The TRACER-Iso project took place from June 1 to September 30, 2022 as part of the intensive observation period (IOP) of the Tracking Aerosol Convection Interactions (TRACER) project at the main project site at the La Porte, Texas, municipal airport. The project sought to use measurements of the stable isotopic composition of water vapor to better understand cloud-aerosol interactions in deep convection in a polluted urban setting. Water vapor isotopologue and humidity measurements were determined using a Picarro L2130 Water Vapor Isotope Analyzer. The instrument was deployed in the guest van and consists of three main components: a water vapor isotope analyzer, and a Los Gatos Research Water Vapor Isotope Standard Source (WVISS), and a Los Gatos Research Dry Air Source. Ambient air samples were collected through an inlet located about one meter above roof of the shipping container. Samples were then delivered to the analyzer through teflon tubing by use of an external pump to minimize the transport time between the inlet and analyzer. The inlet tubing was surrounded by a Briskheat heat trace and insulating material to ensure ambient air samples did not fall below the dew point and result in condensation. The analyzer uses cavity ringdown spectroscopy to report isotopic ratios of ambient air samples at a frequency of 1 Hz. The calibration unit of the instrument was used in conjunction with the dry air source to periodically measure the δ values of standard waters. It uses a nebulizer to push small water droplets into a hot chamber that vaporizes the water without fractionation. This vapor was then transported to the analyzer using a built-in compressor and the dry air source, which allows each standard with known δ values to be measured at a wide range of humidity values for post-measurement calibration of ambient air samples. There are multiple sources of uncertainty introduced at different stages during the data collection and processing. These include (1) instrument precision, (2) uncertainty in the secondary standards, (3) humidity-correction uncertainty, and (4) VSMOW-SLAP calibration uncertainty. Uncertainty from each step is propagated in quadrature to calculate a total uncertainty of each isotopologue. Uncertainty was determined to be 2.3‰ for δD and 0.4‰ for δ18O.
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Metadata Creator:
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Name:
Joseph Galewsky |
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Email:
galewsky@unm.edu |
Phone:
505-688-5470 |
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Street:
221 Yale Blvd NE |
City:
Albuquerque |
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State:
NM |
Postal:
87107 |
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Contact Info:
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Name:
Joseph Galewsky |
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Email:
galewsky@unm.edu |
Phone:
505-688-5470 |
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Street:
221 Yale Blvd NE |
City:
Albuquerque |
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State:
NM |
Postal:
87107 |
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Investigator(s):
| Joseph Galewsky (galewsky@unm.edu) 0000-0001-8236-6839
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| Data Citation: | https://doi.org/10.5439/1988640 |
| Data Format: | csv |
| Abstract: | The TRACER-Iso project took place from June 1 to September 30, 2022 as part of the intensive observation period (IOP) of the Tracking Aerosol Convection Interactions (TRACER) project at the main project site at the La Porte, Texas, municipal airport. The project sought to use measurements of the stable isotopic composition of water vapor to better understand cloud-aerosol interactions in deep convection in a polluted urban setting. Water vapor isotopologue and humidity measurements were determined using a Picarro L2130 Water Vapor Isotope Analyzer. The instrument was deployed in the guest van and consists of three main components: a water vapor isotope analyzer, and a Los Gatos Research Water Vapor Isotope Standard Source (WVISS), and a Los Gatos Research Dry Air Source. Ambient air samples were collected through an inlet located about one meter above roof of the shipping container. Samples were then delivered to the analyzer through teflon tubing by use of an external pump to minimize the transport time between the inlet and analyzer. The inlet tubing was surrounded by a Briskheat heat trace and insulating material to ensure ambient air samples did not fall below the dew point and result in condensation. The analyzer uses cavity ringdown spectroscopy to report isotopic ratios of ambient air samples at a frequency of 1 Hz. The calibration unit of the instrument was used in conjunction with the dry air source to periodically measure the δ values of standard waters. It uses a nebulizer to push small water droplets into a hot chamber that vaporizes the water without fractionation. This vapor was then transported to the analyzer using a built-in compressor and the dry air source, which allows each standard with known δ values to be measured at a wide range of humidity values for post-measurement calibration of ambient air samples. There are multiple sources of uncertainty introduced at different stages during the data collection and processing. These include (1) instrument precision, (2) uncertainty in the secondary standards, (3) humidity-correction uncertainty, and (4) VSMOW-SLAP calibration uncertainty. Uncertainty from each step is propagated in quadrature to calculate a total uncertainty of each isotopologue. Uncertainty was determined to be 2.3‰ for δD and 0.4‰ for δ18O. |
| Purpose: | Data were collected to improve understanding of the links between aerosols and water vapor. |
| Data Credit: | No |
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Arm Sites:
| hou |
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Content Time Range:
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Begin:
2022-06-01
End:
2022-09-30 |
| Instrument(s): | Water Vapor Isotope Analyzer
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| Data Type: | TRACER-iso
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| Scientific Measurements(s): |
| Measurement name | Variables |
| Ratio of stable isotope concentrations | vapor_mixing_ratio
isotoperatio
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| Stratum Keyword(s): |
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| Data Quality: |
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Attribute Accuracy:
| Uncertainty was determined to be 2.3‰ for δD and 0.4‰ for δ18O. |
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Positional Accuracy:
| No formal positional accuracy tests were conducted |
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Consistency and Completeness Report:
| Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. |
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Use Restrictions:
| No use constraints are associated with this data. |
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Distribution Info:
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Organization Name: |
ARM Archive User Services
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Email:
armarchive[at]ornl.gov
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Phone:
1-888-ARM-DATA
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Street:
Oak Ridge National Laboratory
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City:
Oak Ridge
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State:
Tennessee
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Postal:
37831-6290
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