A global electric circuit model within a community climate model

Abstract

To determine the complex dependencies of currents and electric fields within the Global Electric Circuit (GEC) on the underlying physics of the atmosphere, a new modeling framework of the GEC has been developed for use within global circulation models. Specifically, the Community Earth System Modeling framework has been utilized. A formulation of atmospheric conductivity based on ion production and loss mechanisms (including galactic cosmic rays, radon, clouds, and aerosols), conduction current sources, and ionospheric potential changes due to the influence of external current systems are included. This paper presents a full description of the calculation of the electric fields and currents within the model, which now includes several advancements to GEC modeling as it incorporates many processes calculated individually in previous articles into a consistent modeling framework. This framework uniquely incorporates effects from the troposphere up to the ionosphere within a single GEC model. The incorporation of a magnetospheric potential, which is generated by a separate magnetospheric current system, acts to modulate or enhance the surface level electric fields at high‐latitude locations. This produces a distinct phasing signature with the GEC potential that is shown to depend on the observation location around the globe. Lastly, the model output for Vostok and Concordia, two high‐latitude locations, is shown to agree with the observational data obtained at these sites over the same time period.

Toward a Realistic Representation of Global Electric Circuit Generators in Models of Atmospheric Dynamics

“…To summarize, neither of the existing attempts to simulate the diurnal variation of the GEC using a climate or weather forecasting model has succeeded in obtaining a realistic peak‐to‐peak amplitude (cf. Mareev & Volodin, , Figure 1a; Lucas et al, , Figure 7; Jánský et al, , Figure 3a). Our analysis has shown that when parameterizing the IP, it is important to take into account both convective activity (CAPE) and the area covered by electrified clouds (which can be inferred from the amount of precipitation), but neither of various reasonable alterations of our basic IP parameterization is able to significantly improve the agreement in magnitude between the simulated IP variation and the classical Carnegie curve.…”

A TRMM/GPM retrieval of the total mean generator current for the global electric circuit

“…RMS errors for the proxies from the literature range from 20% [ Whipple , ] to 3.3% [ Liu et al , : thunderstorm rainfall] while maximum differences range from 33% to 6.4%. Global currents used by the Frontiers in Earth System Dynamics (FESD) Electrical Connections and Consequences within the Earth System (ECCWES) project [ Kalb et al , ; Lucas et al , ] have RMS difference between 6 and 7% and maximum differences around 10%.…”

“…The GEC establishes a potential difference between the ionosphere and the surface of around 240 kV [ Adlerman and Williams , ; Markson , ]. It has received considerable attention in the past decade [review: Williams , ; Williams and Mareev , ] due in part to its potential for monitoring climate [ Williams , ] and the need to represent the planet's electrical subsystem in Earth system models [ Lucas et al , ]. Moreover, recent advances in observations make it possible to address longstanding questions on what kinds of electrified weather contribute to the GEC, how these contributions are distributed around the globe, and what factors account for its variability.…”

Parameterizing total storm conduction currents in the Community Earth System Model

“…Lucas et al . [] used a more simplified version of the convective mass flux parameterization derived in this paper by computing the currents at each time step. They found that the modeled electric fields agreed well with observed diurnal variations over two Antarctic sites.…”