scholarly journals The Modified Quasi-geostrophic Barotropic Models Based on Unsteady Topography

2017 ◽  
Vol 21 (1) ◽  
pp. 23 ◽  
Author(s):  
Baojun Zhao ◽  
Wenjin Sun ◽  
Tianming Zhan
Keyword(s):  
Shallow Water Equations ◽  
Perturbation Methods ◽  
Global Climate ◽  
Scale Analysis ◽  
Fluid State ◽  
Rational Potential ◽  
The Earth ◽  
Barotropic Fluids ◽  
Vorticity Equations ◽  
Irregular Topography

New models using scale analysis and perturbation methods were derivated starting from the shallow water equations based on barotropic fluids. In the paper, to discuss the irregular topography with different magnitudes, especially considering the condition of the vast terrain, some modified quasi-geostrophic barotropic models were obtained. The unsteady terrain is more suitable to describe the motion of the fluid state of the earth because of the change of global climate and environment, so the modified models are more rational potential vorticity equations. If we do not consider the influence of topography and other factors, the models degenerate to the general quasi-geostrophic barotropic equations in the previous studies. Modelos semigeostróficos barotrópicos modificados con base en topografía inestableResumenEste trabajo deduce nuevos modelos con el uso de los métodos de análisis a escala y de perturbación a partir de las ecuaciones de aguas poco profundas con base en fluidos barotrópicos. En este artículo se obtuvieron algunos modelos semigeostróficos barotrópicos para aplicar en zonas de topografía inestable con diferentes magnitudes y considerar especialmente la condición del extenso terreno. La topografía inestable es más propicia para describir el movimiento del estado fluido de la tierra debido al cambio del clima y ambiente, por lo tanto los modelos modificados son ecuaciones de vorticidad potenciales más razonables. Si no se considera la influencia de la topografía y otros factores, los modelos se reducirían a las ecuaciones generales semigeostróficas barotrópicas de estudios anteriores.

scholarly journals Geomagnetism, volcanoes, global climate change, and predictability. A progress report

1994 ◽  
Vol 37 (5 Sup.) ◽  
Author(s):  
G. P. Gregori
Keyword(s):  
State Of The Art ◽  
Global Climate ◽  
Data Series ◽  
Theoretical Studies ◽  
Data Handling ◽  
Future Perspectives ◽  
Proxy Data ◽  
Interstellar Clouds ◽  
The Earth ◽  
Glacier Melting

A model is investigated, by which the encounters of the solar system with dense interstellar clouds ought to trigger either geomagnetic field reversals or excursions, that produce extra electric currents within the Earth dynamo, that cause extra Joule's heating, that supplies volcanoes and endogenous processes. Volcanoes increase the Earth degassing into the atmosphere, hence the concentration of the minor atmospheric constituents, including the greenhouse gases, hence they affect climate temperature, glacier melting, sea level and global change. This investigation implies both theoretical studies and observational data handling on different time scales, including present day phenomena, instrumental data series, historical records, proxy data, and geological and palaeontological evidences. The state of the art is briefly outlined, mentioning some already completed achievements, investigations in progress, and future perspectives.

scholarly journals Mother Earth, Mother Africa and Biblical Studies : Interpretations in the Context of Climate Change

2021 ◽  
Author(s):  
Paul L. Leshota ◽  
Ericka S. Dunbar ◽  
Musa W. Dube ◽  
Malebogo Kgalemang
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Female Gender ◽  
Biblical Studies ◽  
African Women ◽  
Environmental Crisis ◽  
Cultural Resources ◽  
Marginalized Communities ◽  
The Earth ◽  
Climate Crisis

Climate change and its global impact on all people, especially the marginalized communities, is widely recognized as the biggest crisis of our time. It is a context that invites all subjects and disciplines to bring their resources in diagnosing the problem and seeking the healing of the Earth. The African continent, especially its women, constitute the subalterns of global climate crisis. Can they speak? If they speak, can they be heard? Both the Earth and the Africa have been identified with the adjective “Mother.” This gender identity tells tales in patriarchal and imperial worlds that use the female gender to signal legitimation of oppression and exploitation. In this volume, African women theologians and their female-identifying colleagues, struggle with reading and interpreting religious texts in the context of environmental crisis that are threatening life on Earth. The chapters interrogate how biblical texts and African cultural resources imagine the Earth and our relationship with the Earth: Do these texts offer readers windows of hope for re-imagining liberating relationship with the Earth? How do they intersect with gender, race, empire, ethnicity, sexuality among others? Beginning with Genesis, journeying through Exodus, Ruth, Ecclesiastes and the Gospel of John, the authors seek to read in solidarity with the Earth, for the healing of the whole Earth community.

The Earth energy imbalance – new advances and remaining challenges

2021 ◽  
Author(s):  
Karina von Schuckmann
Keyword(s):  
Global Climate ◽  
Research Effort ◽  
Atmospheric Composition ◽  
Multidisciplinary Research ◽  
Energy Imbalance ◽  
The Past ◽  
The Earth ◽  
Multiple Measurements ◽  
Composition Changes ◽  
Past Half

<p>Human-induced atmospheric composition changes cause a radiative imbalance at the top of the atmosphere which is driving global warming. This simple number, the Earth energy imbalance (EEI), is the most fundamental metric that the scientific community and public must be aware of as the measure of how well the world is doing in the task of bringing climate change under control. Combining multiple measurements and approaches in an optimal way holds considerable promise for estimating EEI and continued quantification and reduced uncertainties can be best achieved through the maintenance of the current global climate observing system, its extension into areas of gaps in the sampling, advance on instrumental limitations, and the establishment of an international framework for concerted multidisciplinary research effort. This talk will provide an overview on the different approaches and their challenges for estimating the EEI. A particular emphasis will be drawn on the heat gain of the Earth system over the past half of a century – and particularly how much and where the heat is distributed – which is fundamental to understanding how this affects warming ocean, atmosphere and land; rising surface temperature; sea level; and loss of grounded and floating ice, which are critical concerns for society.</p><p> </p>

Consuming the Earth

2016 ◽  
Author(s):  
Peter Dauvergne
Keyword(s):  
Tropical Forests ◽  
Renewable Resources ◽  
Ecological Footprint ◽  
Global Climate ◽  
Ocean Currents ◽  
Biological Integrity ◽  
The Earth ◽  
Per Capita

The ecological footprint of humanity, as this chapter documents, is now over 1.5 times higher than the earth’s capacity to regenerate renewable resources and assimilate waste. This crisis is worsening as the biological integrity of ecosystems continues to decline and as the global ecological footprint continues to rise (with per capita footprints rising in most countries). This chapter documents some of the accompanying ecological costs of rising rates of unsustainable consumption for forests, oceans, freshwater, soils, species, and the global climate. More than half of the world’s tropical forests have been cleared since 1950, with loggers, ranchers, and plantation owners continuing to clear millions of hectares a year. The global climate is warming, glaciers are melting, and ocean currents are shifting. And each day another 10 to 500 species (of the earth’s 8–9 million species) are going extinct.

Effects of Continents and Supercontinents on Climate

2004 ◽  
Author(s):  
John J. W. Rogers ◽  
M. Santosh
Keyword(s):  
Global Climate ◽  
Climatic Conditions ◽  
Polar Regions ◽  
The North ◽  
Rock Types ◽  
Control Climate ◽  
The Earth ◽  
History Of ◽  
Earth’S Climate ◽  
Geologic Record

Continents affect the earth’s climate because they modify global wind patterns, control the paths of ocean currents, and absorb less heat than seawater. Throughout earth history the constant movement of continents and the episodic assembly of supercontinents has influenced both global climate and the climates of individual continents. In this chapter we discuss both present climate and the history of climate as far back in the geologic record as we can draw inferences. We concentrate on longterm changes that are affected by continental movements and omit discussion of processes with periodicities less than about 20,000 years. We refer readers to Clark et al. (1999) and Cronin (1999) if they are interested in such short-term processes as El Nino, periodic variations in solar irradiance, and Heinrich events. The chapter is divided into three sections. The first section describes the processes that control climate on the earth and includes a discussion of possible causes of glaciation that occurred over much of the earth at more than one time in the past. The second section investigates the types of evidence that geologists use to infer past climates. They include specific rock types that can form only under restricted climatic conditions, varieties of individual fossils, diversity of fossil populations, and information that the 18O/16O isotopic system can provide about temperatures of formation of ancient sediments. The third section recounts the history of the earth’s climate and relates changes to the growth and movement of continents. This history takes us from the Archean, when climates are virtually unknown, through various stages in the evolution of organic life, and ultimately to the causes of the present glaciation in both the north and the south polar regions. The earth’s climate is controlled both by processes that would operate even if continents did not exist and also by the positions and topographies of continents. We begin with the general controls, then discuss the specific effects of continents, and close with a brief discussion of processes that cause glaciation. The general climate of the earth is determined by the variation in the amount of sunshine received at different latitudes, by the earth’s rotation, and by the amount of arriving solar energy that is retained in the atmosphere.

Introduction

2004 ◽  
Author(s):  
Robert A. Berner
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Carbon Cycle ◽  
Global Climate ◽  
Geological Time ◽  
Short Term ◽  
Quaternary Period ◽  
Geological Time Scale ◽  
The Earth

The cycle of carbon is essential to the maintenance of life, to climate, and to the composition of the atmosphere and oceans. What is normally thought of as the “carbon cycle” is the transfer of carbon between the atmosphere, the oceans, and life. This is not the subject of interest of this book. To understand this apparently confusing statement, it is necessary to separate the carbon cycle into two cycles: the short-term cycle and the long-term cycle. The “carbon cycle,” as most people understand it, is represented in figure 1.1. Carbon dioxide is taken up via photosynthesis by green plants on the continents or phytoplankton in the ocean. On land carbon is transferred to soils by the dropping of leaves, root growth, and respiration, the death of plants, and the development of soil biota. Land herbivores eat the plants, and carnivores eat the herbivores. In the oceans the phytoplankton are eaten by zooplankton that are in turn eaten by larger and larger organisms. The plants, plankton, and animals respire CO2. Upon death the plants and animals are decomposed by microorganisms with the ultimate production of CO2. Carbon dioxide is exchanged between the oceans and atmosphere, and dissolved organic matter is carried in solution by rivers from soils to the sea. This all constitutes the shortterm carbon cycle. The word “short-term” is used because the characteristic times for transferring carbon between reservoirs range from days to tens of thousands of years. Because the earth is more than four billion years old, this is short on a geological time scale. As the short-term cycle proceeds, concentrations of the two principal atmospheric gases, CO2 and CH4, can change as a result of perturbations of the cycle. Because these two are both greenhouse gases—in other words, they adsorb outgoing infrared radiation from the earth surface—changes in their concentrations can involve global warming and cooling over centuries and many millennia. Such changes have accompanied global climate change over the Quaternary period (past 2 million years), although other factors, such as variations in the receipt of solar radiation due to changes in characteristics of the earth’s orbit, have also contributed to climate change.

scholarly journals The Frequency and Predicted Consequences of Cosmic Impacts in the Last 65 Million Years

2004 ◽  
Vol 213 ◽  
pp. 289-294
Author(s):  
Michael Paine ◽  
Benny Peiser
Keyword(s):  
Financial Support ◽  
Global Climate ◽  
Catastrophic Event ◽  
The Past ◽  
The Earth ◽  
Global Events ◽  
Impact Events

Sixty five million years ago a huge asteroid collided with the Earth and ended the long reign of the dinosaurs. In the aftermath of this catastrophic event, the mammals arose and eventually mankind came to dominate the surface of the planet. The Earth, however, has not been free from severe impacts since the time of the dinosaur killer. We examine the likely frequency of major impact events over the past 65 million years, the evidence for these impacts and the predicted consequences of various types of impacts. It is evident that the mammals had to survive frequent severe disruptions to the global climate, and it is likely that over the past 5 million years hominids were faced with several catastrophic global events. Smaller but strategically located impact events could bring down our civilisation if they occurred today. Mankind has recently developed the expertise to predict and mitigate future impacts, but political and financial support are lacking.

Solar Energy and Global Climate Change

2014 ◽  
Vol 875-877 ◽  
pp. 1767-1770
Author(s):  
Jia Lin Lin ◽  
Tao Tao Qian
Keyword(s):  
Solar Energy ◽  
Global Climate ◽  
Surface Energy Budget ◽  
The Earth ◽  
Decadal Variations ◽  
Global Dimming ◽  
The Individual ◽  
Solar Energy Input ◽  
Global Mean

Previous studies have shown that the solar energy input to the earth system underwent significant decadal variations at individual surface energy budget stations, with a global dimming from 1950s to 1980s, but a global brightening from 1980s to 2000s, and a mixed tendency at different locations thereafter. Here we use a new global gridded solar irradiance dataset to show that the previous results from individual stations represent well the regional means but not the global mean or hemisphere means. The global mean has a decadal variation that is quite different from the individual station results reported in previous studies, which comes from the fact that the southern hemisphere mean has an opposite trend with the northern hemisphere mean. No long-term global dimming trend is found associated with global warming

scholarly journals Analytically tractable climate-carbon cycle feedbacks under 21st century anthropogenic forcing

2017 ◽  
Author(s):  
Steven J. Lade ◽  
Jonathan F. Donges ◽  
Ingo Fetzer ◽  
John M. Anderies ◽  
Christian Beer ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Model Test ◽  
Global Climate ◽  
Earth System ◽  
Planetary Boundaries ◽  
Cycle Model ◽  
Carbon Cycle Model ◽  
The Earth ◽  
Analytical Expressions ◽  
Earth System Models

Abstract. Changes to climate-carbon cycle feedbacks may significantly affect the Earth System’s response to greenhouse gas emissions. These feedbacks are usually analysed from numerical output of complex and arguably opaque Earth System Models (ESMs). Here, we construct a stylized global climate-carbon cycle model, test its output against complex ESMs, and investigate the strengths of its climate-carbon cycle feedbacks analytically. The analytical expressions we obtain aid understanding of carbon-cycle feedbacks and the operation of the carbon cycle. We use our results to analytically study the relative strengths of different climate-carbon cycle feedbacks and how they may change in the future, as well as to compare different feedback formalisms. Simple models such as that developed here also provide workbenches for simple but mechanistically based explorations of Earth system processes, such as interactions and feedbacks between the Planetary Boundaries, that are currently too uncertain to be included in complex ESMs.

scholarly journals The “faint young Sun paradox”: further exploration of the role of dynamical heat-flux feed backs in maintaining global climate stability

1995 ◽  
Vol 41 (137) ◽  
pp. 87-90 ◽  
Author(s):  
Gyula I. Molnar ◽  
William J. Gutowski
Keyword(s):  
Heat Flux ◽  
Climate Model ◽  
Climate Modeling ◽  
Global Climate ◽  
Early Earth ◽  
Meridional Heat Transport ◽  
Climate Stability ◽  
The Earth ◽  
Physically Based

AbstractThe climate-modeling problems associated with global change underline the importance of understanding paleoclimates. The available evidence, which suggests that the Earth has never been fully glaciated, poses an especially serious problem for the early Earth when the Sun was about 20–30% fainter than today. In conventional explanations of this “faint young Sun paradox”, presumed very high levels of atmospheric greenhouse gases are required to prevent runaway glaciation of the Earth. Here we explore other possible explanations of this paradox. As an extension of our previous work on this subject, we illustrate how-dynamical beat-flux feed backs may have prevented the early Earth from freezing. Our simulations are carried out using a two-dimensional, seasonal-climate model with physically based parameterizations for atmospheric meridional-heat transport and sea ice. It ís found that dynamical heat-flux feed backs alone may have protected the Archean Earth against a runaway glaciation to a considerable degree.

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