Download or read book Stratosphere Troposphere Interaction During Stratospheric Sudden Warming Events written by Daniela Iris Vera Domeisen and published by . This book was released on 2012 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The stratosphere and the troposphere exhibit a strong coupling during the winter months. However, the coupling mechanisms between the respective vertical layers are not fully understood. An idealized spectral core dynamical model is utilized in the present study in order to clarify the coupling timing, location and mechanisms. Since the coupling between the winter stratosphere and troposphere is strongly intensified during times of strong stratospheric variability such as stratospheric warmings, these events are simulated in the described model for the study of stratosphere - troposphere coupling, while for comparison the coupling is also assessed for weaker stratospheric variability. While the upward coupling by planetary-scale Rossby waves in the Northern Hemisphere is well understood, the Southern Hemisphere exhibits traveling wave patterns with a weaker impact on the stratospheric ow. However the tropospheric generation mechanism of these waves is not well understood and is investigated in this study. It is found that in the model atmosphere without a zonally asymmetric wave forcing, traveling waves are unable to induce a significant wave ux into the stratosphere. In the absence of synoptic eddy activity, however, the tropospheric ow is baroclinically unstable to planetary-scale waves, and the generated planetary waves are able to propagate into the stratosphere and induce sudden warmings comparable in frequency and strength to the Northern Hemisphere. While baroclinic instability of long waves may be further strengthened by the addition of moisture, the real atmosphere also exhibits strong synoptic eddy activity, and it will have to be further explored if the atmosphere exhibits periods where synoptic eddies are weak enough to allow for baroclinic instability of long waves. In order to further investigate the coupling between the stratosphere and the troposphere, cases of strong coupling are investigated in the analysis of a Northern Hemisphere - like winter atmosphere. A realistic frequency and strength of sudden warmings is obtained using a zonal wave-2 topographic forcing. An angular momentum budget analysis yields that the Eliassen-Palm (EP) flux is closely balanced by the residual circulation dominated by the Coriolis term on a daily basis, while the change in zonal wind is a small residual between these dominant terms. In the stratosphere, the EP flux term and the Coriolis term balance well in time but not exactly in magnitude, yielding a polar stratospheric weakening of the zonal mean wind as observed during stratospheric warmings. In the troposphere, the loss of angular momentum before a sudden warming induces a weak negative annular mode response, which is amplified by the downward propagating signal about three weeks after the sudden warming. The angular momentum budget does not reveal the mechanism of downward influence, but it nevertheless clarifies the momentum balance of the stratosphere - troposphere system, indicating that the effects of the waves and the residual circulation have to be considered at the same time. Since the annular mode response cannot be directly investigated using the angular momentum budget, the annular mode coupling between the stratosphere and the troposphere is further investigated using a statistical approach. The annular mode response is often framed in terms of Empirical Orthogonal Functions (EOFs), but it is here found that for the stratosphere - troposphere system with its strong vertical pressure gradient, EOFs are strongly dependent on the weighting of the data, while Principal Oscillation Patterns (POPs) are considerably less sensitive to an applied weighting while returning the dominant structures of variability. This encourages further research and application of POP modes for the use of stratosphere - troposphere coupling. These findings represent an improvement of the understanding of stratosphere - troposphere coupling and the results are another step in the direction of finding the mechanism of stratosphere - troposphere coupling and the downward influence after the occurrence of a stratospheric sudden warming, which may influence long-term weather prediction in the troposphere.
Download or read book Middle Atmosphere written by PLUMB and published by Birkhäuser. This book was released on 2013-11-21 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: PAGEOPH, stratosphere, these differences provide us with new evidence, interpretation of which can materially help to advance our understanding of stratospheric dynamics in general. It is now weil established that smaller-scale motions-in particular gravity waves and turbulence-are of fundamental importance in the general circulation of the mesosphere; they seem to be similarly, if less spectacularly, significant in the troposphere, and probably also in the stratosphere. Our understanding of these motions, their effects on the mean circulation and their mutual interactions is progressing rapidly, as is weil illustrated by the papers in this issue; there are reports of observational studies, especially with new instruments such as the Japanese MV radar, reviews of the state of theory, a laboratory study and an analysis of gravity waves and their effects in the high resolution "SKYHI" general circulation model. There are good reasons to suspect that gravity waves may be of crucial significance in making the stratospheric circulation the way it is (modeling experience being one suggestive piece of evidence for this). Direct observational proof has thus far been prevented by the difficulty of making observations of such scales of motion in this region; in one study reported here, falling sphere observations are used to obtain information on the structure and intensity of waves in the upper stratosphere.
Download or read book Stratosphere Troposphere Interactions written by K. Mohanakumar and published by Springer Science & Business Media. This book was released on 2008-07-03 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stratospheric processes play a signi?cant role in regulating the weather and c- mate of the Earth system. Solar radiation, which is the primary source of energy for the tropospheric weather systems, is absorbed by ozone when it passes through the stratosphere, thereby modulating the solar-forcing energy reaching into the t- posphere. The concentrations of the radiatively sensitive greenhouse gases present in the lower atmosphere, such as water vapor, carbon dioxide, and ozone, control the radiation balance of the atmosphere by the two-way interaction between the stratosphere and troposphere. The stratosphere is the transition region which interacts with the weather s- tems in the lower atmosphere and the richly ionized upper atmosphere. Therefore, this part of the atmosphere provides a long list of challenging scienti?c problems of basic nature involving its thermal structure, energetics, composition, dynamics, chemistry, and modeling. The lower stratosphere is very much linked dynamically, radiatively,and chemically with the upper troposphere,even though the temperature characteristics of these regions are different. The stratosphere is a region of high stability, rich in ozone and poor in water - por and temperature increases with altitude. The lower stratospheric ozone absorbs the harmful ultraviolet (UV) radiation from the sun and protects life on the Earth. On the other hand, the troposphere has high concentrations of water vapor, is low in ozone, and temperature decreases with altitude. The convective activity is more in the troposphere than in the stratosphere.
Download or read book Sub seasonal to Seasonal Prediction written by Andrew Robertson and published by Elsevier. This book was released on 2018-10-19 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Gap Between Weather and Climate Forecasting: Sub-seasonal to Seasonal Prediction is an ideal reference for researchers and practitioners across the range of disciplines involved in the science, modeling, forecasting and application of this new frontier in sub-seasonal to seasonal (S2S) prediction. It provides an accessible, yet rigorous, introduction to the scientific principles and sources of predictability through the unique challenges of numerical simulation and forecasting with state-of-science modeling codes and supercomputers. Additional coverage includes the prospects for developing applications to trigger early action decisions to lessen weather catastrophes, minimize costly damage, and optimize operator decisions. The book consists of a set of contributed chapters solicited from experts and leaders in the fields of S2S predictability science, numerical modeling, operational forecasting, and developing application sectors. The introduction and conclusion, written by the co-editors, provides historical perspective, unique synthesis and prospects, and emerging opportunities in this exciting, complex and interdisciplinary field. Contains contributed chapters from leaders and experts in sub-seasonal to seasonal science, forecasting and applications Provides a one-stop shop for graduate students, academic and applied researchers, and practitioners in an emerging and interdisciplinary field Offers a synthesis of the state of S2S science through the use of concrete examples, enabling potential users of S2S forecasts to quickly grasp the potential for application in their own decision-making Includes a broad set of topics, illustrated with graphic examples, that highlight interdisciplinary linkages
Download or read book Middle Atmosphere Dynamics written by David G. Andrews and published by Academic Press. This book was released on 2016-07-21 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: For advanced undergraduate and beginning graduate students in atmospheric, oceanic, and climate science, Atmosphere, Ocean and Climate Dynamics is an introductory textbook on the circulations of the atmosphere and ocean and their interaction, with an emphasis on global scales. It will give students a good grasp of what the atmosphere and oceans look like on the large-scale and why they look that way. The role of the oceans in climate and paleoclimate is also discussed. The combination of observations, theory and accompanying illustrative laboratory experiments sets this text apart by making it accessible to students with no prior training in meteorology or oceanography. * Written at a mathematical level that is appealing for undergraduates and beginning graduate students * Provides a useful educational tool through a combination of observations and laboratory demonstrations which can be viewed over the web * Contains instructions on how to reproduce the simple but informative laboratory experiments * Includes copious problems (with sample answers) to help students learn the material.
Download or read book Space Physics and Aeronomy Ionosphere Dynamics and Applications written by Chao Huang and published by John Wiley & Sons. This book was released on 2021-05-11 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of global ionospheric research from the polar caps to equatorial regions It's more than a century since scientists first identified the ionosphere, the layer of the Earth’s upper atmosphere that is ionized by solar and cosmic radiation. Our understanding of this dynamic part of the near-Earth space environment has greatly advanced in recent years thanks to new observational technologies, improved numerical models, and powerful computing capabilities. Ionosphere Dynamics and Applications provides a comprehensive overview of historic developments, recent advances, and future directions in ionospheric research. Volume highlights include: Behavior of the ionosphere in different regions from the poles to the equator Distinct characteristics of the high-, mid-, and low-latitude ionosphere Observational results from ground- and space-based instruments Ionospheric impacts on radio signals and satellite operations How earthquakes and tsunamis on Earth cause disturbances in the ionosphere The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about the Space Physics and Aeronomy collection in this Q&A with the Editors in Chief
Download or read book The Stratosphere written by L. M. Polvani and published by John Wiley & Sons. This book was released on 2013-04-30 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 190. The Stratosphere: Dynamics, Transport, and Chemistry is the first volume in 20 years that offers a comprehensive review of the Earth's stratosphere, increasingly recognized as an important component of the climate system. The volume addresses key advances in our understanding of the stratospheric circulation and transport and summarizes the last two decades of research to provide a concise yet comprehensive overview of the state of the field. This monograph reviews many important aspects of the dynamics, transport, and chemistry of the stratosphere by some of the world's leading experts, including up-to-date discussions of Dynamics of stratospheric polar vortices Chemistry and dynamics of the ozone hole Role of solar variability in the stratosphere Effect of gravity waves in the stratosphere Importance of atmospheric annular modes This volume will be of interest to graduate students and scientists who wish to learn more about the stratosphere. It will also be useful to atmospheric science departments as a textbook for classes on the stratosphere.
Download or read book The Stratosphere written by Karin G. Labitzke and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the history, phenomena, and relevance of the stratosphere. Beginning with the discovery of the stratosphere itself, the book explores various unexpected phenomena observed in the stratosphere, such as the ozone hole in 1984 and the influence of the 11-year solar cycle in 1987. It describes the interrelations of stratospheric phenomena and its effects on the variability of the climate system, as well as examines various human impacts on the system such as the decrease in the ozone layer.
Download or read book Downward Influence of Stratospheric Final Warming Events in an Idealized Model written by Lantao Sun and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The stratospheric Ơ̐1nal warming is the Ơ̐1nal transition of the zonal winds from wintertime westerlies to summertime easterlies as the solar heating of the high latitude stratosphere increases in the springtime. Recent observational analyses suggested that stratospheric final warming makes a signiƠ̐1cant contribution to the spring transitions in the lower troposphere, especially in the Northern Hemisphere. It is still not clear, however, whether these transitions are due to the downward inƠ̐2uence from the stratosphere. We Ơ̐1rst explore the hypothesis that much of the observed tropospheric signal of the Ơ̐1nal warming is initiated from the stratosphere. Large ensembles of Ơ̐1nal warmings are simulated in an idealized dynamical core model, by imposing a radiative equilibrium temperature transition from winter to summer only in the stratosphere. Our results suggest that a substantial fraction of the observed tropospheric changes that occur in conjunct with the Ơ̐1nal warming are induced from the stratosphere. We further investigate the mechanisms of the downward inƠ̐2uence of the Ơ̐1nal warmings on the tropospheric circulation. Results from our zonally symmetric model suggest that stratospheric wave driving can induce a residual circulation and aƠ̐0ect the tropospheric circulation. The tropospheric signals due to this mechanism are, however, very weak and are mostly conƠ̐1ned to the upper troposphere. On the other hand, the stratosphere can aƠ̐0ect the propagation of planetary waves from the troposphere, resulting in a burst of wave activity and the zonal wind deceleration prior to the Ơ̐1nal warming in the troposphere. We also perform a series of perturbation experiments for the sudden and Ơ̐1nal warmings to test the roles of the troposphere and the stratosphere in determining the predictability of stratospheric warmings. For a late Ơ̐1nal warming, almost all of the predictability comes from the troposphere. For the rest of the Ơ̐1nal warmings and for sudden warmings, however, the troposphere determines the predictability until very close to the time of warming onset. This Ơ̐1nding, consistent with the conventional view of the warming, reƠ̐2ects that center role of the troposphere in determining the stratospheric warmings. Results from a comprehensive global climate model, the Whole-Atmosphere Community Climate Model (WACCM), are used to analyze the Ơ̐1nal warmings in both hemispheres. Although WACCM has zonal winds that are too strong in the spring, which causes the mean onset dates to be delayed at least one month with respect to the observations, the zonal wind evolutions resemble the observations. The similarity between the models and observations suggests that the downward inƠ̐2uence of the stratospheric Ơ̐1nal warming on the tropospheric circulation is real and substantial, especially in the Northern Hemisphere.
Download or read book Encyclopedia of Atmospheric Sciences written by Gerald R. North and published by Elsevier. This book was released on 2014-09-14 with total page 2874 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Atmospheric Sciences, Second Edition, Six Volume Set is an authoritative resource covering all aspects of atmospheric sciences, including both theory and applications. With more than 320 articles and 1,600 figures and photographs, this revised version of the award-winning first edition offers comprehensive coverage of this important field. The six volumes in this set contain broad-ranging articles on topics such as atmospheric chemistry, biogeochemical cycles, boundary layers, clouds, general circulation, global change, mesoscale meteorology, ozone, radar, satellite remote sensing, and weather prediction. The Encyclopedia is an ideal resource for academia, government, and industry in the fields of atmospheric, ocean, and environmental sciences. It is written at a level that allows undergraduate students to understand the material, while providing active researchers with the latest information in the field. Covers all aspects of atmospheric sciences—including both theory and applications Presents more than 320 articles and more than 1,600 figures and photographs Broad-ranging articles include topics such as atmospheric chemistry, biogeochemical cycles, boundary layers, clouds, general circulation, global change, mesoscale meteorology, ozone, radar, satellite remote sensing, and weather prediction An ideal resource for academia, government, and industry in the fields of atmospheric, ocean, and environmental sciences
Download or read book Aeronomy of the Earth s Atmosphere and Ionosphere written by Mangalathayil Ali Abdu and published by Springer Science & Business Media. This book was released on 2011-02-26 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a multi-author treatise on the most outstanding research problems in the field of the aeronomy of the Earth’s atmosphere and ionosphere, encompassing the science covered by Division II of the International Association of Geomagnetism and Aeronomy (IAGA). It contains several review articles and detailed papers by leading scientists in the field. The book is organized in five parts: 1) Mesosphere-Lower Thermosphere Dynamics and Chemistry; 2) Vertical Coupling by Upward Propagating Waves; 3) Ionospheric Electrodynamics and Structuring; 4) Thermosphere- Ionosphere Coupling, Dynamics and Trends and 5) Ionosphere-Thermosphere Disturbances and Modeling. The book consolidates the progress achieved in the field in recent years and it serves as a useful reference for graduate students as well as experienced researchers.
Download or read book Investigating the Link Between Tropospheric Blocking and Sudden Stratospheric Warming in the Northern Hemisphere written by Michael Ewens Kelleher and published by . This book was released on 2014 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: The link between sudden stratospheric warmings (SSWs) and tropospheric blocking events has been heavily investigated, both in the composite sense, as well as individual case studies. The implications of improved SSW forecasting include improved surface weather predictability, as the warmings have long time scale impacts on the troposphere. In this study, the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis (Kalnay et al., 1996), and NASA's Modern Era Retrospective Reanalysis (MERRA) (Rienecker et al., 2011) data sets were used to differentiate blocking events that occur without the presence of any stratospheric warming from those that are linked with warmings, either preceding or following it. This was accomplished through the generation of composites of geopotential height fields, Ertel's potential vorticity on the longitude-time plane and averaged over the polar cap, zonal mean zonal wind diagnosis, and meridional eddy heat flux. It was found that indeed there are several distinguishing features that discriminate blocking events associated with SSWs from those that are not. Firstly, the zonal mean zonal wind appears to link the stratosphere with the troposphere during blocking events associated with SSWs, while no such link appears in the events that are not. The meridional eddy heat flux features large ten-day averaged values in the period before and just after block onset in the SSW associated composites, while it is absent in the non-associated composites. The polar cap PV average also separates the SSW associated events from the non-events, with an anticyclonic anomaly before block onset, and cyclonic anomaly after onset, whereas the non-events feature only a minimal change in tropospheric PV. The tropospheric polar cap PV and meridional eddy heat flux were used as forecast indicators for historical SSW events in both data sets, and presented nominal skill over climatology. A statistical comparison was also performed on the duration of blocking, that indicates that longer duration blocks are more likely associated with SSW events, but this was only statistically significant in the NCEP/NCAR Reanalysis, and was not replicated with the MERRA data set.
Download or read book Assessment of Intraseasonal to Interannual Climate Prediction and Predictability written by National Research Council and published by National Academies Press. This book was released on 2010-10-08 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: More accurate forecasts of climate conditions over time periods of weeks to a few years could help people plan agricultural activities, mitigate drought, and manage energy resources, amongst other activities; however, current forecast systems have limited ability on these time- scales. Models for such climate forecasts must take into account complex interactions among the ocean, atmosphere, and land surface. Such processes can be difficult to represent realistically. To improve the quality of forecasts, this book makes recommendations about the development of the tools used in forecasting and about specific research goals for improving understanding of sources of predictability. To improve the accessibility of these forecasts to decision-makers and researchers, this book also suggests best practices to improve how forecasts are made and disseminated.
Download or read book Climate Intervention written by National Research Council and published by National Academies Press. This book was released on 2015-06-23 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing problem of changing environmental conditions caused by climate destabilization is well recognized as one of the defining issues of our time. The root problem is greenhouse gas emissions, and the fundamental solution is curbing those emissions. Climate geoengineering has often been considered to be a "last-ditch" response to climate change, to be used only if climate change damage should produce extreme hardship. Although the likelihood of eventually needing to resort to these efforts grows with every year of inaction on emissions control, there is a lack of information on these ways of potentially intervening in the climate system. As one of a two-book report, this volume of Climate Intervention discusses albedo modification - changing the fraction of incoming solar radiation that reaches the surface. This approach would deliberately modify the energy budget of Earth to produce a cooling designed to compensate for some of the effects of warming associated with greenhouse gas increases. The prospect of large-scale albedo modification raises political and governance issues at national and global levels, as well as ethical concerns. Climate Intervention: Reflecting Sunlight to Cool Earth discusses some of the social, political, and legal issues surrounding these proposed techniques. It is far easier to modify Earth's albedo than to determine whether it should be done or what the consequences might be of such an action. One serious concern is that such an action could be unilaterally undertaken by a small nation or smaller entity for its own benefit without international sanction and regardless of international consequences. Transparency in discussing this subject is critical. In the spirit of that transparency, Climate Intervention: Reflecting Sunlight to Cool Earth was based on peer-reviewed literature and the judgments of the authoring committee; no new research was done as part of this study and all data and information used are from entirely open sources. By helping to bring light to this topic area, this book will help leaders to be far more knowledgeable about the consequences of albedo modification approaches before they face a decision whether or not to use them.
Download or read book Stratospheric Ozone Depletion and Climate Change written by Rolf Müller (physicien.) and published by Royal Society of Chemistry. This book was released on 2012 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, several new concepts have emerged in the field of stratospheric ozone depletion, creating a need for a concise in-depth publication covering the ozone-climate issue. This monograph fills that void in the literature and gives detailed treatment of recent advances in the field of stratospheric ozone depletion. It puts particular emphasis on the coupling between changes in the ozone layer and atmospheric change caused by a changing climate. The book, written by leading experts in the field, brings the reader the most recent research in this area and fills the gap between advanced textbooks and assessments.
Download or read book The Role of Wavenumber One and Two in the Development of Sudden Stratospheric Warmings written by Andreas Wolfgang Miller and published by . This book was released on 2017 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we investigate the effects of planetary waves one and two on the polar stratosphere during boreal winter. We use MERRA reanalysis data and the FMS shallow-water model to compare and contrast their propagation into the stratosphere, their interactions within the stratosphere, and their effects on the polar vortex. The results have implications for the predictability of sudden stratospheric warmings (SSWs), theories on the developments of vortex splits and the role of zonal winds in the tropics. In Chapter 2, we use correlations and regressions to demonstrate that the tropopause affects wavenumber one amplitudes more than wavenumber two. Thus, the statistical predictability of SSWs, based on synoptic events in the mid-troposphere (e.g. blockings), is limited. Composites of extreme heat fluxes reveal that they are likely caused by linear interference of the climatology and anomalies. The phases of anomalous planetary waves align with the climatology only during the largest heat fluxes. In Chapter 3, the effect of wave-wave interactions within the stratosphere is quantified by analyzing eddy energy budgets. The energy transfer from wavenumber one toward wavenumber two plays a key role in the vortex split in January 2013 and several other SSWs. This mechanism might explain the growth of wavenumber two in the stratosphere in nonresonant conditions. However, wave-wave interactions are small in averages over all splits since 1979 suggesting that different processes can lead to vortex splits and that the common SSW definitions do not capture the timing of planetary wave growth. In Chapter 4, we employ a shallow-water model to isolate the effects of wave one and two on the polar vortex over a large range of forcing amplitudes and vortex strengths. We are able to simulate SSW splits, which are unequivocally caused by wave-wave interactions. Furthermore, the initial response of the polar vortex depends strongly on the wavenumber of the forcing.
Download or read book Next Generation Earth System Prediction written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-08-22 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the nation's economic activities, security concerns, and stewardship of natural resources become increasingly complex and globally interrelated, they become ever more sensitive to adverse impacts from weather, climate, and other natural phenomena. For several decades, forecasts with lead times of a few days for weather and other environmental phenomena have yielded valuable information to improve decision-making across all sectors of society. Developing the capability to forecast environmental conditions and disruptive events several weeks and months in advance could dramatically increase the value and benefit of environmental predictions, saving lives, protecting property, increasing economic vitality, protecting the environment, and informing policy choices. Over the past decade, the ability to forecast weather and climate conditions on subseasonal to seasonal (S2S) timescales, i.e., two to fifty-two weeks in advance, has improved substantially. Although significant progress has been made, much work remains to make S2S predictions skillful enough, as well as optimally tailored and communicated, to enable widespread use. Next Generation Earth System Predictions presents a ten-year U.S. research agenda that increases the nation's S2S research and modeling capability, advances S2S forecasting, and aids in decision making at medium and extended lead times.
