Download or read book A Projection Pursuit Application to Predict Extratropical Transition of Tropical Cyclones written by Oguz Demirci and published by . This book was released on 2006 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, a multistage projection pursuit technique is presented that is used to predict the end results of the extratropical transition of the tropical cyclones. The technique extracts the spatial features relevant to extratropical transition that can be obtained from NOGAPS analyses and remotely sensed data. Various atmospheric variables at different levels of the atmosphere are used in the spatial and spatiotemporal techniques. The technique is tested in a forecasting environment on tropical cyclones from recent years, and results show prediction comparable to a global numerical weather prediction system with 75% prediction and 30% false alarm rate. The system is further developed to have utility for forecasting by examining ways to utilize forecast fields in various stages of the technique. This allows the prediction to occur ahead of time. Trials in this "forecast mode" indicate results that are slightly less accurate than those obtained using analysis fields during the development phase. However, the results are promising and further possible improvements are discussed.
Download or read book The Extratropical Transition of Tropical Cyclones written by Melanie Bieli and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The model, a logistic regression with elastic net regularization, was developed with a focus on predictive performance as well as physical interpretability and thus resides at the interface between machine learning and traditional statistics. It uses eight predictors that characterize the storm and its environment, the most important ones being latitude and sea surface temperature. The model is shown to have skill in forecasting ET at lead times up to two days, and it can predict the phase evolution of storms that undergo ET as well as of storms that remain tropical throughout their lifetimes. When used as an instantaneous diagnostic of a storm's tropical/extratropical status, the model performs about as well as the CPS in the western North Pacific and better than the CPS in the North Atlantic, and it predicts the timings of the transitions better than the CPS in both basins. The model can be integrated into statistical tropical cyclone risk models, or may be applied to provide baseline guidance for operational forecasts.
Download or read book Diagnosing the Downstream Impact of Extratropical Transition Using Multimodel Operational Ensemble Prediction Systems written by Julia Henriette Keller and published by KIT Scientific Publishing. This book was released on 2014-10-16 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study examines the predictability during the extratropical transition (ET) of tropical cyclones using the THORPEX Interactive Grand Global Ensemble (TIGGE), a multimodel ensemble prediction system (EPS). It is shown that TIGGE exhibits more possible development scenarios than a single EPS. By analysing the eddy kinetic energy budget of forecast scenarios for two ET cases, extracted from an EPS, the impact of the transitioning tropical cyclones on the midlatitude flow is studied in detail.
Download or read book Automating the Analysis of Spatial Grids written by Valliappa Lakshmanan and published by Springer Science & Business Media. This book was released on 2012-06-14 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to create automated algorithms to process gridded spatial data is increasingly important as remotely sensed datasets increase in volume and frequency. Whether in business, social science, ecology, meteorology or urban planning, the ability to create automated applications to analyze and detect patterns in geospatial data is increasingly important. This book provides students with a foundation in topics of digital image processing and data mining as applied to geospatial datasets. The aim is for readers to be able to devise and implement automated techniques to extract information from spatial grids such as radar, satellite or high-resolution survey imagery.
Download or read book Predictability Associated with the Downstream Impact of the Extratropical Transition of Tropical Cyclones written by and published by . This book was released on 2005 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since an extratropical transition (ET) of a decaying tropical cyclone (TC) often results in a fast-moving, rapidly developing extratropical cyclone and amplification of synoptic-scale systems far downstream, proper forecasting of ET events is critical to forecast accuracy over large ocean regions. Past studies have linked forecast accuracy to the phasing of a decaying TC with favorable midlatitudes conditions. Because ET events are sensitive to the analyzed initial conditions, this phasing is examined using 11 member ensemble predictions available four times daily from the National Centers for Environmental Prediction, which were combined into a single 44 member ensemble based on a common forecast verification time. Recurring ET patterns within the 44 member ensemble were objectively identified using a combination of EOF and cluster analysis. Ensemble spread first appears near the point where the TC moves into the midlatitudes and then propagates downstream. Although ensemble spread in the forecast fields was large at extended forecast intervals, the ensemble spread, and the number of ET patterns identified in successive EPS predictions, decreased as the ET process became better defined. Within 48 hours of the ET event, the ensemble prediction system properly identified the ET pattern with a minimum ensemble spread. Similar to Klein et al. (2002), the shifts in the initial position of the TC and the subsequent dynamical coupling can explain differences between weak and strong ET reintensifications.
Download or read book Advances in Hurricane Risk in a Changing Climate written by Jennifer Collins and published by Springer Nature. This book was released on with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Predictability of Extratropical Transition and of Its Impact on the Downstream Flow written by and published by . This book was released on 2008 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project we investigated the basic mechanisms that determine the predictability of tropical cyclones undergoing extratropical transition (ET) and of their impact on the downstream flow. The analysis of ensemble forecasts for five ET cases showed that uncertainty is associated with the location and amplitude of a characteristic upper-level trough-ridge-trough pattern consisting of the trough that interacts with the tropical cyclone, a ridge directly downstream and a second trough downstream of the ridge. Experiments for Typhoon Tokage (2004) with the ensemble prediction system of the European Centre for Medium Range Weather Forecasts showed that targeted perturbations led to increased spread around and shortly after ET time whereas the spread due to stochastic physics increased at a later time as the influence of the targeted perturbations decreased. Idealized modelling combined with potential vorticity inversion was used to quantify the mechanisms responsible for this variability. Furthermore, dropsonde data in the vicinity of tropical cyclones were shown to reduce the medium-range forecast error for the downstream flow.
Download or read book Christus und die Samariterin written by and published by . This book was released on 1967 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Extratropical Transition of Tropical Cyclones written by and published by . This book was released on 2003 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The extratropical transition (ET) of tropical cyclones can sometimes result in rapid changes in the structure and intensity of the tropical cyclone. In particular, the second stage of ET can result in very different results from complete dissipation to rapid intensification into an intense midlatitude cyclone. Whether the tropical cyclone dissipates or reintensifies appears to be strongly dependent on the details of the midlatitude circulation. At the heart of the forecast problem is a lack of knowledge of the fundamental physical changes occurring during ET. Results are presented that show that the details of the midlatitude circulation are probably less important than the basic midlatitude structure for reintensification. Simulations presented here show that variations in the strength of the midlatitude upper-level trough have little impact on the subsequent reintensification of the tropical cyclone. Rather, it is more likely the energy of the background environmental state, and the phasing between the trough and TC that ultimately determine the intensity to which the cyclone can reintensify.
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 Comparison of a Conceptual Model and Objective Indicators of Extratropical Transition in the Western North Pacific written by Gregory D. Fox and published by . This book was released on 2004-03-01 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary purpose of this research is to provide guidance to forecasters from the Joint (Air Force/Navy) Typhoon Warning Center (JTWC) in Pearl Harbor to use in differentiating between the stages of extratropical transition (ET) of tropical cyclones (TCs). Not only is ET relevant to the Department of Defense, since JTWC stops providing TC warnings once they have undergone ET, but it is also applicable to the meteorological community since there currently "is no commonly accepted definition of ET" (Jones et al 2003). This research compares the results of a conceptual model of ET using subjective satellite analysis with the results of objective indicators based on Navy Operational Global Atmospheric Prediction System (NOGAPS) model analyses. The ultimate goal is to find a way to reduce the negative impact of incorrect TC forecasting by providing tools which are more objective in defining stages of ET. This work discusses the birth, growth, and death of TCs by describing what energy sources are necessary for their growth and dissipation. Recent studies provide a conceptual model of ET with definitions of two stages and ways to use satellite analysis to identify them (Klein et al. 2000). While this conceptual model was being analyzed with data from the western North Pacific Ocean, TCs were also being analyzed using data from the Atlantic Ocean (Hart and Evans 2001). The research from the Atlantic led to the exploitation of objective indicators in a hodograph-like display (Evans and Hart 2003).
Download or read book Monitoring and Prediction of Tropical Cyclones in the Indian Ocean and Climate Change written by U.C. Mohanty and published by Springer Science & Business Media. This book was released on 2013-10-12 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with recent advances in our understanding and prediction of tropical cyclogenesis, intensification and movement as well as landfall processes like heavy rainfall, gale wind and storm surge based on the latest observational and numerical weather prediction (NWP) modeling platforms. It also includes tropical cyclone (TC) management issues like early warning systems, recent high impact TC events, disaster preparedness, assessment of risk and vulnerability including construction, archiving and retrieval of the best tracking and historical data sets, policy decision etc., in view of recent findings on climate change aspects and their impact on TC activity. The chapters are authored by leading experts, both from research and operational environments. This book is relevant to cyclone forecasters and researchers, managers, policy makers, graduate and undergraduate students. It intends to stimulate thinking and hence further research in the field of TCs and climate change, especially over the Indian Ocean region and provides high-quality reference materials for all the users mentioned above for the management of TCs over this region.
Download or read book Western North Pacific Tropical Cyclone Formation and Structure Change in TCS 08 and TCS 08 Field Experiment Support written by and published by . This book was released on 2010 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long-term goal of this project is to develop a better understanding of mesoscale and synoptic-scale processes associated with the entire life cycle of tropical cyclones in the western North Pacific. The inability to correctly identify tropical cyclone formation over the period of 24-48 hours poses a threat to shore and afloat assets across the western North Pacific. Furthermore, once a tropical cyclone has formed, the predictability of structure changes during intensification of the cyclone is very low, which is due to complex physical processes that vary over a wide range of space and time scales. Periods of reduced predictability occur throughout the tropical cyclone life cycle, which includes the decaying stage. Because decaying tropical cyclones often transition to a fast-moving and rapidly-developing extratropical cyclone that may contain gale-, storm-, or hurricane-force winds, there is a need to improve understanding and prediction of the extratropical transition phase of a decaying tropical cyclone. The structural evolution of the transition from a tropical to extratropical circulation involves rapid changes to the wind, cloud, and precipitation patterns that potentially impact maritime and shore-based facilities. The research being conducted on the comprehensive data sets gathered during the TCS-08 field program will result in increased accuracy associated with the prediction of tropical cyclone formation, intensification, and structural changes.
Download or read book Evolution of Tropical Cyclone Characteristics and Forecast Assessment written by and published by . This book was released on 1998 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: A long-term goal is to understand how variabilities in the environment and internal tropical cyclone structure influence tropical cyclone track and intensity characteristics and how these influence differ between developing, mature, and decaying tropical cyclones. During the initial stages of tropical cyclone development, structure and track characteristics can exhibit large variabilities that pose difficult forecast situations. Because decaying tropical cyclones often transition to fast-moving and rapidly-developing extratropical cyclones that may contain gale- or storm-force winds, special attention is given to improving understanding and prediction of the extratropical transition phase of a decaying tropical cyclone. Therefore, a tropical cyclone throughout its life cycle has the potential for impacting many fleet components. As increased understanding leads to improved forecasts of tropical cyclone motion and structure characteristics, a long-term goal of this project is to assess the utility of the tropical cyclone forecast products to shore- and sea-based assets.
Download or read book A Potential Vorticity Perspective on the Extratropical Transition of Tropical Cyclones written by Anna Agust©Ư-Panareda and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Extratropical transitions (ET) of tropical cyclones are common in all ocean basins where tropical cyclones recurve polewards. They can result in the development of large and deep extratropical cyclones. Two detailed case studies are presented: hurricane Irene and hurricane Lili which resulted in a reintensification with different deepening rates - two potential vorticity-based conceptual models have been devised from these results - abstract.
Download or read book Climate Change Effects on the Extratropical Transition of Tropical Cyclones in High Resolution Global Simulations written by Allison Claire Michaelis and published by . This book was released on 2019 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
