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.

B–Tm Ash of a Catastrophic Eruption of Baitoushan Volcano in Terrestrial Deposits of Primorye as an Age Marker of the Medieval Warm Period in the Holocene

2020 ◽  
Vol 494 (2) ◽  
pp. 779-786
Author(s):  
N. G. Razjigaeva ◽  
L. A. Ganzey ◽  
T. A. Grebennikova ◽  
L. M. Mokhova ◽  
Kh. A. Arslanov ◽  
...  
Keyword(s):  
Medieval Warm Period ◽  
Warm Period ◽  
The Holocene

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.

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

Simulating Past and Forecasting Future Climates

1993 ◽  
Vol 20 (4) ◽  
pp. 339-346 ◽  
Author(s):  
Reid A. Bryson
Keyword(s):  
Carbon Dioxide ◽  
Global Climate ◽  
Rapid Change ◽  
Carbon Dioxide Content ◽  
Volcanic Origin ◽  
The North ◽  
The Earth ◽  
History Of ◽  
Climatic History ◽  
Volcanic Aerosols

Climatic change is not a new phenomenon, nor is it random, as most of the variation can be explained in terms of variations in the sunlight reaching the surface of the Earth. The solar energy reaching the surface is modified by the aerosols in the atmosphere, however, and that means primarily aerosols of volcanic origin.The climatic history of the Earth is divided up into episodes with abrupt beginnings and ends. Rapid changes from one climatic state to another are normal. The fluctuations within this century do not appear to be unusual in any respect.To the Author's knowledge there is no evidence that past climatic changes, including those of the last decades, are related to changes in carbon dioxide in the atmosphere—except perhaps for warmer nights in the North American mid-west. It is not possible to simulate past climates using carbon dioxide content as the main variable, but it is possible to do so using calculated solar radiation as modified by volcanic aerosols. This strongly suggests that forecasts of the climatic future based on carbon dioxide increases are suspect.Computerized models of the climate that can simulate decadal and century-long variations of climate as well as variations on the millennium scale, suggest that the climate will not warm dramatically in the next fifty years, but will, rather soon after that, begin a rather rapid change towards the next glacial climate.Changes in our global array of cultures, sufficient to affect the global climate in a way which we perceive as beneficial, probably are not possible within centuries without massive physical conflict. There are both winners and losers when the climate changes in a non-uniform pattern, as it always does. It is a well-known fact that a global change of 0.5°C in mean temperature, such as has happened in recent years, might produce some regions of 10°C change in either direction and some regions with no change at all, and additionally an array of rainfall changes of various magnitudes. Russians would welcome warming of their climate!The problems with attempting to modify the global climate in a particular direction are enormous and would be incredibly costly. This is compounded by our not knowing what the climate would do without intervention. Only one thing is truly clear, and it is that the present knowledge of the climatic effect of changing carbon dioxide content of the atmosphere is totally inadequate as a basis for initiating any global attempt to change the climate.The indicated action would appear to be to engage in some high-quality climatic research based on sound science before taking global risks greater than those that might arise from the putative ‘global warming’.

scholarly journals A comprehensive history of climate and habitat stability of the last 800&thinsp,000 years

2019 ◽  
Author(s):  
Mario Krapp ◽  
Robert Beyer ◽  
Stephen L. Edmundson ◽  
Paul J. Valdes ◽  
Andrea Manica
Keyword(s):  
Climate Model ◽  
Temporal Dynamics ◽  
Global Climate ◽  
Global Climate Model ◽  
Regional Scale ◽  
Geological Time ◽  
Comprehensive Overview ◽  
Long Term Stability ◽  
History Of

Abstract. A detailed and accurate reconstruction of the past climate is essential in understanding the interactions between ecosystems and their environment through time. We know that climatic drivers have shaped the distribution and evolution of species, including our own, and their habitats. Yet, spatially-detailed climate reconstructions that continuously cover the Quaternary do not exist. This is mainly because no paleoclimate model can reconstruct regional-scale dynamics over geological time scales. Here we develop a statistical emulator, the Global Climate Model Emulator (GCMET), which reconstructs the climate of the last 800 000 years with unprecedented spatial detail. GCMET captures the temporal dynamics of glacial-interglacial climates as an Earth System Model of Intermediate Complexity would whilst resolving the local dynamics with the accuracy of a Global Climate Model. It provides a new, unique resource to explore the climate of the Quaternary, which we use to investigate the long-term stability of major habitat types. We identify a number of stable pockets of habitat that have remained unchanged over the last 800 thousand years, acting as potential long-term evolutionary refugia. Thus, the highly detailed, comprehensive overview of climatic changes through time delivered by GCMET provides the needed resolution to quantify the role of long term habitat change and fragmentation in an ecological and anthropological context.

scholarly journals A Holocene black carbon ice-core record of biomass burning in the Amazon Basin from Illimani, Bolivia

2018 ◽  
Author(s):  
Dimitri Osmont ◽  
Michael Sigl ◽  
Anja Eichler ◽  
Theo M. Jenk ◽  
Margit Schwikowski
Keyword(s):  
Black Carbon ◽  
Biomass Burning ◽  
Amazon Basin ◽  
Ice Core ◽  
Medieval Warm Period ◽  
Warm Period ◽  
The Holocene ◽  
Holocene Climatic Optimum ◽  
Ice Core Record ◽  
Climatic Optimum

Abstract. The Amazon Basin is one of the major contributors to global biomass burning emissions. However, regional paleofire trends remain partially unknown. Due to their proximity to the Amazon Basin, Andean ice cores are suitable to reconstruct paleofire trends in South America and improve our understanding of the complex linkages between fires, climate and humans. Here we present the first refractory black carbon (rBC) ice-core record from the Andes as a proxy for biomass burning emissions in the Amazon Basin, derived from an ice core drilled at 6300 m a.s.l. from Illimani glacier in the Bolivian Andes and spanning the entire Holocene back to the last deglaciation 13 000 years ago. The Illimani rBC record displays a strong seasonality with low values during the wet season and high values during the dry season due to the combination of enhanced biomass burning emissions in the Amazon Basin and less precipitation at the Illimani site. Significant positive (negative) correlations were found with reanalyzed temperature (precipitation) data, respectively, for regions in Eastern Bolivia and Western Brazil characterized by a substantial fire activity. rBC long-term trends indirectly reflect regional climatic variations through changing biomass burning emissions as they show higher (lower) concentrations during warm/dry (cold/wet) periods, respectively, in line with climate variations such as the Younger Dryas, the 8.2 ka event, the Holocene Climatic Optimum, the Medieval Warm Period or the Little Ice Age. The highest rBC concentrations of the entire record occurred during the Holocene Climatic Optimum between 7000 and 3000 BC, suggesting that this outstanding warm and dry period caused an exceptional biomass burning activity, unprecedented in the context of the past 13 000 years. Recent rBC levels, rising since 1730 AD in the context of increasing temperatures and deforestation, are similar to those of the Medieval Warm Period. No decrease was observed in the 20th century, in contradiction with the global picture (broken fire hockey stick hypothesis).

Asian paleoenvironments, paleogeography and paleobiodiversity interactions during the Greenhouse-Icehouse transition

2020 ◽  
Author(s):  
Guillaume Dupont-Nivet ◽  
Niels Meijer ◽  
Mustafa Kaya ◽  
Jan Westerweel ◽  
Delphine Tardif ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Climate Modeling ◽  
Global Climate ◽  
Sedimentary Records ◽  
Driving Mechanisms ◽  
Magmatic Rocks ◽  
History Of ◽  
Pollen Grain Size ◽  
Forcing Mechanisms

<p>The ongoing surge of international research on Asian Climate and Tectonics enables to better assess interactions between forcing mechanisms (global climate, India-Asia collision, Tibetan Plateau growth) and paleoenvironmental changes (monsoons, aridification), land-sea distribution, surface processes, paleobiogeographic evolution and the global carbon cycle. We review here the progress of the ERC MAGIC project (Monsoons in Asia caused Greenhouse to Icehouse Change?) integrating regional geodynamic constraints, well-dated environmental / biodiversity records and climate modeling. MAGIC focuses on the Paleogene period that includes the global Greenhouse to Icehouse cooling, the early collision and plateau growth and associated regional development of monsoons and westerlies over the Proto-Paratethys sea. Our work focuses on three areas constraining Asian paleoenvironments. (1) In Myanmar, paleomagnetic results, new dating of magmatic rocks and sediments along with additional detrital geochronology and basin analysis of the Burmese subduction margin and implications for the history of India-Asia convergence. (2) Along the Northeastern Tibetan Plateau margin, the combination of multiple proxies (leaf wax stable isotope, pollen, grain size, etc…)  applied to an extended lacustrine Paleogene record enables to identify precisely Asian climate changes and their consequences on ecosystems. (3) In westernmost China and Tajikistan, the proto-Paratethys sea fluctuations and the sedimentary records of Pamir tectonic evolution are now precisely dated enabling to constrain driving mechanisms and paleoenvironmental consequences. Together these results are used to constrain climate modeling experiments which permit validation of hypotheses on interactions between paleogeography, paleoenvironments and paleobiodiversity at Asian and global scales in response to long-term and short-term events.</p>

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 Progress in the Infrared Remote Sensing of Volcanic Activity

2016 ◽  
Author(s):  
Matthew Blackett
Keyword(s):  
Heat Transfer ◽  
Remote Sensing ◽  
Volcanic Activity ◽  
Theoretical Basis ◽  
Safe Distance ◽  
Infrared Sensors ◽  
The Earth ◽  
Infrared Remote Sensing ◽  
Challenges And Opportunities ◽  
History Of

Volcanic activity essentially consists of the transfer of heat from the Earth’ interior to the surface. The precise signature of this heat transfer relates directly to the processes underway at and within a particular volcano and this can be observed, at a safe distance, remotely, using infrared sensors that are present on Earth-orbiting satellites. For over 50 years, scientists have perfected this art using sensors intended for other purposes, and they are now in a position to determine the particular sort of activity that characterizes different volcanoes. This review will describe the theoretical basis of the discipline and then discuss the sensors available for the task and the history of their use. Challenges and opportunities for future development in the discipline are then discussed.

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