Atmospheric Radiation Measurement Climate Research Facility US Department of Energy

MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP

14 March 2005 - 14 September 2005

Lead Scientist: Mark Miller

Observatory: amf, pye

The ARM Mobile Facility (AMF) was deployed to Point Reyes National Seashore on the California coast to study the microphysical and radiative characteristics of marine stratus, one of the most prevalent clouds on Earth. Marine stratus is an important yet undersampled component of the Earth’s climate system. These clouds are known to be susceptible to infusions of human-caused aerosols that likely alter the in-cloud microphysical processes and are known to have at least two stable modes: one with relatively large cloud droplets and relatively large drizzle rates, and another with relatively smaller cloud droplets and little or no drizzle. Cloud condensation nuclei (CCN) apparently play a critical role in determining which stable mode is observed. Marine stratus clouds also exhibit a strong diurnal cycle due to a pronounced cloud and radiation feedback involving changes in the net radiative flux at the cloud top.

Researchers had two main scientific objectives: 1) to investigate the general relationship between cloud mesoscale structure, aerosols, cloud microphysics, drizzle, and radiation in marine stratus clouds; and 2) the specific effects of aerosols on the discrepancy between the measured and modeled amount of solar radiation absorbed by these clouds. These scientific objectives were investigated by combining detailed cloud, drizzle, and radiation measurements from the AMF 94-GHz radar and other sensors with detailed aircraft profiles, which included comprehensive aerosol measurements. The effects of aerosols on the amount of solar radiation absorbed by marine stratus were quantified using similar methods supplemented by state-of-the-art in-cloud radiation measurements made from aircraft. These combined measurements improved on previous studies addressing the discrepancy between models and observations of the solar absorption of clouds by direct and accurate observation of the ambient aerosols, surface albedo, and downwelling solar flux. In particular, highly accurate solar flux measurements were obtained from a state-of-the-art, stabilized platform for making radiometric measurements from an aircraft.

The research proposal leveraged experimental activities conducted in the Point Reyes area during the summer of 2005 in conjunction with research supported by the Office of Naval Research (ONR), the Naval Research Laboratory, and the DOE Aerosol Science Program. The ONR experiments included the use of a scanning (military, phased array) X-band (3.2-centimeter wavelength), scanning Doppler radar to study the mesoscale organization of drizzle patches embedded in marine stratocumulus in the region. There were opportunities for coincident aerosol and radiation data to be collected in the vicinity of the AMF site with the CIRPAS Twin Otter and Pacific Northwest National Laboratory G-1 research aircraft.


  • Child Campaign


Hudson J, S Noble, and S Tabor. 2018. "CCN Spectral Shape and Stratus Cloud and Drizzle Microphysics." Journal of Geophysical Research: Atmospheres, 123(17), 10.1029/2017JD027865.


Berg L and P Lamb. 2016. "Surface Properties and Interactions: Coupling the Land and Atmosphere within the ARM Program." Meteorological Monographs, 57, 10.1175/AMSMONOGRAPHS-D-15-0044.1.


Hudson JG and S Noble. 2015. "Reply to comment by Yangang Liu et al. on “Cloud droplet spectral width relationship to CCN spectra and vertical velocity"." Journal of Geophysical Research: Atmospheres, 119(4), 10.1002/2013jd020559.

Noble S and JG Hudson. 2015. "MODIS comparisons with northeastern Pacific in situ stratocumulus microphysics." Journal of Geophysical Research: Atmospheres, 120(16), 10.1002/2014jd022785.


Hudson JG and S Noble. 2014. "Low-altitude summer/winter microphysics, dynamics, and CCN spectra of northeastern Caribbean small cumuli, and comparisons with stratus." Journal of Geophysical Research: Atmospheres, 119(9), 10.1002/2013jd021442.


de Boer G, SE Bauer, T Toto, S Menon, and AM Vogelmann. 2013. "Evaluation of aerosol-cloud interaction in the GISS ModelE using ARM observations." Journal of Geophysical Research: Atmospheres, 118(12), 10.1002/jgrd.50460.


Oreopoulos L, E Mlawer, J Delamere, T Shippert, J Cole, B Fomin, M Iacono, Z Jin, J Li, J Manners, P Raisanen, F Rose, Y Zhang, MJ Wilson, and WB Rossow. 2012. "The Continual Intercomparison of Radiation Codes: Results from Phase I." Journal of Geophysical Research: Atmospheres, 117(D6), 10.1029/2011jd016821.
Research Highlight

McComiskey A and G Feingold. 2012. "The scale problem in quantifying aerosol indirect effects." Atmospheric Chemistry and Physics, 12(2), 10.5194/acp-12-1031-2012.
Research Highlight

de Boer G, S Menon, S Bauer, T Toto, A Vogelmann, and M Cribb. 2012. Evaluation of Aerosol-cloud Interactions in GISS ModelE Using ARM Observations. Presented at 3rd Atmospheric System Research (ASR) Science Team Meeting. Arlington, VA.

Khaiyer M, P Minnis, D Doelling, R Palikonda, M Nordeen, H Yi, R Boeke, and D Spangenberg. 2012. Improved TOA Broadband Shortwave and Longwave Fluxes over Various ARM Domains. Presented at 3rd Atmospheric System Research (ASR) Science Team Meeting. Arlington, VA.

View All Related Publications

Campaign Data Sets

IOP Participant Data Source Name Final Data
Carl Berkowitz Time of Flight Aerosol Mass Spectrometer Order Data
Richard Coulter 50 and 915 RWP Order Data
Richard Coulter Micropulse Lidar Order Data
Laurie Gregory Rapid Update Cycle Model Data Order Data
Pavlos Kollias 94 GHz Radar Order Data
Alexander Laskin Cloud Condensation Nuclei Counter (CVI inlet) Order Data
Alexander Laskin Scanning Mobility Particle Sizer (CVI inlet) Order Data
Alexander Laskin Time Resolved Aerosol Collectors (AOS inlet) Order Data
Alexander Laskin Time Resolved Aerosol Collectors (CVI inlet) Order Data
Chuck Long Surface Flux Analysis Order Data
Chuck Long Surface Radiation Data- QC Order Data
Anthony Strawa CADENZA Order Data
Warren Wiscombe Narrow Field of View Sensor Order Data

PYE Data Sources

Name Full Name Browse Data
AERI Atmospheric Emitted Radiance Interferometer Browse Data
AERINF AERI Noise Filtered Browse Data
AIP Aerosol Intensive Properties Browse Data
AOD-MFRSR Aerosol Optical Depth (AOD) derived from MFRSR measurements Browse Data
AOS Aerosol Observing System Browse Data
CAMSITE camera that monitors a site area Browse Data
CCN Cloud Condensation Nuclei Particle Counter Browse Data
CEIL Ceilometer 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
MERGESONDE Merged Sounding Browse Data
MET Surface Meteorological Instrumentation Browse Data
MFRSR Multifilter Rotating Shadowband Radiometer Browse Data
MFRSRCLDOD Cloud Optical Properties from MFRSR Using Min Algorithm Browse Data
MOLTS Model Output Location Time Series Browse Data
MPL Micropulse Lidar Browse Data
MWR Microwave Radiometer Browse Data
MWRP Microwave Radiometer Profiler Browse Data
MWRRET MWR Retrievals Browse Data
NCEPGFS National Centers for Environment Prediction Global Forecast System Browse Data
NFOV Narrow Field of View Zenith Radiometer 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
RUC Rapid Update Cycle Model Data Browse Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation Browse Data
SONDE Balloon-Borne Sounding System Browse Data
SONDEADJUST Sonde Adjust Browse Data
TSI Total Sky Imager Browse Data
VISST Minnis Cloud Products Using Visst Algorithm Browse Data