Remote Sensing of Electric Fields Observed Within Winter Precipitation During the 2020 Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) Field Campaign

Journal Article · 16 August 2021 · Journal of Geophysical Research: Atmospheres

DOI: https://doi.org/10.1029/2021jd034704 · OSTI ID:1812361

Schultz, Christopher J.  ^[1]; Harkema, Sebastian S. ^[2]; Mach, Douglas M.  ^[3]; Bateman, Monte  ^[2]; Lang, Timothy J.  ^[1]; Heymsfield, Gerald M.  ^[4]; McLinden, Matthew L. ^[4]; Li, Lihua ^[4]; Poellot, Michael ^[5]; Sand, Kendra ^[5]

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1. NASA Marshall Space Flight Center (MSFC), Huntsville, AL (United States)
2. Univ. of Alabama, Huntsville, AL (United States)
3. Science and Technology Inst. Universities Space Research Association, Huntsville, AL (United States)
4. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
5. Univ. of North Dakota, Grand Forks, ND (United States)

Aircraft electric fields from NASA's Lightning Instrument Package (LIP) were coupled with other airborne and ground-based, and in situ measurements to understand electrification in winter clouds that did not produce lightning. The measurements were made during seven research flights by a NASA ER-2 during the 2020 Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) campaign. Observed total electric field magnitudes were as high as 80 V m^-1 and variability in the electric field was observed along the flight path of the ER-2, indicating horizontal and/or vertical inhomogeneity in the cloud's electrical structure. X-band airborne radar data indicated 20-dBZ echo tops above 5 km in regions where electrification exceeded 10 V m^-1. In these regions, 85-GHz brightness temperatures (TB) from an airborne radiometer were lower than 265 K, with the lowest T_B (~210 K) associated with ice scattering collocated with the strongest electric fields. In situ microphysical measurements from the NASA P-3 aircraft on February 7 indicated that regions near strong electric field contained supercooled water, rimed ice hydrometeors, ice water p- content as high as 1 g m^-3, liquid water content as high as 0.15 g m^-3, and supersaturation as high as 3.5%. Furthermore, these observations support the role of mixed phase microphysics in the generation of electric fields in clouds. In three case studies, ground based S-band polarimetric radar observed depolarization streaks in differential reflectivity near areas where the strongest electrification was observed. This observation reinforces the utility of depolarization streaks to identify areas of electrification prior to lightning occurrence.

• Research Organization: ARM Data Center, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: National Aeronautic and Space Administration (NASA); USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 1812361
• Journal Information: Journal of Geophysical Research: Atmospheres, Journal Name: Journal of Geophysical Research: Atmospheres Journal Issue: 16 Vol. 126; ISSN 2169-897X
• Publisher: American Geophysical UnionCopyright Statement
• Country of Publication: United States
• Language: English