In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 20 ( 2018-10-25), p. 15345-15361
Abstract:
Abstract. Abundance-based model evaluations with observations
provide critical tests for the simulated mean state in models of
intercontinental pollution transport, and under certain conditions may also
offer constraints on model responses to emission changes. We compile
multiyear measurements of peroxy acetyl nitrate (PAN) available from five
mountaintop sites and apply them in a proof-of-concept approach that
exploits an ensemble of global chemical transport models (HTAP1) to identify
an observational “emergent constraint”. In April, when the signal from
anthropogenic emissions on PAN is strongest, simulated PAN at northern
midlatitude mountaintops correlates strongly with PAN source–receptor
relationships (the response to 20 % reductions in precursor emissions
within northern midlatitude continents; hereafter, SRRs). This finding
implies that PAN measurements can provide constraints on PAN SRRs by
limiting the SRR range to that spanned by the subset of models simulating
PAN within the observed range. In some cases, regional anthropogenic
volatile organic compound (AVOC) emissions, tracers of transport from
different source regions, and SRRs for ozone also correlate with PAN SRRs.
Given the large observed interannual variability in the limited available
datasets, establishing strong constraints will require matching meteorology
in the models to the PAN measurements. Application of this evaluation
approach to the chemistry–climate models used to project changes in
atmospheric composition will require routine, long-term mountaintop PAN
measurements to discern both the climatological SRR signal and its
interannual variability.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-18-15345-2018
DOI:
10.5194/acp-18-15345-2018-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1