Atmospheric Radiation Measurement Climate Research Facility US Department of Energy



Carbonaceous Aerosol and Radiative Effects Study (CARES)

2 June 2010 - 28 June 2010

Lead Scientist: Rahul Zaveri

Observatory: aaf, mcc

The primary objective of the Carbonaceous Aerosol and Radiative Effects Study (CARES) in 2010 was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties in central California, with a focus on the Sacramento urban plume. Carbonaceous aerosol components, which include black carbon (BC), urban primary organic aerosols (POA), biomass burning aerosols (BBA), and secondary organic aerosols (SOA) from both urban and biogenic precursors, have been shown to play a major role in the direct and indirect radiative forcing of climate. However, significant knowledge gaps and uncertainties still exist in the process-level understanding of: 1) SOA formation, 2) BC mixing state evolution, and 3) the optical and hygroscopic properties of fresh and aged carbonaceous aerosols. Light absorption by organic aerosols in the near-UV spectrum was discovered to be a very important part of the radiation budget in a past DOE ASP field campaign, although many questions remain. Several specific science questions under these three topics were addressed during CARES 2010. In addition to obtaining new observation-based understanding from the anticipated field data, the CARES campaign strategy was centered on using the data in various focused model evaluation exercises, so that the resulting new knowledge could be integrated into regional and global climate chemistry models. The sampling strategy during CARES was coordinated, to the extent possible, with CalNex 2010, a major field campaign that was planned in California in 2010 by the California Air Resources Board (CARB), the National Oceanic and Atmospheric Administration (NOAA), and the California Energy Commission (CEC).

During summer, the Sacramento urban plume transport is controlled by highly consistent, terrain-driven upslope winds that draw polluted air to the northeast over the oak and pine trees in the Blodgett Forest area by late afternoon. The Sacramento-Blodgett Forest corridor therefore effectively serves as a mesoscale (~100 km) daytime flow reactor in which the urban aerosols undergo significant aging due to coagulation, condensation, and photochemical processes. The CARES campaign observation strategy consisted of the DOE G-1 aircraft sampling upwind, within, and outside of the evolving Sacramento urban plume in the morning and again in the afternoon. The NASA B-200 aircraft carrying a High Spectral Resolution Lidar (HSRL) and a Research Scanning Polarimeter (RSP) was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties. The aircraft measurements were complemented by a well-instrumented ground site within the Sacramento urban source area and a downwind receptor site near Cool, CA, to characterize the diurnal evolution of meteorological variables, trace gases/aerosol precursors, and aerosol composition and properties in freshly polluted and aged urban air. As opportunity allowed, one or more NOAA P-3 aircraft flights were carried out in the Sacramento plume in coordination with the G-1 flights to allow wing-tip to wing-tip inter-comparison and provide valuable additional measurements for CARES. The P-3 measurements throughout California provided a regional context for CARES. The resulting datasets lend themselves to focused model evaluation exercises, including local radiative and CCN closures; constrained Lagrangian modeling of SOA formation, aerosol size and composition evolution, and black carbon aging; and 3-D Eulerian modeling of radiative feedback of aerosols on meteorology and regional climate.

The second objective during CARES was to take advantage of natural wildfires in the vicinity to study the evolution and properties of biomass burning aerosol. Occurrence of natural wildfires is very likely all over the Central Valley during June/July. Thus, the location and timing of the CARES 2010 campaign allowed us to target such an opportunity when it arose.

For more information, see the Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES).


Daniel Cziczo
William Shaw


  • Child Campaign


Chen G, J Wang, Y Wang, J Wang, Y Jin, Y Cheng, Y Yin, H Liao, A Ding, S Wang, J Hao, and C Liu. 2023. "An Aerosol Optical Module with Observation‐Constrained Black Carbon Properties for Global Climate Models." Journal of Advances in Modeling Earth Systems, 15(10), e2022MS003501, 10.1029/2022MS003501.


Beeler P and R Chakrabarty. 2022. "Constraining the particle-scale diversity of black carbon light absorption using a unified framework." Atmospheric Chemistry and Physics, 22(22), 10.5194/acp-22-14825-2022.
Research Highlight


McComiskey A, S Springston, and C Flynn. 2021. ARM Aerosol Measurement Science Group 2019 Strategic Planning Workshop Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-010. 10.2172/1811679.


Goldberger LA, F Mei, J Hubbe, and CD Kluzek. 2020. Navigation and Meteorological Data from Multiple Sensors on Airborne Platform (NAVMET-AIR) Value-Added Product Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-255. 10.2172/1671342.

Goldberger LA, MS Pekour, and JM Hubbe. 2020. Counterflow Virtual Impactor (CVI) Inlet Aboard Aircraft (INLETCVI-AIR) Instrument Handbook. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-254. 10.2172/1671315.

Zaveri R, J Shilling, J Fast, and S Springston. 2020. "Efficient Nighttime Biogenic SOA Formation in a Polluted Residual Layer." Journal of Geophysical Research: Atmospheres, 125(6), e2019JD031583, 10.1029/2019JD031583.
Research Highlight

Pai S, C Heald, J Pierce, S Farina, E Marais, J Jimenez, P Campuzano-Jost, B Nault, A Middlebrook, H Coe, J Shilling, R Bahreini, J Dingle, and K Vu. 2020. "An evaluation of global organic aerosol schemes using airborne observations." Atmospheric Chemistry and Physics, 20(5), 10.5194/acp-20-2637-2020.


Laskin A, R Moffet, and M Gilles. 2019. "Chemical Imaging of Atmospheric Particles." Accounts of Chemical Research, 52(12), 10.1021/acs.accounts.9b00396.
Research Highlight

Bhandari J, S China, K Chandrakar, G Kinney, W Cantrell, R Shaw, L Mazzoleni, G Girotto, N Sharma, K Gorkowski, S Gilardoni, S Decesari, M Facchini, N Zanca, G Pavese, F Esposito, M Dubey, A Aiken, R Chakrabarty, H MoosmĂźller, T Onasch, R Zaveri, B Scarnato, P Fialho, and C Mazzoleni. 2019. "Extensive Soot Compaction by Cloud Processing from Laboratory and Field Observations." Scientific Reports, 9(1), 11824, 10.1038/s41598-019-48143-y.
Research Highlight


Chakrabarty R and W Heinson. 2018. "Scaling Laws for Light Absorption Enhancement Due to Nonrefractory Coating of Atmospheric Black Carbon Aerosol." Physical Review Letters, 121(21), 218701, 10.1103/PhysRevLett.121.218701.

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Campaign Data Sets

IOP Participant Data Source Name Final Data
William Arnott Photoacoustic Spectroscopy- T0 Site Order Data
Dean Atkinson Cavity Ring-down Transmissometer and Radiance Research Nephelometer- T0 Site Order Data
Dean Atkinson Humidity Controlled Cavity Ring-down Transmissometer (HCCRDT)- T1 Site Order Data
James Barnard Multifilter Rotating Shadowband Radiometer- T0 Site Order Data
James Barnard PSP Radiometer Order Data
James Barnard PSP Radiometer- T0 Site Order Data
Larry Berg Radar Wind Profiler- T1 Site Order Data
Larry Berg Radiosonde Data Order Data
Larry Berg Sodar- T1 Site Order Data
Larry Berg Surface Meteorology- T0 Site Order Data
Brian Cairns Research Scanning Polarimeter- B200 Aircraft Order Data
Chris Cappa Cavity Ring Down Photoacoustic Spectrometer Order Data
Daniel Cziczo Cloud Condensation Nuclei Counter Order Data
Daniel Cziczo Particle Analysis by Laser Mass Spectrometry- T1 Site Order Data
Daniel Cziczo f_RH - G1 Aircraft Order Data
Manvendra Dubey Carbon Monoxide and Nitrous Oxide Order Data
Manvendra Dubey Photoacoustic Soot Spectrometer Order Data
Manvendra Dubey Photoacoustic Soot Spectrometer Order Data
Jerome Fast Weather Research and Forecasting (WRF) Model Output Order Data
Richard Ferrare HSR Lidar Order Data
Bertram Jobson Aerodynamic Part Sizer Order Data
Bertram Jobson Carbon Monoxide - G1 Aircraft Order Data
Bertram Jobson Gas Chromatography Mass Spectrometry Order Data
Bertram Jobson Proton Transfer Reaction Mass Spectrometer Order Data
Celine Kluzek Particle-Into-Liquid Sampler (PILS) Order Data
Walter Knighton Proton Transfer Reaction Mass Spectrometer Order Data
Alena Kubatova High Volume Aerosol Sampler- T0 Site Order Data
Alexander Laskin Time Resolved Aerosol Collectors (AOS inlet) Order Data
Alexander Laskin Time Resolved Aerosol Collectors- T0 Site Order Data
Nels Laulainen Actinic Flux- T1 Site Order Data
Nels Laulainen JNO2- T0 Site Order Data
Claudio Mazzoleni Scanning Electron Microscope- T1 Site Order Data
Kimberly Prather Aerosol Time-of-Flight Mass Spectrometer Order Data
Arthur Sedlacek Aethalometer- T1 Site Order Data
Arthur Sedlacek Single Particle Soot Photometer Order Data
Gunnar Senum Accelerometer- G1 Aircraft Order Data
Gunnar Senum Turbulence- G1 Aircraft Order Data
Gunnar Senum Vertical Velocity- G1 Aircraft Order Data
John Shilling Proton Transfer Reaction Mass Spectrometer Order Data
John Shilling Time of Flight Aerosol Mass Spectrometer Order Data
Chen Song Scanning Mobility Particle Sizer and CPC- T0 Site Order Data
Chen Song Sulfur Dioxide Analyzer- T0 Site Order Data
Stephen Springston Cloud, Aerosol and Precipitation Spectrometer Order Data
Stephen Springston Gas Monitors Order Data
Stephen Springston Met Order Data
Stephen Springston Nephelometer Order Data
Stephen Springston Particle Soot Absorption Photometer - G-1 Aircraft Order Data
R. Subramanian Single Particle Soot Photometer Order Data
Jason Tomlinson Condensation Particle Counter Order Data
Jason Tomlinson Ultra High Sensitivity Aerosol Spectrometer- G1 Aircraft Order Data
Jian Wang Cloud Condensation Nuclei Counter Order Data
Jian Wang Fast Integrated Mobility Spectrometer Order Data
Xiao-Ying Yu Organic and Elemental Carbon Analysis- T0 Site Order Data
Alla Zelenyuk-Imre Single Particle Laser Ablasion Time II- T0 Site Order Data
Qi Zhang Particle-Into-Liquid Sampler (PILS) Order Data
Qi Zhang Scanning Mobility Particle Sizer Order Data
Qi Zhang Time of Flight Aerosol Mass Spectrometer Order Data