The Canadian Watershed Information Networks' ERDDAP server making scientific data more accessible
Brought to you by CEOS UM CCADI ECCC
|
CanWIN ERDDAP
The Canadian Watershed Information Networks' ERDDAP server making scientific data more accessible |
Brought to you by CEOS UM CCADI ECCC |
| Dataset Title: | Greenedge standardized nutrient data 2016
|
| Institution: | Centre for Earth Observation Science, University of Manitoba (Dataset ID: GreenEdge_Nutrient_3e39_afd6_0a1e) |
| Range: | longitude = -63.98764 to -55.99096°E, latitude = 67.995 to 70.51318°N, depth = 127.0 to 2216.0m |
| Information: | Summary
| License
| FGDC
| ISO 19115
| Metadata
| Background
| Subset
| Data Access Form
| Files
|
|
Click on the map to specify a new center point.
Zoom: ![[The graph you specified. Please be patient.]](https://CanWINerddap.ad.umanitoba.ca/erddap/tabledap/GreenEdge_Nutrient_3e39_afd6_0a1e.png?longitude,latitude,Longitude_east&.draw=markers&.marker=5%7C5&.color=0x000000&.colorBar=%7C%7C%7C%7C%7C&.bgColor=0xffccccff)
|
Attributes {
s {
project_name {
String Description "Name of project data was collected under";
String ioos_category "Identifier";
String Long_Name "Project name";
String long_name "Project Name";
}
platform_name {
String Description "Name of vessel from which data was collected";
String ioos_category "Unknown";
String Long_Name "platform name";
String long_name "Platform Name";
}
Cruise {
String Description "Cruise identifier";
String ioos_category "Unknown";
String Long_Name "ship cruise";
String long_name "Cruise";
}
Station {
String Description "Station identifier";
String ioos_category "Identifier";
String Long_Name "station name";
String long_name "Station";
}
sample_date {
String Description "Sample date in ISO 8601 format";
String ioos_category "Time";
String Long_Name "Time date";
String long_name "Sample Date";
}
latitude {
String _CoordinateAxisType "Lat";
Float64 actual_range 67.995, 70.51318;
String axis "Y";
Float64 colorBarMaximum 90.0;
Float64 colorBarMinimum -90.0;
String ioos_category "Location";
String Long_Name "Latitude north";
String long_name "Latitude";
String source_name "latitude_north_dd";
String standard_name "latitude";
String units "degrees_north";
}
longitude {
String _CoordinateAxisType "Lon";
Float64 actual_range -63.98764, -55.99096;
String axis "X";
Float64 colorBarMaximum 180.0;
Float64 colorBarMinimum -180.0;
String ioos_category "Location";
String Long_Name "Angular distance from the Prime Meridian along a parallel of the Earth's surface, ranging from 0deg to 180deg to the east, and 0deg to -180deg to the west.";
String long_name "Longitude";
String standard_name "longitude";
String units "degrees_east";
}
Longitude_east {
Float64 actual_range 296.01236, 304.00903999999997;
Float64 colorBarMaximum 180.0;
Float64 colorBarMinimum -180.0;
String ioos_category "Location";
String Long_Name "Longitude east";
String long_name "Longitude";
String standard_name "longitude";
String units "degrees_east";
}
Cast {
Float64 actual_range 3.0, 201.0;
String Analytical_method "Test Cast";
String Description "Cast # (for each CTD/rosette deployment, increases as cruise progresses, may be more than one cast per station)";
String ioos_category "Unknown";
String Long_Name "Cast # (for each CTD/rosette deployment, increases as cruise progresses, may be more than one cast per station)";
String long_name "Cast";
}
Bottle {
Float64 actual_range 1.0, 24.0;
String Description "The number of the niskin bottle sampled. There are 24 niskin-type bottles on the rosette, so this value will be between 1 and 24";
String ioos_category "Unknown";
String Long_Name "The number of the niskin bottle sampled. There are 24 niskin-type bottles on the rosette, so this value will be between 1 and 24";
String long_name "Bottle";
}
depth {
String _CoordinateAxisType "Height";
String _CoordinateZisPositive "down";
Float64 actual_range 127.0, 2216.0;
String axis "Z";
Float64 colorBarMaximum 8000.0;
Float64 colorBarMinimum -8000.0;
String colorBarPalette "TopographyDepth";
String Description "The depth of the sea floor at each station.";
String ioos_category "Location";
String Long_Name "The depth of the sea floor at each station";
String long_name "Sea Floor Depth";
String positive "down";
String source_name "Bottom_Depth_m";
String standard_name "depth";
String units "m";
}
sample_depth_m {
Float64 actual_range 0.6, 2050.9;
String Description "The depth at which the sample was collected";
String ioos_category "Location";
String Long_Name "The depth at which the sample was collected";
String long_name "Sample Depth M";
String units "m";
}
NO2_um_l {
String activity_collection_type "Lab Measurement";
Float64 actual_range 0.0, 0.69;
String analytical_instrument_detection_limit "detection limit= 0.03 µmoles.l-1 accuracy = ± 0.03µmoles.l-1";
String analytical_instrument_units "µmoles.l-1";
String Analytical_method "Analysis is performed at the laboratory using an automated colorimetric procedure (Aminot and Kerouel, 2007). For ammonium determination, 20 ml of water samples or melted ice (in filtered surface water) were transferred into 60 ml polycarbonate tubes. Analysis was immediately performed at field using the fluorometric procedure (Holmes et al., 1999).";
Float64 colorBarMaximum 1.0;
Float64 colorBarMinimum 0.0;
String Description "The measured concentration of nitrite (NO2)";
String ioos_category "Dissolved Nutrients";
String Long_Name "Nitrite";
String long_name "Mole Concentration Of Nitrite In Sea Water";
String Sample_Collection_Method "Water samples or melted ice (in filtered surface water for the 0-1 cm cores or in artificial seawater for the 0-3 and 3-10 cm cores) were collected in duplicate into 20 ml polyethylene flasks. One sample was filtered onto a 0.2µm polycarbonate membrane; a second was filtered Whatman a GF/F filter. 100 µl of mercuric chloride (600mg/100ml) were added to poison; then samples were stored at dark until analysis at laboratory (Kirkwood, 1992). Analysis is performed at the laboratory using an automated colorimetric procedure (Aminot and Kerouel, 2007). For ammonium determination, 20 ml of water samples or melted ice (in filtered surface water) were transferred into 60 ml polycarbonate tubes. Analysis was immediately performed at field using the fluorometric procedure (Holmes et al., 1999).";
String standard_name "mole_concentration_of_nitrite_in_sea_water";
String units "um/l";
String variable_detail_description "Concentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [unknown phase]";
String variable_detail_sample_fraction "Filtrate";
String variable_detail_speciation "NO2";
String Variable_Value_Type "Actual";
}
NO2_result_value_qualifier {
String ioos_category "Dissolved Nutrients";
String Long_Name "Nitrite Result value qualifier";
String long_name "NO2 Result Value Qualifier";
}
NO3_um_l {
String activity_collection_type "Lab Measurement";
Float64 actual_range 0.0, 28.48;
String analytical_instrument_detection_limit "detection limit= 0.05 µmoles.l-1 accuracy = ± 0.05µmoles.l-1";
String analytical_instrument_units "µmoles.l-1";
String Analytical_method "Analysis is performed at the laboratory using an automated colorimetric procedure (Aminot and Kerouel, 2007). For ammonium determination, 20 ml of water samples or melted ice (in filtered surface water) were transferred into 60 ml polycarbonate tubes. Analysis was immediately performed at field using the fluorometric procedure (Holmes et al., 1999).";
Float64 colorBarMaximum 50.0;
Float64 colorBarMinimum 0.0;
String Description "Concentration of nitrate {NO3- CAS 14797-55-8} per unit volume of the water body [unknown phase]";
String ioos_category "Dissolved Nutrients";
String Long_Name "Nitrate";
String long_name "Mole Concentration Of Nitrate In Sea Water";
String Sample_Collection_Method "Water samples or melted ice (in filtered surface water for the 0-1 cm cores or in artificial seawater for the 0-3 and 3-10 cm cores) were collected in duplicate into 20 ml polyethylene flasks. One sample was filtered onto a 0.2µm polycarbonate membrane; a second was filtered Whatman a GF/F filter. 100 µl of mercuric chloride (600mg/100ml) were added to poison; then samples were stored at dark until analysis at laboratory (Kirkwood, 1992).";
String standard_name "mole_concentration_of_nitrate_in_sea_water";
String units "um/l";
String variable_detail_description "Concentration of nitrate {NO3- CAS 14797-55-8} per unit volume of the water body [unknown phase]";
String variable_detail_sample_fraction "Filtrate";
String variable_detail_speciation "NO3";
String Variable_Value_Type "Actual";
}
NO3_result_value_qualifier {
String ioos_category "Dissolved Nutrients";
String Long_Name "Nitrate Result value qualifier";
String long_name "NO3 Result Value Qualifier";
}
SiOx_um_l {
Float64 _FillValue NaN;
String activity_collection_type "Lab Measurement";
Float64 actual_range 0.0, 131.44;
String analytical_instrument_detection_limit "detection limit= 0.05 µmoles.l-1 accuracy = ± 0.05µmoles.l-1";
String analytical_instrument_units "µmoles.l-1";
String Analytical_method "Analysis is performed at the laboratory using an automated colorimetric procedure (Aminot and Kerouel, 2007). For ammonium determination, 20 ml of water samples or melted ice (in filtered surface water) were transferred into 60 ml polycarbonate tubes. Analysis was immediately performed at field using the fluorometric procedure (Holmes et al., 1999).";
String Description "Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [unknown phase]";
String ioos_category "Dissolved Nutrients";
String Long_Name "Silicate";
String long_name "Si Ox Um L";
String Sample_Collection_Method "Water samples or melted ice (in filtered surface water for the 0-1 cm cores or in artificial seawater for the 0-3 and 3-10 cm cores) were collected in duplicate into 20 ml polyethylene flasks. One sample was filtered onto a 0.2µm polycarbonate membrane; a second was filtered Whatman a GF/F filter. 100 µl of mercuric chloride (600mg/100ml) were added to poison; then samples were stored at dark until analysis at laboratory (Kirkwood, 1992).";
String units "um/l";
String variable_detail_description "Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [unknown phase]";
String variable_detail_sample_fraction "Whole";
String variable_detail_speciation "SiO4";
String Variable_Value_Type "Actual";
}
SiOx_result_value_qualifier {
String ioos_category "Dissolved Nutrients";
String Long_Name "Silicate Result Value qualifier";
String long_name "Si Ox Result Value Qualifier";
}
PO4_Filt_um_l {
Float64 _FillValue NaN;
String activity_collection_type "Lab Measurement";
Float64 actual_range 0.0, 2.19;
String analytical_instrument_detection_limit "detection limit= 0.02 µmoles.l-1 accuracy = ± 0.05µmoles.l-1";
String analytical_instrument_units "µmoles.l-1";
String Analytical_method "Analysis is performed at the laboratory using an automated colorimetric procedure (Aminot and Kerouel, 2007). For ammonium determination, 20 ml of water samples or melted ice (in filtered surface water) were transferred into 60 ml polycarbonate tubes. Analysis was immediately performed at field using the fluorometric procedure (Holmes et al., 1999).";
String Description "Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate <unknown phase]";
String ioos_category "Dissolved Nutrients";
String Long_Name "Phosphate";
String long_name "Mass Concentration Of Phosphate In Sea Water";
String Sample_Collection_Method "Water samples or melted ice (in filtered surface water for the 0-1 cm cores or in artificial seawater for the 0-3 and 3-10 cm cores) were collected in duplicate into 20 ml polyethylene flasks. One sample was filtered onto a 0.2µm polycarbonate membrane; a second was filtered Whatman a GF/F filter. 100 µl of mercuric chloride (600mg/100ml) were added to poison; then samples were stored at dark until analysis at laboratory (Kirkwood, 1992).";
String standard_name "mass_concentration_of_phosphate_in_sea_water";
String units "um/l";
String variable_detail_description "Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate <unknown phase]";
String variable_detail_sample_fraction "Whole";
String variable_detail_speciation "PO4";
String Variable_Value_Type "Actual";
}
PO4_Filt_result_value_qualifier {
String ioos_category "Dissolved Nutrients";
String Long_Name "Phosphate Result Value Qualifier";
String long_name "PO4 Filt Result Value Qualifier";
}
NH4_um_l {
Float64 _FillValue NaN;
String activity_collection_type "Lab Measurement";
Float64 actual_range -0.03, 1.14;
Float64 colorBarMaximum 5.0;
Float64 colorBarMinimum 0.0;
String Description "concentration of ammonium {NH4+ CAS 14798-03-9} per unit mass of the water body [unknown phase]";
String ioos_category "Dissolved Nutrients";
String Long_Name "Ammonia";
String long_name "Mole Concentration Of Ammonium In Sea Water";
String standard_name "mole_concentration_of_ammonium_in_sea_water";
String units "um/l";
String variable_detail_description "concentration of ammonium {NH4+ CAS 14798-03-9} per unit mass of the water body [unknown phase]";
String variable_detail_sample_fraction "Whole";
String variable_detail_speciation "NH4";
String Variable_Value_Type "Actual";
}
NH4_result_value_qualifier {
String ioos_category "Dissolved Nutrients";
String Long_Name "Ammonia result Value qualifier";
String long_name "NH4 Result Value Qualifier";
}
DissInorgN_um_l {
String activity_collection_type "Lab Measurement";
Float64 actual_range 0.0, 28.49;
String analytical_instrument_detection_limit "0.04";
String analytical_instrument_units "µmoles.l-1";
String Description "The sum of all measured species of inorganic nitrogen – nitrate + nitrite+ ammonium";
String ioos_category "Statistics";
String Long_Name "Dissolved Inorganic Nitrogen";
String long_name "Diss Inorg N Um L";
String units "um/l";
String variable_detail_description "Total concentration of all dissolved inorganic nitrogen species in the water column, usually derived by summation of individual nutrient concentrations (NO3+NO2+NH4). Some workers may also include urea";
String variable_detail_sample_fraction "Whole";
String Variable_Value_Type "Actual";
}
DissInorgN_result_value_qualifier {
String ioos_category "Statistics";
String Long_Name "Dissolved Inorganic Nitrogen Result Value qualifier";
String long_name "Diss Inorg N Result Value Qualifier";
}
Type {
String Description "This variable is only required for plotting in Ocean Data View. “B” indicates a rosette bottle measurement";
String ioos_category "Unknown";
String long_name "Type";
}
o_18O_Per_mille {
Float64 _FillValue NaN;
String activity_collection_type "Lab Measurement";
Float64 actual_range -2.55, 0.42;
String analytical_instrument_detection_limit "0.05";
String analytical_instrument_units "0/00";
String Analytical_method "The methods we use are essentially those in: Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. Guide to best practices for ocean CO2 measurements.PICES Special Publication 3, 191 pp. This is freely available on the web: http://cdiac.ornl.gov/oceans/Handbook_2007.html";
String Description "Stable oxygen isotope ratio measurement. Samples were analyzed using the CO2 equilibration method. The CO2 was then analyzed on a mass spectromoter in dual inlet mode with an AquaPrep system. For each analytical sequence two internal reference water samples were used to normalize the sample data.";
String ioos_category "Unknown";
String Long_Name "Stable oxygen isotope ratio measurement (O18)";
String long_name "O 18 O Per Mille";
String Sample_Collection_Method "Sampling from the rosette niskin bottles was completed as soon as possible, using a tygon tube and overflowing one and a half sample volumes before shutting off the water flow. Each sample was poisoned with 100 μL of HgCl2, sealed with electrical tape and then stored in the dark at 4 °C.";
String units "mille";
}
o_18O_result_value_qualifier {
String ioos_category "Unknown";
String Long_Name "Oxygen 18 Result Value Qualifier";
String long_name "O 18 O Result Value Qualifier";
}
DIC_um_l {
Float64 _FillValue NaN;
String activity_collection_type "Lab Measurement";
Float64 actual_range 1033.456781, 2279.202407;
String analytical_instrument_detection_limit "0.09";
String analytical_instrument_units "umol/kg";
String Analytical_method "The methods we use are essentially those in: Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. Guide to best practices for ocean CO2 measurements.PICES Special Publication 3, 191 pp. This is freely available on the web: http://cdiac.ornl.gov/oceans/Handbook_2007.html";
String Description "Dissolved inorganic carbon";
String ioos_category "Unknown";
String Long_Name "Total Dissolved Inorganic Carbon";
String long_name "DIC Um L";
String Sample_Collection_Method "Sampling from the rosette niskin bottles was completed as soon as possible, using a tygon tube and overflowing one and a half sample volumes before shutting off the water flow. Each sample was poisoned with 100 μL of HgCl2, sealed with electrical tape and then stored in the dark at 4 °C.";
}
DIC_result_value_qualifier {
String ioos_category "Unknown";
String Long_Name "Total Dissolved Inorganic Carbon Result Value Qualifier";
String long_name "DIC Result Value Qualifier";
}
TotAlk_l_um_l {
Float64 _FillValue NaN;
String activity_collection_type "Lab Measurement";
Float64 actual_range 2176.0490809999997, 2315.238146;
String analytical_instrument_detection_limit "2";
String analytical_instrument_units "umo/kg";
String Analytical_method "The methods we use are essentially those in: Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. Guide to best practices for ocean CO2 measurements.PICES Special Publication 3, 191 pp. This is freely available on the web: http://cdiac.ornl.gov/oceans/Handbook_2007.html";
String Description "Total alkalinity";
String ioos_category "Unknown";
String Long_Name "Total Alkalinity";
String long_name "Tot Alk L Um L";
String Sample_Collection_Method "Sampling from the rosette niskin bottles was completed as soon as possible, using a tygon tube and overflowing one and a half sample volumes before shutting off the water flow. Each sample was poisoned with 100 μL of HgCl2, sealed with electrical tape and then stored in the dark at 4 °C.";
String units "um/l";
}
TotAlk_l_result_value_qualifier {
String ioos_category "Unknown";
String Long_Name "Total Alkalinity Result Value Qualifier.";
String long_name "Tot Alk L Result Value Qualifier";
}
SalinomSal_psu {
Float64 _FillValue NaN;
String activity_collection_type "Field Measurement";
Float64 actual_range 31.74609005, 34.66143506;
String analytical_instrument_detection_limit "0.002";
String analytical_instrument_name "Autosal 8400B";
Float64 colorBarMaximum 37.0;
Float64 colorBarMinimum 32.0;
String Description "Salinity – measured from a bottle seawater measurement using an Autosal 8400B on-board the Amundsen";
String ioos_category "Salinity";
String Long_Name "Bench salinometer conductivity measurement";
String long_name "Salinom Sal Psu";
String units "PSU";
}
SalinomSal_result_value_qualifier {
String ioos_category "Unknown";
String Long_Name "Bench salinometer conductivity measurement result qualifier";
String long_name "Salinom Sal Result Value Qualifier";
}
}
NC_GLOBAL {
String cdm_data_type "Other";
String Conventions "COARDS, CF-1.6, ACDD-1.3";
String creator_name "Centre for Earth Observation Science, University of Manitoba";
String creator_type "institution";
String creator_url "https://umanitoba.ca/ceos/";
String Data_collection_end_date "2016-08-23";
String Data_collection_start_date "2016-06-09";
String Dataset__Role "Curator";
String Dataset_Author "Burgers, Tonya";
String Dataset_Author_Affiliation "The Centre for Earth Observation Science, University of Manitoba";
String Dataset_Author_Email "tonya.burgers@umanitoba.ca";
String Dataset_Contributor_Afiliation "Institute of Ocean Sciences";
String Dataset_Contributor_Role "Researcher";
String Dataset_Keywords "Beaufort Sea, Carbonate, nutrients, carbon dioxide";
Float64 Dataset_Level 1.5;
String Dataset_Maintenance_&_Update_Frequency "None Planned";
String Dataset_Maintenance_Update_Frequency "None Planned";
String Dataset_Status "Complete";
String Dataset_Summary "Carbonate chemistry dataset, including associated nutrient data (from the CTD/Rosette system) and stable oxygen isotope (O-18) measurements from Legs 1 and 2 of the 2016 cruise of CCGS Amundsen through the eastern Canadian Arctic (Baffin Bay, Nares Strait, Lancaster Sound, and Coronation Gulf).";
Float64 Dataset_Version 1.0;
Float64 Easternmost_Easting -55.99096;
String Email "Lisa.Miller@dfo-mpo.gc.ca";
Float64 geospatial_lat_max 70.51318;
Float64 geospatial_lat_min 67.995;
String geospatial_lat_units "degrees_north";
Float64 geospatial_lon_max -55.99096;
Float64 geospatial_lon_min -63.98764;
String geospatial_lon_units "degrees_east";
Float64 geospatial_vertical_max 2216.0;
Float64 geospatial_vertical_min 127.0;
String geospatial_vertical_positive "down";
String geospatial_vertical_units "m";
String history
"2023-03-24T16:25:41Z (local files)
2023-03-24T16:25:41Z http://CanWINerddap.ad.umanitoba.ca/tabledap/GreenEdge_Nutrient_3e39_afd6_0a1e.das";
String infoUrl "https://umanitoba.ca/ceos/";
String institution "Centre for Earth Observation Science, University of Manitoba";
String keywords "alk, altimetry, ammonia, ammonium, bathymetry, bottle, cast, centre, chemistry, concentration, cruise, data, date, depth, dic, DIC_result_value_qualifier, DIC_um_l, diss, DissInorgN_result_value_qualifier, DissInorgN_um_l, dissolved, dissolved nutrients, earth, Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry, Earth Science > Oceans > Ocean Chemistry > Ammonia, Earth Science > Oceans > Ocean Chemistry > Nitrate, Earth Science > Oceans > Ocean Chemistry > Phosphate, filt, floor, greenedge, identifier, inorg, laboratory, latitude, longitude, Longitude_east, manitoba, mass, mass_concentration_of_phosphate_in_sea_water, mille, mole, mole_concentration_of_ammonium_in_sea_water, mole_concentration_of_nitrate_in_sea_water, mole_concentration_of_nitrite_in_sea_water, n02, name, nh4, NH4_result_value_qualifier, NH4_um_l, nitrate, nitrite, no2, NO2_result_value_qualifier, NO2_um_l, no3, NO3_result_value_qualifier, NO3_um_l, nutrient, nutrients, o_18O_Per_mille, o_18O_result_value_qualifier, observation, ocean, oceans, per, phosphate, platform, platform_name, po4, PO4_Filt_result_value_qualifier, PO4_Filt_um_l, practical, project, project_name, psu, qualifier, result, sal, salinity, salinom, SalinomSal_psu, SalinomSal_result_value_qualifier, sample, sample_date, sample_depth_m, satellite, science, sea, sea_floor_depth, seafloor, seawater, SiOx_result_value_qualifier, SiOx_um_l, station, statistics, time, topography, tot, TotAlk_l_result_value_qualifier, TotAlk_l_um_l, type, unit, university, value, water";
String keywords_vocabulary "GCMD Science Keywords";
String license "Creative Commons Attribution 4.0 International";
String Name "Miller, Lisa";
Float64 Northernmost_Northing 70.51318;
String Related_resouce_type "Dataset";
String Related_Resource_Name "ArcticNet Inorganic Carbon Dataset, Cruise AN1601 and AN1602";
String Relation_to_the_main_dataset "Is Part Of";
String Research_Area "Beaufort Sea";
String Series "Greenedge data series";
String sourceUrl "(local files)";
Float64 Southernmost_Northing 67.995;
String standard_name_vocabulary "CF Standard Name Table v55";
String subsetVariables "project_name, platform_name, Cruise, NO2_result_value_qualifier, NO3_result_value_qualifier, DissInorgN_result_value_qualifier, Type";
String summary "Standardized nutrient data from the GreenEdge project 2016. Headers standardized in accordance with the NERC vocabulary. Used for CCADI UC3 Jupyter Notebooks application.";
String title "Greenedge standardized nutrient data 2016";
String Type "Dataset";
Float64 Westernmost_Easting -63.98764;
}
}
Data Access Protocol (DAP) and its
selection constraints.
The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.
Tabledap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/pmelTaoDySst.htmlTable?longitude,latitude,time,station,wmo_platform_code,T_25&time>=2015-05-23T12:00:00Z&time<=2015-05-31T12:00:00Z
Thus, the query is often a comma-separated list of desired variable names,
followed by a collection of
constraints (e.g., variable<value),
each preceded by '&' (which is interpreted as "AND").
For details, see the tabledap Documentation.