English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this study we report on airborne imaging DOAS measurements ofNO2 from two flights performed in Bucharest during the AROMATcampaign (Airborne ROmanian Measurements of Aerosols and Trace gases) inSeptember 2014. These measurements were performed with the Airborne imagingDifferential Optical Absorption Spectroscopy (DOAS) instrument forMeasurements of Atmospheric Pollution (AirMAP) and provide nearly gaplessmaps of column densities of NO2 below the aircraft with a highspatial resolution of better than 100 m. The air mass factors, whichare needed to convert the measured differential slant column densities(dSCDs) to vertical column densities (VCDs), have a strong dependence on thesurface reflectance, which has to be accounted for in the retrieval. This isespecially important for measurements above urban areas, where the surfaceproperties vary strongly. As the instrument is not radiometricallycalibrated, we have developed a method to derive the surface reflectance fromintensities measured by AirMAP. This method is based on radiative transfercalculation with SCIATRAN and a reference area for which the surfacereflectance is known. While surface properties are clearly apparent in theNO2 dSCD results, this effect is successfully corrected for in theVCD results. Furthermore, we investigate the influence of aerosols on theretrieval for a variety of aerosol profiles that were measured in the contextof the AROMAT campaigns. The results of two research flights are presented,which reveal distinct horizontal distribution patterns and strong spatialgradients of NO2 across the city. Pollution levels range frombackground values in the outskirts located upwind of the city to about4  ×  1016 molec cm−2 in the polluted city center.Validation against two co-located mobile car-DOAS measurements yields goodagreement between the datasets, with correlation coefficients of R =  0.94 andR =  0.85, respectively. Estimations on the NOx emission rate ofBucharest for the two flights yield emission rates of15.1 ± 9.4 and 13.6 ± 8.4 mol s−1,respectively

High-resolution airborne imaging DOAS measurements of NO&lt;sub&gt;2&lt;/sub&gt; above Bucharest during AROMAT

High-resolution airborne imaging DOAS measurements of NO<sub>2</sub> above Bucharest during AROMAT