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Regional budgets for Nitrogen Oxides from Continental Sources: Variations of rates for oxidation and deposition with season and distance from source regions

Journal Article

Measurements of nitrogen deposition and concentrations of NO, NO2, NOy (total oxidized N), and 03 have been made at Harvard Forest in central Massachusetts since 1990 to define the atmospheric budget for reactive N near a major source region. Total (wet...

Interannual variability in ozone removal by a temperate deciduous forest

Resource

Interannual variability in ozone removal by a temperate deciduous forest

Journal Article

The ozone (O3) dry depositional sink and its contribution to observed variability in tropospheric O3 are both poorly understood. Distinguishing O3 uptake through plant stomata versus other pathways is relevant for quantifying the O3 influence on carbon...

Where Has All the Carbon Gone?

Journal Article

The combustion of fossil fuels continues to rise, but the amount of COaccumulating in the atmosphere has not increased accordingly. As Wofsy explains in his Perspective, this discrepancy is explained by the ability of trees and organic matter in forests...

Uncertainties in, and interpretation of, carbon flux estimates using the eddy covariance technique

Journal Article

Whole ecosystem carbon dioxide (CO2) exchange estimated with the eddy covariance (EC) technique has been central to studies on the responses of terrestrial ecosystems to disturbance and intra-annual and interannual variations in climate, but challenges...

Global-scale black carbon profiles observed in the remote atmosphere and compared to models

Journal Article

Refractory black carbon (rBC) aerosol loadings and mass size distributions have been quantified during the HIPPO campaign above the remote Pacific from 80N to 67S. Over 100 vertical profiles of rBC loadings, extending from ∼0.3 to ∼14 km were obtained...

HIAPER Pole-to-Pole Observations (HIPPO): fine-grained global-scale measurements of climatically important atmospheric gases and aerosols

Journal Article

The HIAPER Pole-to-Pole Observations (HIPPO) programme has completed three of five planned aircraft transects spanning the Pacific from 85° N to 67° S, with vertical profiles every approximately 2.2° of latitude. Measurements include greenhouse gases...

Vertical profiles of CO2 above eastern Amazonia suggest a net carbon flux to the atmosphere and balanced biosphere between 2000 and 2009

Journal Article

From 2000 until January 2010 vertical profiles were collected above eastern Amazonia to help determine regional-scale (∼10⁵–10⁶ km²) fluxes of carbon cycle-related greenhouse gases. Samples were collected aboard light aircraft between the surface and 4.3...

Objective Threshold Determination for Nighttime Eddy Flux Filtering

Journal Article

We recommend an automated statistical method (Moving Point Test, or MPT) to determine the friction velocity (u*) thresholds in nighttime eddy flux filtering. Our intention is to make the determination of the u* thresholds objective and reproducible and to...

Dry Deposition of Ozone Over Land: Processes, Measurement, and Modeling

Journal Article

Dry deposition of ozone is an important sink of ozone in near-surface air. When dry deposition occurs through plant stomata, ozone can injure the plant, altering water and carbon cycling and reducing crop yields. Quantifying both stomatal and nonstomatal...

Estimation of Regional Net Surface Fluxes of CO2 and O3 over Amazonia from Aircraft Data (ABLE 2B)

Thesis

Evidence suggests the existence of a 1-2 Gt so-called “missing” sink of atmospheric
CO2 in the terrestrial biosphere, but the distribution of this sink among the world’s
ecosystems is still unknown. Tropical forests, of which the Amazon Basin represents
the...

Evaluation of single-footprint AIRS CH4 profile retrieval uncertainties using aircraft profile measurements

Journal Article

We evaluate the uncertainties of methane optimal estimation retrievals from single-footprint thermal infrared observations from the Atmospheric Infrared Sounder (AIRS). These retrievals are primarily sensitive to atmospheric methane in the mid-troposphere...