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

BER Research Highlights


New Approach for Simultaneously Retrieving Cloud Brightness and Amount from Surface Measurements
Published: October 30, 2013
Posted: February 07, 2014

As climate changes, clouds respond in multiple ways. Observing these various responses consistently is challenging, making the science of cloud-climate interactions especially difficult. Two ways that clouds respond to climate change include the fraction of a region covered by clouds, and cloud brightness resulting from changes in cloud droplet number or phase (i.e., water versus ice). Surface-based measurements of sunlight or “solar radiation” contain valuable information needed to understand these cloud properties, but they have not been fully utilized. Department of Energy researchers have developed a new approach that simultaneously infers cloud brightness (or “albedo”) and cloud fraction from surface-based measurements of solar radiative fluxes. The radiative fluxes include both the “direct” incoming radiation, as well as “diffuse” radiation that includes radiation scattered from clouds, land, and atmospheric particles. Cloud fraction is primarily determined by the difference between all-sky and clear-sky “direct” radiation. The cloud brightness calculation incorporates further information from diffuse as well as direct radiation. The new method is tested using a computer algorithm that combines various types of measurements, including both satellite and surface measurements. The new approach demonstrates the utility of partitioning total radiation into direct and diffuse components, eliminating the potential contamination of errors in existing approaches that retrieve cloud fraction and cloud albedo separately. The method also has the potential for a consistent model evaluation.

Reference: Xie, Y., and Y. Liu. 2013. “A New Approach for Simultaneously Retrieving Cloud Albedo and Cloud Fraction from Surface-Based Shortwave Radiation Measurements,” Environmental Research Letters 8, 044023. DOI:10.1088/1748-9326/8/4/044023. (Reference link)

Contact: Dorothy Koch, SC-23.1, (301) 903-0105, Sally McFarlane, SC-23.1, (301) 903-0943
Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Atmospheric System Research

Division: SC-23.1 Climate 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

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)