A TRMM/GPM Retrieval of the Mean Generator Current for the Global Electric Circuit

M. J. Peterson, W. Deierling, C. Liu, D. Mach, C. Kalb

TRMM/GPM global mean current distirbution

Electrified weather across the globe powers the Global Electric Circuit (GEC) that regulates the electrical potential of the ionosphere. As it is impossible to measure the current provided by every electrified cloud directly, we use a retrieval algorithm to quantify this current from Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) satellite measurements. We then examine the variability of this generator current on time scales that range from one day to more than a decade.

We estimate that electrified weather provides an average current of 1.4 kA and 1.6 kA globally. Though current contributions can be found in land and ocean regions across the globe, large concentrations are found in the tropics near the equator and in the "tropical chimneys" of the Americas, Africa, and Asia. The greatest source of variability in the GEC generator current is on the semi‐annual time scale (110%) followed by local hour (58%), and universal time (34% ‐ Carnegie curve). The smallest variations are on the decadal (7.5%) and weekly (2%) time scales.

Peterson, M. J., W. Deierling, C. Liu, D. Mach, C. Kalb, 2017: A TRMM/GPM retrieval of the mean generator current for the Global Electric Circuit, J. Geophys. Res., 122, 27, 10,025-10,049.