Campaign : Marine ARM GPCI Investigation of Clouds (MAGIC)

2012.10.01 - 2013.09.30

Website :

Lead Scientist : Ernie Lewis

For data sets, see below.


Clouds remain a major source of uncertainty in climate projections. In this context, subtropical marine boundary layer (MBL) clouds play a key role in cloud-climate feedbacks that are not well understood yet play a large role in biases both in seasonal coupled model forecasts and annual mean climate forecasts. In particular, current climate models do not accurately represent the transition from the stratocumulus (Sc) regime, with its high albedo and large impact on the global radiative balance of Earth, to shallow trade-wind cumulus (Cu), which play a fundamental role in global surface evaporation and also albedo. Climate models do not yet adequately parameterize the small-scale physical processes associated with turbulence, convection, and radiation in these clouds. Part of this inability results from lack of accurate data on these clouds and the conditions responsible for their properties, including aerosol properties, radiation, and atmospheric and oceanographic conditions.

In MAGIC, the Marine ARM (Atmospheric Radiation Measurement) GPCI Investigation of Clouds, the Second ARM Mobile Facility, AMF2, was deployed on the Horizon Lines cargo ship Spirit traversing the route between Los Angeles, CA and Honolulu, HI for one full year, from October, 2012, through September, 2013, during which the unique capabilities provided by AMF2 were utilized to observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. Additionally, two Intensive Observational Periods (IOPs) were conducted January and July of 2013 during which more detailed measurements of the atmospheric structure were made.

This first marine deployment of AMF2 yielded an unparalleled and extremely rich data set that will greatly enhance the ability to understand and parameterize clouds and precipitation, aerosols, and radiation and the interactions among them; the processes that determine their properties; and factors that control these processes. Deployment of AMF2 on a ship that routinely traverses this route provided an opportunity to collect a long-term data set over a vast cloud region which is of intense interest to climate modelers. Specifically, the transect lies closely along the cross section used for the GPCI, and the data collected provided constraint, validation, and support for this modeling effort, and for associated modeling efforts such as the CGILS and EUCLIPSE. The founders of ARM recognized the importance of these marine cloud regimes and the original document recommending locales for ARM sites explicitly called for sites in the Eastern North Pacific or Eastern North Atlantic Ocean. This deployment, at long last, met the identified requirement for ARM measurements in this region.

Other Contacts

Bruce Albrecht
Geoffrey Bland
Charles Flagg
Stephen Klein
Pavlos Kollias
Michael Reynolds
Stephen Schwartz
A. Siebesma
Joao Teixeira
Warren Wiscombe
Robert Wood
Minghua Zhang

Campaign Data Sets

IOP ParticipantData Source DescriptionFinal Data Submitted to Archive
WagenerEuropean Centre for Medium Range Weather ForecastingOrder Data
LewisShip Leg SummariesOrder Data
ReynoldsBest Estimate 1-min Time Series DataOrder Data
ReynoldsShip Leg ReportsOrder Data
SpringstonMeteorological DataOrder Data
SpringstonOzoneOrder Data
ReynoldsRaw Navigation/GPS DataOrder Data
ReynoldsFlux DataOrder Data
SenumCloud Condensation Nuclei CounterOrder Data
SenumNephelometerOrder Data
SpringstonParticle Soot Absorption PhotometerOrder Data

Additional Data Sets

IOP ParticipantData Source DescriptionFinal Data Submitted to Archive
ChiuCIMEL SunphotometerOrder Data
BartholomewParcivel DisdrometerOrder Data
ReynoldsAtmospheric Optical DepthOrder Data
ReynoldsInfrared Seasurface Skin Temperature Autonomous RadiometerOrder Data
ReynoldsWindOrder Data
ReynoldsPsychrometerOrder Data
ReynoldsSunshine PyranometerOrder Data

ARM Mobile Facility Instruments

Data Source DescriptionFinal Data Submitted to Archive
Aerosol Observing System
Browse Data
Meteorological Measurements associated with the Aerosol Observing System
Browse Data
Atmospheric Sounder Spectrometer for Infrared Spectral Technology
Browse Data
Cloud Condensation Nuclei Particle Counter
Browse Data
Condensation Particle Counter
Browse Data
Cimel Sunphotometer
High Spectral Resolution Lidar
Browse Data
Humidified Tandem Differential Mobility Analyzer
Browse Data
Infrared Thermometer
Browse Data
Ka ARM Zenith Radar
Browse Data
Laser Disdrometer
Browse Data
Surface Meteorological Instrumentation
Browse Data
Micropulse Lidar
Browse Data
Marine W-Band (95 GHz) ARM Cloud Radar
Browse Data
Microwave Radiometer
Browse Data
Microwave Radiometer, 3 Channel
Browse Data
Navigational Location and Attitude
Browse Data
Browse Data
Ozone Monitor
Browse Data
Portable Radiation Package
Browse Data
Particle Soot Absorption Photometer
Browse Data
Radar Wind Profiler
Browse Data
Stabilized Platform
Browse Data
Shortwave Array Spectroradiometer-Zenith
Browse Data
Balloon-Borne Sounding System
Browse Data
Total Sky Imager
Browse Data
Ultra-High Sensitivity Aerosol Spectrometer
Browse Data
Vaisala Ceilometer
Browse Data