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Book Sub seasonal to Seasonal Prediction

Download or read book Sub seasonal to Seasonal Prediction written by Andrew Robertson and published by Elsevier. This book was released on 2018-10-19 with total page 585 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. Contains contributed chapters from leaders and experts in sub-seasonal to seasonal science, forecasting and applications Provides a one-stop shop for graduate students, academic and applied researchers, and practitioners in an emerging and interdisciplinary field Offers a synthesis of the state of S2S science through the use of concrete examples, enabling potential users of S2S forecasts to quickly grasp the potential for application in their own decision-making Includes a broad set of topics, illustrated with graphic examples, that highlight interdisciplinary linkages

Book Intraseasonal Variability in the Atmosphere Ocean Climate System

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 2011-10-25 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: Improving the reliability of long-range forecasts of natural disasters, such as severe weather, droughts and floods, in North America, South America, Africa and the Asian/Australasian monsoon regions is of vital importance to the livelihood of millions of people who are affected by these events. In recent years the significance of major short-term climatic variability, and events such as the El Nino/Southern Oscillation in the Pacific, with its worldwide effect on rainfall patterns, has been all to clearly demonstrated. Understanding and predicting the intra-seasonal variability (ISV) of the ocean and atmosphere is crucial to improving long range environmental forecasts and the reliability of climate change projects through climate models. In the second edition of this classic book on the subject, the authors have updated the original chapters, where appropriate, and added a new chapter that includes short subjects representing substantial new development in ISV research since the publication of the first edition.

Book Next Generation Earth System Prediction

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.

Book Assessment of Intraseasonal to Interannual Climate Prediction and Predictability

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 2010-09-08 with total page 193 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.

Book Tropical Intraseasonal Variability and the Stochastic Skeleton Method

Download or read book Tropical Intraseasonal Variability and the Stochastic Skeleton Method written by Andrew J. Majda and published by Springer Nature. This book was released on 2019-09-24 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this text, modern applied mathematics and physical insight are used to construct the simplest and first nonlinear dynamical model for the Madden-Julian oscillation (MJO), i.e. the stochastic skeleton model. This model captures the fundamental features of the MJO and offers a theoretical prediction of its structure, leading to new detailed methods to identify it in observational data. The text contributes to understanding and predicting intraseasonal variability, which remains a challenging task in contemporary climate, atmospheric, and oceanic science. In the tropics, the Madden-Julian oscillation (MJO) is the dominant component of intraseasonal variability. One of the strengths of this text is demonstrating how a blend of modern applied mathematical tools, including linear and nonlinear partial differential equations (PDEs), simple stochastic modeling, and numerical algorithms, have been used in conjunction with physical insight to create the model. These tools are also applied in developing several extensions of the model in order to capture additional features of the MJO, including its refined vertical structure and its interactions with the extratropics. This book is of interest to graduate students, postdocs, and senior researchers in pure and applied mathematics, physics, engineering, and climate, atmospheric, and oceanic science interested in turbulent dynamical systems as well as other complex systems.

Book The Role of Sub seasonal Tropical Convective Variability for the Extratropical Response to ENSO

Download or read book The Role of Sub seasonal Tropical Convective Variability for the Extratropical Response to ENSO written by Erik T. Swenson and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The boreal winter extratropical response to tropical heating associated with a significant El Niño Southern Oscillation (ENSO) event has been understood primarily in terms of a seasonal average. However, the development and variability of the response forced by a highly sub-seasonally variable atmospheric forcing is still unclear. Significant modes of sub-seasonal tropical convective variability exist that have well documented transient impacts on the extratropics, e.g. the Madden-Julian Oscillation (MJO). Does sub-seasonal tropical convective variability impact the seasonal mean extratropical response? If so, what matters for the response: short-lived strong events or more persistent moderate events? Does sub-seasonal convective variability have implications for predictability during El Niño? Using the Community Atmospheric Model v. 4.0 (CAM4) of the National Center for Atmospheric Research, the response to ENSO is simulated using large ensembles of seasonal integrations forced with observed SST from multiple El Niño events. We decompose the diabatic heating rate (Q) across the tropical Indo-Pacific in terms of temporal and intra-ensemble variability. We then repeat the simulations by prescribing subsets of Q in an effort to diagnose the impact of sub-seasonal and intra-ensemble Q variability. Neglecting sub-seasonal Q variability has a systematic impact on the response, generally extending the Pacific jet and deepening upper-level heights across the North Pacific. A local enhancement is simulated in tropical upper-level divergence, likely related to the vertical redistribution of Q resulting from averaging together vertical profiles associated with moderate and deep convection. Persistence may also play a role. When prescribing nearly all Q variability (for frequencies greater than one day), we find that Q-circulation coupling is locally unimportant, i.e. the temporal evolution, mean, and variance of upper-level divergence from a coupled control simulation are reproducible. However, interestingly the amplification of the extratropical response to El Niño is still simulated. It follows that these differences are attributed to the neglect of tropical-extratropical two-way coupling. This is the primary finding of the study and suggests that the extratropical response to a significant El Niño event is not simply a forced response to tropical heating. Regarding the variability of the response to El Niño, we find a robust relationship in the seasonal mean ensemble spread, linking Q variations in the west/central tropical Pacific and extratropical fluctuations projecting onto the Arctic Oscillation (AO). This mode accounts for about a third of the ensemble spread (in 200 hPa geopotential height). Previous studies have revealed a similar relationship in observed interannual variability and have simulated the tropically forced component. In CAM4, this relationship in the ensemble spread is only evident during El Niño and is the dominant contributor to the enhanced ensemble spread simulated during El Niño, acting to lower predictability of the response. Extratropical forcing of the tropics is important for this mode, as prescribing Q variability weakens the relationship and cannot reproduce the enhancement in spread. We find that this relationship emerges as residue of a low frequency sub-seasonal tropical-extratropical coupled mode for which a significant extratropical influence is evident. Over the Pacific, coherent interaction is simulated between evolving persistent planetary waves and convectively coupled waves bearing a resemblance to equatorial Kelvin waves or MJO-like behavior. We hypothesize that the two-way tropical-extratropical interaction for this mode acts to weaken the extratropical response to El Niño.

Book Origins and predictability of the intraseasonal to interannual variabilities of regional climate

Download or read book Origins and predictability of the intraseasonal to interannual variabilities of regional climate written by Zhiwei Zhu and published by Frontiers Media SA. This book was released on 2023-01-13 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Intraseasonal Variability

Download or read book Intraseasonal Variability written by Carlos D. Hoyos and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The intraseasonal Oscillation (ISO) is a very strong and coherent mode of variability observed in the Earths climate. Rainfall variability in the intraseasonal timescale is particularly strong in the Tropics and it directly interacts with the South Asian monsoon during boreal summer and with the Australian monsoon during winter. A detailed analysis of the horizontal and vertical structure of the ISO during both summer and winter is presented in this work considering the coupled ocean-atmosphere system. In addition, the role of the intraseasonal variability of the Southeast Asian monsoon is studied in detail. From the applications point of view, the intraseasonal time scale is arguably the most important period of variability. However, extended forecasting of intraseasonal activity has proven to be a difficult task for the state of the art numerical models. In order to improve the forecasts of the ISO activity over the Southeast Asian monsoon region, a physically based empirical scheme was designed. The scheme uses wavelet banding to separate the predictand and predictors into physically significant bands where linear regression followed by recombination of the bands is used to generate the forecast. Results of the empirical scheme suggest that isolating the evolution of the intraseasonal signal from higher frequency variability and noise improve the skill of the prediction. The hypothesis is that a similar phenomenon occurs in numerical models: The strong intraseasonal signal is eroded by high frequency errors due to the model parameterizations, especially in convection. To evaluate the hypothesis, a coupled ocean-atmosphere model was run in ensemble mode for 30 day periods initialized daily for 20 days before to 20 days after major intraseasonal oscillations, allowing the examination of the skill of the model relative to the phase of the oscillation. The results, which confirm the previous hypothesis, represent well the observations for about 7 days after which the magnitude of the errors is greater than the signal itself. An integration scheme was developed for the coupled ocean-atmosphere general circulation model in order to mimic the philosophy of the empirical scheme and use for 30-day forecasts. The propagation features associated to ISO activity are improved.

Book The Impact of Air sea Coupling on Tropical Intraseasonal Variability Simulation and Predictability

Download or read book The Impact of Air sea Coupling on Tropical Intraseasonal Variability Simulation and Predictability written by Kathleen V. Pegion and published by . This book was released on 2007 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: A coupled interactive ensemble technique is also applied to the CFS to determine the relative importance of internal atmospheric dynamics and coupled air-sea feedbacks in the interannual and intraseasonal variability in the CFS. A 40-year interactive ensemble simulation has been performed with the CFS. By comparing this simulation to the standard coupled simulation and the uncoupled simulation, we estimate the importance of internal atmospheric dynamics to the interannual and intraseasonal variability in the CFS.

Book Understanding Seasonal Climate Predictability in the Atlantic Sector

Download or read book Understanding Seasonal Climate Predictability in the Atlantic Sector written by Marcelo Barreiro and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation aims at understanding ocean-atmosphere interactions in the Atlantic basin, and how this coupling may lead to increased climate predictability on seasonal-to-interannual time scales. Two regions are studied: the South Atlantic convergence zone (SACZ), and the tropical Atlantic. We studied the SACZ during austral summer and separated its variability into forced and internal components. This was done by applying a signal-to-noise optimization procedure to an ensemble of integrations of the NCAR Community Climate Model (CCM3) forced with observed Sea Surface Temperature (SST). The analysis yielded two dominant responses: (1) a response to local Atlantic SST consisting of a dipole-like structure in precipitation close to the coast of South America; (2) a response to Pacific SST which manifests mainly in the upper-level circulation consisting of a northeastward shift of the SACZ during El Niño events. The land portion of the SACZ was found to be primarily dominated by internal variability, thereby having limited potential predictability at seasonal time scales. We studied two aspects of tropical Atlantic Variability (TAV). First, we investigated the effect of extratropical variability on the gradient mode. We found that the intensive Southern Hemisphere (SH) winter variability can play a pre-conditioning role in the onset of the interhemispheric anomalies in the deep tropics during boreal spring. This SH influence on TAV is contrasted with its northern counterpart that primarily comes from the North Atlantic Oscillation during boreal winter. Second, we explored the importance of ocean dynamics in the predictability of TAV. We used the CCM3 coupled to a slab ocean as a tier-one prediction system. The ocean processes are included as a statistical correction that parameterizes the heat transport due to anomalous linear ocean dynamics. The role of ocean dynamics was studied by comparing prediction runs with and without the correction. We showed that in the corrected region the corrected model outperformed the non-corrected one particularly at long lead times. Furthermore, when the model was initialized with global initial conditions, tropical Atlantic SST anomalies are skillfully predicted for lead times of up to six months. As result, the corrected model showed high skill in predicting rainfall in the ITCZ during boreal spring.

Book Weather Climate Services for the Energy Industry

Download or read book Weather Climate Services for the Energy Industry written by Alberto Troccoli and published by Springer. This book was released on 2018-01-03 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book showcases the burgeoning area of applied research at the intersection between weather and climate science and the energy industry. It illustrates how better communication between science and industry can help both sides. By opening a dialogue, scientists can understand the broader context for their work and the energy industry is able to keep track of and implement the latest scientific advances for more efficient and sustainable energy systems. Weather & Climate Services for the Energy Industry considers the lessons learned in establishing an ongoing discussion between the energy industry and the meteorological community and how its principles and practises can be applied elsewhere. This book will be a useful guiding resource for research and early career practitioners concerned with the energy industry and the new field of research known as energy meteorology.

Book Evaluation of Climate Predictability for Multiple Climae Models at Various Time Scales

Download or read book Evaluation of Climate Predictability for Multiple Climae Models at Various Time Scales written by Waqar Younas and published by . This book was released on 2014 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The predictability of the Pacific North American (PNA) pattern is evaluated on time scales from days to months using state-of-the-art dynamical multiple model ensembles including the Canadian Historical Forecast Project (HFP2) ensemble, the Development of a European Multimodel Ensemble System for Seasonal-to-Interannual prediction (DEMETER) ensemble, and the Ensemble Based Predictions of Climate Changes and their Impacts (ENSEMBLES). Some interesting findings in this study include (i) Multiple-model ensemble (MME) skill was better than skill from most of the individual models; (ii) both actual prediction skill and potential predictability increased as the averaging time scale increased from days to months; (iii) There is no significant difference in actual skill between coupled and uncoupled models, in contrast with the potential predictability where coupled models performed better than uncoupled models; (iv) relative entropy (RE[subscript]A) is an effective measure in characterizing the potential predictability of individual predictions, whereas the mutual information (MI) is a reliable indicator of overall prediction skill; (v) Compared with conventional potential predictability measures of the signal-to-noise ratio, the MI-based measures characterized more potential predictability when the ensemble spread varied over initial conditions. It is also confirmed that from monthly to seasonal time scales, the potential predictability of PNA is teleconnected with ENSO. The predictive skill on intra-seasonal time scales in the tropics is linked to Madden-Julian Oscillations (MJO). Using recently developed framework of potential predictability, information-based and ensemble based predictability measures were explored on multiple time scales for MJO predictability. Results show that there is no significant difference in the simulation of MJO in coupled (CanCM3) and uncoupled (GCM3) models. Both models simulated the tropical low frequency variability reasonably well compared with observations with some positive bias in CanCM3 in simulating the precipitation, whereas GCM3 could not capture the upper zonal wind variability on eastern Pacific. The MJO prediction skill is significantly better in CanCM3 than in GCM3 in terms of correlation and Root Mean Square Error (RMSE). In terms of potential predictability of MJO, coupled models forecast skill again dominated uncoupled models prediction skill. It was found that AC[subscript]MI estimate more potential predictability than AC[subscript]P. MI is seen to be reliable predictor of model overall skill. MJO index is found to be strong component of internal variability in terms of DC. There is no significant difference found in MJO prediction skill with time average (both for actual and potential skill), where time average skill is calculated using 3-days, 5-days and 7-days mean."--Leaves ii-iii.

Book Seasonal Climate Forecasting and Managing Risk

Download or read book Seasonal Climate Forecasting and Managing Risk written by Alberto Troccoli and published by Springer Science & Business Media. This book was released on 2008-01-29 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally formed around a set of lectures presented at a NATO Advanced Study Institute (ASI), this book has grown to become organised and presented rather more as a textbook than as a standard "collection of proceedings". This therefore is the first unified reference ‘textbook’ in seasonal to interannual climate predictions and their practical uses. Written by some of the world’s leading experts, the book covers a rapidly-developing science of prime social concern.