<div><p>Research cruises were conducted on R/V Neeskay and R/V Osprey. CTD profile data were collected by lowering a Sea-Bird SBEplus 25 CTD at a rate of 0.5 meters per second. Variables measured included depth, temperature, conductivity, photosynthetically active radiation (PAR), pH, dissolved oxygen, pH, and chlorophyll <em>a</em> fluorescence.</p>
<p>The CTD was returned to Sea-Bird annually for servicing and calibration of all sensors.</p></div>
CTD
<div><p>CTD data were collected from Lake Michigan during 2017, 2018, and 2019.</p></div>
CTD
<div><p><strong>Data Processing:</strong><br />
All nutrient data are stored in a common database Following analyses, nutrient standard curves are examined to ensure that calibration coefficients are within the range of variability of a long-term (5-year) dataset (±3%). Fluorometer measurements are entered into a spreadsheet containing the fluorometer calibration coefficients, which are used to calculate chlorophyll <em>a</em> and phaeophytin concentrations. The fluorometer is calibrated annually against extracted chlorophyll <em>a</em>standards. CO2 and DIC gas chromatograph measurements are entered into a spreadsheet program that calculates all inorganic carbon species concentrations, as well as pH and carbonate alkalinity. Concentrations are then corrected for any temperature difference between in situ and time of analysis. Stable isotope measurements are stored in a stable isotope database, while DOC measurement data are stored along with nutrient, chlorophyll and inorganic carbon measurements in a chemistry database.</p>
<p>CTD data are processed using the "SBE Data Processing" software package provided by Sea-Bird Scientific. The processing modules used were configured as follows:</p>
<p>Data Conversion. Potential temperature anomaly set to 0. Tau correction is applied to dissolved oxygen measurements, with a 2-second window.</p>
<p>Filter. Low pass filter A time constant = 0.1 seconds. Low pass filter B time constant = 0.5 seconds.</p>
<p>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.</p>
<p>Loop Edit. Minimum CTD velocity set to 0.1 meters per second. Scans marked bad are excluded.</p>
<p>Bin Average. Bin type = Depth. Bin size = 0.25 meters. Both the upcast and the downcast were processed.<br />
</p></div>
737534
CTD
2018-05-23T16:06:14-04:00
2018-05-23T16:06:14-04:00
2024-02-12T15:54:07-05:00
urn:bcodmo:dataset:737534
Version 1 and 2:
- converted date/time field 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 2019-05-22.
Version 3:
- converted date/time field to ISO 8601 format;
- modified parameter names to conform with BCO-DMO naming conventions;
- rounded latitude and longitude values to 5 decimal places;
- removed 'nd' as the missing data identifier (missing data are empty/blank in the final CSV file);
- updated to version 3 on 2022-11-01.
Depth profiles of temperature, conductivity, dissolved oxygen, pH, chlorophyll fluorescence, etc., collected with a SeaBird SBE 25plus CTD in Lake Michigan during 2017, 2018, and 2019
This dataset provides conductivity-temperature-depth (CTD) data from Lake Michigan collected over several cruises conducted during 2017, 2018, and 2019. Data were obtained using a SeaBird SBE 25plus CTD.
Water chemistry and CTD profiles were measured at several stations in Lake Michigan, ranging in depth from 10 to 55 m, in a region northeast of Milwaukee Harbor. Measurements included soluble reactive phosphorus, total dissolved phosphorus, particulate phosphorus, chlorophyll a, the concentrations and stable isotope ratios of particulate carbon and particulate nitrogen, dissolved carbon dioxide, dissolved total inorganic carbon, and dissolved organic carbon. In addition, continuous lake surface and atmospheric CO2 data collected in 2019 and 2021 on a Lake Michigan transect between Milwaukee, WI and Muskegon MI. The chemistry and CO2 data are provided in separate datasets.
These data have several applications, including: 1) Constructing an annual carbon and nutrient budget for the water column, which is used along with direct measurements of quagga mussel nutrient recycling to assess the role of invasive quagga mussels in the lake's carbon and nutrient cycles; 2) When combined with separate measurements of the vertical structure of water density and currents, to quantify vertical fluxes of dissolved nutrients and inorganic carbon, to determine how carbon and nutrient recycling by profundal quagga mussels may affect plankton production in the euphotic zone; 3) The calibration and validation of physical / biogeochemical models used to better understand how invasive quagga mussel have altered energy flow and nutrient dynamics in the Great Lakes, and guide management decisions with regard to nutrients and fish stocking.
false
Bootsma, H., Liao, Q. (2024) Depth profiles of temperature, conductivity, dissolved oxygen, pH, chlorophyll fluorescence, etc., collected with a SeaBird SBE 25plus CTD in Lake Michigan during 2017, 2018, and 2019. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 3) Version Date 2022-11-01 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.737534.3 [access date]
true
3
10.26008/1912/bco-dmo.737534.3
false
2022-11-01
Datapackage.json
Frictionless Data Package
https://www.bco-dmo.org/dataset/737534/datapackage.json
application/vnd.datapackage+json
PDF
https://www.bco-dmo.org/dataset/737534/Dataset_description.pdf
application/pdf
ISO 19115-2 (NOAA Profile)
https://www.bco-dmo.org/dataset/737534/iso
application/xml
http://www.isotc211.org/2005/gmd-noaa
Dublin Core
https://www.bco-dmo.org/dataset/737534/dublin-core
application/xml
http://purl.org/dc/elements/1.1/
737534
http://lod.bco-dmo.org/id/dataset/737534
2017-05-11 - 2019-10-01
2017-05-11
2017-05-11
---11
130
--05
2017
2019-10-01
2019-10-01
---01
273
--10
2019
OSPREY
http://www.opengis.net/def/crs/OGC/1.3/CRS84
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