Identification

Title

Understanding the role of the ground surface in HONO vertical structure: High resolution vertical profiles during NACHTT-11

Abstract

A negative-ion proton-transfer chemical ionization mass spectrometer was deployed on a mobile tower-mounted platform during Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (NACHTT) to measure nitrous acid (HONO) in the winter of 2011. High resolution vertical profiles revealed (i) HONO gradients in nocturnal boundary layers, (ii) ground surface dominates HONO production by heterogeneous uptake of NO₂, (iii) significant quantities of HONO may be deposited to the ground surface at night, (iv) daytime gradients indicative of ground HONO production or emission, and (v) an estimated surface HONO reservoir comparable or larger than integrated daytime HONO surface production. Nocturnal integrated column observations of HONO and NO₂ allowed direct evaluation of nocturnal ground surface uptake coefficients for these species (ώNO₂, surf = 2 x 10⁻⁶ to 1.6 × 10⁻⁵ and γHONO, surf = 2 × 10⁻⁵ to 2 × 10⁻⁴). A chemical model showed that the unknown source of HONO was highest in the morning, 4 × 106 molecules cm⁻³ s⁻¹ (600 pptv h⁻¹), declined throughout the day, and minimized near 1 × 106 molecules cm⁻³ s⁻¹ (165 pptv h⁻¹). The quantity of surface-deposited HONO was also modeled, showing that HONO deposited to the surface at night was at least 25%, and likely in excess of 100%, of the calculated unknown daytime HONO source. These results suggest that if nocturnally deposited HONO forms a conservative surface reservoir, which can be released the following day, a significant fraction of the daytime HONO source can be explained for the NACHTT observations.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7kd1zt8

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

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Text

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title

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reference date

date type

publication

effective date

2016-01-01T00:00:00Z

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East bounding longitude

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date type

publication

effective date

2013-09-16T00:00:00Z

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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

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