Campaign : MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP

2005.03.14 - 2005.09.14

Website : http://www.arm.gov/sites/amf/pye/

Lead Scientist : Mark Miller

For data sets, see below.

Description

The ARM Mobile Facility (AMF) was deployed to the Monterey region on the central California coast to study the microphysical and radiative characteristics of marine stratus, one of the most prevalent clouds on the planet Earth. Marine stratus is an important, yet undersampled, component of the Earths climate system. These clouds are known to be susceptible to infusions of anthropogenic aerosols that likely alter the incloud 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 diurna l cycle due to a pronounced cloud and radiation feedback involving changes in the net radiative flux at cloud top. We 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 include 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. Our proposal leveraged experimental activities conducted in the Monterey 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 cm wavelength), scanning Doppler radar to study the mesoscale organization of drizzle patches embedded in marine stratocumulus in the Monterey Bay region. There were opportunities for coincident aerosol and radiation data to be collected in the vicinity of the Monterey AMF site with the CIRPAS Twin Otter and PNNL G1 research aircraft.

Routine Operations Data Sets

Instrument Archived Data
AERI Atmospheric Emitted Radiance Interferometer
Order Data
AOS Aerosol Observing System
Order Data
CCN Cloud Condensation Nuclei Particle Counter
Order Data
ECOR Eddy Correlation Flux Measurement System
Order Data
GNDRAD Ground Radiometers on Stand for Upwelling Radiation
Order Data
IRT Infrared Thermometer
Order Data
MET Surface Meteorological Instrumentation
Order Data
MFRSR Multifilter Rotating Shadowband Radiometer
Order Data
MPL Micropulse Lidar
Order Data
MWR Microwave Radiometer
Order Data
MWRP Microwave Radiometer Profiler
Order Data
NFOV Narrow Field of View Zenith Radiometer
Order Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation
Order Data
SONDE Balloon-Borne Sounding System
Order Data
TSI Total Sky Imager
Order Data
TWRCAM Tower Camera
Order Data
VCEIL Vaisala Ceilometer
Order Data

Campaign Data Sets

Campaign Participant Data Set Archived Data
Kollias, Pavlos 94 GHz Radar Order Data
Long, Chuck Surface Flux Analysis Order Data
Long, Chuck Surface Radiation Data- QC Order Data