READ ME for EUREC4A_M161_Picarro_1min_v1.2.nc netcdf EUREC4A_M161_Picarro_1min_v1.2 { dimensions: time = UNLIMITED ; // (0 currently) variables: double time(time) ; time:units = "seconds since 2020-01-01 00:00:00 UTC" ; double lon(time) ; lon:long_name = "Longitude" ; lon:units = "degrees_east" ; double lat(time) ; lat:long_name = "Latitude" ; lat:units = "degrees_north" ; double ppmv_H2O(time) ; ppmv_H2O:long_name = "H2O Concentration" ; ppmv_H2O:units = "ppmv" ; ppmv_H2O:missing_value = 9.969209968386869e+36 ; double q_H2O(time) ; q_H2O:long_name = "Specific Humidity" ; q_H2O:units = "kg/kg" ; q_H2O:missing_value = 9.969209968386869e+36 ; double d18O(time) ; d18O:long_name = "Oxygen 18/16 isotope delta value of water vapor" ; d18O:units = "delta per mil" ; d18O:missing_value = 9.969209968386869e+36 ; double dD(time) ; dD:long_name = "D/H isotope delta value of water vapor" ; dD:units = "delta per mil" ; dD:missing_value = 9.969209968386869e+36 ; double qc_flag(time) ; qc_flag:long_name = "Data Quality Control Flag" ; qc_flag:key = "1 = Normal, 2 = Rain Occurring, 3 = Post Rain, 4 = Smokestack/Wind Mask, 5 = NaN/Missing/Unusable " // global attributes: :Title = "EUREC4A M161 Continuous In-Situ Water Vapor Isotopic Composition 1-min v1.2" ; :Author = "Sebastian Los <slos@unm.edu https://orcid.org/0000-0002-6310-6414" ; :PI = "Dr. Joseph Galewsky <galewsky@unm.edu https://orcid.org/ 0000-0001-8236-6839" ; :Collector = "Sebastian Los <slos@unm.edu" ; :Experiment = "EUREC4A Field Campaign" ; :Platform = "RV Meteor" ; :Instrument = "Picarro L2130-i Cavity Ring-Down Spectroscopy (CRDS) Water Vapor Isotopic Analyzer :Collected = "2020 Jan 18 00:01:00 - 2020 Feb 21 23:59:00" ; :Created = "Aug 23, 2020" ; :Updated = "March 17, 2022, July 1, 2022" :Description = "Continuous water vapor isotopic time series. Delta values per mil on VSMOW-SLAP scale. Bulk uncertainties: d18O = 0.29, dD = 1.24. READ ME available at DOI." ; :History = "Verison 1.0: Original Level 1 data, Version 1.1 improves the calibration of isotopic time series, Version 1.2 updates the quality control flag" ; :version = "1.2" ; :DOI = "https://doi.org/10.25326/83" } #================================================================= Level 1 data (Version 1.0): - Picarro L2130-i cavity ring-down spectrometer deployed aboard the Research Vessel Meteor during research cruise M161 of EUREC4A - Inlet sampled relatively undisturbed air from above the air chemistry lab with a forward facing fetch (above the bow) - Inlet sampling height was 20.3 m above the mean sea surface, from downward facing funnel to minimize rain and seaspray effects - Inlet line of 505 cm length was heated to prevent condensation - Daily calibration runs done throughout the cruise using a rotation of four reference standards - Post-processing includes water vapor concentration dependence correction and VSMOW-SLAP normalisation - Averaged from 1 Hz to 1 minute resolution Version 1.1 - Calibration updated to remove 4 problematic calibration runs. Bulk uncertainies estimated at 0.29 and 1.24 per mil for d18O and dD respectively. Version 1.2 - Qualtiy control flag updated. Previously masked wind/ship emission times now unmasked and flagged. qc_flag = 1 --> Normal conditions, high quality qc_flag = 2 --> Periods with rain occurring qc_flag = 3 --> Post rain periods (rain ending + 3 hours). Generally higher than typical delta values affected by precipitation processes that may or may not represent ambient conditions (rain evaporation from ship surfaces, cold pool air mass, etc.) qc_flag = 4 --> Periods with wind from 120 and 250 degrees relative to the bow (behind instrument). These may be contaminated by ship smokestack or other ship emissions qc_flag = 5 --> NaN values for missing data points due to instrument issues, calibration runs, measurement restrictions. Fill Value 9.969209968386869e+36 Variables in file: #================ time, seconds since 01.01.2020 00:00:00 (UTC) latitude, deg N, 1 min mean longitude, deg E, 1 min mean ppmv_h20, Water vapor concentration ppmv, 1 min mean q_h2o, Specific humidity g/kg, 1 min mean d18O Oxygen ratio (18/16)in permil, 1 min mean dD, Deuterium/Hydrogen (D/H) ratio in permil, 1 min mean Contacts for questions: #================ Dr. Joseph Galewsky, galewsky@unm.edu, https://orcid.org/ 0000-0001-8236-6839 Sebastian Los, slos@unm.edu, https://orcid.org/0000-0002-6310-6414 DOI: #================ https://doi.org/10.25326/83