Download or read book Evolution of African Easterly Waves and Their Relationship to Tropical Cyclogenesis written by Alan Brammer and published by . This book was released on 2015 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 African Easterly Waves written by Lourdes B. Avilés Bramer and published by . This book was released on 2004 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Studies of African Easterly Waves in Relation to Tropical Cyclogenesis Along the West African Coast written by Claiborne Forbes Tompkins and published by . This book was released on 2010 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of African Easterly Waves on Atlantic Tropical Cyclone Variability written by Susanna B. Hopsch and published by . This book was released on 2008 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atlantic Tropical Cyclone Formation Pre genesis Evolution of Tropical Easterly Waves and Impacts of the Middle to Upper Tropospheric Dry Air written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Remote Sensing and Global Environmental Change written by Sam J. Purkis and published by John Wiley & Sons. This book was released on 2011-03-03 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remote Sensing plays a key role in monitoring the various manifestations of global climate change. It is used routinely in the assessment and mapping of biodiversity over large areas, in the monitoring of changes to the physical environment, in assessing threats to various components of natural systems, and in the identification of priority areas for conservation. This book presents the fundamentals of remote sensing technology, but rather than containing lengthy explanations of sensor specifications and operation, it concentrates instead on the application of the technology to key environmental systems. Each system forms the basis of a separate chapter, and each is illustrated by real world case studies and examples. Readership The book is intended for advanced undergraduate and graduate students in earth science, environmental science, or physical geography taking a course in environmental remote sensing. It will also be an invaluable reference for environmental scientists and managers who require an overview of the use of remote sensing in monitoring and mapping environmental change at regional and global scales. Additional resources for this book can be found at: http://www.wiley.com/go/purkis/remote.
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 Easterly Waves and Tropical Cyclogenesis in the Caribbean written by Kay L. Shelton and published by . This book was released on 2011 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Practical Meteorology written by Roland Stull and published by Sundog Publishing, LLC. This book was released on 2018 with total page 942 pages. Available in PDF, EPUB and Kindle. Book excerpt: A quantitative introduction to atmospheric science for students and professionals who want to understand and apply basic meteorological concepts but who are not ready for calculus.
Download or read book Meteorology of Tropical West Africa written by Douglas J. Parker and published by John Wiley & Sons. This book was released on 2017-04-24 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Meteorology of tropical West Africa: the Forecasters’ Handbook presents the science and practice of weather forecasting for an important region of the tropics. Connecting basic theory with forecasting practice, the book provides a unique training volume for operational weather forecasters, and is also suitable for students of tropical meteorology. The West African region contains a number of archetypal climatic zones, meaning that the science of its weather and climate applies to many other tropical regions. West Africa also exhibits some of the world’s most remarkable weather systems, making it an inspiring region for students to investigate. The weather of West Africa affects human livelihoods on a daily basis, and can contribute to hardship, poverty and mortality. Therefore, the ability to understand and predict the weather has the potential to deliver significant benefits to both society and economies. The book includes comprehensive background material alongside documentation of weather forecasting methods. Many examples taken from observations of West African weather systems are included and online case-studies are referenced widely.
Download or read book The Genesis and Evolution of African Easterly Waves written by Hyeok Joe Kwon and published by . This book was released on 1988 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book African Easterly Waves and Their Transformation Into Tropical Cyclones in North Atlantic written by Ioannis Pytharoulis and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Tracing the Origins and Propagation of African Easterly Waves and Mesoscale Convective Systems Using Pattern Recognition and Data Fusion written by Chaunté W. Lacewell and published by . This book was released on 2011 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focuses on developing pattern recognition techniques to trace the origins and propagation of pre-tropical storm Debby (2006) African easterly waves (AEW) and mesoscale convective systems (MCS) using satellite imagery. Uses the results to verify a numerical weather prediction (NWP) model.
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 Atmospheric and Oceanic Fluid Dynamics written by Geoffrey K. Vallis and published by Cambridge University Press. This book was released on 2006-11-06 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid dynamics is fundamental to our understanding of the atmosphere and oceans. Although many of the same principles of fluid dynamics apply to both the atmosphere and oceans, textbooks tend to concentrate on the atmosphere, the ocean, or the theory of geophysical fluid dynamics (GFD). This textbook provides a comprehensive unified treatment of atmospheric and oceanic fluid dynamics. The book introduces the fundamentals of geophysical fluid dynamics, including rotation and stratification, vorticity and potential vorticity, and scaling and approximations. It discusses baroclinic and barotropic instabilities, wave-mean flow interactions and turbulence, and the general circulation of the atmosphere and ocean. Student problems and exercises are included at the end of each chapter. Atmospheric and Oceanic Fluid Dynamics: Fundamentals and Large-Scale Circulation will be an invaluable graduate textbook on advanced courses in GFD, meteorology, atmospheric science and oceanography, and an excellent review volume for researchers. Additional resources are available at www.cambridge.org/9780521849692.
