Paul O. Wennberg

TL;DR: In this paper, the photon path length probability density function (PDF) method was applied to validate CO 2 retrievals from GOSAT data obtained during 22 months starting from June 2009, which allowed direct evaluation of optical path modifications due to atmospheric light scattering that would have a negligible impact on ground-based TCCON measurements but could significantly affect gas retrieval when observing reflected sunlight from space.

TL;DR: In this article, the authors used an observationally constrained steady state box model to compare the results of the two Arctic phases of the airborne campaign ARCTAS-A and B to the observations from the Penn State ATHOS instrument.

TL;DR: The model generally reproduces the magnitude and seasonality of cOHRobs but underestimates the contribution of oxygenated VOCs, mainly acetaldehyde, which is severely underestimated throughout the troposphere despite its calculated lifetime of less than a day.

TL;DR: It is found that the National Emission Inventory (NEI) for NOx from the US Environmental Protection Agency (EPA) is too high, and only half of isoprene oxidation proceeds by the high-NOx pathway to produce ozone; this fraction is only moderately sensitive to changes in NOx emissions.

TL;DR: In this article, the authors assess the large-scale, top-down constraints on regional fossil fuel emissions provided by observations of atmospheric total column CO2, XCO2, using an atmo-spheric general circulation model (GCM) with underlying fossil emissions.