Download or read book Data Assimilation in the Ecosystem Carbon Pool Model Using the Forward Sensitivity Method written by Dung Tuan Phan and published by . This book was released on 2011 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forecast Error Correction using Dynamic Data Assimilation written by Sivaramakrishnan Lakshmivarahan and published by Springer. This book was released on 2016-10-21 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the reader to a new method of data assimilation with deterministic constraints (exact satisfaction of dynamic constraints)—an optimal assimilation strategy called Forecast Sensitivity Method (FSM), as an alternative to the well-known four-dimensional variational (4D-Var) data assimilation method. 4D-Var works with a forward in time prediction model and a backward in time tangent linear model (TLM). The equivalence of data assimilation via 4D-Var and FSM is proven and problems using low-order dynamics clarify the process of data assimilation by the two methods. The problem of return flow over the Gulf of Mexico that includes upper-air observations and realistic dynamical constraints gives the reader a good idea of how the FSM can be implemented in a real-world situation.
Download or read book Global Sensitivity Analysis Probabilistic Calibration and Predictive Assessment for the Data Assimilation Linked Ecosystem Carbon Model written by and published by . This book was released on 2015 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we propose a probabilistic framework for an uncertainty quantification (UQ) study of a carbon cycle model and focus on the comparison between steady-state and transient simulation setups. A global sensitivity analysis (GSA) study indicates the parameters and parameter couplings that are important at different times of the year for quantities of interest (QoIs) obtained with the data assimilation linked ecosystem carbon (DALEC) model. We then employ a Bayesian approach and a statistical model error term to calibrate the parameters of DALEC using net ecosystem exchange (NEE) observations at the Harvard Forest site. The calibration results are employed in the second part of the paper to assess the predictive skill of the model via posterior predictive checks.
Download or read book An Improved Analysis of Forest Carbon Dynamics Using Data Assimilation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are two broad approaches to quantifying landscape C dynamics - by measuring changes in C stocks over time, or by measuring fluxes of C directly. However, these data may be patchy, and have gaps or biases. An alternative approach to generating C budgets has been to use process-based models, constructed to simulate the key processes involved in C exchange. However, the process of model building is arguably subjective, and parameters may be poorly defined. This paper demonstrates why data assimilation (DA) techniques - which combine stock and flux observations with a dynamic model - improve estimates of, and provide insights into, ecosystem carbon (C) exchanges. We use an ensemble Kalman filter (EnKF) to link a series of measurements with a simple box model of C transformations. Measurements were collected at a young ponderosa pine stand in central Oregon over a 3-year period, and include eddy flux and soil C02 efflux data, litterfall collections, stem surveys, root and soil cores, and leaf area index data. The simple C model is a mass balance model with nine unknown parameters, tracking changes in C storage among five pools; foliar, wood and fine root pools in vegetation, and also fresh litter and soil organic matter (SOM) plus coarse woody debris pools. We nested the EnKF within an optimization routine to generate estimates from the data of the unknown parameters and the five initial conditions for the pools. The efficacy of the DA process can be judged by comparing the probability distributions of estimates produced with the EnKF analysis vs. those produced with reduced data or model alone. Using the model alone, estimated net ecosystem exchange of C (NEE)= -251 f 197g Cm-2 over the 3 years, compared with an estimate of -419 f 29gCm-2 when all observations were assimilated into the model. The uncertainty on daily measurements of NEE via eddy fluxes was estimated at 0.5gCm-2 day-1, but the uncertainty on assimilated estimates averaged 0.47 g Cm-2 day-1, and onl
Download or read book Land Carbon Cycle Modeling written by Yiqi Luo and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Carbon moves through the atmosphere, through the oceans, onto land, and into ecosystems. This cycling has a large effect on climate - changing geographic patterns of rainfall and the frequency of extreme weather - and is altered as the use of fossil fuels adds carbon to the cycle. The dynamics of this global carbon cycling are largely predicted over broad spatial scales and long periods of time by Earth system models. This book addresses the crucial question of how to assess, evaluate, and estimate the potential impact of the additional carbon to the land carbon cycle. The contributors describe a set of new approaches to land carbon cycle modeling for better exploring ecological questions regarding changes in carbon cycling; employing data assimilation techniques for model improvement; doing real- or near-time ecological forecasting for decision support; combining newly available machine learning techniques with process-based models to improve prediction of land carbon cycle under climate change. This new edition includes 7 new chapters on machine learning and its applications to carbon cycle research (5 chapters). on principles underlying carbon dioxide removal from the atmosphere (1 chapter), a contemporary active research and management issue, and on community infrastructure for ecological forecasting"--
Download or read book Land Carbon Cycle Modeling written by Yiqi Luo and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon moves through the atmosphere, through the oceans, onto land, and into and between various ecosystems. This cycling has a large effect on climate - changing geographic patterns of rainfall and the frequency of extreme weather. The impact of changes in global carbon cycling are altered as the use of fossil fuels add carbon to the cycle. This book addresses the crucial question of how to assess, evaluate, and estimate the potential impact of the additional carbon to the global carbon cycle. The contributors describe a set of models for exploring ecological questions regarding changes in carbon cycling; provide background for developing new models; employs data assimilation techniques for model improvement; and do real- or near-time ecological forecasting for decision support. This book strives to balance theoretical considerations, technical details, and applications of ecosystem modeling for research, assessment, and crucial decision making. Key Features Helps readers understand, implement and criticize carbon cycling models Does not require computer programming skills or deep knowledge of mathematics Describes a suite of modeling skills - modeling questions, building models, data assimilation Combines modeling with statistical analysis of models Introduces data assimilation, statistical analysis, Markov chain Mote Carlo methods, and decision supporting systems
Download or read book Data Model Assimilation at the FACE and AmeriFlux Sites Toward Predictive Understanding of Carbon Sequestration at Ecosystem and Regional Scales written by and published by . This book was released on 2013 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The project was conducted during the period from 9/1/2007 to 8/31/2011 with three major tasks: (1) development of data assimilation (DA) techniques for terrestrial carbon research; (2) applications of DA techniques to analysis of carbon cycle at Duke and other FACE sites; and (3) inverse analysis at AmeriFlux sites. During this period, we have developed a variety of techniques, including (1) ensemble Kalman filter to estimate model parameters or state variables (Gao et al. 2011), (2) Conditional inversion to estimate parameters of a carbon cycle model (Wu et al. 2009), and (3) various methods to quantify uncertainty of estimated parameters and predicted C sinks (e.g., Weng et al. 2011), and (4) information theory to evaluate information content of different model structures and data sets (Weng and Luo 2011). We applied the DA techniques to and did modeling at the Duke FACE and other global change experimental sites. We addressed the following issues: (1) interactive effects of CO2, warming and precipitation on ecosystem processes (e.g., Luo et al. 2008, Weng and Luo 2008, Zhou et al. 2008), (2) effects of warming on estimated parameters related to photosynthesis and residence times (Zhou et al. 2010); and (3) uncertainty in estimated parameters and predicted C sequestration (Gao et al. 2011, Weng and Luo 2011). In addition, we have done data assimilation to estimate carbon residence and carbon sequestration in US continent (Zhou and Luo 2008) and temperature sensitivity at the global scale (Zhou et al. 2009).
Download or read book A Qualitative Analysis of the Data Assimilation Linked Ecosystem Carbon Model DALEC written by Ann M. Chuter and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecological Forecasting written by Michael C. Dietze and published by Princeton University Press. This book was released on 2017-05-30 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative and accessible introduction to the concepts and tools needed to make ecology a more predictive science Ecologists are being asked to respond to unprecedented environmental challenges. How can they provide the best available scientific information about what will happen in the future? Ecological Forecasting is the first book to bring together the concepts and tools needed to make ecology a more predictive science. Ecological Forecasting presents a new way of doing ecology. A closer connection between data and models can help us to project our current understanding of ecological processes into new places and times. This accessible and comprehensive book covers a wealth of topics, including Bayesian calibration and the complexities of real-world data; uncertainty quantification, partitioning, propagation, and analysis; feedbacks from models to measurements; state-space models and data fusion; iterative forecasting and the forecast cycle; and decision support. Features case studies that highlight the advances and opportunities in forecasting across a range of ecological subdisciplines, such as epidemiology, fisheries, endangered species, biodiversity, and the carbon cycle Presents a probabilistic approach to prediction and iteratively updating forecasts based on new data Describes statistical and informatics tools for bringing models and data together, with emphasis on: Quantifying and partitioning uncertainties Dealing with the complexities of real-world data Feedbacks to identifying data needs, improving models, and decision support Numerous hands-on activities in R available online
Download or read book Introduction to Stochastic Search and Optimization written by James C. Spall and published by John Wiley & Sons. This book was released on 2005-03-11 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: * Unique in its survey of the range of topics. * Contains a strong, interdisciplinary format that will appeal to both students and researchers. * Features exercises and web links to software and data sets.
Download or read book Thriving on Our Changing Planet written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-01-20 with total page 717 pages. Available in PDF, EPUB and Kindle. Book excerpt: We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet presents prioritized science, applications, and observations, along with related strategic and programmatic guidance, to support the U.S. civil space Earth observation program over the coming decade.
Download or read book Data Assimilation written by William Lahoz and published by Springer Science & Business Media. This book was released on 2010-07-23 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data assimilation methods were largely developed for operational weather forecasting, but in recent years have been applied to an increasing range of earth science disciplines. This book will set out the theoretical basis of data assimilation with contributions by top international experts in the field. Various aspects of data assimilation are discussed including: theory; observations; models; numerical weather prediction; evaluation of observations and models; assessment of future satellite missions; application to components of the Earth System. References are made to recent developments in data assimilation theory (e.g. Ensemble Kalman filter), and to novel applications of the data assimilation method (e.g. ionosphere, Mars data assimilation).
Download or read book Earth Stewardship written by Ricardo Rozzi and published by Springer. This book was released on 2015-03-26 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book advances Earth Stewardship toward a planetary scale, presenting a range of ecological worldviews, practices, and institutions in different parts of the world and to use them as the basis for considering what we could learn from one another, and what we could do together. Today, inter-hemispheric, intercultural, and transdisciplinary collaborations for Earth Stewardship are an imperative. Chapters document pathways that are being forged by socio-ecological research networks, religious alliances, policy actions, environmental citizenship and participation, and new forms of conservation, based on both traditional and contemporary ecological knowledge and values. “The Earth Stewardship Initiative of the Ecological Society of America fosters practices to provide a stable basis for civilization in the future. Biocultural ethic emphasizes that we are co-inhabitants in the natural world; no matter how complex our inventions may become” (Peter Raven).
Download or read book A Practical Guide to Ecological Modelling written by Karline Soetaert and published by Springer Science & Business Media. This book was released on 2008-10-14 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical modelling is an essential tool in present-day ecological research. Yet for many ecologists it is still problematic to apply modelling in their research. In our experience, the major problem is at the conceptual level: proper understanding of what a model is, how ecological relations can be translated consistently into mathematical equations, how models are solved, steady states calculated and interpreted. Many textbooks jump over these conceptual hurdles to dive into detailed formulations or the mathematics of solution. This book attempts to fill that gap. It introduces essential concepts for mathematical modelling, explains the mathematics behind the methods, and helps readers to implement models and obtain hands-on experience. Throughout the book, emphasis is laid on how to translate ecological questions into interpretable models in a practical way. The book aims to be an introductory textbook at the undergraduate-graduate level, but will also be useful to seduce experienced ecologists into the world of modelling. The range of ecological models treated is wide, from Lotka-Volterra type of principle-seeking models to environmental or ecosystem models, and including matrix models, lattice models and sequential decision models. All chapters contain a concise introduction into the theory, worked-out examples and exercises. All examples are implemented in the open-source package R, thus taking away problems of software availability for use of the book. All code used in the book is available on a dedicated website.
Download or read book Australian Journal of Botany written by and published by . This book was released on 2005 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book GlobalSoilMap written by Dominique Arrouays and published by CRC Press. This book was released on 2014-01-27 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: GlobalSoilMap: Basis of the global spatial soil information system contains contributions that were presented at the 1st GlobalSoilMap conference, held 7-9 October 2013 in Orléans, France. These contributions demonstrate the latest developments in the GlobalSoilMap project and digital soil mapping technology for which the ultimate aim is to produce a high resolution digital spatial soil information system of selected soil properties and their uncertainties for the entire world. GlobalSoilMap: Basis of the global spatial soil information system aims to stimulate capacity building and new incentives to develop full GlobalSoilMap products in all parts of the world.
Download or read book Evaluation of Soil Organic Matter Models written by David S. Powlson and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil organic matter (SOM) represents a major pool of carbon within the biosphere, roughly twice than in atmospheric CO2. SOM models embody our best understanding of soil carbon dynamics and are needed to predict how global environmental change will influence soil carbon stocks. These models are also required for evaluating the likely effectiveness of different mitigation options. The first important step towards systematically evaluating the suitability of SOM models for these purposes is to test their simulations against real data. Since changes in SOM occur slowly, long-term datasets are required. This volume brings together leading SOM model developers and experimentalists to test SOM models using long-term datasets from diverse ecosystems, land uses and climatic zones within the temperate region.
