Identification

Title

Empirical insights into the fate of ammonia in western U.S. wildfire smoke plumes

Abstract

Wildfires are a major source of gas-phase ammonia (NH3) to the atmosphere. Quantifying the evolution and fate of this NH3 is important to understanding the formation of secondary aerosol in smoke and its accompanying effects on radiative balance and nitrogen deposition. Here, we use data from the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) to add new empirical constraints on the e-folding loss timescale of NH3 and its relationship with particulate ammonium (pNH(4)) within wildfire smoke plumes in the western U.S. during summer 2018. We show that the e-folding loss timescale of NH3 with respect to particle-phase partitioning ranges from similar to 24 to similar to 4000 min (median of 55 min). Within these same plumes, oxidation of nitrogen oxides is observed concurrent with increases in the fraction of pNH(4) in each plume sampled, suggesting that formation of ammonium nitrate (NH4NO3) is likely. We find wide variability in how close our in situ measurements of NH4NO3 are to those expected in a dry thermodynamic equilibrium, and find that NH4NO3 is most likely to form in fresh, dense smoke plumes injected at higher altitudes and colder temperatures. In chemically older smoke we observe correlations between both the fraction of pNH(4) and the fraction of particulate nitrate (pNO(3)) in the aerosol with temperature, providing additional evidence of the presence of NH4NO3 and the influence of injection height on gas-particle partitioning of NH3.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7r78jnj

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

2021-06-16T00:00:00Z

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