Atmospheric Radiation Measurement Climate Research Facility US Department of Energy

Colorado: SP2 Deployment at StormVEx

15 November 2010 - 25 April 2011

Lead Scientist: Arthur Sedlacek

Observatory: AMF, SBS

How does the boundary layer influence BC encapsulation?

Is there a correlation between BC loading and precipitation?

And if so, what is the correlation between BC age with precipitation washout?

These scientific questions are part of our community's larger research effort to better understand cloud-aerosol interactions in mixed and ice-phase clouds and how these interactions affect climate change. However, the extremely low BC number densities present at the Storm Peak Laboratory have confounded previous attempts to measure BC absorption or required signal averaging measured in days (Mazzoleni 2009). In an effort to get at the rich, and as yet untapped, data set that is present at Storm Peak Lab, the SP2 (single particle Soot Photometer) was deployed at two sites during the STORMVEX (Storm Peak Lab Validation Experiment) campaign. The SP2 measured the mass on individual BC particles through laser-induced incandescence thereby providing data on BC loading (#/m3 and ng/m3), size distribution (nominally 80 – 600 nm: mass equivalent diameter) and fresh versus aged soot (via coating thickness).

One of the unique aspects of the STORMVEX campaign is that the chosen deployment sites provided the opportunity to examine boundary layer processing of BC. Specifically, deployment of both ARM SP2s, one within the AMF2-AOS platform located at Christie Peak (~2500 m) and the other at Storm Peak Laboratory (~3200 m), provided BC measurements in the free troposphere (SPL site) and in/below the boundary layer. Updraft conditions provided the opportunity for both SP2 instruments to sample the same air mass and, using the Leading Edge Optimization technique (Gao et al. 2007), extract BC coating information – fresh soot possessing negligible coating whereas aged BC is characterized by a thick coating of organic/inorganic.

STORMVEX also provided the equally unique opportunity to examine what correlation(s) exists between BC age and precipitation washout. Since fresh soot is known to be hydrophobic and aged soot hydrophilic, it is reasonable to expect that aged BC would be more efficiently washed out during a precipitation episode by serving as IN/CCN. By looking for correlations of coating thickness estimates with washout, we can begin to answer this type of question. Admittedly, while STORMVEX is a winter campaign and provided ample opportunity to examine the correlation between BC age and mixed and ice-phase clouds, the measurement campaign lasted into the late April, thus providing similar opportunities to ask the same question with respect to wet precipitation.

References: Gao, R. S. J. P. Schwarz, K. K. Kelly, D. W. Fahey, L. A. Watts, T. L. Thompson, J.R. Spackman, J. G. Slowik, E. S. Cross, J. –H. Han, P. Davidovits, T. B. Onasch, and D. R. Worsnop, (2007) A Novel Method for Estimate Light-Scattering Properties of Soot Aerosols Using a Modified Single-Particle Soot Photometer, Aerosol Sci. Tech. 41:125-135. Mazzoleni, C. (private communication, 2009)

Related Publications


Mace G. 2016. Small Particles in Cirrus (SPartICus) and Storm Peak Lab Validation Experiment (StormVEx) Science Final Technical Report. Ed. by Robert Stafford, U.S. Department of Energy, Office of Science, BER. DOE_Utah_DESC0007062.

View All Related Publications

Campaign Data Sets

IOP Participant Data Source Name Final Data
Arthur Sedlacek Black Carbon Mass Concentrations- Christy Peak Order Data
Arthur Sedlacek Black Carbon Mass Concentrations- Storm Peak Order Data

SBS Data Sources

Name Full Name Browse Data
AOD Aerosol Optical Depth, derived from atmospheric extinction of solar irradiance Browse Data
AOSMET Meteorological Measurements associated with the Aerosol Observing System Browse Data
CCN Cloud Condensation Nuclei Particle Counter Browse Data
CEIL Ceilometer Browse Data
CPC Condensation Particle Counter Browse Data
CSPHOT Cimel Sunphotometer Browse Data
ECOR Eddy Correlation Flux Measurement System Browse Data
GNDRAD Ground Radiometers on Stand for Upwelling Radiation Browse Data
HSRL High Spectral Resolution Lidar Browse Data
MET Surface Meteorological Instrumentation Browse Data
MFRSR Multifilter Rotating Shadowband Radiometer Browse Data
MPL Micropulse Lidar Browse Data
MWR Microwave Radiometer Browse Data
MWR3C Microwave Radiometer, 3 Channel Browse Data
MWRRET MWR Retrievals Browse Data
NEPHELOMETER Nephelometer Browse Data
OZONE Ozone Monitor Browse Data
PSAP Particle Soot Absorption Photometer Browse Data
QCRAD Data Quality Assessment for ARM Radiation Data Browse Data
RWP Radar Wind Profiler Browse Data
SEBS Surface Energy Balance System Browse Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation Browse Data
SONDE Balloon-Borne Sounding System Browse Data
SONDEADJUST Sonde Adjust Browse Data
SWACR W-Band (95 GHz) ARM Cloud Radar, mounted to scan Browse Data
TSI Total Sky Imager Browse Data