Identification

Title

Impact of biomass burning plumes on photolysis rates and ozone formation at the Mount Bachelor Observatory

Abstract

In this paper, we examine biomass burning (BB) events at the Mt. Bachelor Observatory (MBO) during the summer of 2015. We explored the photochemical environment in these BB plumes, which remains poorly understood. Because we are interested in understanding the effect of aerosols only (as opposed to the combined effect of aerosols and clouds), we carefully selected three cloud-free days in August and investigate the photochemistry in these plumes. At local midday (solar zenith angle (SZA) = 35 degrees), j(NO2) values were slightly higher (0.2-1.8%) in the smoky days compared to the smoke-free day, presumably due to enhanced scattering by the smoke aerosols. At higher SZA (70 degrees), BB aerosols decrease j(NO2) by 14-21%. We also observe a greater decrease in the actinic flux at 310-350 nm, compared to 360-420 nm, presumably due to absorption in the UV by brown carbon. We compare our measurements with results from the Tropospheric Ultraviolet-Visible v.5.2 model. As expected, we find a good agreement (to within 6%) during cloud-free conditions. Finally, we use the extended Leighton relationship and a photochemical model (Aerosol Simulation Program v.2.1) to estimate midday HO2 and RO2 concentrations and ozone production rates (P(O-3)) in the fire plumes. We observe that Leighton-derived HO2 and RO2 values (49-185 pptv) and instantaneous P(O-3) (2.0-3.6 ppbv/h) are higher than the results from the photochemical model.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7jq13qc

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

2018-02-27T00:00:00Z

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