Download or read book The Influence of Equatorial Rossby Waves on the Flow Convection and Tropical Cyclones Over the Australian Tropics and Southeastern Indonesia written by Joan Patricia Fernon and published by . This book was released on 2014 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines Equatorial Rossby Waves (ERWs) and their modulation of the low to middle level flow, convection and tropical cyclogenesis associated with the passage of over northern Australia, southeastern Indonesia and adjoining waters during the Austral summer wet season. ERWs are equatorially trapped, convectively coupled, westward propagating waves, which are symmetric about the equator. In the Southern Hemisphere the enhanced (suppressed) convective phase of these waves is associated with northwesterly (southeasterly) low to middle level wind anomalies. In the western Pacific, in the absence of dominating low to middle level easterly flow, ERWs manifest themselves as twin cyclonic circulations on either side of the equator. In this thesis ERWs are identified using 9.7 to 48 day band pass filtered outgoing long-wave radiation (OLR) data. Nine strong ERW events, and also thirteen tropical cyclone (TC) genesis events where the initial circulation formed in the Banda Sea, are investigated using a case study and compositing approach. Principal component analysis was employed to investigate all Austral wet season ERW events from January 1979 to 30 April 2011. These data indicated that on average there were 11 ERW events moving through Australian longitudes each wet season. Conclusions reached in this thesis are based on the two sets of events/case studies and the principle component analysis.Analysis of the data over Australian longitudes indicates that there are two classes of ERW events, in which both the propagation of the ERWs and the modulation of the flow, convection and TC genesis differ. These classes are associated with the pre-existing synoptic situation over the region. The first class is characterised by a pre-existing monsoon trough. Four of the nine case studies fall into this class, the remaining five case studies fall into the second class. This class is characterised by a pre-existing, near equatorial trough and easterly low to middle level mean flow extending southward over northern Australia. For the first class of ERW event the focus of enhanced convection and precipitation is over northern Australia and the Coral Sea with the monsoon trough moving south and the flow to its north strengthening and becoming more northerly. Pre-existing circulations within the trough can intensify or new circulations can form. These circulations sometimes reach tropical cyclone intensity. Over the northern Australian, southeastern Indonesian region during the mid wet season months of January through March the monsoon trough is the persistent synoptic feature. Hence over this region during these months most ERW events fall into the first class of event. During these months ERWs propagate to the southwest and tend to weaken. They have an average wave length of 6090km, with an average westward ground based phase speed of 4.4ms-1. For the second class of ERW event a typical scenario occurs when the Southern Hemisphere member of the ERW twin moves westward from the Pacific basin and loses its structure as it traverses the Papua New Guinea (PNG) highlands then rapidly reforms to the west of PNG, thus initiating the formation of the monsoon trough to the north of Australia. In individual events the subsequent development and movement of this system and the trough affect the deep layer flow and precipitation over northern Australia and southeastern Indonesia. In a number of scenarios investigated in this thesis the circulation reached tropical cyclone intensity. In these scenarios the system initially moved to the west and then generally recurved towards the southeast, making landfall on the northwest Australian coast.During the early and late wet season months of November, December and April the near equatorial trough is the typical synoptic situation, so most ERW events fall into the second class of event. During these months ERWs have an average wave length of 6570km, with an average westward phase speed of 4.8ms-1. On average during these months ERWs propagate parallel to the equator and maintain their strength as they move through Australian/Indonesian longitudes.ERWs were found to modulate tropical cyclogenesis (TC genesis) over the Australian/eastern Indonesian region. During the mid wet season months ERWs modulate TC genesis in the east and central parts of the region and in far west. During the early and late wet season ERWs modulate TC genesis in the central parts of the region.Thirteen TCs were found to have initially formed as circulations in the Banda Sea. Eleven of these systems formed in the early or late wet season. The initial formation and movement of each of these eleven systems were intimately associated with the passage of active ERW phases. Subsequent to their initial formation as cyclonic circulations most of the thirteen systems rapidly intensified to tropical cyclone strength and beyond in a favourable environment provided by an active phase of a Madden Julian Oscillation (MJO). These systems can bring severe weather to the eastern Indonesian Archipelago with heavy rainfall and landslides due to steep topography and very deep soil profiles.
Download or read book Publications Abstracts written by Environmental Research Laboratories (U.S.) and published by . This book was released on 1994 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Meteorology of the Southern Hemisphere written by David Karoly and published by Springer. This book was released on 2015-04-03 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book looks at the circulation features of the Southern Hemisphere, both for the atmosphere and oceans. It includes observational techniques based on satellites, anchored and drifting buoys, and the research carried out at research stations in the Southern Hemisphere. The book was originally published in 1972 by the American Meteorological Society. It has been revised and updated in 1999, following the expansion of research bases and the development of research in the region at the time.
Download or read book Influence of Equatorial Rossby Waves on Tropical Cyclogensis in the Western Pacific written by Kelly Lombardo and published by . This book was released on 2004 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Satellite Rainfall Applications for Surface Hydrology written by Mekonnen Gebremichael and published by Springer Science & Business Media. This book was released on 2009-12-02 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions from a panel of researchers from a wide range of fields, the chapters of this book focus on evaluating the potential, utility and application of high resolution satellite precipitation products in relation to surface hydrology.
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 On Intraseasonal Variability in the Tropics written by Jonathan Lin (Earth scientist) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation addresses some aspects of tropical intraseasonal variability, which is dominated by tropical cyclones, equatorial waves, and the Madden-Julian Oscillation (MJO). Because these phenomena have significant societal impacts on sub-seasonal time scales, and it is important to understand how they interact with the large-scale atmosphere. The first part of this thesis develops Forecasts of Hurricanes using Large Ensemble Output (FHLO), a large-ensemble, probabilistic tropical cyclone forecast model. FHLO incorporates the state-dependent forecast uncertainty by sampling the internal variability of ensemble numerical weather prediction models. It is shown that including state-dependent forecast uncertainty can lead to significant improvements in pointwise wind speed forecasts on lead times longer than around 3-days. The second part of this thesis addresses how tropical disturbances interact with the stratosphere. A linear framework in which a convecting, quasi-equilibrium troposphere is coupled to a dry, passive stratosphere is developed. It is shown that smaller scale waves are strongly damped by the stratosphere, while slower propagating waves, such as Rossby waves and the MJO, are less affected by the stratosphere. Excitation of the barotropic mode by the stratosphere and surface friction is also analyzed. In particular, it is found that surface friction can excite the barotropic mode far away from the equator, though the poleward extent of the barotropic mode is strongly controlled by how much energy leaks into the stratosphere. The last part of this thesis extends the linear framework to include non-zero zonal wind in the stratosphere, to understand how stratospheric circulations, like the Quasi-Biennial Oscillation, can influence the strength of the MJO. It is found that the tropospheric barotropic mode can be phase-shifted by stratospheric winds, but only under unrealistic forcings at the tropopause. Upward wave radiation is found to be stronger under easterly than westerly winds in the stratosphere, because of increased upward energy flux by Kelvin waves. The effect of the stratosphere on cirrus clouds is also investigated. It is shown that dynamical modulation of lower stratospheric clouds, and anomalous advection of upper-tropospheric ice clouds, can explain why the MJO is stronger under easterly than westerly phases of the QBO.
Download or read book Effects of Zonal Asymmetry and Divergence on Upper Troposheric Responses to Equatorial Forcing written by Yuxia Zhang and published by . This book was released on 1994 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation written by Intergovernmental Panel on Climate Change and published by Cambridge University Press. This book was released on 2012-05-28 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme weather and climate events, interacting with exposed and vulnerable human and natural systems, can lead to disasters. This Special Report explores the social as well as physical dimensions of weather- and climate-related disasters, considering opportunities for managing risks at local to international scales. SREX was approved and accepted by the Intergovernmental Panel on Climate Change (IPCC) on 18 November 2011 in Kampala, Uganda.
Download or read book Relationship Between Tropical Atlantic Sea Surface Temperature Variability and Southern Indian Ocean Tropical Cyclones written by Evan F. DeBlander and published by . This book was released on 2012 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies have found that equatorial Atlantic sea surface temperature (SST) variability may be influencing tropical Indian Ocean climate (Kucharski 2009, Wang 2009). Due to the economic and social impact of tropical cyclones, it is important to investigate how an Atlantic-Indian Ocean connection may be affecting tropical cyclone behavior in the southern Indian Ocean. In this study, the International Best Track Archive for Climate Stewardship (IBTrAC) tropical cyclone database is used to derive metrics of tropical cyclone behavior, which are then compared with indices of tropical Atlantic SST variability representing Atlantic Niño, and Benguela Niño events. Changes in tropical Atlantic SSTs are found to coincide with significant differences in tropical cyclone activity for portions of the southern Indian Ocean. In addition, for these same regions, tropical Atlantic SST variability is associated with changes in large-scale atmospheric conditions, including steering flow, low level vorticity, and humidity, typically associated with tropical cyclogenesis, and tropical cyclone track. The changes in steering flow related to both indices of Atlantic SST anomaly are reproduced by an atmospheric model. The changes in steering flow are also found to be linked to changes in TC translational velocity, and TC tracking. These findings indicate a possible link between tropical Atlantic conditions and cyclone activity in the Indian Ocean mediated through a teleconnection between tropical Atlantic SSTs and large scale atmospheric conditions over the southern Indian Ocean. The teleconnection related to the Benguela Niño region of SST variability was found to consist of a Rossby wave initiated off the coast of South America, and propagating into the Indian Ocean, thereby influencing several atmospheric variables, including steering flow. The teleconnection related to the Atlantic Niño region of SST variability was not well defined, although there was some evidence of a Walker circulation anomaly extending from the equatorial Atlantic over the continent of Africa, and influencing SIO steering flow.
Download or read book Monsoon Meteorology written by Chih-Pei Chang and published by Oxford University Press, USA. This book was released on 1987 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Very Good,No Highlights or Markup,all pages are intact.
Download or read book Tropical Cyclones written by James P. Terry and published by Springer Science & Business Media. This book was released on 2007-09-20 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: This original book describes the behavior of tropical cyclones in the South Pacific. It investigates the broad range of disturbance effects these violent storms have on the physical environments of the islands that lie in their path and the people who live on them. It is the first book to link these two themes – the characteristics of cyclones and their landscape impacts. Examples and illustrations are drawn widely from across the region, resulting in a highly readable volume.
Download or read book Intraseasonal Variability in the Atmosphere Ocean Climate System written by William K.-M. Lau and published by Springer Science & Business Media. This book was released on 2007-06-10 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first comprehensive review of intra-seasonal variability (ISV); the contents are balanced between observation, theory and modeling. Starting with an overview of ISV and historical observations, the book addresses the coupling between ocean and atmosphere, and the worldwide role of ISV in monsoon variability. Also considered are the connections between oscillations like the Madden, Julian and El Nino/Southern and short-term climate.
Download or read book A Literature Review Effect of Climate Change on Tropical Cyclones written by Kopal Arora and published by GRIN Verlag. This book was released on 2014-06-11 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essay from the year 2011 in the subject Geography / Earth Science - Meteorology, Aeronomy, Climatology, grade: 11.0, University of Exeter, language: English, abstract: Since tropical cyclones(TCs) are one of the major geophysical cause of loss of life and property, it is important to understand if there is any change in the frequency and intensity of TCs due to anthropogenic climate change. IPCC considers 0.25-0.5 C increase in warming over tropical oceans over the past few decades due to increase in greenhouse gas concentration over past 50years. During 6th International Workshop on Tropical Cyclones, a statement was released on the connection between the TCs and anthropogenic climate change. The statement was in response to the increase in number of recent high-impact TC events which includes, 10 land falling Tcs in Japan in 2004, 5 TCs affecting the Cook island in a five week period during 2005, cyclone Gafilo in Madagascar in 2004, cyclone Larry in Australia in 2006, typhoon Saomai in China in 2006, and violently active Atlantic TC season during the period of 2004 to 2005, including the catastrophic socioeconomic impact of Hurricane Katrina. A few recent articles [1] have noted a large increase in TC’s intensity, frequency and wind-speeds in some regions during past 5 decades, which could be attributed to the increase in the concentration of green house gases in past 50years. However, other studies explain this noticed increase as a result of better observations made and instruments used, making it easier to detect TCs. Consensus statement by the International workshop on TC-6 reported uncertain conclusions about the influence of climate change on TC after taking into account evidence both for and against. It was concluded that no TC could be solely attributed to the anthropogenic climate change. Model and theory predicts 3-5% increase in wind speed per degree C increase in SST. But, there is inconsistency between the small change in wind speed projected by theory and modelling versus large variations reported by some observational studies. Significant limitation of measurements over some regions make detection of trends difficult. It was suggested that if increase in SST continues, susceptibility to TC storm surge flooding would strengthen.
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.
