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.


  • Child Campaign


Shi Y, X Liu, M Wu, X Zhao, Z Ke, and H Brown. 2022. "Relative importance of high-latitude local and long-range-transported dust for Arctic ice-nucleating particles and impacts on Arctic mixed-phase clouds." Atmospheric Chemistry and Physics, 22(4), 10.5194/acp-22-2909-2022.
Research Highlight

Khain A, M Pinsky, and A Korolev. 2022. "Combined Effect of the Wegener–Bergeron–Findeisen Mechanism and Large Eddies on Microphysics of Mixed-Phase Stratiform Clouds." Journal of the Atmospheric Sciences, 79(2), 10.1175/JAS-D-20-0269.1.


Silber I, P McGlynn, J Harrington, and J Verlinde. 2021. "Habit‐Dependent Vapor Growth Modulates Arctic Supercooled Water Occurrence." Geophysical Research Letters, 48(10), e2021GL092767, 10.1029/2021GL092767.
Research Highlight

Fridlind A, C Chiu, S Collis, J Comstock, S Giangrande, N Hickmon, M Jensen, M Kumjian, P Muradyan, R Newsom, A Sockol, M Sturm, and A Theisen. 2021. ARM Cloud and Precipitation Measurements and Science Group (CPMSG) Workshop Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-005.


Keita S, E Girard, J Raut, M Leriche, J Blanchet, J Pelon, T Onishi, and A Cirisan. 2020. "A new parameterization of ice heterogeneous nucleation coupled to aerosol chemistry in WRF-Chem model version 3.5.1: evaluation through ISDAC measurements." Geoscientific Model Development, 13(11), 10.5194/gmd-13-5737-2020.

Ahola J, H Korhonen, J Tonttila, S Romakkaniemi, H Kokkola, and T Raatikainen. 2020. "Modelling mixed-phase clouds with the large-eddy model UCLALES–SALSA." Atmospheric Chemistry and Physics, 20(19), 10.5194/acp-20-11639-2020.

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.

View All Related Publications

Campaign Data Sets

IOP Participant Data Source Name Final Data
Sarah Brooks Continuous Flow Thermal Diffusion Chamber - Aboard Aircraft 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 Climatronics Aerosol Profiler Order Data
Ismail Gultepe Cloud Spectrometer and Impactor (CSI) Order Data
Ismail Gultepe Fog Monitoring Device Order Data
Ismail Gultepe Radiometer Suite (Tilt Corrected Data) 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 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
Ismail Gultepe disdro 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 Droplet Probe Order Data
Greg McFarquhar Cloud, Aerosol and Precipitation Spectrometer Order Data
Greg McFarquhar Microphysical Cloud Properties-McFarquhar-Zhang Order Data
John Ogren Nephelometer Order Data
John Ogren Particle Soot Absorption Photometer - G-1 Aircraft Order Data
J. Walter Strapp 2D Probes Order Data
J. Walter Strapp Cloud Aerosol Precip Spectrometer(CAPS)/Cloud Imaging Probe (CIP) Order Data
J. Walter Strapp Convair 580 State Parameters 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