Research Highlights

Validating Water Vapor Turbulence Measurements from Lidar
Dec 08, 2014       
Turbulence in the convective boundary layer is important for redistributing water vapor and other atmospheric gases, sensible heat, and momentum. Turbulent mixing works over a wide range of scales from kilometers down to millimeters. The horizontal and vertical resolutions of most atmospheric models, such as general circulation and cloud resolving models, are too coarse to [...]

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Hail Generation and Melting in Deep Convective Clouds from the Perspective of Dual-polarization
Dec 02, 2014       
Large hail is generated in vigorous convective updrafts which are commonly associated with columnar regions of enhanced differential reflectivity (ZDR columns) often capped with the depression of the cross-correlation coefficient ρhv measured by dual-polarization radars. After hailstones fall below the freezing level, they melt and produce large raindrops making a hail/rain mixture, which is characterized [...]

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On the Right Track for Tropical Clouds
Nov 27, 2014       
Researchers at Pacific Northwest National Laboratory and collaborators are hot on the trail of a large and lumbering atmospheric wave. Originating in the tropics, the intra-seasonal force wields influence on weather patterns around the world. Using high-resolution regional modeling along with field data, the scientists found that the frequency of the wave’s shallow-to-deep convective cloud [...]

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Double Bonus: Win-Win for Atmospheric Particles
Nov 18, 2014       
It’s a slam dunk for scientists measuring atmospheric particle properties. Typically calculated from their chemical composition and size distribution data, the larger particles often escape characterization. Scientists at Pacific Northwest National Laboratory and the University of Colorado developed a new method that simultaneously connects two critical properties: real refractive index, a measure of how much [...]

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Observing Warm Clouds in 3D Using ARM Scanning Cloud Radars and a Novel Ensemble Method
Nov 05, 2014       
Boundary-layer clouds make a significant contribution to the planetary albedo and thus are fundamentally important to the Earth’s radiation budget. Due to their complex turbulent structures, coupled with a strong susceptibility to aerosol, they remain a key source of uncertainty in climate projections. While Atmospheric Radiation Measurement Climate Research Facility (ARM)’s long-term observations from vertically [...]

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Validation of Climate Model Ice Cloud Properties
Oct 31, 2014       
General circulation models are used for understanding the past, present, and future climate. To be able to project future climate it is important that models provide a realistic depiction of the physical processes. Researchers at the National Center for Atmospheric Research (NCAR) have recently addressed how well properties of ice particles are represented in the [...]

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Fast and Rigorous: Finding Surface Reflectivity by Looking Up at Clouds
Oct 28, 2014       
Capturing sunlight reflected off the Earth's surface and bounced off a cloud back to the Earth is an effective measure of surface reflectivity—or surface albedo, the measure of how mirror-like the Earth's surface is. Researchers at Pacific Northwest National Laboratory developed a new way to measure surface albedo by capturing that cloud-bounced sunlight. In collaboration [...]

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Dust Takes Detour on Ice-Cloud Journey
Oct 15, 2014       
Wrapped in pollution, dust diverts from its usual course and steers clear of water. Researchers at Pacific Northwest National Laboratory found the result closes one more gap in understanding how and when cloud ice crystals form. They found that dust, usually a primary catalyst encouraging ice formation, when modified by pollution from combustion, becomes less [...]

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Interactions Between Cumulus Convection and Its Environment as Revealed by MC3E
Oct 13, 2014       
After decades of effort, accurately representing cumulus convection is still one of the most challenging tasks for weather and climate modeling. This is primarily because the interaction between cumulus convection and its environment has not been fully understood. Previous budget diagnostic studies have often targeted tropical convective systems given the dominant role these convective systems [...]

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First Observations of Tracking Clouds Using Scanning ARM Cloud Radars
Oct 05, 2014       
Scanning cloud radars provide new opportunities to map clouds and their evolution. Specifically, these radars observe cloud particles well in advance of large droplet formation, while also capturing the clouds at spatial and temporal scales sufficient for continuous tracking algorithms. To better demonstrate the capabilities of the new Scanning ARM Cloud Radars (SACR) at the [...]

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