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Toward Improved Regional Estimates Of Carbon Dioxide Sources And Sinks Through Coupled Carbon Atmospheric Data Assimilation
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Book Synopsis Toward Improved Regional Estimates of Carbon Dioxide Sources and Sinks Through Coupled Carbon--atmospheric Data Assimilation by : Hans Weiteng Chen
Download or read book Toward Improved Regional Estimates of Carbon Dioxide Sources and Sinks Through Coupled Carbon--atmospheric Data Assimilation written by Hans Weiteng Chen and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate estimates of regional carbon dioxide (CO2) sources and sinks are necessary to further our understanding of the carbon cycle and improve predictions of future climate change. CO2 surface fluxes can be constrained using atmospheric CO2 observations combined with atmospheric transport models through so-called top-down or inverse methods. At regional scales, however, inverse estimates of CO2 fluxes have been shown to be sensitive to errors in model representation of atmospheric transport. How to account for such atmospheric transport errors in inversions is currently not well understood.This dissertation examines the impact of atmospheric transport errors on simulated atmospheric CO2 mole fractions and inferred CO2 fluxes at subcontinental scales and hourly to monthly time scales. We first investigate how much space for improvement there is in two contemporary CO2 analysis datasets by comparing CO2 mole fractions from the analyses with airborne in situ measurements of CO2 from the Atmospheric Carbon and Transport - America field campaigns in summer 2016 and winter 2017. The analyses show an overall good agreement with observations except for large biases in near-surface CO2 mole fractions in the Mid-Atlantic region of the United States during summer, which suggests that CO2 fluxes can be further optimized in this region. Next, we quantify how transport errors due to uncertainties in meteorological initial conditions propagate to errors in atmospheric CO2 mole fractions through ensemble sensitivity experiments in a regional mesoscale model. Transport errors in CO2 are found to be of comparable magnitude and share similar spatiotemporal characteristics as errors due to uncertainties in CO2 fluxes on sub-monthly time scales. Finally, we present the development of a coupled carbon--atmospheric data assimilation system for regional CO2 flux inversion. This data assimilation system uses the ensemble Kalman Filter to optimize both meteorological variables and CO2 mole fractions and fluxes. Coupling the atmospheric and carbon states allows us to investigate the role of atmospheric transport errors in the CO2 flux optimization. The data assimilation system is tested in a series of perfect model experiments with synthetic observations to examine how well the CO2 flux inversion performs when different types of errors are introduced.
Book Synopsis Carbon Dioxide Information Analysis Center Catalog of Data Bases and Reports by :
Download or read book Carbon Dioxide Information Analysis Center Catalog of Data Bases and Reports written by and published by . This book was released on 1989 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Carbon Dioxide Information Analysis Center, World Data Center-A for Atmospheric Trace Gases by : Carbon Dioxide Information Analysis Center (U.S.)
Download or read book Carbon Dioxide Information Analysis Center, World Data Center-A for Atmospheric Trace Gases written by Carbon Dioxide Information Analysis Center (U.S.) and published by . This book was released on 1993 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Towards Robust Regional Estimates of Carbon Sources and Sinks Using Atmospheric Transport Models by : Kevin Gurney
Download or read book Towards Robust Regional Estimates of Carbon Sources and Sinks Using Atmospheric Transport Models written by Kevin Gurney and published by . This book was released on 2004 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :Sivakiruthika Natchimuthu Publisher :Linköping University Electronic Press ISBN 13 :917685812X Total Pages :56 pages Book Rating :4.1/5 (768 download)
Book Synopsis Freshwater methane and carbon dioxide fluxes by : Sivakiruthika Natchimuthu
Download or read book Freshwater methane and carbon dioxide fluxes written by Sivakiruthika Natchimuthu and published by Linköping University Electronic Press. This book was released on 2016-09-05 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freshwater bodies such as lakes and streams release the greenhouse gases methane (CH4) and carbon dioxide (CO2) into the atmosphere. Global freshwater CH4 and CO2 emissions have been estimated to be of a similar magnitude to the global land or ocean carbon sink, and are thus significant components of global carbon budgets. However, the data supporting global estimates frequently lacks information regarding spatial and temporal variability and are thus highly inaccurate. In this thesis, detailed studies of the spatio-temporal variability of CH4 and CO2 fluxes were conducted in the open water areas of lakes and streams within a whole catchment in Sweden. One aim was also to evaluate the importance of spatio-temporal variability in lake and stream fluxes when making whole catchment aquatic or large scale assessments. Apart from the expected large spatio-temporal variability in lake fluxes, interactions between spatial and temporal variability in CH4 fluxes were found. Shallow lakes and shallow areas of lakes were observed to emit more CH4 as compared to their deeper counterparts. This spatial variability interacted with the temporal variability driven by an exponential temperature response of the fluxes, which meant that shallow waters were more sensitive to warming than deeper ones. Such interactions may be important for climate feedbacks. Surface water CO2 in lakes showed significant spatio-temporal variability and, when considering variability in both space and time, CO2 fluxes were largely controlled by concentrations, rather than gas transfer velocities. Stream fluxes were also highly variable in space and time and in particular, stream CH4 fluxes were surprisingly large and more variable than CO2 fluxes. Fluxes were large from stream areas with steep slopes and periods of high discharge which occupied a small fraction of the total stream area and the total measurement period, respectively, and a failure to account for these spatially distinct or episodic high fluxes could lead to underestimates. The total aquatic fluxes from the whole catchment were estimated by combining the measurements in open waters of lakes and streams. Using our data, recommendations on improved study designs for representative measurements in lakes and streams were provided for future studies. Thus, this thesis presents findings relating to flux regulation in lakes and streams, and urges forthcoming studies to better consider spatio-temporal variability so as to achieve unbiased large-scale estimates.
Book Synopsis Land Carbon Cycle Modeling by : Yiqi Luo
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
Book Synopsis Improving the Temporal and Spatial Resolution of Carbon Dioxide Emissions Estimates from Fossil-fuel Consumption by : Jay Sterling Gregg
Download or read book Improving the Temporal and Spatial Resolution of Carbon Dioxide Emissions Estimates from Fossil-fuel Consumption written by Jay Sterling Gregg and published by . This book was released on 2005 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Overview of Scripps Program to Observe Atmospheric Carbon Dioxide by : Charles D. Keeling
Download or read book Overview of Scripps Program to Observe Atmospheric Carbon Dioxide written by Charles D. Keeling and published by . This book was released on 1989 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling Regional Carbon Dioxide Flux Over California Using the WRF-ACASA Coupled Model by :
Download or read book Modeling Regional Carbon Dioxide Flux Over California Using the WRF-ACASA Coupled Model written by and published by . This book was released on 2016 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many processes and interactions in the atmosphere and the biosphere influence the rate of carbon dioxide exchange between these two systems. However, it is difficult to estimate the carbon dioxide flux over regions with diverse ecosystems and complex terrains, such as California. Traditional carbon dioxide measurements are sparse and limited to specific ecosystems. Therefore, accurately estimating carbon dioxide flux on a regional scale remains a major challenge. In this study, we couple the weather Research and Forecasting Model (WRF) with the Advanced Canopy- Atmosphere-Soil Algorithm (ACASA), a high complexity land surface model. Although WRF is a state-of- the-art regional atmospheric model with high spatial and temporal resolutions, the land surface schemes available in WRF lack the capability to simulate carbon dioxide. ACASA is a complex multilayer land surface model with interactive canopy physiology and full surface hydrological processes. It allows microenvironmental variables such as air and surface temperatures, wind speed, humidity, and carbon dioxide concentration to vary vertically. Carbon dioxide, sensible heat, water vapor, and momentum fluxes between the atmosphere and land surface are estimated in the ACASA model through turbulence equations with a third order closure scheme. It therefore permits counter-gradient transports that low-order turbulence closure models are unable to simulate. A new CO2 tracer module is introduced into the model framework to allow the atmospheric carbon dioxide concentration to vary according to terrestrial responses. In addition to the carbon dioxide simulation, the coupled WRF-ACASA model is also used to investigate the interactions of neighboring ecosystems in their response to atmospheric carbon dioxide concentration. The model simulations with and without the CO2 tracer for WRF-ACASA are compared with surface observations from the AmeriFlux network.
Book Synopsis Regional Estimates of Net Ecosystem-atmosphere Exchange of Carbon Dioxide Over a Heterogeneous Ecosystem by : Weiguo Wang
Download or read book Regional Estimates of Net Ecosystem-atmosphere Exchange of Carbon Dioxide Over a Heterogeneous Ecosystem written by Weiguo Wang and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Data-Model Assimilation at the FACE and AmeriFlux Sites Toward Predictive Understanding of Carbon Sequestration at Ecosystem and Regional Scales by :
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).
Book Synopsis Metadata Compiled and Distributed by the Carbon Dioxide Information Analysis Center for Global Climate Change and Greenhouse Gas-related Data Bases by :
Download or read book Metadata Compiled and Distributed by the Carbon Dioxide Information Analysis Center for Global Climate Change and Greenhouse Gas-related Data Bases written by and published by . This book was released on 1992 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Carbon Dioxide Information Analysis Center (CDIAC) compiles and provides information to help international researchers, policymakers, and educators evaluate complex environmental issues associated with elevated levels of atmospheric carbon dioxide (CO2) and other trace gases, including potential climate change. CDIAC is located within the Environmental Sciences Division of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee and is line funded by the U.S. Department of Energy's (DOE) Global Change Research Program (GCRP). CDIAC is an information analysis center (IAC). In operation since 1982, CDIAC identifies sources of primary data at national and international levels; obtains, archives, evaluates and distributes data and computer models; fully documents select data sets and computer models and offers them as numeric data packages (NDPs) and computer model packages (CMPs); distributes data and computer models on a variety of magnetic and electronic medias including 9-track magnetic tapes; IBM-formatted floppy diskettes; CD-ROM; and over Internet, Omnet, and Bitnet electronic networks; develops derived, often multidisciplinary data products useful for carbon cycle and climate-change research; distributes reports pertinent to greenhouse effect and climate change issues; produces the newsletter, CDIAC Communications; and in general acts as the information focus for the GCRPs research projects. Since its inception, CDIAC has responded to thousands of requests for information, and since 1985 has distributed more than 70,000 reports, NDPs and CMPs to 97 countries worldwide.
Book Synopsis Atmospheric Carbon Dioxide Retrieved from the Greenhouse Gases Observing SATellite by : Austin James Cogan
Download or read book Atmospheric Carbon Dioxide Retrieved from the Greenhouse Gases Observing SATellite written by Austin James Cogan and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon dioxide is the largest anthropogenic contributor to global warming and atmospheric concentrations have rapidly increased since the start of the industrial revolution. Networks of surface in-situ carbon dioxide sensors provide precise and accurate measurements of the global carbon dioxide concentration, including large scale temporal, seasonal and latitudinal variations. However, these observations are too sparse to allow the establishment of sub-continental carbon budgets, limiting the accuracy of climate change projections and the ability to mitigate future levels of atmospheric carbon dioxide. Satellite observations can provide data with dense spatial and temporal coverage over regions poorly sampled by surface networks. Specifically, observations in the shortwave infrared region are well suited for constraining carbon fluxes as they can provide total column carbon dioxide with high sensitivity to the source and sink locations at the surface. The first dedicated greenhouse gases sensor, the Greenhouse gases Observing SATellite (GOSAT), was launched in January 2009 by the Japanese Aerospace eXploration Agency (JAXA) and has successfully started to acquire global observations of greenhouse gases, including carbon dioxide. The University of Leicester Full Physics (UOL-FP) retrieval algorithm has been designed to estimate total column carbon dioxide from GOSAT shortwave infrared observations. The initial results were compared to coincident ground based measurements for a number of locations and compared on a global scale to a model. This showed an accuracy and precison that should provide improved surface flux estimates. Additionally, a bias correction scheme was developed that reduced observed geographical biases, allowing surface flux uncertainties to be potentially reduced further. To further develop the UOL-FP retrieval algorithm, a simulator capable of creating realistic GOSAT observations was built, allowing the investigation of different retrieval algorithm modifications, which may lead to reduced source and sink flux uncertainties and therefore aid future climate change forecasts.
Book Synopsis Integrating Remote Sensing, Field Observations, and Models to Understand Disturbance and Climate Effects on the Carbon Balance of the West Coast U.S. by :
Download or read book Integrating Remote Sensing, Field Observations, and Models to Understand Disturbance and Climate Effects on the Carbon Balance of the West Coast U.S. written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: GOAL: To develop and apply an approach to quantify and understand the regional carbon balance of the west coast states for the North American Carbon Program. OBJECTIVE: As an element of NACP research, the proposed investigation is a two pronged approach that derives and evaluates a regional carbon (C) budget for Oregon, Washington, and California. Objectives are (1) Use multiple data sources, including AmeriFlux data, inventories, and multispectral remote sensing data to investigate trends in carbon storage and exchanges of CO2 and water with variation in climate and disturbance history; (2) Develop and apply regional modeling that relies on these multiple data sources to reduce uncertainty in spatial estimates of carbon storage and NEP, and relative contributions of terrestrial ecosystems and anthropogenic emissions to atmospheric CO2 in the region; (3) Model terrestrial carbon processes across the region, using the Biome-BGC terrestrial ecosystem model, and an atmospheric inverse modeling approach to estimate variation in rate and timing of terrestrial uptake and feedbacks to the atmosphere in response to climate and disturbance. APPROACH: In performing the regional analysis, the research plan for the bottom-up approach uses a nested hierarchy of observations that include AmeriFlux data (i.e., net ecosystem exchange (NEE) from eddy covariance and associated biometric data), intermediate intensity inventories from an extended plot array partially developed from the PI's previous research, Forest Service FIA and CVS inventory data, time since disturbance, disturbance type, and cover type from Landsat developed in this study, and productivity estimates from MODIS algorithms. The BIOME-BGC model is used to integrate information from these sources and quantify C balance across the region. The inverse modeling approach assimilates flux data from AmeriFlux sites, high precision CO2 concentration data from AmeriFlux towers and four new calibrated CO2 sites, reanalysis meteorology and various remote sensing products to generate statewide estimates of biosphere carbon exchange from the atmospheric point of view.
Book Synopsis Mapping the Missing Carbon by : Miroslav Honz K
Download or read book Mapping the Missing Carbon written by Miroslav Honz K and published by LAP Lambert Academic Publishing. This book was released on 2011-10 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific consensus is that the recently observed increase in levels of atmospheric carbon dioxide is caused primarily by burning of fossil fuels, industrial processes and deforestation. However, the rate of this increase has been much slower than would be expected from a simple tally of known carbon sources and sinks, suggesting that carbon is "missing" from the existing carbon budget. New research indicates that tropical forests are absorbing significantly more carbon than previously thought, a finding that could help account for the missing carbon. A critical question remains: how much carbon sequestration is carried out by mature versus by regenerating forests? This work begins to answer this question by improving our understanding of the role that regenerating forests play in the carbon budget of tropical forests. The author presents an operational methodology for mapping carbon pools of tropical regenerating forests at regional scales. Integrating site-level forest inventory measurements with satellite imagery in the Amazon and the Congo Basin, the author presents wall-to-wall maps of carbon pools at different stages of forest regeneration in both regions.
Book Synopsis The North American Carbon Program Multi-scale Synthesis and Terrestrial Model Intercomparison Project - Part 2 by :
Download or read book The North American Carbon Program Multi-scale Synthesis and Terrestrial Model Intercomparison Project - Part 2 written by and published by . This book was released on 2014 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecosystems are important and dynamic components of the global carbon cycle, and terrestrial biospheric models (TBMs) are crucial tools in further understanding of how terrestrial carbon is stored and exchanged with the atmosphere across a variety of spatial and temporal scales. Improving TBM skills, and quantifying and reducing their estimation uncertainties, pose significant challenges. The Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) is a formal multi-scale and multi-model intercomparison effort set up to tackle these challenges. The MsTMIP protocol prescribes standardized environmental driver data that are shared among model teams to facilitate model model and model observation comparisons. In this article, we describe the global and North American environmental driver data sets prepared for the MsTMIP activity to both support their use in MsTMIP and make these data, along with the processes used in selecting/processing these data, accessible to a broader audience. Based on project needs and lessons learned from past model intercomparison activities, we compiled climate, atmospheric CO2 concentrations, nitrogen deposition, land use and land cover change (LULCC), C3 / C4 grasses fractions, major crops, phenology and soil data into a standard format for global (0.5° x 0.5° resolution) and regional (North American: 0.25° x 0.25° resolution) simulations. In order to meet the needs of MsTMIP, improvements were made to several of the original environmental data sets, by improving the quality, and/or changing their spatial and temporal coverage, and resolution. The resulting standardized model driver data sets are being used by over 20 different models participating in MsTMIP. Lastly, the data are archived at the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC, http://daac.ornl.gov) to provide long-term data management and distribution.
Book Synopsis Response of a Coupled Ocean-atmosphere Model to Increasing Atmospheric Carbon Dioxide by : S. Manabe
Download or read book Response of a Coupled Ocean-atmosphere Model to Increasing Atmospheric Carbon Dioxide written by S. Manabe and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
