BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Evaluating Measurement of Supercooled Liquid Water Clouds
Published: August 01, 2011
Posted: April 09, 2012

The retrieval of cloud liquid water is an important climatic measurement because the earth radiative balance is strongly affected by cloud cover. The microwave radiometer, which is deemed to be the primary instrument for making these measurements, uses radiative transfer models to determine this property. Because of the propensity of clouds with small liquid water path (LWP) amounts and the importance of these clouds, the research community has recently started using higher frequencies, in the 90-200 GHz region. These frequencies have higher sensitivity to small amounts of cloud liquid water and, thereby, can improve the retrieval of liquid water by reducing the random uncertainties in the current LWP retrievals. Thus the accuracy of the radiative transfer code in the spectral region above 90 GHz was a major research focus. Scientists used measurements from microwave radiometers at the Southern Great Plains and North Slope of Alaska sites to assess four radiative transfer models. An ancillary dataset of measurements from cloud radars, ceilometers, radiosondes, and atmospheric emitted radiance interferometers was used to derive additional information (such as cloud boundaries, cloud temperature, and cloud LWP) that could be used as input for the analysis of the code. The study compared measurements of microwave absorption with model computations in supercooled liquid clouds that have temperatures between 0°C and -30°C. Findings from this study will be implemented by the Atmospheric Radiation Measurement Climate Research Facility to improve the accuracy of these measurements.

Reference: Cadeddu, M. P. and D. D. Turner. 2011. "Evaluation of Water Permittivity Models from Ground-Based Observations of Cold Clouds at Frequencies Between 23 and 170 GHz," IEEE Transactions on Geoscience and Remote Sensing 49(8), 2999-3008. DOI: 10.1109/TGRS.2011.2121074. (Reference link)

Contact: Wanda Ferrell, SC-23.1, (301) 903-0043, Rickey Petty, SC-23.1, (301) 903-5548
Topic Areas:

  • Research Area: Atmospheric System Research
  • Facility: DOE ARM User Facility

Division: SC-33.1 Earth and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco
Objectives

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)