Dataset: DMS Flux
Deployment: RB-08-02

Hourly mean data for DMS flux, transfer velocity, and associated variables

Principal Investigator:

Dr Byron Blomquist (University of Hawai'i, UH)

Co-Principal Investigator:

Dr Barry Huebert (University of Hawaiʻi at Mānoa, SOEST)

Contact:

Burke Hales (Oregon State University, OSU-CEOAS)

BCO-DMO Data Manager:

Stephen R. Gegg (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Southern Ocean Gas Exchange Experiment (SO_GasEx)

Current State:

Final no updates expected

Version:

16 March 2010

Deployment Synonyms:

RB0802, RHB_SO-GasEx

Version Date:

2010-03-16

Data URL:

https://osprey.bco-dmo.org/dataset-deployment/453021/data

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Description

These data are hourly mean data for DMS flux, transfer velocity,
and associated variables. Most associated variables are derived
from the Univ. Conn.10 min meteorological data product (Sept 2009 version).
Seawater DMS data are from S. Archer, Plymouth Marine Labs, Jan 2010 release.

Notes:
1) DMS flux and transfer velocity measurements have been filtered to remove hours
of atmospheric stability when z/L > 0.05.

2) Additional periods of anamalously low flux during the first tracer patch and the
high wind event on transit to Uruguay are not presented in this release. We
are currently examining this data to better understand the reason for the low
results. For access to these measurements contact the investigators.

Contact: Barry Huebert, University of Hawaii Oceanography, huebert@hawaii.edu

Methods & Sampling

Dataset acquisition description

See: SO-GasEx cruise report, Section 5.1.3 ppgs 11-12

Operation description:
Continuous measurement of atmospheric DMS concentration at 20 Hz,
sampled from the 18m level of the bow jackstaff.

Sampling times and locations:
Continuous, except for periods when ship speed and heading is
changing frequently, typically during the tracer injection.

Overall sampling strategy:
Air is sampled into a 3/8" ID teflon tube at a flow rate of 110-120
Standard Liters Per Minute (SLPM) and brought to a lab van located
on the O2 deck, forward of the bridge. The inlet tip is located near
a sonic anemometer to facilitate eddy correlation analysis of the data.

Analytical method:
A continuous internal standard gas (isotopically labeled: d-3 dimethylsulfide
in nitrogen) is injected into the sample flow at the inlet tip. In the
lab van, the sample flow is subsampled at 3-4 SLPM into an atmospheric
pressure ionization mass spectrometer (APIMS), where the ambient to standard
DMS isotopomer ratio is measured at 20 Hz. We calculate the ambient DMS
concentration from the isotopomer ratio, sample flow rate and known
concentration of standard in the sample air.

Instrument details:
Atmospheric Pressure Ionization Mass Spectrometer: designed and built
at Univ. of Hawaii, based on the APIMS developed in Alan Bandy's lab
at Drexel University (Bandy et al, JGR 107, D24, p.4743, 2002).

Operation Log - During Cruise

Affected data			Comments
3/1/2008 2300 GMT		Commence atmospheric DMS flux measurements.
3/3/2008 1640 GMT		End atmospheric DMS sampling.
3/3/2008 1826 GMT		Commence seawater DMS measurements.
3/6/2008 1800 GMT		End seawater DMS trials.
3/7/2008 0045 GMT		Commence atmospheric DMS flux measurements.
3/7/2008 2130 GMT		Suspend DMS measurements during injection and buoy deployment.
3/8/2008 2134 GMT		Resume atmospheric DMS flux measurements.
3/19/2008 1300 GMT		Stop DMS flux system during downwind survey legs.
3/19/2008 1500 GMT		Restart DMS flux system on upwind survey legs.
3/19/2008 2000 GMT		Stop DMS flux system.
3/20/2008 1300 GMT		Restart DMS flux system during CTD.
3/20/2008 1957 GMT		Stop DMS flux system during tracer injection.
3/21/2008 1600 GMT		Restart DMS flux system.
3/22/2008 1240-1300 GMT		Stop DMS flux system briefly to adjust source flow.
3/23/2008 1055-1100 GMT		Stop DMS flux system briefly to remove inlet filter.
3/24/2008 0004-0027 GMT		Stop DMS flux system briefly due to ship exhaust.
3/25/2008 2020 GMT		Stop DMS flux system: sensitivity gone.
3/26/2008 0200 GMT		Restart DMS flux system after cleaning mass spec inlet aperture.
3/26/2008 1500-1600 GMT		Missing data, files not written.
4/4/2008 1600 GMT		END atmospheric DMS sampling.
4/4/2008 1800 GMT		Begin 2nd trial, seawater DMS sampling.

Data Processing Description

Dataset Processing Description

See: SO-GasEx cruise report, Section 5.1.3 ppgs 11-12

BCO-DMO Processing Notes
- Generated from original file SO-GasEX_UH_DMS_Flux_Hourly_Ver2.txt

BCO-DMO Edits
- parameter names modified to conform to BCO-DMO convention
- 'NaN' changed to 'nd'
- date/time separated into two fields (date, time)
- date reformatted as YYYYMMDD
- time reformatted as HHMM (all secondss were 00)

More information about this dataset deployment

Funding

Award Number	Funding Source
unknown SO_GasEx NASA	National Aeronautics & Space Administration
unknown SO_GasEx NOAA	National Oceanic and Atmospheric Administration
unknown SO_GasEx NSF	National Science Foundation

Instruments

Atmospheric Pressure Ionization Mass Spectrometer

Supplied Description:

Instrument Type

Generic Name: Atmospheric Pressure Ionization Mass Spectrometer

Acronym: APIMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic Description:

The Atmospheric Pressure Ionization Mass Spectrometer measures dimethylsulfide (DMS) in ambient air and in sea water. This instrument is used to measure DMS fluxes directly in the marine boundary layer.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
date	Date variable GMT start of hour for flux measurement	YYYYMMDD	date
time	Time variable GMT start of hour for flux measurement	HHMM	time
lon	GPS longitude	decimal degrees	lon
lat	GPS latitude	decimal degrees	lat
SOG	GPS speed over ground in knots	knots	sog
Gyro	Ship gyro heading in degrees	degrees	heading
FluxDuration	Duration of flux measurement seconds	seconds	no_bcodmo_term
DMS	Atmospheric mean DMS concentration measured in parts per trillion by volume (pptv)	pptv	no_bcodmo_term
DMSflux	Corrected DMS flux in uMoles m^-2 day^-1 at ambient conditions	uMoles m^-2 day^-1	no_bcodmo_term
DMSflux_error	Flux error (uMoles m^-2 day^-1) computed following Blomquist et al. Atm.Meas.Tech; 3; 1-20; 2010	uMoles m^-2 day^-1	no_bcodmo_term
kDMS	DMS transfer velocity for ambient conditions in cm/hr (not Sc corrected)	cm/hr	no_bcodmo_term
kDMS_error	Transfer velocity error in cm/hr	cm/hr	no_bcodmo_term
U10N	10 m neutral wind speed in m/s from COARE 3.0 bulk flux model	m/sec	no_bcodmo_term
Ustar_COARE	Friction velocity in m/s from COARE 3.0	m/sec	no_bcodmo_term
Rwspd	Relative wind speed in m/s	m/sec	wind_speed_r
Sc_DMS	DMS Schmidt number at ambient sea surface temperature and salinity	dimensionless	no_bcodmo_term
swDMS	Sea water DMS concentration in nM (or uMoles m-3)	nM	no_bcodmo_term
Rwdir	Relative wind direction zero degrees on bow starboard positive	degrees	wind_dir_r
Tair	Air temperature deg C	degrees Celcius	temp_air
SST	Sea surface temperature deg C	degrees Celcius	SST
Sal	Salinity in parts per thousand	ppth	sal
Longwave	Longwave radiation	w m^-2	no_bcodmo_term
Shortwave	Shortwave radiation	w m^-2	no_bcodmo_term
z_L	Dimensionless stability parameter z=18m L from COARE 3.0.	dimensionless	no_bcodmo_term

Database

Contribute Data

Dataset: DMS Flux
Deployment: RB-08-02

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: DMS FluxDeployment: RB-08-02

Dataset acquisition description

Dataset Processing Description

Dataset: DMS Flux
Deployment: RB-08-02