A joint application of multiple satellite-derived model inputs to improve Texas O3 SIP modeling is demonstrated in this study. The GOES-retrieved clouds are applied to correct the modeled photolysis rates, and the DKF inversion approach is incorporated into the CAMx-DDM model to adjust NOx emissions using OMI NO2. Using both GOES-derived photolysis rates and OMI-constrained NOx emissions together improves O3 simulations and makes O3 more sensitive to NOx emissions in the O3 non-attainment areas.

We present new observations of ice nucleation on substrate surfaces that affirm the ``puzzle'' of very high supersaturations required for nucleation from the vapor phase. To explain the observations, the kinetics and thermodynamics of nucleation theory are explored. The results explicitly connect the nucleation to the substrate material's surface binding energy and demonstrate that an improved fundamental understanding must include a strict understanding of the relevant microphysics.

The multi-wavelength lidar technique was applied to the study of a smoke event near Washington, DC on 26-28 August 2013. Satellite observations combined with transport model predictions imply that the smoke plume originated mainly from Wyoming/Idaho forest fires. The NASA GSFC multi-wavelength Mie-Raman lidar was used to profile the smoke particle parameters such as volume density, effective radius and the real part of the refractive index.

This paper investigates the discrepancy between the rate coefficients for the deactivation of the bending mode of CO2 by atomic oxygen, a process of great importance in the energy budget of the mesosphere and the lower thermosphere, measured in the laboratory and arrived at by space-based measurements. It is concluded that super-thermal rotational levels of N2, produced by the impact of hot O atoms or by N + NO reaction, have the potential to provide the unknown mechanism.

Gas/particle partitioning for polybrominated diphenyl ethers (PBDEs) in global air was investigated and an equation to predict the partition coefficients under steady state was developed, indicating that equilibrium is a special case of steady state when the non-equilibrium factor can be ignored. The results of the equation matched the worldwide monitoring data well, showing its superiority to the equilibrium-state-based equation that has been used in recent decades.

This study presents a regional-scale modeling analysis of aerosols in the Central Asia region including detailed characterization of seasonal source region and sector contributions along with the predicted changes in distribution of aerosols using 2030 future emission scenarios. The influence of long transport and impact of varied emission sources including dust, biomass burning, and anthropogenic sources on the regional aerosol distributions and the associated transport pathways are discussed.

our study suggests that future aerosol abatement may be the primary driver of increased blocking events over the western Mediterranean. This modification of the atmospheric circulation over the Euro-Atlantic sector leads to more stagnant weather conditions that favour air pollutant accumulation especially in the western Mediterranean sector. Changes in atmospheric circulation should therefore be included in future air pollution mitigation assessments.

This paper reports on the first measurements of aerosol particles embedded in the convectively active southwest monsoonal flow of the South China Sea. The paper describes the research cruise and discusses how variability in aerosol characteristics relates to regional meteorological phenomena such as and the Madden Julian Oscillation, tropical cyclones, squall lines and the monsoonal flow itself. Of special interest is how aerosol transport relates to meteorological drivers of convective activity.

Understanding the impact of black carbon (BC) particles on human health and radiative forcing requires knowledge of the BC mixing state. This work investigates the mixing state of BC and other aerosol species in a typical urban area using a single particle mass spectrometry technique. Our results provide quantitative insight into the physical and chemical nature of BC-containing particles near emission and can be used as a basis for our developing understanding of BC evolution in the atmosphere.

This work represents the first application of two-dimensional gas chromatography to broadly characterize the gas-phase emissions of biomass burning, including comparisons among the emissions from burns of selected conifer, grass, crop residue, and peat fuel types. In these smoke samples, over 700 compounds were detected, which are discussed in the context of potential secondary organic aerosol formation.

We present observational data on δ18O(O3) from the UT/LMS, the region to date not covered by the ozone isotope composition measurements. It is to bridge the gap between the tropospheric (mostly surface) and stratospheric measurement data. We demonstrate an approach suitable for isotope mass-balance calculations (“Keeling plot”) in intricate cases, i.e. admixing of the (unknown) source in question to the reservoirs with (unknown) variable starting compositions.

Using levoglucosan as a biomass burning tracer, influence of biomass burning on the air quality of Okinawa Island in the western North Pacific Rim was evaluated. High levels of levoglucosan were found in the atmospheric aerosols during winter probably due to the open burning and domestic heating and cooking in north/northeast China, Mongolia and Russia, together with enhanced continental outflow.

In this work, secondary formation of formic acid at an urban site and a site in an oil and gas production region is studied. We investigated various gas phase formation pathways of formic acid, including those recently proposed, using a box model. The contributions from aerosol-related processes, fog events and air-snow exchange to formic acid are also quantified.

Humic-like substances (HULIS), the hydrophobic part of water soluble organic material, account for ~10% of PM2.5 mass in the Pearl River Delta, China. Source analysis using PM2.5 chemical composition data revealed that secondary formation process, biomass burning, and residual oil combustion from shipping as significant sources of HULIS. Vehicle emissions contributed little to HULIS. Primary sources of HULIS appeared to be linked to inefficient combustion.

We use multi-year simulations of the chemistry--climate model EMAC to investigate the impact that the various types of PSCs have on Antarctic chlorine activation and ozone loss. Heterogeneous chemistry on liquid particles is responsible for more than 90% of the ozone depletion in Antarctic spring in the model simulations. In high southern latitudes, heterogeneous chemistry on ice particles causes only up to 5 DU of additional ozone depletion and chemistry on NAT particles less than 0.5 DU.

This study aims to provide an optimal network design for the placement of new atmospheric monitoring stations around South Africa, to best estimate the emission and uptake of carbon dioxide fluxes due to both anthropogenic and natural sources. In addition, a sensitivity analysis was performed on the impact that certain parameters would have on the final network solution, considering the inverse modelling framework, the transport model and the use of a different optimisation routine.

We developed methods to measure the vertical distribution of bromine monoxide, a gas that oxidizes pollutants, above sea ice based upon MAX-DOAS observations from Barrow, Alaska, and find that atmospheric stability exerts a strong control on BrO's vertical distribution. Specifically, more stable (temperature inversion) situations result in BrO being closer to the ground while more neutral (not inverted) atmospheres allow BrO to ascend further aloft and grow to larger column abundance.

Breathing particles from polluted air is known to cause increased health complaints and higher death rates. Airborne particles come from a range of sources; in order to implement cost-effective control measures, it is necessary to understand the amount contributed by each. In this paper, two advanced procedures for estimating the contributions of particle sources in London are compared with one another, revealing a wide range of sources including traffic, woodsmoke and cooking particles.

Stratospheric turbulence is essential for the atmospheric energy budget. We compare in situ observations with our LITOS method based on spectral analysis of mm-scale wind fluctuations with the Thorpe method applied to standard radiosondes. Energy dissipations rates from both methods differ by up to 3 orders of magnitude. Nevertheless, mean values are in good agreement. We present case studies on both methods and examine the applicability of the Thorpe method for calculation of dissipation rates.

For the first time, real-case simulations of ship tracks are performed at the 2km scale and evaluated against observations. Simulations show that ship tracks are quantitatively and qualitatively captured by the model. Therefore, this approach could be used to evaluate the interplay between parameterisations for aerosol–cloud interactions which occur, in the case of ship tracks, in spatially defined regions and under constrained environmental conditions.

The main goal of this paper is to show the geographical distribution of meridional wind for several reanalyses and to analyse the wind trends in different areas. We show two areas (100°E-160°E and 140°W-80°W) where the meridional wind is as strong as zonal wind (which is normally dominant in the stratosphere). The trends of meridional wind are significant mostly at 99% level in these areas and insignificant outside. The problem with zonal averages could affect the results.