Now showing items 1-20 of 56

• #### Amazon Forest Response to Changes in Rainfall Regime: Results from an Individual-Based Dynamic Vegetation Model ﻿

(2014-02-25)
The Amazon is the largest tropical rainforest in the world, and thus plays a major role on global water, energy, and carbon cycles. However, it is still unknown how the Amazon forest will respond to the ongoing changes ...
• #### Amazon Rain Forest Subcanopy Flow and the Carbon Budget: Santarém LBA-ECO Site ﻿

(American Geophysical Union, 2008)
Horizontal and vertical CO<sub>2</sub> fluxes and gradients were made in an Amazon tropical rain forest, the Tapajós National Forest Reserve (FLONA-Tapajós: 54°58′W, 2°51′S). Two observational campaigns in 2003 and 2004 ...
• #### The Arctic Boundary Layer Expedition (ABLE 3A): July–August 1988 ﻿

(Wiley-Blackwell, 1992)
The Arctic Boundary Layer Expedition (ABLE 3A) used measurements from ground, aircraft, and satellite platforms to characterize the chemistry and dynamics of the lower atmosphere over Arctic and sub-Arctic regions of North ...
• #### Atmosphere-biosphere exchange of CO 2 and O 3 in the central Amazon Forest ﻿

(Wiley-Blackwell, 1990)
Measurements of vertical fluxes for CO2 and O3 were made at a level 10 m above the canopy of the Amazon forest during the wet season, using eddy correlation techniques. Vertical profiles of CO2 and O3 were recorded ...
• #### Atmospheric chemistry in the Arctic and subarctic: Influence of natural fires, industrial emissions, and stratospheric inputs ﻿

(Wiley-Blackwell, 1992)
Haze layers with perturbed concentrations of trace gases, believed to originate from tundra and forest wild fires, were observed over extensive areas of Alaska and Canada in 1988. Enhancements of CH, CH, CH, CH, and CH ...
• #### Atmospheric distribution of 85 Kr simulated with a general circulation model ﻿

(Wiley-Blackwell, 1987)
A three-dimensional chemical tracer model for the troposphere is used to simulate the global distribution of 85Kr, a long-lived radioisotope released at northern mid-latitudes by nuclear industry. Simulated distributions ...
• #### Atmospheric Observations and Models of Greenhouse Gas Emissions in Urban Environments ﻿

(2015-05-18)
Greenhouse gas emission magnitudes, trends, and source contributions are highly uncertain, particularly at sub-national scales. As the world becomes increasingly urbanized, one potential strategy for reducing these ...
• #### Biomass-burning emissions and associated haze layers over Amazonia ﻿

(Wiley-Blackwell, 1988)
Biomass-burning plumes and haze layers were observed during the ABLE 2A flights in July/August 1985 over the central Amazon Basin. The haze layers occurred at altitudes between 1000 and 4000 m and were usually only some ...
• #### Budgets of reactive nitrogen, hydrocarbons, and ozone over the Amazon forest during the wet season ﻿

(Wiley-Blackwell, 1990)
The atmospheric composition over the Amazon forest during the wet season is simulated with a onedimensional photochemical model for the planetary boundary layer (PBL) extending from the ground to 2000‐m altitude. The model ...
• #### Calibration of the Total Carbon Column Observing Network Using Aircraft Profile Data ﻿

(Copernicus GmbH, 2010)
The Total Carbon Column Observing Network (TCCON) produces precise measurements of the column average dry-air mole fractions of $CO_2$, $CO$, $CH_4$, $N_2O$ and $H_2O$ at a variety of sites worldwide. These ...
• #### A continuous measure of gross primary production for the conterminous United States derived from MODIS and AmeriFlux data ﻿

(Elsevier BV, 2010)
The quantification of carbon fluxes between the terrestrial biosphere and the atmosphere is of scientific importance and also relevant to climate-policy making. Eddy covariance flux towers provide continuous measurements ...
• #### Coupled weather research and forecasting–stochastic time-inverted lagrangian transport (WRF–STILT) model ﻿

(Springer Nature, 2010)
This paper describes the coupling between a mesoscale numerical weather prediction model, the Weather Research and Forecasting (WRF) model, and a Lagrangian Particle Dispersion Model, the Stochastic Time-Inverted Lagrangian ...
• #### Deposition of ozone to tundra ﻿

(Wiley-Blackwell, 1992)
Vertical turbulent fluxes of O were measured by eddy correlation from a 12‐m high tower erected over mixed tundra terrain (dry upland tundra, wet meadow tundra, and small lakes) in western Alaska during the Arctic Boundary ...
• #### Deriving a Light Use Efficiency Model from Eddy Covariance Flux Data for Predicting Daily Gross Primary Production Across Biomes ﻿

(Elsevier, 2007)
The quantitative simulation of gross primary production (GPP) at various spatial and temporal scales has been a major challenge in quantifying the global carbon cycle. We developed a light use efficiency (LUE) daily GPP ...
• #### Development and Field-Deployment of an Absorption Spectrometer to Measure Atmospheric HONO and NO2 ﻿

(2012-07-20)
Field observations show daytime HONO levels in urban, rural and remote environments are greater than those expected at photostationary state, that is, balance between production by $NO+OH$ reaction and loss by UV-photolysis ...
• #### Dynamics of Carbon, Biomass, and Structure in Two Amazonian Forests ﻿

(American Geophysical Union, 2008)
Amazon forests are potentially globally significant sources or sinks for atmospheric carbon dioxide. In this study, we characterize the spatial trends in carbon storage and fluxes in both live and dead biomass (necromass) ...
• #### Emissions of CH4 and N2O over the United States and Canada Based on a Receptor-oriented Modeling Framework and COBRA-NA Atmospheric Observations ﻿

(American Geophysical Union, 2008)
We present top-down emission constraints for two non-CO2 greenhouse gases in large areas of the U.S. and southern Canada during early summer. Collocated airborne measurements of methane and nitrous oxide acquired during ...
• #### Emissions of Nitrous Oxide and Methane in North America ﻿

(2015-05-13)
Methane (CH_4) and nitrous oxide (N_2O) are the second- and third-most important long-lived greenhouse gas species after carbon dioxide (CO_2) in terms of radiative forcing. This thesis describes the magnitude, spatial ...
• #### Estimation of Net Ecosystem Carbon Exchange for the Conterminous United States by Combining MODIS and AmeriFlux Data ﻿

(Elsevier, 2008)
Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of ...
• #### Evaluation of the airborne quantum cascade laser spectrometer (QCLS) measurements of the carbon and greenhouse gas suite – CO2, CH4, N2O, and CO – during the CalNex and HIPPO campaigns ﻿

(Copernicus GmbH, 2014)
We present an evaluation of aircraft observations of the carbon and greenhouse gases CO2, CH4, N2O, and CO using a direct-absorption pulsed quantum cascade laser spectrometer (QCLS) operated during the HIPPO and CalNex ...