Dataset: CTD

Name: Depth profiles of temperature, conductivity, dissolved oxygen, pH, chlorophyll fluorescence, etc., collected with a SeaBird SBE 25plus CTD in Lake Michigan during 2017 and 2018.
Published: 2019-05-22
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.737534.2

Spatial Extent: N:43.09932 E:-87.7187 S:43.09503 W:-87.861117

Temporal Extent: 2017-05-11 - 2018-10-25

Project:

Collaborative Research: Regulation of plankton and nutrient dynamics by hydrodynamics and profundal filter feeders (Filter Feeders Physics and Phosphorus)

Principal Investigator:

Harvey Bootsma (University of Wisconsin, UW-Milwaukee)

Co-Principal Investigator:

Qian Liao (University of Wisconsin, UW-Milwaukee)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2019-05-22

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Data URL:

https://www.bco-dmo.org/dataset/737534/data

Depth profiles of temperature, conductivity, dissolved oxygen, pH, chlorophyll fluorescence, etc., collected with a SeaBird SBE 25plus CTD in Lake Michigan during 2017 and 2018.

Abstract:

Depth profiles of temperature, conductivity, dissolved oxygen, pH, chlorophyll fluorescence, etc., collected with a SeaBird SBE 25plus CTD in Lake Michigan during 2017 and 2018.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2019-05-22	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.737534.2	2021-04-26
2018-05-25	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.1575/1912/bco-dmo.737534.1	2019-03-15

Description

CTD data collected in 2017 and 2018 from Lake Michigan, depth = 55-75 m, approximately 12-16 km northeast of Milwaukee Harbor.

Acquisition Description

Data were collected using a SeaBird SBEplus 25 CTD, calibrated annually by SeaBird.

Data are processed using the "SBE Data Processing" software package provided by Sea-Bird Scientific. The processing modules used were as follows:

Data Conversion. Potential temperature anomaly set to 0. Tau correction is applied to dissolved oxygen measurements, with a 2-second window.

Filter. Low pass filter A time constant = 0.1 seconds. Low pass filter B time constant = 0.5 seconds.

Align CTD. An advance value of 0.1 seconds was applied to conductance measurements, and an advance value of 5 seconds was applied to dissolved oxygen measurements.

Loop Edit. Minimum CTD velocity set to 0.1 meters per second. Scans marked bad are excluded.

Bin Average. Bin type = Depth. Bin size = 0.25 meters. Both the upcast and the downcast were processed.

Processing Description

BCO-DMO Processing:
- converted date/time to ISO 8601 format;
- modified parameter names to conform with BCO-DMO naming conventions;
- replaced blanks (missing data), -9.99E-29, 9.99E-29, and #VALUE! with "nd" (no data);
- updated to version 2 on 22-May-2019.

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1658390

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
Neeskay_Cruises_2017	Station AT55 Neeskay Cruise 1	2017-08-01	R/V Neeskay	Harvey Bootsma (Chief Scientist)	data info
Neeskay_Cruises_2018	Station AT55 Neeskay Cruise 1	2018-04-05	R/V Neeskay	Harvey Bootsma (Chief Scientist)	data info
Osprey_Lake_Michigan_2017		2017-05-11	R/V Osprey	Harvey Bootsma (Chief Scientist)	data info
Osprey_Lake_Michigan_2018		2018-05-10	R/V Osprey	Harvey Bootsma (Chief Scientist)	data info

Instruments

CTD Sea-Bird 25

Supplied Name: SeaBird SBEplus 25 CTD

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird 25

Acronym: CTD SBE 25

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0040/

Generic Description:

The Sea-Bird SBE 25 SEALOGGER CTD is battery powered and is typically used to record data in memory, eliminating the need for a large vessel, electrical sea cable, and on-board computer. All SBE 25s can also operate in real-time, transmitting data via an opto-isolated RS-232 serial port. Temperature and conductivity are measured by the SBE 3F Temperature sensor and SBE 4 Conductivity sensor (same as those used on the premium SBE 9plus CTD). The SBE 25 also includes the SBE 5P (plastic) or 5T (titanium) Submersible Pump and TC Duct. The pump-controlled, TC-ducted flow configuration significantly reduces salinity spiking caused by ship heave, and in calm waters allows slower descent rates for improved resolution of water column features. Pressure is measured by the modular SBE 29 Temperature Compensated Strain-Gauge Pressure sensor (available in eight depth ranges to suit the operating depth requirement). The SBE 25's modular design makes it easy to configure in the field for a wide range of auxiliary sensors, including optional dissolved oxygen (SBE 43), pH (SBE 18 or SBE 27), fluorescence, transmissivity, PAR, and optical backscatter sensors. More information from Sea-Bird Electronics: http:www.seabird.com.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Deployment	Deployment name/date.	unitless	deploy
Year	4-digit year	unitless	year
Lat	Latitude. Locations south of equator are negative.	Decimal degrees	lat
Long	Longitude. Locations west of prime meridian are negative.	Decimal degrees	lon
ISO_DateTime_UTC	UTC Date and time. Local time + 5 hours between March 12, 2:00 a.m. and November 5, 2:00 a.m. Local time + 6 hours between November 5, 2:00 a.m. and March 12, 2:00 a.m. Formatted to ISO 8601 standard (yyyy-mm-ddTHH:MM).	unitless	ISO_DateTime_UTC
Depth	Depth below lake surface; resolution = 0.01; accuracy = 0.15	meters (m)	depth
Temp	Water Temperature; resoultion = 0.0003; accuracy = 0.001	Degrees celsius (°C)	temp
Cond	Water conductance; resoultion = 0.4 uS/cm; accuracy = 3 uS/cm	microsiemens per cm (uS/cm)	cond
SpCond	Water Specific Conductance (conductance normalized to a temperature of 25 degrees celcius). Resolution = 0.4 uS/cm; accuracy = 3 uS/cm.	microsiemens per cm (uS/cm)	specc
flECO_AFL	Chlorophyll a fluorescence.	Fluorescence units that are calibrated to approximate chlorophyll concentration in units of microgram per liter (ug/L)	chl_a_fluor
PAR	Photosyntheticall active radiation (within the range of approximately 400 to 700 nm wavelength). Accuracy = 3%	micromoles of photons per square meter per second	PAR
pH	pH is a measure of the concentration of free hydrogen ions. Resolution = 0.01 ; accuracy = 0.1	pH = -log10 [H+], where [H+] = moles per liter of the hydrogen ion.	pH
DO	Dissolved oxygen concentration; resolution = 0.01 ; accuracy = 2%.	milligrams per liter (mg/L)	O2
prdM	Pressure; resolution = 0.01; accuracy = 0.15	decibars (dbar)	press
DOSat_pcnt	Dissolved oxygen concentration as % saturation at in situ temperature and a pressure of 1.0 atmospheres. Calculated as: DOSat% = DO(mg/L)100/(-0.00007T^3+0.0075T^2-0.3976T+14.602. T = water temperature (oC). Resolution = 0.1; accuracy = 2%	percent (%) saturation	O2sat
BeamAtt	Beam attenuation over 25 cm path length; accuracy = 0.02%	inverse meters (m-1)	beam_cp
Beam_pcnt	Beam % transmission over 25 cm path length; accuracy = 0.02%	percent (%)	trans

Database

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Dataset: CTD