News Center

New MICROBASE Ensemble Data Set Available
Apr 28, 2015 [ Data Announcements ]       
A new data set of ensemble cloud retrievals from the March 2000 intensive observational period at the Southern Great Plains Central Facility is now available in the ARM Data Archive evaluation area. The new data set uses the baseline cloud microphysical algorithm, known as MICROBASE, along with a variance-based method that varies the empirical parameters [...]

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Navigation Best Estimate Value-Added Product Released
Apr 27, 2015 [ Data Announcements ]       
Developed in response to the first ship-based deployment of the second ARM Mobile Facility (AMF2), the Navigation Best Estimate (NAVBE) Value-Added Product (VAP) has been released for evaluation. Meteorological, cloud, and aerosol measurements were collected during nearly 20 round trips of the container ship, Horizon Spirit, between Los Angeles, CA, and Honolulu, HI, from September [...]

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AmeriFlux and Methane Evaluation VAP Now Available for Barrow Data
Apr 21, 2015 [ Data Announcements ]       
Greenhouse gases (GHGs) are suspected to be key drivers of global climate change. As Arctic permafrost melts, it unlocks stored carbon, which may contribute to large increases in the atmospheric mixing ratios of these gases. Understanding the rates and controlling mechanisms of these releases is of great importance for climate prediction and modeling. The ARM Climate [...]

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First Ever ARM / ASR Joint User Facility PI Meeting
Apr 21, 2015 [ Facility News ]       
A recent joint meeting of the users and staff from the Atmospheric Radiation Measurement (ARM) Climate Research Facility and principal investigators from the Atmospheric System Research (ASR) program provided invaluable input on scientific priorities, needs, and gaps to the ARM Facility, as well as insight into ASR research and scientific progress. This first ever joint [...]

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Light Absorption of Primary Organic Aerosol Paper Named ACS Editors' Choice
Apr 20, 2015 [ Research Highlights ]       
Organic aerosols (OAs) in the atmosphere affect Earth’s energy budget by not only scattering but also absorbing solar radiation due to the presence of the so-called “brown carbon” (BrC) component. However, the absorptivities of OAs are not represented or are poorly represented in current climate and chemical transport models. Most models still treat primary OA [...]

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The Two Faces of Aerosols
Apr 15, 2015 [ Research Highlights ]       
It's a double dose of climate disturbance. Tiny particles of pollution—also known as aerosols—both cool and warm the planet. Now, a team of scientists from Pacific Northwest National Laboratory and NASA identified how current climate models may be far off in estimating the actual amounts of these particles and their total impact on the atmosphere. [...]

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Intersecting Cold Pools: Convective Cloud Organization by Cold Pools over Tropical Ocean
Apr 06, 2015 [ Research Highlights ]       
As rain drops descend to the surface, they can evaporate and cool the air. The cold air then spreads horizontally and forms pools at the surface that displace surrounding warm air. The dynamics of cold pools are an important mechanism of organizing convection. Researchers, including Department of Energy scientists at Pacific Northwest National Laboratory, [...]

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Comparison of Vertical Velocities in Cirrus Derived from Aircraft and Ground-based Radar
Mar 31, 2015 [ Research Highlights ]       
Vertical velocities and turbulence in the upper troposphere are key elements affecting the microphysical properties and dynamical evolution of cirrus clouds. In particular, vertical velocities contribute to the cooling rates in the upper troposphere thereby affecting the values of ice supersaturations, the number concentrations of ice crystals formed by ice nucleation, and the growth rates [...]

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Satellite Inference of Thermals and Cloud Base Updraft Speeds
Mar 30, 2015 [ Research Highlights ]       
Thermals transfer and distribute heat, moisture, momentum, and pollutant materials from the surface layer to the upper part of the convective mixed layer. Thermals also play a central role in the formation of convective clouds and precipitation. Cloud base updrafts govern water vapor supersaturation there, determining the concentration of cloud condensation nuclei (CCN) activated into [...]

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Are Increases in Thunderstorm Activity in Southeast China Related to Air Pollution?
Mar 12, 2015 [ Research Highlights ]       
Pollution aerosols are thought to have an invigorative effect on convective clouds by suppressing warm precipitation in moist and convectively unstable environments. As clouds develop to above the freezing level, mixed-phase clouds containing ice and supercooled water can grow further more readily and induce cloud electrification and thunderstorms during summertime. In southeastern China, the summer [...]

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Strongly Absorbing Aerosols Affect Retrievals of Cloud Optical Depth
Mar 12, 2015 [ Research Highlights ]       
Surface-based and satellite remote sensing techniques have proven indispensable for learning more about cloud temporal and spatial variations. Comparisons between cloud properties retrieved from surface and spaceborne platforms are commonly done as a way of validating satellite retrievals. Observations made at the surface are often treated as the “ground-truth” with respect to satellite retrievals. Both [...]

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Filling Gaps Within Instrument Records
Mar 09, 2015 [ Research Highlights ]       
The ARM SGP site in Lamont, Oklahoma, is home to one of the longest records of actively sensed cloud information anywhere on the planet. Despite the best efforts of the program, instruments occasionally misbehave or are taken down for maintenance, resulting in holes within this record. Utilizing the Active Remote Sensing of Clouds Value-Added Product [...]

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Quantifying the Importance of Cold Pool Mechanisms for Convection Triggering
Mar 09, 2015 [ Research Highlights ]       
The organization of the subcloud layer into cold pools, areas of evaporatively cooled downdraft air spreading on the surface, is one of the key processes that help sustainin deep convection. It has long been known cold pools can spawn new convective cells by mechanically lifting air along their gust front. Such lifting could be the [...]

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Modeling Precipitating Cumulus Congestus Observed by the ARM Radar Suite During the MC3E Field Campaign
Mar 04, 2015 [ Research Highlights ]       
Much of the uncertainty in climate model projections stems from the limited understanding of cloud and precipitation processes and the parameterization of these processes in global climate models (GCMs). Typically, results from cloud-resolving models (CRMs) or large-eddy simulation (LES) models serve as benchmarks for developing and tuning single-column models (SCMs), which, in turn, form the [...]

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Evaluation of Trigger Functions for Convective Parameterization Schemes
Mar 03, 2015 [ Research Highlights ]       
In a convective parameterization scheme, the trigger function activates the onset of convection. Hence, an accurate trigger function is important to the correct simulation of convection in global climate models (GCMs). However, the formulation of trigger functions in many of convective schemes is ad hoc and convection is often activated too easily. The over-activation of [...]

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