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


Who Can Sort the Rain?
Published: April 26, 2018
Posted: November 20, 2019

Surface measurements of rain drop sizes shed light on cloud processes and cloud types.

The Science
To predict extreme rainstorms, knowing how small processes, such as condensation, affect bigger systems is vital. These small processes, however, are hard to study. To learn more about these microphysical processes, researchers performed a statistical analysis on a global dataset of rain drop size distributions. They revealed the rain drops fit into six groups. These groups are independent of location; that is, the drop size distributions revealed six main groups that are linked to cloud processes and types.

The Impact
The results offer two key benefits. First, they improve physical understanding of how small, microphysical processes impact rainfall. Second, they provide new information regarding the global variability of rain cloud type (e.g., warm rain and ice-based precipitation). Scientists can use the results in two key ways. They can fine tune models to better represent precipitation processes, and they can improve remote sensing retrievals of rainfall.

Summary
The team analyzed 12 disdrometer datasets (including four from the U.S. Department of Energy's Atmospheric Radiation Measurement user facility). Disdrometers are surface instruments that measure the size of rain drops. The team gathered the data across three latitude bands, spanning a broad range of precipitation regimes: light rain, orographic, deep convective, organized midlatitude, and tropical oceanic. The team used principal component analysis to reveal comprehensive modes of global drop size distribution spatial and temporal variability. Although the locations contain different distributions of individual drop size distribution parameters, all locations have the same modes of variability.

Based on the principal component analysis, six groups of points with unique drop size distribution characteristics emerge. The physical processes that underpin these groups are revealed through supporting radar observations. These groups are consistent with different types of convection: weak, ice-dominated, and robust warm rain/collision-coalescence; and stratiform processes governed by vapor deposition and aggregation. The low latitudes have more frequent robust warm rain/collision-coalescence, while the midlatitudes have a larger component of ice-based convection. Although all locations exhibit the same co-variance of parameters associated with these groups, it is likely that the physical processes responsible for shaping the drop size distributions vary as a function of location. This is a subject of future study, as is linking the modes of variability to environmental parameters.

Program Managers
Shaima Nasiri
U.S. Department of Energy Office of Science, Office of Biological and Environmental Research
Climate and Environmental Sciences Division (SC-23.1)
Atmospheric System Research
shaima.nasiri@science.doe.gov

Sally McFarlane
U.S. Department of Energy Office of Science, Office of Biological and Environmental Research
Climate and Environmental Sciences Division (SC-23.1)
DOE Atmospheric Radiation Measurement User Facility
sally.mcfarlane@science.doe.gov

Principal Investigator
Brenda Dolan
Colorado State University
bdolan@atmos.colostate.edu

Funding
Datasets were provided by National Oceanic and Atmospheric Administration’s Earth Science Research Laboratory, U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) user facility, and Australia's Bureau of Meteorology. This work was supported by DOE’s, Office of Science, Office of Biological and Environmental Research, Atmospheric System Research program, the National Aeronautics and Space Administration (NASA) Precipitation Measurement Mission (PMM), and the NASA PMM Ground Validation program. The Python ARM Radar Toolkit was used in the analysis performed.

Publications
Dolan, B., B. Fuchs, S. A. Rutledge, E. A. Barnes, and E. J. Thompson. "Primary modes of global drop size distributions." Journal of the Atmospheric Sciences 75(5), 1453–76 (2018). [DOI:10.1175/JAS-D-17-0242.1]

Related Links

Atmospheric System Research highlight: Primary Modes of Global Drop-Size Distributions   

Topic Areas:

  • Research Area: Atmospheric System Research
  • Cross-Cutting: Scientific Computing and SciDAC
  • 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)