Download or read book Short Term Teleconnections Associated with Western Pacific Tropical Cyclones written by Cory A. Springer and published by . This book was released on 1994 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The short term teleconnections arising from an individual tropical cyclone in the western Pacific were examined using a global operational data assimilation system and forecast model. In the data assimilation, the tropical cyclone was modified using a tropical cyclone bogusing procedure that other maintained the storm in, or eliminated the storm from, the model's initial conditions. These different initial conditions were used as the initial fields for several 20 day runs of the forecast model. These runs were used to simulate the global atmosphere with and without the tropical cyclone. The differences between these simulations were used to infer the global teleconnection response to the tropical cyclone. This response was dominated by a strong, quasi- stationary Rossby wave train that extended from east Asia across the North Pacific into North America. This wave train was initiated when an anticyclonic circulation formed near Japan as the tropical cyclone approached the east Asian jet. The anticyclone formation was primarily the result of the absolute vorticity advection by the divergent wind and vortex stretching (i.e., the Rossby wave source) associated with the tropical cyclone. The wave response continued to develop after this wave source, and the tropical cyclone itself, dissipated. This development was clearly seen in the growth and eastward propagation of Rossby wave energy across the mid latitude North Pacific and North America. The growth tended to be greater near areas of potential barotropic instability along the North Pacific jet, while the propagation tended to occur parallel to the jet.

Download or read book Short Term Teleconnections Associated with Western Pacific Tropical Cyclones written by Cory A. Springer and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The short term teleconnections arising from an individual tropical cyclone in the western Pacific were examined using a global operational data assimilation system and forecast model. In the data assimilation, the tropical cyclone was modified using a tropical cyclone bogusing procedure that other maintained the storm in, or eliminated the storm from, the model's initial conditions. These different initial conditions were used as the initial fields for several 20 day runs of the forecast model. These runs were used to simulate the global atmosphere with and without the tropical cyclone. The differences between these simulations were used to infer the global teleconnection response to the tropical cyclone. This response was dominated by a strong, quasi- stationary Rossby wave train that extended from east Asia across the North Pacific into North America. This wave train was initiated when an anticyclonic circulation formed near Japan as the tropical cyclone approached the east Asian jet. The anticyclone formation was primarily the result of the absolute vorticity advection by the divergent wind and vortex stretching (i.e., the Rossby wave source) associated with the tropical cyclone. The wave response continued to develop after this wave source, and the tropical cyclone itself, dissipated. This development was clearly seen in the growth and eastward propagation of Rossby wave energy across the mid latitude North Pacific and North America. The growth tended to be greater near areas of potential barotropic instability along the North Pacific jet, while the propagation tended to occur parallel to the jet.

Download or read book Short Term Teleconnections Associated with an Individual Tropical Cyclone written by Stephen C. Woll and published by . This book was released on 1993 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: The short term teleconnections associated with an individual western Pacific tropical cyclone have been investigated using an atmospheric general circulation model. The general strategy was to use the GCM, in combination with several tropical cyclone bogusing procedures, to isolate the effects on the global circulation of the tropical cyclone. The bogusing procedures were used to alter the tropical cyclone in the initial conditions for the model. The primary modeling experiments involved using the tropical cyclone bogusing procedures to include or exclude the tropical cyclone from the initial conditions. The difference between model results that contained the tropical cyclone and those that did not were used to analyze the global response to the tropical cyclone. These results showed a strong and persistent teleconnection response in the extratropical northern hemisphere. This response was mainly evident in slowly propagating Rossby waves in the 200 mb height field. Examinations of the teleconnection mechanisms showed that the east Asian-north Pacific jet played a major role in the development of the teleconnection. In particular: (1) the 200 mb height responses showed a consistent relationship with the jet; (2) the jet acted as a waveguide for the Rossby wave energy; and (3) the regions of potential barotropic instability which flank the jet were often colocated with areas of wave amplification.

Download or read book The Remote Impacts of a Western Pacific Tropical Cyclone written by Craig E. Jakus and published by . This book was released on 1995 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The short term teleconnections arising from an individual tropical cyclone in tne western Pacific (typhoon Seth, October 1994) were examined using an operational global data assimilation system and numerical weather prediction model. During the data assimilation, the model's initial conditions were modified using a tropical cyclone bogusing procedure that either maintained or eliminated the individual storm. These different initial conditions were used in six extended-range forecasts of about 3.5 weeks duration. Three of these forecasts simulated the atmosphere with tne tropical cyclone and three without the storm. The ensemble average differences between the forecasts with the storm and those without it were used to infer the global teleconnection response to the tropical cyclone. This response was dominated by a strong and persistent Rossby wave train that extended from east Asia across the North Pacific into North America. This wave train was initiated when an anticyclonic circulation formed near Japan as the tropical cyclone approached the east Asian jet. The anticyclone formation was primarily the result of two factors: (1) vortex stretching; and (2) absolute vorticity advection as divergent outflow from the tropical cyclone crossed the large absolute vorticity gradient of the east Asian jet. The wave response was quasi-stationary. However, the basic wave train (i.e., the teleconnection pattern) developed within a week due to a relatively rapid eastward propagation of wave energy across the North Pacific and North America. In regions of strong jet flow, this propagation tended to parallel the flow while in regions of weaker flow, the propagation had stronger poleward or equatorward components. The wave train intensified well after the tropical cyclone and the initial wave formation process had dissipated.

Download or read book Short Term Teleconnections Associated with an Individual Tropical Cyclone written by Stephen C. Woll and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The short term teleconnections associated with an individual western Pacific tropical cyclone have been investigated using an atmospheric general circulation model. The general strategy was to use the GCM, in combination with several tropical cyclone bogusing procedures, to isolate the effects on the global circulation of the tropical cyclone. The bogusing procedures were used to alter the tropical cyclone in the initial conditions for the model. The primary modeling experiments involved using the tropical cyclone bogusing procedures to include or exclude the tropical cyclone from the initial conditions. The difference between model results that contained the tropical cyclone and those that did not were used to analyze the global response to the tropical cyclone. These results showed a strong and persistent teleconnection response in the extratropical northern hemisphere. This response was mainly evident in slowly propagating Rossby waves in the 200 mb height field. Examinations of the teleconnection mechanisms showed that the east Asian-north Pacific jet played a major role in the development of the teleconnection. In particular: (1) the 200 mb height responses showed a consistent relationship with the jet; (2) the jet acted as a waveguide for the Rossby wave energy; and (3) the regions of potential barotropic instability which flank the jet were often colocated with areas of wave amplification.

Download or read book Short Term Teleconnections Associated with Western Pacific Tropical Cyclones written by and published by . This book was released on 1900 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book North Pacific Tropical Cyclones and Teleconnections written by and published by . This book was released on 2005 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigated the hypothesis that variations in tropical cyclone (TC) activity in the western North Pacific (WNP) may affect the teleconnection between the tropical WNP and North America. The teleconnection patterns of the 500 hPa geopotential height between a base point in the WNP (20 N 115 E) and a domain over North America (30 - 45 N, 70 -90 W) from 1951-2001 were examined. The 25 most active and the 25 least active TC years for two regions with the highest climatological average of TC activity, near the Philippines and Taiwan, respectively, were compared to determine if stronger teleconnection patterns occur during the more active years. For both regions, the correlation pattern is significant during active years and insignificant during inactive years, with the results based on TC activity in the Philippines region showing a larger difference. An analysis of 500 hPa mean winds showed weaker winds in the midlatitudes during active TC years when the teleconnection is stronger, which suggests that the teleconnection may consist mainly of Lau and Weng's (2000) zonally-elongated mode (Mode 1). Further cross correlations of the geopotential height and TC frequency parameters with the tropical eastern and western Pacific sea-surface temperatures (SST's) showed a significant correlation between TC activity and tropical eastern Pacific SST's, but the North America-WNP correlation is unlikely to be a result of a direct influence of SST's on the two regions.

Download or read book Global Perspectives On Tropical Cyclones From Science To Mitigation written by Johnny C L Chan and published by World Scientific. This book was released on 2010-04-30 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a completely rewritten, updated and expanded new edition of the original Global Perspectives on Tropical Cyclones published in 1995. It presents a comprehensive review of the state of science and forecasting of tropical cyclones together with the application of this science to disaster mitigation, hence the tag: From Science to Mitigation.Since the previous volume, enormous progress in understanding tropical cyclones has been achieved. These advances range from the theoretical through to ever more sophisticated computer modeling, all underpinned by a vast and growing range of observations from airborne, space and ocean observation platforms. The growth in observational capability is reflected by the inclusion of three new chapters on this topic. The chapter on the effects of climate change on tropical cyclone activity is also new, and appropriate given the recent intense debate on this issue. The advances in the understanding of tropical cyclones which have led to significant improvements in forecasting track, intensity, rainfall and storm surge, are reviewed in detail over three chapters. For the first time, a chapter on seasonal prediction is included. The book concludes with an important chapter on disaster mitigation, which is timely given the enormous loss of life in recent tropical cyclone disasters.World Scientific Series on Asia-Pacific Weather and Climate is indexed in SCOPUS.

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 Interacting Climates of Ocean Basins written by Carlos R. Mechoso and published by Cambridge University Press. This book was released on 2020-11-26 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of interactions between the climates of different ocean basins and their key contributions to global climate variability and change. Providing essential theory and discussing outstanding examples as well as impacts on monsoons, it a useful resource for graduate students and researchers in the atmospheric and ocean sciences.

Download or read book A Satellite Analysis of Twin Tropical Cyclones in the Western Pacific written by James L. Cox and published by . This book was released on 1969 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: During November 1967, an unusual set of twin tropical cyclones, ANNIE and GILDA, formed about the same time on opposite sides of the equator in the Western Pacific. They illustrate the unique role of satellite cloud photographs play in providing meteorologists with an important tool for studying tropical disturbances in various stages of their life cycles and their related environments. Satellite derived data, particularly cirrus-level wind estimates from cloud photographs, are used to recount the story of ANNIE and GILDA. It is the change which takes place in the cirrus-level wind field that enables the meteorologist to discern the step by step development of the respective cyclones as well as the interaction between the high-level winds of the two hemispheres and the twins themselves.

Download or read book The Dynamics of Teleconnections Induced by Short Term Tropical Forcing written by Mark D. Malsick and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent observational and modeling studies have suggested that transient tropical perturbations may induce significant intraseasonal teleconnections between the tropics and midlatitudes. We have investigated the mechanisms for such teleconnections using a nonlinear global shallow water model with a realistically wavy basic state. The model perturbations were designed to simulate tropical cyclones with prescribed growth, decay, and propagation. The model responses to the tropical perturbations showed distinct midlatitude wavetrain responses to the perturbation. The typical response became large within a few days and retained as a coherent pattern for two to three weeks after the demise of the tropical perturbation. The response was particularly strong if the perturbation propagated close to an extratropical jet. This propagation allowed Rossby wave induction as divergent outflow from the perturbation crossed the jet's region of high ambient vorticity gradient. This initial wave response was then guided by the jet and amplified in barotropically unstable regions on the jet flanks. This produced a persistent response downstream of the jet exit (e.g., over the northeast Pacific and North America). The response showed a marked variation with the season and with the tropical ocean basin in which the perturbation occurred, apparently because of temporal and spatial changes in the basic state conditions. The responses closely resemble observed anomaly patterns associated with transient tropical perturbations, and are dynamically consistent with the responses to more persistent tropical perturbations (e.g., ENSO events).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Extratropical Transition of Western North Pacific Tropical Cyclones written by Peter M. Klein and published by . This book was released on 1997-09-01 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extratropical transition (ET) of a tropical cyclone (TC) often results in a mid-latitude storm that threatens maritime and coastal interests. Cases of ET between 1 July through 31 October during 1994-1996 are reviewed using Navy Operational Global Atmospheric Prediction System (NOGAPS) analyses and hourly geostationary satellite imagery. Current conceptual models are found to be inadequate to explain the physical processes in ET. ET is redefined to have two stages: transformation, where the TC is transformed from a warm-core vortex into a baroclinic, cold-core extratropical cyclone, and re- intensification, where the transformed TC either deepens or dissipates, depending on the existence of upper4ropospheric support for extratropical cyclogenesis. ET is further defined in terms of two characteristic mid-latitude synoptic patterns: meridional, in which the cyclones have meridional tracks and tend to re-intensify less vigorously than zonal, which have zonal tracks and may deepen explosively. Review of NOGAPS 5OO-mb anomaly correlation scores in 1996 demonstrated that ET may be associated with significant NOGAPS errors. Sea-level pressure forecasts during ET events involving a merger tend to be too deep. In ET cases of rapidly deepening storms, NOGAPS tends to overforecast their intensity during transformation, and then underforecast during re- intensification. Rules of thumb are provided to assist forecasters in improving predictions of the track and intensity of storms undergoing ET.

Download or read book Large scale Circulation Regimes and Tropical Cyclone Characteristics Over the Western Pacific Ocean written by Patrick A. Harr and published by . This book was released on 1993 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: The basic structure of the variability Of the large-scale circulations over the tropical western North Pacific is investigated with respect to its influence on tropical cyclone characteristics. A vector empirical orthogonal function analysis and a fuzzy cluster algorithm are used to define six recurrent 700 mb circulation patterns that represent large-scale variabilities associated with the monsoon trough and subtropical ridge. Three circulation patterns are associated with an active monsoon trough, and two patterns represent an inactive monsoon trough. One pattern depicts small deviations from the long-term climatology. The 700 mb circulation patterns are shown to be physically consistent with outgoing longwave radiation anomalies and the 200 mb stream function and velocity potential anomalies. A seventh set of circulation patterns is defined to contain transition periods between the active, inactive and small anomaly patterns. Transitions between recurrent circulation patterns may be within the active or the inactive patterns, or be transitions across the active/inactive boundary that are associated with major circulation changes. These significant transitions occur over a very limited set of paths, which are shown to be associated with interactions among tropical and midlatitude circulation systems. The recurrent circulation patterns and their transitions are shown to explain much of the observed intraseasonal variability in the occurrence and track types (recurving versus straight-moving) of tropical cyclones over the western North Pacific. Tropical cyclones, Circulation regimes, Low-frequency variability, Tropical cyclone motion, Monsoons, Cluster analysis.

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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: