Distribution of hydrogen peroxide, methyl hydroperoxide and formaldehyde over central Europe during the HOOVER project

Abstract

In this study we report measurements of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), methyl hydroperoxide (CH<sub>3</sub>OOH) and formaldehyde (HCHO) from the HO<sub>x</sub> OVer EuRope (HOOVER) project (HO<sub>x</sub>=OH+HO<sub>2</sub>). HOOVER included two airborne field campaigns, in October 2006 and July 2007. Measurement flights were conducted from the base of operation Hohn (Germany, 54° N, 9° E) towards the Mediterranean and to the subpolar regions over Norway. We find negative concentration gradients with increasing latitude throughout the troposphere for H<sub>2</sub>O<sub>2</sub> and CH<sub>3</sub>OOH. In contrast, observed HCHO is almost homogeneously distributed over Central and Northern Europe and is elevated over the Mediterranean. In general, the measured gradients tend to be steepest entering the Mediterranean region, where we also find the highest abundances of the 3 species. Mixing ratios of these tracers generally decrease with altitude. H<sub>2</sub>O<sub>2</sub> and CH<sub>3</sub>OOH show maxima above the boundary layer at 2–5 km, being more distinct over Southern than over Northern Europe. <br><br> We also present a comparison of our data with simulations by two global 3-D-models, MATCH-MPIC and EMAC, and with the box model CAABA. The models realistically represent altitude and latitude gradients for both HCHO and hydroperoxides (ROOH). In contrast, the models have problems reproducing the absolute mixing ratios, in particular of H<sub>2</sub>O<sub>2</sub>. Large uncertainties about retention coefficients and cloud microphysical parameters suggest that cloud scavenging might be a large source of error for the simulation of H<sub>2</sub>O<sub>2</sub>. A sensitivity study with EMAC shows a strong influence of cloud and precipitation scavenging on the budget of H<sub>2</sub>O<sub>2</sub> as simulations improve significantly with this effect switched off

Unravelling the molecular phenomena of hydrogen peroxide (H2O2) through many-body fragmentation dynamics

“…Therefore it has been identified as a benchmark molecule to model atmosphere of exoplanets, cool stars and other (hot) bodies [15]. Also, it has been identified to be a prominent molecule in understanding the chemistry of ozone [18,19], and radiation damage of biological matter [18,20]. Besides all this, it has also been detected in the interstellar medium [21,22] and also plays important role during (surface) chemical reactions in the formation of water, oxygen and H2O4 [23,24].…”