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Atmospheric Radiation Measurement (ARM) Climate Research Facility

Cloud Life Cycle Infrastructure

An important component of any long-term atmospheric measurement program is the quality control and maintenance of the datastreams from instrument systems. Further, the raw measurements from atmospheric remote sensing instrumentation are not directly useable by the majority of the scientific community. These raw measurements must be interpreted and converted to geophysical quantities that can be more readily used by a greater number of scientists to address important questions regarding the Earth’s climate system.

The cloud life cycle infrastructure group at BNL is led by Dr. Michael Jensen and is responsible for the development and production of cloud-related value-added products (VAPs). The cloud life cycle infrastructure group also provides mentorships for the millimeter cloud radar datastreams (Karen Johnson) and the ARM disdrometers (Mary Jane Bartholomew).  A major focus of value-added product activities is the retrieval of geophysical properties from millimeter cloud radar observations.

Group Products

Active Remote Sensing of Clouds (ARSCL)

The ARSCL VAP combines data from multiple active remote sensing instruments to produce an objective determination of cloud hydrometeor height distributions and best-estimates of their radar reflectivities, vertical velocities, and Doppler spectral widths.  Much of the algorithm's calculations deal with ensuring accuracy and optimally merging data from the millimeter cloud radar's sequential operating modes, which have various advantages and limitations. [Developer: Karen Johnson]


The Micro-ARSCL VAP is a microscale cloud radar data product with the radar’s high temporal resolution. It includes information about the local maxima in each Doppler spectrum, uncertainty estimates for the Doppler moments of the primary peak, Doppler moment shape parameters (e.g., skewness and kurtosis), and more accurate identification of radar clutter. [Developer: Edward Luke]

Merged Sounding

The Merged Sounding VAP uses a combination of observations from radiosonde soundings, the microwave radiometer, surface meteorological instruments, and European Centre for Medium Range Weather Forecasts model output with a sophisticated scaling/interpolation/smoothing scheme in order to define profiles of the atmospheric thermodynamic state at 1 minute intervals and a total of 266 altitude levels. [Developer: David Troyan]

Continuous Baseline Microphysical Retrieval (MICROBASE)

The MICROBASE VAP uses a combination of observations from the millimeter cloud radar, ceilometer, micropulse lidar, microwave radiometer and balloon-borne sounding profiles in order to determine the profiles of liquid/ice water content, liquid/ice cloud particle effective radius and cloud fraction. This baseline retrieval is calculated every 10 seconds and then averaged over 20-minute intervals with a vertical resolution of greater than 230 levels. [Developer: Maureen Dunn]