Nitrous acid (HONO) source and sink processes in a disturbed forest ecosystem - interactions of heterogeneous chemistry and turbulent transport

DFG HE 5214/4-1

From 01/2011 to 09/2014

Principal Investigator: Andreas Held
Staff: Matthias Sörgel, Erika Durán, Jennifer Klein, Milan Flach, Mirella Glor

Within this project, the complex interplay of source and sink processes of nitrous acid (HONO) will be studied in a disturbed forest ecosystem integrated into the PAK446 project field activities in 2011. In previous field experiments, a tight correlation of the atmospheric mixing ratios of HONO and NO2, the most probable precursor, was not observed, while the interaction of heterogeneous chemistry (with a strong dependence on humidity conditions) and turbulent transport was found to play a significant role. The proposed measurements extend the previous field measurements of HONO within the forest to a second contrasting site in a forest clear cut. New near-surface profile measurements of HONO, NO, NO2 and O3 within the lowest two meters above the ground both in the trunk space and the clear cut will contribute to an advanced assessment of the temporal evolution and spatial distribution of relevant HONO sources and sinks. The proposed research tasks are designed to fill the scientific gaps that became evident from analyzing HONO field data from our forest ecosystem research site. In particular, we aim at untangling interactions of heterogeneous chemistry (influenced by radiation and humidity conditions) and turbulent transport under different atmospheric coupling regimes. This project will also contribute to the fundamental understanding of turbulent transport in a disturbed forest ecosystem, and provide basic observational data to evaluate and enhance reactive trace gas modeling on the canopy scale.

Homepage: http://www.bayceer.uni-bayreuth.de/eger/

List of publications of this Project

Sörgel, M; Riederer, M; Held, A; Plake, D; Zhu, Z; Foken, T; Meixner, FX: Trace Gas Exchange at the Forest Floor in Foken, T.: Energy and Matter Fluxes of a Spruce Forest Ecosystem, Springer(Ecological Studies Vol. 229), 157-179 (2017), doi:10.1007/978-3-319-49389-3_8 [Link] -- Details

Sörgel, M; Trebs, I; Wu, D; Held, A: A comparison of measured HONO uptake and release with calculated source strengths in a heterogeneous forest environment, Atmospheric Chemistry and Physics, 15, 9237–9251 (2015), doi:10.5194/acp-15-9237-2015

Bartolomei, V; Sörgel, M; Gligorovski, S; Gomez Alvarez, E; Gandolfo, A; Strekowski, R; Quivet, E; Held, A; Zetzsch, C; Wortham, H: Formation of indoor nitrous acid (HONO) by light-induced NO2 heterogeneous reactions with white wall paint, Environmental Science and Pollution Research, 21, 9259-9269 (2014), doi:10.1007/s11356-014-2836-5