Identification

Title

ICARUS Chamber Experiment: 2014 FIXCIT Study_20140119_/ISOPRENE/4-hydroxy-3-hydroperoxy ISOPOOH/hydrogen peroxide_Hydroxyl radical_Ammonium sulfate_Isoprene and 4,3-ISOPOOH + OH, low NO, 50% humidity, (NH4)2SO4 seeds

Alternative title(s)

d789011

Abstract

Goals:; Investigate the gas and particle phase composition of the isoprene low NO oxidation mixture, in the presence of moderate relative humidity and wet ammonium sulfate seeds. Test out ozone addition to GTHOS inlet. Summary:; This was an interesting experiment. We meant to inject only isoprene, but 4,3-ISOPOOH was also injected due to unexpected contamination of the "hydrocarbon injection" line from Friday's experiment. So there was ~60 ppb isoprene, and ~10-30 ppb ISOPOOH in the bag. The RH was 50.5% and the particle sulfate mass concentration was ~54 ug/m^3 when the experiment started. The particles were injected deliquesced, so they should have water still on them in some form. Once the OH-oxidation started, a few things stood out as interesting. First, very little IEPOX was observed in the gas-phase despite plenty of isoprene and ISOPOOH around. In comparison, the low NO isoprene photooxidation produced an order of magnitude more IEPOX, relatively. The NO was low (~20 ppt throughout the experiment) so the RO2 radicals were not reacting with NO preferentially. During SOAS, gas-phase IEPOX was also low. Not much particle organic mass formed (~5 ug/m^3 overall) and the organic fraction was seemingly oxidized away from the gas-phase OH, something that we have also noticed in the past. Second, ISOPOOH was lost faster than isoprene, which was not expected based on OH reaction alone, so heterogenous chemistry might be important for ISOPOOH as well in the presence of wet seed aerosol or wet walls. Lots of hydroxyacetone and glycolaldehyde were produced from the oxidation of isoprene low-NO products. Some mystery masses were observed by the PTRMS and I-CIMS, that were not seen in other isoprene low NO experiments (perhaps products of the aqueous chemistry.) GTHOS got a chance to try out ozone addition to the inlet, which did produce plenty of what appears to be interference, but post-processing is needed to gauge the success of this trial. At the end of the experiment, the temperature was ramped up to 45 degreeC, held for 30 minutes, then ramped down again to room temperature. Changes in the AMS organic signal was observed. Organization: 2014 FIXCIT Study; Lab Affiliation: California Institute of Technology; Chamber: Seinfeld chambers Experiment Category: Gas phase chemical reaction, Aerosol formation; Oxidant: Hydroxyl radical; Reactants: ISOPRENE, 4-hydroxy-3-hydroperoxy ISOPOOH, hydrogen peroxide; Reaction Type: Photooxidation; Relative Humidity: 51; Temperature: 28; Seed Name: Ammonium sulfate; Pressure: 750 Torr

Resource type

dataset

Resource locator

https://rda.ucar.edu/datasets/d789011/

protocol: https

applicationProfile: browser

name: Dataset Description

description: Related Link

function: information

https://rda.ucar.edu/datasets/d789011/dataaccess/

protocol: https

applicationProfile: browser

name: Data Access

description: Related Link

function: download

Unique resource identifier

code

codeSpace

Dataset language

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

environment

Keywords

Keyword set

keyword value

dataset

originating controlled vocabulary

title

reference date

date type

revision

effective date

2014-10-16

Keyword set

keyword value

LABORATORY > LABORATORY

originating controlled vocabulary

title

reference date

date type

revision

effective date

2025-06-10

Keyword set

keyword value

ICARUS > Integrated Chamber Atmospheric data Repository for Unified Science

originating controlled vocabulary

title

reference date

date type

revision

effective date

2025-06-16

Keyword set

keyword value

EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC CHEMISTRY > TRACE GASES/TRACE SPECIES

originating controlled vocabulary

title

reference date

date type

revision

effective date

2025-05-23

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

2014-01-19

End position

2014-01-19

Dataset reference date

date type

publication

effective date

2021-10-12

Frequency of update

notPlanned

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Creative Commons Attribution 4.0 International License

Limitations on public access

None

Responsible organisations

Responsible party

organisation name

UCAR/NCAR - Research Data Archive

full postal address

National Center for Atmospheric Research

CISL/DECS

P.O. Box 3000

Boulder

80307

U.S.A.

telephone number

(303)-497-1825

facsimile number

303-497-1291

email address

dattore@ucar.edu

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

NCAR Research Data Archive

full postal address

National Center for Atmospheric Research

CISL/DECS

P.O. Box 3000

Boulder

80307

U.S.A.

facsimile number

303-497-1291

email address

rdahelp@ucar.edu

web address

https://rda.ucar.edu/

name: NCAR Research Data Archive

description: The Research Data Archive (RDA), managed by the Data Engineering and Curation Section (DECS) of the Computational and Information Systems Laboratory (CISL) at NCAR, contains a large and diverse collection of meteorological and oceanographic observations, operational and reanalysis model outputs, and remote sensing datasets to support atmospheric and geosciences research, along with ancillary datasets, such as topography/bathymetry, vegetation, and land use.

function: downlaod

responsible party role

pointOfContact

Metadata date

2025-06-17T03:05:02Z

Metadata language