Identification

Title

Quantifying the contributions of aerosol - and snow-produced ClNO 2 through observations and 1D modeling

Abstract

Nitryl chloride (ClNO2) is a radical reservoir that forms and accumulates in the nocturnal atmospheric boundary layer influenced by combustion emissions and chloride (e.g., sea salt and road salt). Upon sunrise, ClNO2 rapidly photolyzes to generate highly reactive chlorine radicals (Cl-center dot) that affect the air quality by generating secondary air pollutants. Recent studies have shown road salt aerosols and saline snowpack to be sources of ClNO2 in the wintertime urban environment; however, the quantitative contributions of each chloride source are not known. In this study, we examine the vertically resolved contributions of aerosol particles and saline snowpack as sources of ClNO2 by using an observationally constrained snow-atmosphere coupled one-dimensional model applied to wintertime Kalamazoo, Michigan, U.S. Model simulations show that ClNO2 emitted from urban snowpack can be vertically transported throughout the entire atmospheric boundary layer and can be a significant source of ClNO2, contributing up to similar to 60% of the ClNO2 budget near the surface. Modeled snowpack ClNO2 emission rates were 6 (+/- 7) times higher than the observationally derived emission rates, suggesting that not all snow chloride is available for reaction. ClNO2 production from both aerosol particles and snow emissions are required to best simulate the observed surface-level ClNO2. Using the traditional bulk parameterization for ClNO2 produced from particles significantly overestimated ClNO2 due to the assumption of having equivalent dinitrogen pentoxide (N2O5) uptake and chloride availability for the entire particle population. In comparison, the chemically resolved surface area-based parameterization slightly underestimated the observations and had uncertainties deriving from ClNO2 production from residential wood burning particles.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7tm7g7c

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

2023-12-21T00:00:00Z

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