Identification

Title

Using observed urban NOx sinks to constrain VOC reactivity and the ozone and radical budget in the Seoul Metropolitan Area

Abstract

Ozone (O-3) is an important secondary pollutant that impacts air quality and human health. Eastern Asia has high regional O-3 background due to the numerous sources and increasing and rapid industrial growth, which impacts the Seoul Metropolitan Area (SMA). However, SMA has also been experiencing increasing O-3 driven by decreasing NOx emissions, highlighting the role of local, in-situ O-3 production on SMA. Here, comprehensive gas-phase measurements collected on the NASA DC-8 during the NIER/NASA Korea United States-Air Quality (KORUS-AQ) study are used to constrain the instantaneous O-3 production rate over the SMA. The observed NOx oxidized products support the importance of non-measured peroxy nitrates (PNs) in the O-3 chemistry in SMA, as they accounted for similar to 49 % of the total PNs. Using the total measured PNs (Sigma PNs) and alkyl and multifunctional nitrates (Sigma ANs), unmeasured volatile organic compound (VOC) reactivity (R(VOC)) is constrained and found to range from 1.4 - 2.1 s(-1). Combining the observationally constrained R(VOC) with the other measurements on the DC-8, the instantaneous net O-3 production rate, which is as high as similar to 10 ppbv hr(-1), along with the important sinks of O-3 and radical chemistry, are constrained. This analysis shows that Sigma PNs play an important role in both the sinks of O-3 and radical chemistry. Since Sigma PNs are assumed to be in steady-state, the results here highlight the role Sigma PNs play in urban environments in reducing net O-3 production, but Sigma PNs can potentially lead to increased net O-3 production downwind due to their short lifetime (similar to 1 hr). The results provide guidance for future measurements to identify the missing R(VOCs) and Sigma PNs production.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7j38xvj

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2024-08-29T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact