Download or read book A Multi scale Analysis of Tropical Cyclogenesis Within the Critical Layer of Tropical Easterly Waves in the Atlantic and Western North Pacific Sectors written by Louis L. Lussier and published by . This book was released on 2010 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: A newly proposed tropical cyclogenesis sequence that describes the transition of a tropical wave's critical layer to a tropical cyclone is used to examine two formation cases in the western North Pacific basin. Typhoon Nuri (2008), formed from a precursor easterly wave during the Tropical Cyclone Structure 2008 field experiment, and Typhoon Man-yi (2007), formed within an equatorial Rossby wave as it interacted with a monsoon trough. In each case, i) the critical layer of the parent wave protects a proto-vortex from an external hostile environment and allows it to strengthen until it becomes a self-sustained entity and ii) the intersection between the wave trough and critical latitude, within the Kelvin cat's eye, is the preferred location for tropical cyclogenesis. Numerical simulations suggest that the so-called "bottom-up" pathway to tropical cyclogenesis is favored within Typhoon Man-yi's critical layer. Additionally, Tropical Rainfall Measurement Mission (TRMM) composite analyses of 55 developing easterly waves indicate that as genesis approaches, i) convection is favored in the Kelvin cat's eye circulation, ii) the convective contribution to total rain rate becomes dominant, iii) the radius of maximum convection decreases, and iv) a convective-type heating profile is present. These findings support the "bottom-up" development model within easterly wave critical layers.
Download or read book Tropical Cyclogenesis Within the Critical Layer of Tropical Easterly Waves written by Ali Asaadi and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This study provides new insight into the longstanding problem in tropical cyclogenesis involving the transformation of tropical easterly waves (EWs) into coherent cyclonic vortices. Observation indicates that only a small fraction of EWs in a single hurricane season become tropical cyclones. However, this small fraction accounts for a large portion of intense hurricanes. Some recent studies proposed the "Marsupial" paradigm and showed that named storms over the Atlantic and eastern Pacific basins are almost all associated with a cyclonic Kelvin cat's eye of an EW critical layer, located equatorward of the easterly jet axis. Yet no definitive study on the mechanism for the formation of the cat's eye has appeared in the literature. It is the purpose of this study to fill this gap. A climatological study of 54 developing EWs during 1998-2001 over the Atlantic and eastern Pacific was conducted using the European Centre for Medium-Range Weather Forecasts(ECMWF) reanalysis data. Time-lagged composites in a translating reference frame following the disturbances indicate a weak meridional potential vorticity (PV) gradient of the easterly jet, and a cyclonic critical layer located slightly south of the weak PV gradient. Using closed PV contour as a criterion for the formation of the cat's eye, it was shown that on average, it takes ~2.6 days for open contours to transform to a closed coherent structure. Additionally, it is found that EW train over the Atlantic and eastern Pacific is oriented in a southeast-northwest direction, due to the observed tilt in the easterly jet. Bootstrap analysis was then applied to determine the reliability of the EW train-like pattern in the composite perturbation PV analysis. The results indicate that the coexistence of a nonlinear critical layer and a region of weak meridional PV gradient over several days occurred in only ~25% of the EWs due to the aforementioned geometrical tilt. This geometric criterion may distinguish developing and non-developing disturbances and may constitute a necessary condition for EWs to develop into named storms. It also offers an explanation as to why only a small fraction of EWs contribute to tropical cyclogenesis. Additionally, using asymptotic theory we obtained an analytic time scale that governs the onset of nonlinearity for forced disturbances on a parabolic jet critical layer. This time scale is consistent with that found in 54 cases of EWs that developed into named storms, highlighting the importance of nonlinear and diabatic processes in cat's eye formation. A shallow water model is then used to study forced and unforced problems of disturbances on a parabolic jet and the observed jet in the composite. The nonlinear forced simulations, with the convective heating represented by a mass sink, produced a realistic time scale for cat's eye formation, and confirm our above-mentioned analytic solution. The modeling results further confirm the synergic role of the dynamical mechanisms of wave breaking and PV redistribution within the nonlinear critical layer, and the thermodynamical mechanism of convectively generated PV anomalies, in the formation of the cat's eye in tropical cyclogenesis. Finally, an objective tracking technique is used to track both developing and nondeveloping EWs. Composite analysis of the large scale structure and characteristics of nondeveloping EWs show that ~91% of non-developing waves are not located on a critical layer with weak PV gradient, while the remaining ~9% indicates characteristics similar to the developing waves. Examination of the composite OW parameter indicates that the nondeveloping waves are characterized by negative values implying that they are dominated by deformation, unlike developing waves which are dominated by vorticity. Our analysis and modeling results thus lend support to the proposed geometric criterion for cat's eye formation in tropical cyclogenesis." --
Download or read book An Observational Analysis of Tropical Cyclogenesis in the Western North Pacific written by Bing Fu and published by . This book was released on 2003 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-resolution satellite data are used to analyze 34 tropical storms in the Western North Pacific (WNP) during the 2000 and 2001 storm seasons. Three scenarios: Tropical Cyclone Energy Dispersion (TCED), Synoptic Wavetrain/Mixed Rossby-Gravity wave (SWT/MRG) and Easterly Wave (EW) forcing, are identified as dominant synoptic-scale triggers for TC genesis. Among these 34 cases, 6 cases are associated with TCED, 11 cases are associated with SWTIMRG and 7 cases are associated with EW forcing. For the remaining cases, three presumable scenarios are proposed. Our analyses suggest that TCED has a close relationship with TC intensity and the background wind field. Not all mature TCs produce Rossby wavetrains at their wakes; and not all wavetrains lead to the formation of new TCs. The vertical divergence profile of the Rossby wavetrain has a baroclinic structure, while the vorticity profile shows an equivalent barotropic structure, penetrating from the surface to 200mb. The large-scale environmental flow plays an important role in determining whether a wavetrain can further develop into a TC. Evolution characteristics and vertical structures of easterly waves and synoptic-scale wavetrains and their roles in cyclogenesis are also investigated. Our results also show that tropical Intraseasonal Oscillation (ISO) has a significant modulation on TC formation, especially in 2000.
Download or read book Advanced Numerical Modeling and Data Assimilation Techniques for Tropical Cyclone Predictions written by U.C. Mohanty and published by Springer. This book was released on 2016-11-21 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals primarily with monitoring, prediction and understanding of Tropical Cyclones (TCs). It was envisioned to serve as a teaching and reference resource at universities and academic institutions for researchers and post-graduate students. It has been designed to provide a broad outlook on recent advances in observations, assimilation and modeling of TCs with detailed and advanced information on genesis, intensification, movement and storm surge prediction. Specifically, it focuses on (i) state-of-the-art observations for advancing TC research, (ii) advances in numerical weather prediction for TCs, (iii) advanced assimilation and vortex initialization techniques, (iv) ocean coupling, (v) current capabilities to predict TCs, and (vi) advanced research in physical and dynamical processes in TCs. The chapters in the book are authored by leading international experts from academic, research and operational environments. The book is also expected to stimulate critical thinking for cyclone forecasters and researchers, managers, policy makers, and graduate and post-graduate students to carry out future research in the field of TCs.
Download or read book Cyclones written by Kazuyoshi Oouchi and published by Nova Science Publishers. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is edited for the young researchers and students who are interested in overviewing and knowing the specific progress of tropical cyclone research. This book is devoted to either an up-to-date review or report of new research on the tropical cyclone, encompassing the problems of the genesis, development, climate control of tropical cyclone in terms of wide-ranging scales based on every types of method - theoretical, modelling, and observational analysis. Not only comprehensive climate model but stand-alone theoretical and conceptual modelling researches will continue to play important role in illustrating the essential physics of tropical cyclone, and observational studies will support their specific features.
Download or read book El Ni o Southern Oscillation in a Changing Climate written by Michael J. McPhaden and published by John Wiley & Sons. This book was released on 2020-11-24 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive and up-to-date information on Earth’s most dominant year-to-year climate variation The El Niño Southern Oscillation (ENSO) in the Pacific Ocean has major worldwide social and economic consequences through its global scale effects on atmospheric and oceanic circulation, marine and terrestrial ecosystems, and other natural systems. Ongoing climate change is projected to significantly alter ENSO's dynamics and impacts. El Niño Southern Oscillation in a Changing Climate presents the latest theories, models, and observations, and explores the challenges of forecasting ENSO as the climate continues to change. Volume highlights include: Historical background on ENSO and its societal consequences Review of key El Niño (ENSO warm phase) and La Niña (ENSO cold phase) characteristics Mathematical description of the underlying physical processes that generate ENSO variations Conceptual framework for understanding ENSO changes on decadal and longer time scales, including the response to greenhouse gas forcing ENSO impacts on extreme ocean, weather, and climate events, including tropical cyclones, and how ENSO affects fisheries and the global carbon cycle Advances in modeling, paleo-reconstructions, and operational climate forecasting Future projections of ENSO and its impacts Factors influencing ENSO events, such as inter-basin climate interactions and volcanic eruptions 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 this book from this Q&A with the editors.
Download or read book Tropical Cyclogenesis and Its Relation to Interactions Between African Easterly Waves and Mesoscale Convective Systems written by Kelly Nunez Ocasio and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Tropical cyclogenesis remains a challenging research topic, in part due to the limited understanding of the interactions between the mesoscale processes and the TC-seedling synoptic-scale vortex. The interactions between African easterly waves (AEWs) and mesoscale convective systems (MCSs) over Africa and east Atlantic and how they pertain to the formation of tropical cyclone (TCs) are documented. First, an algorithm that objectively tracks MCSs over Africa is developed to analyze the morphology and climatology of these systems over Africa. It is shown that realistic MCS propagation over Africa is attained when the tracker accounts for the African Easterly Jet (AEJ) mean background flow in which the MCSs propagate on. With an MCS dataset in place, a climatology AEW-MCS dataset is developed to perform a wave-relative analysis of AEW-MCS systems over Africa and over the Main Development Region. It is found that the MCSs of developing AEW-MCS systems (those that develop into TCs) are more likely to be in phase with and propagate at the same speed as the AEW trough. In contrast, the MCSs of non-developing AEW-MCS systems are more likely to be positioned south of the AEW trough and do not necessarily propagate at the same speed. In addition, it is found that developing AEWs over West Africa are associated with a larger number of Convective Cloud Clusters (CCCs; squall line-type systems) than non-developing AEWs. Over West Africa, the fraction of extremely large MCS areas associated with developing AEWs is larger than for non-developing AEWs. These findings support the notion that both the position of moisture and latent heating relative to the AEW trough are essential for cyclogenesis. At the synoptic-scale, significant differences between developing and non-developing AEWs are identified over eastern Africa (region of AEW onset) that can inform tropical cyclogenesis prediction. TC precursors when compared to non-developing AEWs experience: anomalously active West African Monsoon, stronger northerly flow, more intense zonal Somali jet, anomalous convergence over the Marrah Mountains (region of AEW forcing), and a more intense and elongated African easterly jet (AEJ). These more favorable large scale condition for developers reflect in their initial 850-hPa dynamic and thermodynamic structure over eastern Africa. It is found that AEWs that initiate over eastern Africa and cross the west coast of Africa are more likely to undergo tropical cyclogenesis than those initiating over central or west Africa. Developing AEWs are also more likely to be southern-track AEWs than non-developers.
Download or read book Global Perspectives on Tropical Cyclones written by Johnny C. L. Chan and published by World Scientific. This book was released on 2010 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pt. I. Theory of tropical cyclones. ch. 1. Tropical cyclone structure and dynamics / Jeffrey D. Kepert. ch. 2. Tropical cyclone formation / Kevin J. Tory and William M. Frank. ch. 3. Air-sea interactions in tropical cyclones / Lynn K. Shay. ch. 4. Movement of tropical cyclones / Johnny C.L. Chan. ch. 5. The extratropical transition of tropical cyclones : structural characteristics, downstream impacts, and forecast challenges / Patrick A. Harr -- pt. II. Observations of tropical cyclones. ch. 6. Observing and analyzing the near-surface wind field in tropical cyclones / Mark D. Powell. ch. 7. Satellite observations of tropical cyclones / Christopher Velden and Jeffrey Hawkins. ch. 8. Aircraft observations of tropical cyclones / Sim D. Aberson [und weitere] -- pt. III. Climate variations of tropical cyclone activity. ch. 9. Tropical cyclones and climate change : a review / Thomas Knutson, Chris Landsea and Kerry Emanuel -- pt. IV. Forecasting of tropical cyclones. ch. 10. Track and structure forecasts of tropical cyclones / Julian Heming and Jim Goerss. ch. 11. The influence of natural climate variability on tropical cyclones, and seasonal forecasts of tropical cyclone activity / Suzana J. Camargo [und weitere] -- pt. V. Hydrological aspects of tropical cyclones. ch. 12. Storm surge modeling and applications in coastal areas / Shishir K. Dube [und weitere] -- pt. VI. Societal impacts of tropical cyclones. ch. 13. Disaster mitigation and societal impacts / David King, Jim Davidson and Linda Anderson-Berry
Download or read book Multi Scale Multi Proxy Investigation of Late Holocene Tropical Cyclone Activity in the Western North Atlantic Basin written by François Oliva and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleotempestology, the study of past tropical cyclones (TCs) using geological proxy techniques, is a growing discipline that utilizes data from a broad range of sources. Most paleotempestological studies have been conducted using "established proxies", such as grain-size analysis, loss-on-ignition, and micropaleontological indicators. More recently researchers have been applying more advanced geochemical analyses, such as X-ray fluorescence (XRF) core scanning and stable isotopic geochemistry to generate new paleotempestological records. This is presented as a four article-type thesis that investigates how changing climate conditions have impacted the frequency and paths of tropical cyclones in the western North Atlantic basin on different spatial and temporal scales. The first article (Chapter 2; Oliva et al., 2017, Prog Phys Geog) provides an in-depth and up-to-date literature review of the current state of paleotempestological studies in the western North Atlantic basin. The assumptions, strengths and limitations of paleotempestological studies are discussed. Moreover, this article discusses innovative venues for paleotempestological research that will lead to a better understanding of TC dynamics under future climate change scenarios. The second article (Chapter 3; Oliva et al., submitted, The Holocene) presents the development of the first database summarizing the most up-to-date paleotempestological proxy data available for TC reconstructions for the western North Atlantic basin. Subsets of this new database are then used to reconstruct TC variability in the western North Atlantic basin. Using our new developed subsets, we investigate a key hypothesis, the Bermuda High Hypothesis that has been proposed to have influenced TC paths over centennial to millennial timescales. Results show an oscillation in the distribution of TC landfalls along the North American coast, suggesting a centennial oscillation in the mean summer position of the high pressure system. We suggest that a more serious, millennial scale shift in the Bermuda High to a northeastern (NE position) may have occurred at 3̃000 and 1̃000 cal yr BP. The third article (Chapter 4; Oliva et al., under review, Marine Geology) presents a local multi-proxy reconstruction of TC activity during the past 800 years from Robinson Lake, Chezzetcook Inlet in Nova Scotia, Canada. Here, we are testing the more recent use of the XRF scanning approach to paleotempestology at a local scale. Two sediment cores were extracted from Robinson Lake that were dated by 210Pb and 14C, analyzed for organic matter content, benthic foraminifera and thecamoebians, sediment grain size, and a range of elements and elemental ratios determined by XRF core scanning. Results show two periods of low TC activity based on multiple proxies including XRF technology: one from 1̃150 to 1475 CE (800 - 475 cal yr BP) and the other from 1670 CE (280 cal yr BP) to the present, with the intervening period from 1̃475 to 1670 CE (475 - 280 cal yr BP) as a time of more frequent and possibly higher magnitude TC activity. The fourth article (Chapter 5. Oliva et al., in preparation, Canadian Journal of Earth Sciences) explores the potential use of stable oxygen isotopes in tree ring ?-cellulose to reconstruct past local TC activity surrounding areas of known TC strikes. Cores of 12 Picea mariana trees were extracted adjacent to Robinson Lake, Chezzetcook Inlet, Nova Scotia in order to test more contemporary and historically documented records of TC activity in this region as per Chapter 4. TCs precipitate 18O-depleted rain, leaving a unique signature in the source water that trees use to form cellulose. Using an autoregressive integrated moving average (ARIMA AR-1) model to detrend the data, local and regional time series were reconstructed. Local reconstructions led to most (> 95%) hurricanes and all major hurricane (± 1 year) being recorded in the isotope record, whereas the regional reconstruction shows no major hurricane, only a few hurricanes ( 40%) and one signal with a higher error ( 1 year). This thesis contributes to advancing our knowledge in paleotempestology of the western North Atlantic basin by: 1) bringing an up-to-date current status on paleotempestology, 2) the development and ongoing use of a new paleotempestology database for the western North Atlantic basin publicly available, 3) a local scale study using new XRF core elemental technology and 4) the exploratory use of tree-ring ?-cellulose oxygen isotopic analysis based on contemporary and historical documents at local sites.
Download or read book Relation Between Tropical Easterly Wave Convection and Tropical Cyclogenesis Over the Atlantic and East Pacific written by Kenneth D. Leppert (II.) and published by . This book was released on 2012 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hurricanes written by Henry F. Diaz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hurricanes of the North Atlantic Ocean have left their imprint on the landscape and human cultures for thousands of years. In modern times, fewer lifes have been lost due, in part, to the development of modern communication systems, and to improved understanding of the mechanisms of storm formation and movement. However, the immense growth of human populations in coastal areas, which are at risk to hurricanes, has resulted in very large increases in the amount of property damage sustained in the last decade in the Atlantic, Gulf of Mexico and Caribbean regions. This book is of interest to climatologists and meteorologists and as source of information for policymakers and emergency management planners.
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.
Download or read book Sub seasonal to Seasonal Prediction written by Andrew Robertson and published by Elsevier. This book was released on 2018-10-24 with total page 0 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.
Download or read book Aviation Weather for Pilots and Flight Operations Personnel written by United States. Federal Aviation Administration and published by . This book was released on 1975 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book GLOBAL TROPICAL CYCLOGENESIS written by Eugene A. Sharkov and published by Springer Science & Business Media. This book was released on 2011-12-09 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cyclogenesis research is a central issue of meteorology and climatology. This book gives a deep specific view and fundamentally and effectively contributes to the discussion of the problem. It treats cyclogenisis as a stochastic process in a very fundamental way. Since the publication of the first edition of Global Tropical Cyclogenesis in 2001, a number of important scientific results has been obtained using methods and techniques proposed in that first edition. There is therefore a great need for a revised 2nd edition of this book. It is based on scientific findings from the performance of satellite data processing and a series of scientific marine expeditions to the tropics as part of major Russian Science Academy research projects. Professor Eugene A. Sharkov has proposed the main approaches, experimental techniques and theoretical explanations for many scientific findings as well as new methods of satellite processing. He is recognized as a leading scientist in the field of microwave remote sensing of terrestrial surfaces and atmosphere and in nonlinear geophysics (origination and evolution of atmospheric catastrophes) and has published around 100 scientific works on the problems of global tropical cyclogenesis structure and evolution.
Download or read book The Ocean and Cryosphere in a Changing Climate written by Intergovernmental Panel on Climate Change (IPCC) and published by Cambridge University Press. This book was released on 2022-04-30 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the science related to climate change. It provides policymakers with regular assessments of the scientific basis of human-induced climate change, its impacts and future risks, and options for adaptation and mitigation. This IPCC Special Report on the Ocean and Cryosphere in a Changing Climate is the most comprehensive and up-to-date assessment of the observed and projected changes to the ocean and cryosphere and their associated impacts and risks, with a focus on resilience, risk management response options, and adaptation measures, considering both their potential and limitations. It brings together knowledge on physical and biogeochemical changes, the interplay with ecosystem changes, and the implications for human communities. It serves policymakers, decision makers, stakeholders, and all interested parties with unbiased, up-to-date, policy-relevant information. This title is also available as Open Access on Cambridge Core.
Download or read book Climate Variability and Tropical Cyclone Activity written by Pao-Shin Chu and published by Cambridge University Press. This book was released on 2022-03-10 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive summary of tropical cyclone variability at time scales from intraseasonal and interannual to interdecadal and centennial. Major climate oscillations (Madden-Julian, El Niño, Atlantic Meridional Mode and Pacific Decadal) are covered, and their impacts on tropical cyclone activity in the Pacific and Atlantic oceans are discussed.
