Relationship between Lightning, Precipitation, and Environmental
Characteristics at Mid-/high Latitudes from a GLM and GPM Perspective
- Lena Heuscher,
- Chuntao Liu,
- Patrick Gatlin,
- Walter A. Petersen
Abstract
This study applies new satellite datasets and methodologies to build on
previous research exploring the physical relationship between lightning
and precipitation in mid-/high latitudes. Specifically, three years of
Geostationary Lightning Mapper (GLM) and Global Precipitation
Measurement (GPM) Mission core satellite coincident observations are
examined to investigate relationships between lightning flash rate and
microwave characteristics of convective precipitation features (cPFs)
over the Americas and surrounding oceans between ± 50° latitude.
Mid-/high latitude cPFs with lightning are characterized by colder
temperatures of maximum 30 dBz echo top height and a smaller range of
microwave brightness temperatures when compared to the tropics.
Brightness temperature characteristics of electrically active cPFs are
highly correlated to radar-diagnosed ice mass and largely insensitive to
synoptic-scale proxies for convective strength and organization. Low
flash density cPFs tend to be more sensitive to synoptic-scale
instability and shear than high flash density cPFs. Regional differences
in the environmental forcing and characteristics of electrically active
cPFs are shown. For example, the elevated terrain surrounding the Amazon
River Basin is characterized by stronger vertical updrafts indicated by
higher values of normalized CAPE (NCAPE) while the La Plata River Basin
is characterized by both stronger updrafts and higher values of
radar-diagnosed ice water mass.