A5041666616- Remote Sensing in Agriculture
- Atmospheric and Environmental Gas Dynamics
- Plant Water Relations and Carbon Dynamics
- Fire effects on ecosystems
- Rangeland and Wildlife Management
- Remote Sensing and LiDAR Applications
- Climate variability and models
- Climate change and permafrost
- Cryospheric studies and observations
- Soil Carbon and Nitrogen Dynamics
- Land Use and Ecosystem Services
- Peatlands and Wetlands Ecology
- Forest ecology and management
- Aeolian processes and effects
- Tree-ring climate responses
- Soil Geostatistics and Mapping
- Species Distribution and Climate Change
- Hydrology and Watershed Management Studies
- Atmospheric chemistry and aerosols
- Geochemistry and Geologic Mapping
- Remote-Sensing Image Classification
- Urban Heat Island Mitigation
- Plant responses to elevated CO2
- Remote Sensing and Land Use
- Botany, Ecology, and Taxonomy Studies
Ames Research Center
2015-2024
Naval Research Laboratory Information Technology Division
2024
Brigham and Women's Hospital
2023
National Aeronautics and Space Administration
2011-2020
Desert Research Center
2015
California Institute of Technology
2011
Boston University
2006
NASA Research Park
2005
Johnson Controls (United States)
1993-1997
Stanford University
1993
This paper presents a modeling approach aimed at seasonal resolution of global climatic and edaphic controls on patterns terrestrial ecosystem production soil microbial respiration. We use satellite imagery (Advanced Very High Resolution Radiometer International Satellite Cloud Climatology Project solar radiation), along with historical climate (monthly temperature precipitation) attributes (texture, C N contents) from (1°) data sets as model inputs. The Carnegie‐Ames‐Stanford (CASA)...
We use semi‐mechanistic, empirically based statistical models to predict the spatial and temporal patterns of global carbon dioxide emissions from terrestrial soils. Emissions include respiration both soil organisms plant roots. At scale, rates CO 2 efflux correlate significantly with temperature precipitation; they do not well pools, nitrogen or C:N. Wetlands cover about 3% land area but diminish predicted by only 1%. The estimated annual flux soils atmosphere is be 76.5 Pg C yr −1 , 1–9...
Abstract We used a climate‐driven regression model to develop spatially resolved estimates of soil‐CO 2 emissions from the terrestrial land surface for each month January 1980 December 1994, evaluate effects interannual variations in climate on global soil‐to‐atmosphere CO fluxes. The mean annual flux over this 15‐y period was estimated be 80.4 (range 79.3–81.8) Pg C. Monthly followed closely temperature cycle Northern Hemisphere. Globally, reached their minima February and peaked July...
[1] Forest disturbances greatly alter the carbon cycle at various spatial and temporal scales. It is critical to understand disturbance regimes their impacts better quantify regional global dynamics. This review of status major challenges in representing modeling dynamics across North America revealed some advances challenges. First, significant have been made representation, scaling, characterization that should be included efforts. Second, there a need develop effective comprehensive...
We report on an ecosystem modeling approach that integrates global satellite, climate, vegetation, and soil data sets to (1) examine conceptual controls nitrogen trace gas (NO, N 2 O, ) emissions from soils (2) identify weaknesses in our bases of knowledge for these fluxes. Nitrous nitric oxide well‐drained were estimated by using expanded version the Carnegie‐Ames‐Stanford (CASA) Biosphere model, a coupled production carbon‐nitrogen model 1° grid. estimate monthly NO, based predicted rates...
Fluxes of methane from field observations native and cropped grassland soils in Colorado Nebraska were used to model CH 4 oxidation as a function soil water content, temperature, porosity, capacity (FC). A beta is characterize the effect on physical limitation gas diffusivity when high biological low. Optimum volumetric content ( W opt ) increases with FC. The site specific maximum rate (CH 4max varies directly D bulk density Although properties are primary controls uptake, potential for...
Global land surface characteristics are important boundary conditions for global models that describe exchanges of water, energy, and carbon dioxide between the atmosphere biosphere. Existing data sets cover based on classification schemes characterize each grid cell as a discrete vegetation type. Consequently, parameter fields derived from these dependent particular scheme number types it includes. The functional controls biosphere now well enough understood is increasingly feasible to...
The CASA (Carnegie-Ames-Stanford) ecosystem model has been used to estimate monthly carbon fluxes in terrestrial ecosystems from 2000 2009, with global data inputs NASA’s Terra Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation cover mapping. Net primary production (NPP) flux for atmospheric dioxide varied slightly year-to-year, but was predicted have increased over short multi-year periods the regions of high-latitude Northern Hemisphere, South Asia, Central Africa, and...
Abstract Ecosystems in the North American Arctic-Boreal Zone (ABZ) experience a diverse set of disturbances associated with wildfire, permafrost dynamics, geomorphic processes, insect outbreaks and pathogens, extreme weather events, human activity. Climate warming ABZ is occurring at over twice rate global average, as result extent, frequency, severity these are increasing rapidly. Disturbances span wide gradient spatiotemporal scales have varying impacts on ecosystem properties function....
This paper describes the use of satellite data to calibrate a new climate vegetation greenness relation for global change studies. We examined statistical relations between annual indexes (temperature, precipitation, and surface radiation) seasonal attributes AVHRR Normalized Difference Vegetation Index (NDVI) time series mid-1980s in order refine our understanding intra-annual patterns controls on natural dynamics. Multiple linear regression results using 1 gridded sets suggest that three...
nvironmental policymakers, particularly those who consider options for mitigating global warming, require accurate assessments of sources and sinks atmospheric carbon dioxide.A case in point is the Kyoto Protocol 1997, first negotiated agreement reducing net terrestrial emissions dioxide on an international scale.Emissions may be reduced by curbing air pollution sources, slowing "slash burn" deforestation, promoting regrowth forest areas that have been logged.The goal to restrict average...
Nine ecosystem process models were used to predict CO 2 and water vapor exchanges by a 150‐year‐old black spruce forest in central Canada during 1994–1996 evaluate improve the models. Three had hourly time steps, five daily one monthly steps. Model input included site characteristics meteorology. predictions compared eddy covariance (EC) measurements of whole‐ecosystem exchange evapotranspiration, chamber nighttime moss‐surface release, ground‐based estimates annual gross primary production,...
In this paper, we estimate the year‐to‐year variations in northern vegetation greenness as they relate to dominant modes of climate variability. particular, analyze spatial data Northern Hemisphere satellite‐sensed greenness, surface temperature, precipitation, and upper air for 1982–1998 period isolate well correlated variability between temperature assess their relationship large‐scale circulation anomalies. It is found that during spring, interannual are strongly with spatiotemporal...
To analyze the effect of oceans and atmosphere on land climate, Earth Scientists have developed climate indices, which are time series that summarize behavior selected regions Earth's atmosphere. In past, scientists used observation and, more recently, eigenvalue analysis techniques, such as principal components (PCA) singular value decomposition (SVD), to discover indices. However, techniques only useful for finding a few strongest signals. Furthermore, they impose condition all discovered...
Abstract Ecosystem scientists have yet to develop a proven methodology monitor and understand major disturbance events their historical regimes at global scale. This study was conducted evaluate patterns in an 18‐year record of satellite observations vegetation phenology from the Advanced Very High Resolution Radiometer (AVHRR) as means characterize ecosystem regimes. The fraction absorbed photosynthetically active radiation (FPAR) by canopies worldwide has been computed monthly time...
Previous chapter Next Full AccessProceedings Proceedings of the 2009 SIAM International Conference on Data Mining (SDM)Detection and Characterization Anomalies in Multivariate Time SeriesHaibin Cheng, Pang-Ning Tan, Christopher Potter, Steven KloosterHaibin Kloosterpp.413 - 424Chapter DOI:https://doi.org/10.1137/1.9781611972795.36PDFBibTexSections ToolsAdd to favoritesExport CitationTrack CitationsEmail SectionsAboutAbstract Anomaly detection multivariate time series is an important data...
SUMMARY (1) Incident precipitation, throughfall and stemflow were collected to examine the importance of factors potentially determining net canopy element fluxes, quantify exchange dry deposition rates in a regenerating southern Appalachian forest. (2) Net fluxes (throughfall minus precipitation transfers) showed consistent effects on rainfall chemistry, with SO42~, PO43~, Cl~, K+, Ca2+ Mg2+ added by foliage, whereas NO3~-N, NH4+-N H+ ions absorbed from precipitation. Storm characteristics...
Abstract. This study assesses the impact of different state art global biospheric CO2 flux models, when applied as prior information, on inverse model “top-down” estimates terrestrial fluxes obtained assimilating Orbiting Carbon Observatory 2 (OCO-2) observations. is done with a series observing system simulation experiments (OSSEs) using synthetic column-average dry air mole fraction (XCO2) retrievals sampled at OCO-2 satellite spatiotemporal frequency. The OSSEs utilized 4-D variational...