impact of sea ice in a global ocean circulation model

1997 ◽  
Vol 25 ◽  
pp. 111-115 ◽  
Author(s):  
Achim Stössel
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Ocean Circulation ◽  
General Circulation ◽  
Thermohaline Circulation ◽  
Circulation Model ◽  
Deep Ocean ◽  
Global Ocean ◽  
Convective Activity ◽  
The Impact

This paper investigates the long-term impact of sea ice on global climate using a global sea-ice–ocean general circulation model (OGCM). The sea-ice component involves state-of-the-art dynamics; the ocean component consists of a 3.5° × 3.5° × 11 layer primitive-equation model. Depending on the physical description of sea ice, significant changes are detected in the convective activity, in the hydrographic properties and in the thermohaline circulation of the ocean model. Most of these changes originate in the Southern Ocean, emphasizing the crucial role of sea ice in this marginally stably stratified region of the world's oceans. Specifically, if the effect of brine release is neglected, the deep layers of the Southern Ocean warm up considerably; this is associated with a weakening of the Southern Hemisphere overturning cell. The removal of the commonly used “salinity enhancement” leads to a similar effect. The deep-ocean salinity is almost unaffected in both experiments. Introducing explicit new-ice thickness growth in partially ice-covered gridcells leads to a substantial increase in convective activity, especially in the Southern Ocean, with a concomitant significant cooling and salinification of the deep ocean. Possible mechanisms for the resulting interactions between sea-ice processes and deep-ocean characteristics are suggested.

Biogeochemical Cycles and Climate

2019 ◽  
Author(s):  
Han Dolman
Keyword(s):  
Ocean Circulation ◽  
Biogeochemical Cycles ◽  
Integrated System ◽  
General Introduction ◽  
Complex Interplay ◽  
Climate Agreements ◽  
Mitigation And Adaptation ◽  
The Earth ◽  
Geological Past ◽  
Recent Climate

This book describes the interaction of the main biogeochemical cycles of the Earth and the physics of climate. It takes the perspective of Earth as an integrated system and provides examples of both changes in the current climate and those in the geological past. The first three chapters offer a general introduction to the context of the book, outlining the climate system as a complex interplay between biogeochemistry and physics and describing the tools available for understanding climate: observations and models. These chapters describe the basics of the system, the rates and magnitudes and the crucial aspects of biogeochemical cycles needed to understand their functioning. The second part of the book consists of four chapters that describe the physics required to understand the interaction of the climate with biogeochemistry and change. These chapters describe the physics of radiation, and that of the atmosphere, ocean circulation and thermodynamics. The interaction of aerosols with radiation and clouds is addressed in an additional chapter. The third part of the book deals with Earth’s (bio)geochemical cycles. These chapters focus on the stocks and fluxes of the main reservoirs of Earth’s biogeochemical cycles—atmosphere, land and ocean—and their role in the cycles of carbon, oxygen, nitrogen, iron, phosphorus, oxygen, sulphur and water, as well as their interactions with climate. The final two chapters describe possible mitigation and adaptation actions, in relation to recent climate agreements, but always with an emphasis on the biogeochemical aspects.

scholarly journals A potential feedback loop underlying glacial-interglacial cycles

2021 ◽  
Author(s):  
Els Weinans ◽  
Anne Willem Omta ◽  
George A. K. van Voorn ◽  
Egbert H. van Nes
Keyword(s):  
Ocean Circulation ◽  
Feedback Loop ◽  
Atmospheric Temperature ◽  
Earth System ◽  
Biological Productivity ◽  
Ocean Ventilation ◽  
The Earth ◽  
Main Driver ◽  
Underlying Mechanisms ◽  
Convergent Cross Mapping

AbstractThe sawtooth-patterned glacial-interglacial cycles in the Earth’s atmospheric temperature are a well-known, though poorly understood phenomenon. Pinpointing the relevant mechanisms behind these cycles will not only provide insights into past climate dynamics, but also help predict possible future responses of the Earth system to changing CO$$_2$$ 2 levels. Previous work on this phenomenon suggests that the most important underlying mechanisms are interactions between marine biological production, ocean circulation, temperature and dust. So far, interaction directions (i.e., what causes what) have remained elusive. In this paper, we apply Convergent Cross-Mapping (CCM) to analyze paleoclimatic and paleoceanographic records to elucidate which mechanisms proposed in the literature play an important role in glacial-interglacial cycles, and to test the directionality of interactions. We find causal links between ocean ventilation, biological productivity, benthic $$\delta ^{18}$$ δ 18 O and dust, consistent with some but not all of the mechanisms proposed in the literature. Most importantly, we find evidence for a potential feedback loop from ocean ventilation to biological productivity to climate back to ocean ventilation. Here, we propose the hypothesis that this feedback loop of connected mechanisms could be the main driver for the glacial-interglacial cycles.

scholarly journals The effect of earthquakes on the ERP during 1977–1985

1988 ◽  
Vol 128 ◽  
pp. 399-404 ◽  
Author(s):  
Richard S. Gross
Keyword(s):  
Earth Rotation ◽  
The Earth ◽  
Time Period ◽  
Earth Rotation Parameters ◽  
Rotation Parameters ◽  
Large Earthquakes

The effect on the Earth Rotation Parameters (ERP) of all the large earthquakes that occurred during 1977–1985 is evaluated. It is found that they cannot have caused the variations observed in the ERP during this time period.

The Terrestrial Coordinate System and International Earth-rotation Services

1985 ◽  
Vol 38 (02) ◽  
pp. 216-217
Author(s):  
G. A. Wilkins
Keyword(s):  
Coordinate System ◽  
Earth Rotation ◽  
Reference System ◽  
New Techniques ◽  
Crustal Movements ◽  
Earth Observations ◽  
The Earth ◽  
External Reference ◽  
External Objects ◽  
Rotation Of The Earth

New techniques of measurement make it possible in 1984 to determine positions on the surface of the Earth to a much higher precision than was possible in 1884. If we look beyond the requirements of navigation we can see useful applications of global geodetic positioning to centimetric accuracy for such purposes as the control of mapping and the study of crustal movements. These new techniques depend upon observations of external objects, such as satellites or quasars rather than stars, and they require that the positions of these objects and the orientation of the surface of the Earth are both known with respect to an appropriate external reference system that is ‘fixed’ in space. We need networks of observing stations and analysis centres that monitor the motions of the external objects and the rotation of the Earth. Observations of stars by a transit circle are no longer adequate for this purpose.

scholarly journals Simulating natural carbon sequestration in the Southern Ocean: on uncertainties associated with eddy parameterizations and iron deposition

2017 ◽  
Vol 14 (6) ◽  
pp. 1561-1576 ◽  
Author(s):  
Heiner Dietze ◽  
Julia Getzlaff ◽  
Ulrike Löptien
Keyword(s):  
Carbon Sequestration ◽  
Southern Ocean ◽  
Ocean Circulation ◽  
Spatial Scales ◽  
Carbon Uptake ◽  
Comprehensive Understanding ◽  
Biogeochemical Models ◽  
Anthropogenic Carbon ◽  
Natural Carbon ◽  
Oceanic Carbon

Abstract. The Southern Ocean is a major sink for anthropogenic carbon. Yet, there is no quantitative consensus about how this sink will change when surface winds increase (as they are anticipated to do). Among the tools employed to quantify carbon uptake are global coupled ocean-circulation–biogeochemical models. Because of computational limitations these models still fail to resolve potentially important spatial scales. Instead, processes on these scales are parameterized. There is concern that deficiencies in these so-called eddy parameterizations might imprint incorrect sensitivities of projected oceanic carbon uptake. Here, we compare natural carbon uptake in the Southern Ocean simulated with contemporary eddy parameterizations. We find that very differing parameterizations yield surprisingly similar oceanic carbon in response to strengthening winds. In contrast, we find (in an additional simulation) that the carbon uptake does differ substantially when the supply of bioavailable iron is altered within its envelope of uncertainty. We conclude that a more comprehensive understanding of bioavailable iron dynamics will substantially reduce the uncertainty of model-based projections of oceanic carbon uptake.

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