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 Investigations of long-term trends in the ionosphere with world-wide ionosonde observations*

2005 ◽  
Vol 2 ◽  
pp. 253-258 ◽  
Author(s):  
J. Bremer
Keyword(s):  
Data Series ◽  
Model Calculations ◽  
Maximum Electron Density ◽  
Model Predictions ◽  
Density Values ◽  
Long Term Trends ◽  
Experimental Values ◽  
The Individual ◽  
Global Mean

Abstract. Basing on model calculations by Roble and Dickinson (1989) for an increasing content of atmospheric greenhouse gases in the Earth’s atmosphere Rishbeth (1990) predicted a lowering of the ionospheric F2- and E-regions. Later Rishbeth and Roble (1992) also predicted characteristic longterm changes of the maximum electron density values of the ionospheric E-, F1-, and F2-layers. Long-term observations at more than 100 ionosonde stations have been analyzed to test these model predictions. In the E- and F1-layers the derived experimental results agree reasonably with the model trends (lowering of h'E and increase of ƒoE and ƒoF1, in the E-layer the experimental values are however markedly stronger than the model data). In the ionospheric F2-region the variability of the trends derived at the different individual stations for hmF2 as well as ƒoF2 values is too large to estimate reasonable global mean trends. The reason of the large differences between the individual trends is not quite clear. Strong dynamical effects may play an important role in the F2-region. But also inhomogeneous data series due to technical changes as well as changes in the evaluation algorithms used during the long observation periods may influence the trend analyses.

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 Proxy evidence for state-dependence of climate sensitivity in the Eocene greenhouse

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
E. Anagnostou ◽  
E. H. John ◽  
T. L. Babila ◽  
P. F. Sexton ◽  
A. Ridgwell ◽  
...  
Keyword(s):  
Climate Sensitivity ◽  
Global Climate ◽  
State Dependence ◽  
The State ◽  
State Dependency ◽  
The Past ◽  
Global Mean Temperature ◽  
The Earth ◽  
Modelling Studies ◽  
Global Mean

Abstract Despite recent advances, the link between the evolution of atmospheric CO2 and climate during the Eocene greenhouse remains uncertain. In particular, modelling studies suggest that in order to achieve the global warmth that characterised the early Eocene, warmer climates must be more sensitive to CO2 forcing than colder climates. Here, we test this assertion in the geological record by combining a new high-resolution boron isotope-based CO2 record with novel estimates of Global Mean Temperature. We find that Equilibrium Climate Sensitivity (ECS) was indeed higher during the warmest intervals of the Eocene, agreeing well with recent model simulations, and declined through the Eocene as global climate cooled. These observations indicate that the canonical IPCC range of ECS (1.5 to 4.5 °C per doubling) is unlikely to be appropriate for high-CO2 warm climates of the past, and the state dependency of ECS may play an increasingly important role in determining the state of future climate as the Earth continues to warm.

scholarly journals Taking Students on a Journey to El Yunque

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Steven McGee ◽  
Jess K. Zimmerman
Keyword(s):  
Temporal Dynamics ◽  
Science Curriculum ◽  
Global Climate ◽  
Ecosystem Dynamics ◽  
Long Term Ecological Research ◽  
Hurricane Impact ◽  
The Individual ◽  
Long Term Impact ◽  
The Impact

As the developers of Journey to El Yunque, we have taken a different approach to the process of designing a science curriculum. Rather than start with a specific set of concepts or skills to target as learning outcomes, we started by identifying a specific community of practice to which we sought to connect students. Researchers in the El Yunque rainforest in Puerto Rico have been studying the impact of hurricanes on ecosystem dynamics and have been modeling what the long-term impact would be if changes to the global climate increase the frequency of severe hurricanes. Therefore, hurricane impact became the focal phenomenon for the unit. We modeled the process of investigating hurricane impact after the long-term ecological research practices of researchers in El Yunque. Students begin by investigating the long-term impact of hurricanes on the producers in El Yunque. Next students investigate the long-term impact of hurricanes on various consumers in the rainforest. Finally, students investigate how hurricanes impact the cycling of resources directly as well as indirectly through changes in organisms’ use of those resources in the rainforest. A central tension in the design process is how to coherently represent the spatial relationships between the components of the ecosystem and the temporal dynamics of the individual components. In this paper, we present the evolution of the program as we sought to balance that design tension and build an environment that connects students to the central phenomenon and practices of the community of researchers in El Yunque. 

scholarly journals Analysis of Long-Term Moon-Based Observation Characteristics for Arctic and Antarctic

2019 ◽  
Vol 11 (23) ◽  
pp. 2805 ◽  
Author(s):  
Yue Sui ◽  
Huadong Guo ◽  
Guang Liu ◽  
Yuanzhen Ren
Keyword(s):  
Global Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
Earth Observation ◽  
Polar Regions ◽  
The Moon ◽  
The North ◽  
The Earth ◽  
The Antarctic

The Antarctic and Arctic have always been critical areas of earth science research and are sensitive to global climate change. Global climate change exhibits diversity characteristics on both temporal and spatial scales. Since the Moon-based earth observation platform could provide large-scale, multi-angle, and long-term measurements complementary to the satellite-based Earth observation data, it is necessary to study the observation characteristics of this new platform. With deepening understanding of Moon-based observations, we have seen its good observation ability in the middle and low latitudes of the Earth’s surface, but for polar regions, we need to further study the observation characteristics of this platform. Based on the above objectives, we used the Moon-based Earth observation geometric model to quantify the geometric relationship between the Sun, Moon, and Earth. Assuming the sensor is at the center of the nearside of the Moon, the coverage characteristics of the earth feature points are counted. The observation intervals, access frequency, and the angle information of each point during 100 years were obtained, and the variation rule was analyzed. The research showed that the lunar platform could carry out ideal observations for the polar regions. For the North and South poles, a continuous observation duration of 14.5 days could be obtained, and as the latitude decreased, the duration time was reduced to less than one day at the latitude of 65° in each hemisphere. The dominant observation time of the North Pole is concentrated from mid-March to mid-September, and for the South Pole, it is the rest of the year, and as the latitude decreases, it extends outward from both sides. The annual coverage time and frequency will change with the relationship between the Moon and the Earth. This study also proves that the Moon-based observation has multi-angle observation advantages for the Arctic and the Antarctic areas, which can help better understand large-scale geoscientific phenomena. The above findings indicate that the Moon-based observation can be applied as a new type of remote sensing technology to the observation field of the Earth’s polar regions.

scholarly journals Testing for the Possible Influence of Unknown Climate Forcings upon Global Temperature Increases from 1950 to 2000

2012 ◽  
Vol 25 (20) ◽  
pp. 7163-7172 ◽  
Author(s):  
Bruce T. Anderson ◽  
Jeff R. Knight ◽  
Mark A. Ringer ◽  
Jin-Ho Yoon ◽  
Annalisa Cherchi
Keyword(s):  
Twentieth Century ◽  
Climate Variability ◽  
Radiative Forcing ◽  
Global Climate ◽  
Global Scale ◽  
Sea Surface ◽  
Near Surface ◽  
Surface Temperatures ◽  
Global Mean

Abstract Global-scale variations in the climate system over the last half of the twentieth century, including long-term increases in global-mean near-surface temperatures, are consistent with concurrent human-induced emissions of radiatively active gases and aerosols. However, such consistency does not preclude the possible influence of other forcing agents, including internal modes of climate variability or unaccounted for aerosol effects. To test whether other unknown forcing agents may have contributed to multidecadal increases in global-mean near-surface temperatures from 1950 to 2000, data pertaining to observed changes in global-scale sea surface temperatures and observed changes in radiatively active atmospheric constituents are incorporated into numerical global climate models. Results indicate that the radiative forcing needed to produce the observed long-term trends in sea surface temperatures—and global-mean near-surface temperatures—is provided predominantly by known changes in greenhouse gases and aerosols. Further, results indicate that less than 10% of the long-term historical increase in global-mean near-surface temperatures over the last half of the twentieth century could have been the result of internal climate variability. In addition, they indicate that less than 25% of the total radiative forcing needed to produce the observed long-term trend in global-mean near-surface temperatures could have been provided by changes in net radiative forcing from unknown sources (either positive or negative). These results, which are derived from simple energy balance requirements, emphasize the important role humans have played in modifying the global climate over the last half of the twentieth century.

MEDIEVAL WARM PERIOD OF THE HOLOCENE AND ITS POSSIBLE CAUSES

2020 ◽  
Vol 42 (4) ◽  
pp. 395-405
Author(s):  
Valeriy FEDOROV ◽  
◽  
Pavel GREBENNIKOV ◽  
Keyword(s):  
Heat Transfer ◽  
Global Climate ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Meridional Transport ◽  
The Holocene ◽  
The Earth ◽  
Winter Half ◽  
History Of

A brief overview of reliably established global climate events in the Holocene is provided. On the basis of high-precision astronomical ephemeris with high spatial and temporal resolution, the annual and seasonal insolation of the Earth and hemispheres was calculated for the period 3000 BC-AD 2999. According to the results of calculations, the values of insolation contrast were obtained in a generalized manner (for the regions of the heat source and sink), reflecting the changes in the meridional insolation gradient that controls the meridional heat transfer in the hemispheres. The character of long-term variations of both the annual and seasonal arrival, and the annual and seasonal meridional transport of radiation heat in the hemispheres was obtained. The long-term distribution of insolation characteristics of the Earth and hemispheres (annual and seasonal insolation and insolation contrast in the hemispheres) is analyzed. The synchronicity of the extrema of the irradiation characteristics with the global climatic event in the history of the Earth (the Medieval Warm Period of the Holocene) was revealed. On the basis of the revealed synchronicity, the maximum insolation contrast in the winter half of the year in the Northern Hemisphere (the maximum of meridional heat transfer in the winter half of the year), as well as the maximum of interhemispheric heat transfer may be determined to be the reasons for the Medieval Warm Period.

scholarly journals Deep-reaching acceleration of global mean ocean circulation over the past two decades

2020 ◽  
Vol 6 (6) ◽  
pp. eaax7727 ◽  
Author(s):  
Shijian Hu ◽  
Janet Sprintall ◽  
Cong Guan ◽  
Michael J. McPhaden ◽  
Fan Wang ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Ocean Circulation ◽  
Global Climate ◽  
Circulation System ◽  
The Past ◽  
Tropical Oceans ◽  
Increasing Trend ◽  
Long Term Trend ◽  
Global Mean

Ocean circulation redistributes Earth’s energy and water masses and influences global climate. Under historical greenhouse warming, regional ocean currents show diverse tendencies, but whether there is an emerging trend of the global mean ocean circulation system is not yet clear. Here, we show a statistically significant increasing trend in the globally integrated oceanic kinetic energy since the early 1990s, indicating a substantial acceleration of global mean ocean circulation. The increasing trend in kinetic energy is particularly prominent in the global tropical oceans, reaching depths of thousands of meters. The deep-reaching acceleration of the ocean circulation is mainly induced by a planetary intensification of surface winds since the early 1990s. Although possibly influenced by wind changes associated with the onset of a negative Pacific decadal oscillation since the late 1990s, the recent acceleration is far larger than that associated with natural variability, suggesting that it is principally part of a long-term trend.

scholarly journals The influence of vegetation dynamics on anthropogenic climate change

2012 ◽  
Vol 3 (2) ◽  
pp. 485-522 ◽  
Author(s):  
U. Port ◽  
V. Brovkin ◽  
M. Claussen
Keyword(s):  
Climate Change ◽  
Vegetation Cover ◽  
Vegetation Dynamics ◽  
Global Climate ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Tree Cover ◽  
Atmospheric Co2 Concentration ◽  
The Earth ◽  
Global Mean

Abstract. In this study, vegetation-climate and vegetation-carbon cycle interactions during anthropogenic climate change are assessed by using the Earth System Model MPI ESM including a module for vegetation dynamics. We assume anthropogenic CO2 emissions according to the RCP 8.5 scenario in the period from 1850 to 2120 and shut them down afterwards to evaluate the equilibrium response of the Earth System by 2300. Our results suggest that vegetation dynamics have a considerable influence on the changing global and regional climate. In the simulations, global mean tree cover extends by 2300 due to increased atmospheric CO2 concentration and global warming. Thus, land carbon uptake is higher and atmospheric CO2 concentration is lower by about 40 ppm when considering dynamic vegetation compared to a static pre-industrial vegetation cover. The reduced atmospheric CO2 concentration is equivalent to a lower global mean temperature. Moreover, biogeophysical effects of vegetation cover shifts influence the climate on a regional scale. Expanded tree cover in the northern high latitudes results in a reduced albedo and additional warming. In the Amazon region, declined tree cover causes a higher temperature as evapotranspiration is reduced. In total, we find that vegetation dynamics have a slight attenuating effect on global climate change as the global climate cools by 0.22 K in 2300 due to natural vegetation cover shifts.

scholarly journals Heat stored in the Earth system: Where does the energy go? The GCOS Earth heat inventory team

2020 ◽  
Author(s):  
Karina von Schuckmann ◽  
Lijing Cheng ◽  
Matthew D. Palmer ◽  
Caterina Tassone ◽  
Valentin Aich ◽  
...  
Keyword(s):  
Global Climate ◽  
Atmospheric Composition ◽  
Global Ocean ◽  
Earth System ◽  
Heat Gain ◽  
The Past ◽  
The Earth ◽  
International Assessment ◽  
Composition Changes

Abstract. Human-induced atmospheric composition changes cause a radiative imbalance at the top-of-atmosphere which is driving global warming. This Earth Energy Imbalance (EEI) is a fundamental metric of climate change. Understanding the heat gain of the Earth system from this accumulated heat – and particularly how much and where the heat is distributed in the Earth system – is fundamental to understanding how this affects warming oceans, atmosphere and land, rising temperatures and sea level, and loss of grounded and floating ice, which are fundamental concerns for society. This study is a Global Climate Observing System (GCOS) concerted international effort to update the Earth heat inventory, and presents an updated international assessment of ocean warming estimates, and new and updated estimates of heat gain in the atmosphere, cryosphere and land over the period 1960–2018. The study obtains a consistent long-term Earth system heat gain over the past 58 years, with a total heat gain of 393 ± 40 ZJ, which is equivalent to a heating rate of 0.42 ± 0.04 W m−2. The majority of the heat gain (89 %) takes place in the global ocean (0–700 m: 53 %; 700–2000 m: 28 %; > 2000 m: 8 %), while it amounts to 6 % for the land heat gain, to 4 % available for the melting of grounded and floating ice, and to 1 % for atmospheric warming. These new estimates indicate a larger contribution of land and ice heat gain (10 % in total) compared to previous estimates (7 %). There is a regime shift of the Earth heat inventory over the past 2 decades, which appears to be predominantly driven by heat sequestration into the deeper layers of the global ocean, and a doubling of heat gain in the atmosphere. However, a major challenge is to reduce uncertainties in the Earth heat inventory, which can be best achieved through the maintenance of the current global climate observing system, its extension into areas of gaps in the sampling, as well as to establish an international framework for concerted multi-disciplinary research of the Earth heat inventory. Earth heat inventory is published at DKRZ (https://www.dkrz.de/) under the doi: https://doi.org/10.26050/WDCC/GCOS_EHI_EXP (von Schuckmann et al., 2020).

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