Atmospheric Radiation Measurement Climate Research Facility US Department of Energy

Indirect and Semi-Direct Aerosol Campaign (ISDAC)

1 April 2008 - 30 April 2008

Lead Scientist: Steven Ghan

Observatory: AAF, NSA

An intensive cloud and aerosol observing system was deployed to the ARM Climate Research Facility’s (ACRF) North Slope of Alaska (NSA) locale for three weeks in April 2008. This period was chosen because it was during the International Polar Year when many ancillary observing systems were collecting data that would be synergistic for interpreting the Indirect and Semi-Direct Aerosol Campaign (ISDAC) data. It also provided an important contrast with the October 2004 Mixed-Phase Arctic Cloud Experiment (M-PACE). Thirty to 45 hours of flight time were required with aircraft capable of measuring temperature, humidity, total particle number, aerosol size distribution, aerosol hygroscopicity, cloud condensation nuclei concentration, ice nuclei concentration, optical scattering and absorption, updraft velocity, cloud liquid water and ice contents, cloud droplet and crystal size distributions, cloud particle shape, and cloud extinction. In addition to these aircraft measurements, there was a surface deployment of a spectroradiometer for retrieving cloud optical depth and effective radius.

These measurements will be used by members of the ARM Science Team to answer the following key questions:

  1. How do properties of the arctic aerosol during April differ from those measured during the MPACE in October?

  2. To what extent do the different properties of the arctic aerosol during April produce differences in the microphysical and macrophysical properties of clouds and the surface energy balance?

  3. To what extent can cloud models and the cloud parameterizations used in climate models simulate the sensitivity of arctic clouds and the surface energy budget to the differences in aerosol between April and October?

  4. How well can long-term surface-based measurements at the ACRF NSA locale provide retrievals of aerosol, cloud, precipitation, and radiative heating in the Arctic?

By using many of the same instruments used during M-PACE, we were able to contrast the arctic aerosol and cloud properties during October and April. The aerosol measurements can be used in cloud models driven by objectively analyzed boundary conditions to test whether the cloud models can simulate the aerosol influence on the clouds. The influence of aerosol and boundary conditions on the simulated clouds can be separated by running the cloud models with all four combinations of M-PACE and ISDAC aerosol and boundary conditions: M-PACE aerosol and boundary conditions, M-PACE aerosol and ISDAC boundary conditions, ISDAC aerosol and M-PACE boundary conditions, and ISDAC aerosol and boundary conditions. ISDAC and M-PACE boundary conditions were likely to be very different because of the much more extensive ocean water during M-PACE. The uniformity of the surface conditions during ISDAC greatly simplifies the objective analysis (surface fluxes and precipitation are very weak), so that it can largely rely on the European Centre for Medium-Range Weather Forecasts analysis. The ISDAC cloud measurements can be used to evaluate the cloud simulations and to evaluate cloud retrievals. The aerosol measurements can also be used to evaluate the aerosol retrievals. By running the cloud models with and without solar absorption by the aerosols, we can determine the semi-direct effect of the aerosol on the clouds.

Additional Information

Related Projects

The U.S. Department of Energy, primary sponsor for ISDAC, is collaborating with the following agencies, universities, and companies.

  • Canadian National Research Council
  • Environment Canada
  • University of Alaska, Fairbanks
  • Pacific Northwest National Laboratory
  • University of Illinois
  • Stratton Park Engineering Company
  • Droplet Measurement Technologies
  • Texas A&M University
  • The Pennsylvania State University
  • Scripps Institution of Oceanography
  • NOAA Earth System Research Laboratory
  • CIRES, University Colorado
  • Los Alamos National Laboratory
  • Sandia National Laboratory


Zhang X, T Schneider, and C Kaul. 2020. "Sensitivity of idealized mixed‐phase stratocumulus to climate perturbations." Quarterly Journal of the Royal Meteorological Society, , 10.1002/qj.3846. ONLINE.

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.


Joe P, S Melo, W Burrows, B Casati, R Crawford, A Deghan, G Gascon, Z Mariani, J Milbrandt, and K Strawbridge. 2019. "The Canadian Arctic Weather Science Project: Introduction to the Iqaluit Site." Bulletin of the American Meteorological Society, 101(2), 10.1175/BAMS-D-18-0291.1.

Lawson R, S Woods, E Jensen, E Erfani, C Gurganus, M Gallagher, P Connolly, J Whiteway, A Baran, P May, A Heymsfield, C Schmitt, G McFarquhar, J Um, A Protat, M Bailey, S Lance, A Muehlbauer, J Stith, A Korolev, O Toon, and M Krämer. 2019. "A Review of Ice Particle Shapes in Cirrus formed In Situ and in Anvils." Journal of Geophysical Research: Atmospheres, 124, 10.1029/2018JD030122.

Keita S, E Girard, J Raut, J Pelon, J Blanchet, O Lemoine, and T Onishi. 2019. "Simulating Arctic Ice Clouds during Spring Using an Advanced Ice Cloud Microphysics in the WRF Model." Atmosphere, 10(8), 10.3390/atmos10080433.

Matrosov S, M Maahn, and G de Boer. 2019. "Observational and modeling study of ice hydrometeor radar dual-wavelength ratios." Journal of Applied Meteorology and Climatology, 58(9), 10.1175/JAMC-D-19-0018.1.
Research Highlight

Shi Y and X Liu. 2019. "Dust Radiative Effects on Climate by Glaciating Mixed‐Phase Clouds." Geophysical Research Letters, , doi:10.1029/2019GL082504.
Research Highlight

Ghate V, P Kollias, S Crewell, A Fridlind, T Heus, U Löehnert, M Maahn, G McFarquhar, D Moisseev, M Oue, M Wendisch, and C Williams. 2019. "The Second ARM Training and Science Application Event: Training the Next Generation of Atmospheric Scientists." Bulletin of the American Meteorological Society, 100(1), 10.1175/BAMS-D-18-0242.1.


Solomon A, G de Boer, J Creamean, A McComiskey, M Shupe, M Maahn, and C Cox. 2018. "The relative impact of cloud condensation nuclei and ice nucleating particle concentrations on phase partitioning in Arctic mixed-phase stratocumulus clouds." Atmospheric Chemistry and Physics, 18(23), 10.5194/acp-18-17047-2018.

Chen Y, J Verlinde, E Clothiaux, A Ackerman, A Fridlind, M Chamecki, P Kollias, M Kirkpatrick, B Chen, G Yu, and A Avramov. 2018. "On the Forward Modeling of Radar Doppler Spectrum Width From LES: Implications for Model Evaluation." Journal of Geophysical Research: Atmospheres, 123(14), 10.1029/2017JD028104.

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Campaign Data Sets

IOP Participant Data Source Name Final Data
Sarah Brooks Continuous Flow Thermal Diffusion Chamber Order Data
Don Collins Tandem Differential Mobility Analyzer Order Data
Manvendra Dubey Photoacoustic Soot Spectrometer Order Data
Richard Ferrare HSR Lidar Order Data
Ismail Gultepe Campbell Scientific Data Logger Order Data
Ismail Gultepe Climatronics Aerosol Profiler Order Data
Ismail Gultepe Fog Monitoring Device Order Data
Ismail Gultepe Ott Laser Optical Disdrometer Order Data
Ismail Gultepe Road Surface State Sensor Order Data
Ismail Gultepe Sentry Visibility Sensor Order Data
Ismail Gultepe Snow Depth Order Data
Ismail Gultepe Sunshine Pyranometer Order Data
Ismail Gultepe Total Precipitation Sensor Order Data
Ismail Gultepe Vaisala Precipitation Gauge Order Data
Ismail Gultepe Vaisala Weather Sensor Order Data
Ismail Gultepe Young Ultrasonic Anemometer Order Data
Alexei Korolev Korolev Cloud Extinction Probe Order Data
Alexander Laskin Cloud Condensation Nuclei Counter Order Data
Paul Lawson 2D-S Particle Size Order Data
Paul Lawson Cloud Particle Imager (CPI) Order Data
Dan Lubin ASD Spectroradiometer Order Data
Ann Marie Macdonald Counterflow Virtual Impactor (CVI) Order Data
Greg McFarquhar Cloud Aerosol Precip Spectrometer Order Data
Greg McFarquhar Cloud Droplet Probe Order Data
Greg McFarquhar Microphysical Cloud Properties Order Data
John Ogren Nephelometer Order Data
John Ogren Particle Soot Absorption Photometer Order Data
J. Walter Strapp 2D Probes Order Data
J. Walter Strapp Convair 580 State Parameters Order Data
J. Walter Strapp DOE Cloud Imaging Probe Order Data
J. Walter Strapp EC Cloud Imaging Probe Order Data
J. Walter Strapp FSSP 100 Order Data
J. Walter Strapp FSSP 300 Order Data
J. Walter Strapp Passive Cavity Aerosol Spectrometer Order Data
J. Walter Strapp Radiometer Order Data
J. Walter Strapp Ultra-High Sensitivity Aerosol Spectrometer and Condensation Particle Counter Order Data
Mengistu Wolde CONVAIR Cabin Order Data
Mengistu Wolde NAWX Radar Order Data
Shaocheng Xie Constrained Variational Objective Analysis Data Order Data
Shaocheng Xie European Centre for Medium Range Weather Forecasting Order Data
Alla Zelenyuk-Imre Single Particle Laser Ablasion Time Order Data

NSA Data Sources

Name Full Name Browse Data
ACARS Aircraft Communications Addressing and Reporting System Browse Data
AERI Atmospheric Emitted Radiance Interferometer Browse Data
AERINF AERI Noise Filtered Browse Data
AIP Aerosol Intensive Properties Browse Data
AOS Aerosol Observing System Browse Data
ARMBE ARM Best Estimate Data Products Browse Data
ARSCL Active Remote Sensing of CLouds Browse Data
AVHRR Advanced Very High Resolution Radiometer Browse Data
CAMSITE camera that monitors a site area Browse Data
CCN Cloud Condensation Nuclei Particle Counter Browse Data
CEIL Ceilometer Browse Data
CSPHOT Cimel Sunphotometer Browse Data
ECMWFDIAG European Centre for Medium Range Weather Forecasts Diagnostic Analyses Browse Data
ECOR Eddy Correlation Flux Measurement System Browse Data
GNDRAD Ground Radiometers on Stand for Upwelling Radiation Browse Data
GVR G-band (183 GHz) Vapor Radiometer Browse Data
GVRP G-band (183 GHz) Vapor Radiometer Profiler Browse Data
INTERPSONDE Interpolated Sonde Browse Data
IRT Infrared Thermometer Browse Data
MERGESONDE Merged Sounding Browse Data
MET Surface Meteorological Instrumentation Browse Data
MFR Multifilter Radiometer Browse Data
MFRSR Multifilter Rotating Shadowband Radiometer Browse Data
MFRSRCLDOD Cloud Optical Properties from MFRSR Using Min Algorithm Browse Data
MMCR Millimeter Wavelength Cloud Radar Browse Data
MMCRMODE MMCR mode moments, derived by ARSCL process Browse Data
MOLTS Model Output Location Time Series Browse Data
MPL Micropulse Lidar Browse Data
MPLAVG MPL: data averaged to fixed 30 second interval, e.g. for polarized data Browse Data
MPLCMASK Cloud mask from Micropulse Lidar Browse Data
MWR Microwave Radiometer Browse Data
MWRHF Microwave Radiometer - High Frequency Browse Data
MWRP Microwave Radiometer Profiler Browse Data
MWRRET MWR Retrievals Browse Data
NCEPGFS National Centers for Environment Prediction Global Forecast System Browse Data
NIMFR Normal Incidence Multifilter Radiometer Browse Data
NOAACRN NOAA Climate Reference Network Browse Data
NOAARAD NOAA/ESRL/GMD Radiometers Browse Data
NWSUPA National Weather Service Upper Air Measurements Browse Data
ORG Optical Rain Gauge Browse Data
PBLHT Planetary Boundary Layer Height Browse Data
QCECOR Quality Controlled Eddy Correlation Flux Measurement Browse Data
QCRAD Data Quality Assessment for ARM Radiation Data Browse Data
RADFLUXANAL Radiative Flux Analysis Browse Data
RWP Radar Wind Profiler Browse Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation Browse Data
SONDE Balloon-Borne Sounding System Browse Data
SONDEADJUST Sonde Adjust Browse Data
SONICWIND ultrasonic wind sensor Browse Data
SURFSPECALB Surface Spectral Albedo Browse Data
SWFLUXANAL Shortwave Flux Analysis Browse Data
TPS Total Precipitation Sensor Browse Data
TSI Total Sky Imager Browse Data
TWR Facility-specific multi-level Meteorological Instrumentation Browse Data
VISST Minnis Cloud Products Using Visst Algorithm Browse Data