Attributes {
 s {
  ID_Number {
    Int16 _FillValue 32767;
    Int16 actual_range 2, 323;
    String bcodmo_name "sample";
    Float64 colorBarMaximum 100.0;
    Float64 colorBarMinimum 0.0;
    String description "Sequential ID number indicting an individual period during which performance and/or mPMA properties were characterized with the generator operated in the same configuration.";
    String long_name "ID Number";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P02/current/ACYC/";
    String units "unitless";
  }
  Sample_Type {
    String bcodmo_name "sample_type";
    String description "Type of measurement and/or sample: T (Performance test) = Physical characterization only; S = Physical characterization + seawater grab sample for chemical characterization; CI = Physical characterization + cascade impactor sample or blank for analysis of major ions and organic carbon (OC); B = Physical characterization + bulk sample or blank for analysis of major ions and OC or for photochemical manipulation experiments";
    String long_name "Sample Type";
    String units "unitless";
  }
  Start_Date_local {
    String bcodmo_name "date_start";
    String description "For T period: start date for the first 5-minute measurement interval for the sizing instruments (scanning mobility particle sizer and aerodynamic particle sizer) or measurement date for water displacement characterization. Other periods (S, CI, B): Start date for mPMA sample or date for mPMA blank or seawater grab sample. Formatted as yyyy-mm-dd.";
    String long_name "Start Date Local";
    String source_name "Start_Date_local";
    String time_precision "1970-01-01";
    String units "unitless";
  }
  Start_Time_local {
    String bcodmo_name "time_start";
    String description "For T period: start time (Atlantic Daylight Time - ADT) for the first 5-minute measurement interval for the sizing instruments (scanning mobility particle sizer and aerodynamic particle sizer) or measurement time for water displacement characterization. Other periods (S, CI, B): Start time for mPMA sample or time for mPMA blank or seawater grab sample. Note: Times for many void fraction measurements were not recorded.";
    String long_name "Start Time Local";
    String units "unitless";
  }
  End_Date_local {
    String bcodmo_name "date_end";
    String description "For T period: stop datefor the last 5-minute measurement interval for the sizing instruments. Other periods:  Stop date for mPMA sample.  Formatted as yyyy-mm-dd.";
    String long_name "End Date Local";
    String units "unitless";
  }
  End_time_local {
    String bcodmo_name "time_end";
    String description "For T period: stop time (Atlantic Daylight Time - ADT) for the last 5-minute measurement interval for the sizing instruments. Other periods:  Stop time for mPMA sample.";
    String long_name "End Time Local";
    String units "unitless";
  }
  water_depth_type {
    String bcodmo_name "unknown";
    String description "Depth from which feed seawater was drawn: NS = near-surface (~5 m); NADW = North Atlantic deep water (~2500 m). The 2500 m seawater was transferred from a CTD to 20 L HDPE Teflon-lined carboys, warmed to room temperature, and pneumatically transferred from the carboys to the generator.";
    String long_name "Water Depth Type";
    String units "unitless";
  }
  Generator_Seawater_flowrate {
    Float32 _FillValue NaN;
    Float32 actual_range 0.0, 4.0;
    String bcodmo_name "flow_rate";
    String description "Flow rate of feed seawater into base of generator";
    String long_name "Generator Seawater Flowrate";
    String units "liters/minute";
  }
  Jet_Flowrate {
    Float32 _FillValue NaN;
    Float32 actual_range 0.0, 2.9;
    String bcodmo_name "flow_rate";
    String description "Flow rate of seawater though jet";
    String long_name "Jet Flowrate";
    String units "liters/minute";
  }
  Sweep_Bubble_Air_rate {
    Byte _FillValue 127;
    Byte actual_range 70, 70;
    String bcodmo_name "flow_rate";
    String description "Total flow rate of air through generator (sweep + bubble air)";
    String long_name "Sweep Bubble Air Rate";
    String units "liters/minute";
  }
  plumes_Venturi {
    String bcodmo_name "unknown";
    String description "Plumes produced by shallow (S) or deep (D) Venturi. Note: Immediately preceding the final two observation periods, seawater flow into the generator was turned off and the seawater level in the reservoir was lowered to approximately 4 cm above the top of the shallow Venturi (designated as S*).";
    String long_name "Plumes Venturi";
    String units "unitless";
  }
  Venturi_Air_flowrate {
    Float32 _FillValue NaN;
    Float32 actual_range 0.0, 5.0;
    String bcodmo_name "flow_rate";
    String description "Flow rate of bubble air through Venturi";
    String long_name "Venturi Air Flowrate";
    String units "liters/minute";
  }
  Venturi_Seawater_flowrate {
    Float32 _FillValue NaN;
    Float32 actual_range 0.0, 5.0;
    String bcodmo_name "flow_rate";
    String description "Flow rate of seawater through Venturi";
    String long_name "Venturi Seawater Flowrate";
    String units "liters/minute";
  }
  Rel_Humidity {
    Float32 _FillValue NaN;
    Float32 actual_range 63.6, 86.0;
    String bcodmo_name "humidity";
    String description "Average RH of air in generator?s head space (%)";
    String long_name "Rel Humidity";
    String units "unitless";
  }
 }
  NC_GLOBAL {
    String access_formats ".htmlTable,.csv,.json,.mat,.nc,.tsv";
    String acquisition_description "The marine aerosol generator was operated by William Keene
([wck@virginia.edu](\\\\\"mailto:wck@virginia.edu\\\\\")) and John Maben. Please
direct any related questions to William Keene.
 
Description and Operation of the Marine Aerosol Generator:\\u00a0Model primary
marine aerosol (mPMA) was produced in a high-capacity generator fabricated
from Pyrex and Teflon.\\u00a0 See Keene et al. [2007] for a description and
schematic of the original configuration of the device and Long et al. [2014]
for an explanation of modifications implemented for deployment on ships at sea
during the 2010 California Nexis (CalNex) campaign in the eastern North
Pacific Ocean and the 2012 Western Atlantic Climate Study (WACS) in the
western North Atlantic Ocean.\\u00a0 During all previous deployments, bubble
plumes were produced using sintered-glass frits and/or plunging seawater
jets.\\u00a0 During the Endeavor cruise, frits were replaced with force-air
Venturis as described below.\\u00a0
 
Briefly, the 20-cm-diameter generator consisted of a 122-cm-deep seawater
reservoir underlying a 97-cm-deep atmosphere. During most periods, fresh
seawater drawn from approximately 5-m depth through the ship\\u2019s clean
seawater line flowed into the base of the seawater reservoir (typically at 4 L
min-1) and drained evenly to exhaust over the top annular rim thereby
continuously replacing the seawater surface and minimizing formation of
standing bubble rafts.\\u00a0 During two periods, feed seawater flowing through
the generator was transferred from carboys containing seawater that had been
collected at a depth of 2500 m, stored in 20 L Teflon lined carboys, and
warmed to room temperature.\\u00a0 Bubble plumes were generated by two
mechanisms. (1) Ultra-pure air and seawater (drawn from the base of the
generator\\u2019s seawater reservoir) were pumped at adjustable rates of 1 to 5
L min-1 each through one of two force-air Venturi nozzles that were fabricated
from Teflon and positioned at depths of 42 (shallow) and 72 cm (deep),
respectively, below the air-seawater interface.\\u00a0 (2) Bubble plumes were
also produced by a seawater jet at flow rates of 1 to 3 L min-1 that impinged
on the air-seawater interface.\\u00a0 The jet nozzle was 0.32-cm ID and
positioned at 50 cm above the interface.
 
mPMA was emitted to the headspace when bubbles rose to and burst at the air-
seawater interface. Ultra-pure sweep air flowed through the headspace above
the seawater reservoir at 70 L min-1. During most sampling periods, sweep air
was hydrated to a relative humidity (RH) of ~80%. mPMA was sampled for
chemical and physical characterization through isokinetic ports at the top of
the generator.
 
The generator was blank tested by measuring mPMA number concentrations in the
headspace at typical flow rates of bubble and sweep air but with no seawater
in the reservoir. All blank tests yielded undetectable particle number
concentrations (less than 2 cm-3) indicating that all particles measured
during routine operation originated from seawater.
 
Bubble-plume void fractions were quantified over ranges of conditions by
filling the generator, turning off the flow of feed seawater, incrementally
increasing the flow of air through the Venturi, and measuring the volume of
displaced water.
 
Refer to the elated papers below for additional details regarding the design
and operation of the marine aerosol generator and associated analytical
methods.";
    String awards_0_award_nid "708309";
    String awards_0_award_number "OCE-1536608";
    String awards_0_data_url "http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1536608";
    String awards_0_funder_name "NSF Division of Ocean Sciences";
    String awards_0_funding_acronym "NSF OCE";
    String awards_0_funding_source_nid "355";
    String awards_0_program_manager "Henrietta N Edmonds";
    String awards_0_program_manager_nid "51517";
    String awards_1_award_nid "708317";
    String awards_1_award_number "OCE-1536605";
    String awards_1_data_url "https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536605";
    String awards_1_funder_name "NSF Division of Ocean Sciences";
    String awards_1_funding_acronym "NSF OCE";
    String awards_1_funding_source_nid "355";
    String awards_1_program_manager "Henrietta N Edmonds";
    String awards_1_program_manager_nid "51517";
    String awards_2_award_nid "708320";
    String awards_2_award_number "OCE-1536674";
    String awards_2_data_url "https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536674";
    String awards_2_funder_name "NSF Division of Ocean Sciences";
    String awards_2_funding_acronym "NSF OCE";
    String awards_2_funding_source_nid "355";
    String awards_2_program_manager "Henrietta N Edmonds";
    String awards_2_program_manager_nid "51517";
    String awards_3_award_nid "708323";
    String awards_3_award_number "OCE-1536597";
    String awards_3_data_url "https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536597";
    String awards_3_funder_name "NSF Division of Ocean Sciences";
    String awards_3_funding_acronym "NSF OCE";
    String awards_3_funding_source_nid "355";
    String awards_3_program_manager "Henrietta N Edmonds";
    String awards_3_program_manager_nid "51517";
    String cdm_data_type "Other";
    String comment "EN589: Marine Aerosol Generator Operating Conditions 
   PI: W. Keene (UVA) 
   version: 2018-12-03";
    String Conventions "COARDS, CF-1.6, ACDD-1.3";
    String creator_email "info@bco-dmo.org";
    String creator_name "BCO-DMO";
    String creator_type "institution";
    String creator_url "https://www.bco-dmo.org/";
    String data_source "extract_data_as_tsv version 2.3  19 Dec 2019";
    String date_created "2018-12-05T15:37:57Z";
    String date_modified "2019-03-18T13:46:27Z";
    String defaultDataQuery "&time<now";
    String doi "10.1575/1912/bco-dmo.750862.1";
    String history "2024-05-04T09:15:17Z (local files)
2024-05-04T09:15:17Z https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_750862.das";
    String infoUrl "https://www.bco-dmo.org/dataset/750862";
    String institution "BCO-DMO";
    String instruments_0_acronym "Flow Meter";
    String instruments_0_dataset_instrument_description "Airflow rates were regulated with needle valves and quantified with Teledyne Hastings mass flowmeters. Seawater flow rates were measured at the exhaust. RH and temperature were measured continuously at the outlet with a Vasala model HMP 233 probe and meter.";
    String instruments_0_dataset_instrument_nid "750916";
    String instruments_0_description "General term for a sensor that quantifies the rate at which fluids (e.g. water or air) pass through sensor packages, instruments, or sampling devices. A flow meter may be mechanical, optical, electromagnetic, etc.";
    String instruments_0_instrument_external_identifier "https://vocab.nerc.ac.uk/collection/L05/current/388/";
    String instruments_0_instrument_name "Flow Meter";
    String instruments_0_instrument_nid "650";
    String instruments_0_supplied_name "Teledyne Hastings mass flowmeters and Vasala model HMP 233 probe and meter.";
    String keywords "air, bco, bco-dmo, biological, bubble, chemical, data, dataset, date, depth, dmo, end, End_Date_local, End_time_local, erddap, flowrate, generator, Generator_Seawater_flowrate, humidity, ID_Number, jet, Jet_Flowrate, local, management, number, oceanography, office, plumes, plumes_Venturi, preliminary, rate, rel, Rel_Humidity, sample, Sample_Type, sea, seawater, start, Start_Time_local, sweep, Sweep_Bubble_Air_rate, time, type, venturi, Venturi_Air_flowrate, Venturi_Seawater_flowrate, water, water_depth_type";
    String license "https://www.bco-dmo.org/dataset/750862/license";
    String metadata_source "https://www.bco-dmo.org/api/dataset/750862";
    String param_mapping "{'750862': {}}";
    String parameter_source "https://www.bco-dmo.org/mapserver/dataset/750862/parameters";
    String people_0_affiliation "University of Virginia";
    String people_0_affiliation_acronym "UVA";
    String people_0_person_name "William C. Keene";
    String people_0_person_nid "708330";
    String people_0_role "Principal Investigator";
    String people_0_role_type "originator";
    String people_1_affiliation "Woods Hole Oceanographic Institution";
    String people_1_affiliation_acronym "WHOI BCO-DMO";
    String people_1_person_name "Nancy Copley";
    String people_1_person_nid "50396";
    String people_1_role "BCO-DMO Data Manager";
    String people_1_role_type "related";
    String project "Refractory DOC Recycling";
    String projects_0_acronym "Refractory DOC Recycling";
    String projects_0_description "The oceans hold a massive quantity of organic carbon that is greater than all terrestrial organic carbon biomass combined. Nearly all marine organic carbon is dissolved and more than 95% is refractory, and cycled through the oceans several times before complete removal. Refractory dissolved organic carbon (RDOC) concentrations are uniform with depth in the water column and represent the \"background\" carbon present throughout the oceans. However, very little is known regarding RDOC production and removal processes. One potential removal pathway is through adsorption of RDOC onto surfaces of rising bubbles produced by breaking waves and ejection via bubble bursting into the atmosphere. Building on prior research, the investigators will evaluate the importance of ocean- atmosphere processing in recycling marine RDOC during a research cruise in the northwestern Atlantic Ocean. Results of the research will provide important insights regarding the coupled ocean-atmosphere loss of RDOC, thereby improving understanding of and ability to predict the role of RDOC in oceanic and atmospheric biogeochemistry, the global carbon cycle, and Earth's climate. The research will involve three early career faculty, and will provide training for undergraduate and graduate researchers.
Recent results based on a limited set of observations indicate that the organic matter (OM) associated with primary marine aerosol (PMA) produced by bursting bubbles from breaking waves at the sea surface is comprised partly to wholly of RDOC rather than OM of recent biological origin as has been widely assumed. The injection of RDOC into the atmosphere in association with PMA and its subsequent photochemical oxidation is a potentially important and hitherto unrecognized sink for RDOC in the oceans of sufficient magnitude to close the marine carbon budget and help resolve a long-standing conundrum regarding removal mechanisms for marine RDOC. This project will involve a shipboard investigation and modeling study to (1) quantify the relative contributions of marine refractory dissolved organic carbon (RDOC) to primary marine aerosol organic matter (PMA OM) produced from near-surface seawater in biologically productive and oligotrophic regions and from North Atlantic Deep Water, and to (2) determine the importance of atmospheric photochemical processing as a recycling pathway for RDOC. To test these hypotheses, a high-capacity aerosol generator will be deployed at four hydrographic stations in the NW Atlantic Ocean to characterize (1) the natural abundance of 14C in PMA and in surface and deep seawater; (2) the surface tension and physical properties of bubble plumes; (3) size-resolved production fluxes, chemical composition, organic carbon enrichments, spectral absorbance, and photochemical evolution of PMA; and (4) the carbon content, optical properties, and physical properties of seawater. The importance of RDOC recycling via PMA production and photochemical evolution will be interpreted with model calculations.
EN589 Cruise Track";
    String projects_0_end_date "2018-12";
    String projects_0_geolocation "Northwest Atlantic Ocean";
    String projects_0_name "Collaborative Research: Coupled Ocean-Atmosphere Recycling of Refractory Dissolved Organic Carbon in Seawater";
    String projects_0_project_nid "708310";
    String projects_0_start_date "2015-09";
    String publisher_name "Biological and Chemical Oceanographic Data Management Office (BCO-DMO)";
    String publisher_type "institution";
    String sourceUrl "(local files)";
    String standard_name_vocabulary "CF Standard Name Table v55";
    String subsetVariables "Sweep_Bubble_Air_rate";
    String summary "This dataset describes the operating conditions for the high-capacity generator that produced primary marine aerosol from western North Atlantic seawater during cruise EN589 on RV/Endeavor during September and October 2016.";
    String title "Configuration and Operation of Marine Aerosol Generator Deployed on R/V Endeavor EN589 during Sept.- Oct. 2016";
    String version "1";
    String xml_source "osprey2erddap.update_xml() v1.3";
  }
}