Assessment of online water-soluble brown carbon measuring systems for aircraft sampling

Brown carbon (BrC) consists of particulate organic species that preferentially absorb light at visible and ultraviolet wavelengths. Ambient studies show that as a component of aerosol particles, BrC affects photochemical reaction rates and regional to global climate. Some organic chromophores are especially toxic, linking BrC to adverse health effects. The lack of direct measurements of BrC has limited our understanding of its prevalence, sources, evolution, and impacts. We describe the first direct, online measurements of water-soluble BrC on research aircraft by three separate instruments. Each instrument measured light absorption over a broad wavelength range using a liquid waveguide capillary cell (LWCC) and grating spectrometer, with particles collected into water by a particle-into-liquid sampler (CSU PILS-LWCC and NOAA PILS-LWCC) or a mist chamber (MC-LWCC). The instruments were deployed on the NSF C-130 aircraft during WE-CAN 2018 as well as the NASA DC-8 and the NOAA Twin Otter aircraft during FIREX-AQ 2019, where they sampled fresh and moderately aged wildfire plumes. Here, we describe the instruments, calibrations, data analysis and corrections for baseline drift and hysteresis. Detection limits (3 sigma) at 365 nm were 1.53 Mm(-1) (MC-LWCC; 2.5 min sampling time), 0.89 Mm(-1) (CSU PILS-LWCC; 30 s sampling time), and 0.03 Mm(-1) (NOAA PILS-LWCC; 30 s sampling time). Measurement uncertainties were 28 % (MC-LWCC), 12 % (CSU PILS-LWCC), and 11 % (NOAA PILS-LWCC). The MC-LWCC system agreed well with offline measurements from filter samples, with a slope of 0.91 and R-2=0.89. Overall, these instruments provide soluble BrC measurements with specificity and geographical coverage that is unavailable by other methods, but their sensitivity and time resolution can be challenging for aircraft studies where large and rapid changes in BrC concentrations may be encountered.

To Access Resource:

Questions? Email Resource Support Contact:

    UCAR/NCAR - Library

Resource Type publication
Temporal Range Begin N/A
Temporal Range End N/A
Temporal Resolution N/A
Bounding Box North Lat N/A
Bounding Box South Lat N/A
Bounding Box West Long N/A
Bounding Box East Long N/A
Spatial Representation N/A
Spatial Resolution N/A
Related Links N/A
Additional Information N/A
Resource Format N/A
Standardized Resource Format N/A
Asset Size N/A
Legal Constraints

Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Access Constraints None
Software Implementation Language N/A

Resource Support Name N/A
Resource Support Email
Resource Support Organization UCAR/NCAR - Library
Distributor N/A
Metadata Contact Name N/A
Metadata Contact Email
Metadata Contact Organization UCAR/NCAR - Library

Author Zeng, Linghan
Sullivan, Amy P.
Washenfelder, Rebecca A.
Dibb, Jack
Scheuer, Eric
Campos, Teresa L.
Katich, Joseph M.
Levin, Ezra
Robinson, Michael A.
Weber, Rodney J.
Publisher UCAR/NCAR - Library
Publication Date 2021-10-01T00:00:00
Digital Object Identifier (DOI) Not Assigned
Alternate Identifier N/A
Resource Version N/A
Topic Category geoscientificInformation
Progress N/A
Metadata Date 2021-12-06T22:46:12.020850
Metadata Record Identifier edu.ucar.opensky::articles:24760
Metadata Language eng; USA
Suggested Citation Zeng, Linghan, Sullivan, Amy P., Washenfelder, Rebecca A., Dibb, Jack, Scheuer, Eric, Campos, Teresa L., Katich, Joseph M., Levin, Ezra, Robinson, Michael A., Weber, Rodney J.. (2021). Assessment of online water-soluble brown carbon measuring systems for aircraft sampling. UCAR/NCAR - Library. Accessed 29 May 2023.

Harvest Source