资源环境科技发展态势分析平台

We propose a new method that uses the World-Wide Lightning Location Network (WWLLN) to estimate both the local and the drift lightning power density at the Van Allen Probes footprints during 4.3 years (similar to 2 x 10(8) strokes.). The ratio of the drift power density to the local power density defines a time-resolved WWLLN-based model of lightning-generated wave (LGW) power density ratio, R-WWLLN. R-WWLLN is computed every similar to 34 s. This ratio multiplied by the time-resolved LGW intensity measured by the Probes allows direct computation of pitch angle diffusion coefficients used in radiation belt codes. Statistical analysis shows the median power density ratio is (R) over cap (WWLLN) = 0.3-4 over the Americas. Elsewhere, (R) over cap (WWLLN)> 1 in general. Over oceans, (R) over cap (WWLLN) is larger than similar to 10. (R) over cap (WWLLN) varies with season, (R) over cap (WWLLN) similar to 2.5 from winter to summer. The yearly-median (R) over cap (WWLLN) decays as (R) over cap (similar to)(WWLLN)9.9/L-0.91. The strong geographical and temporal variation should be kept in assessing effects in space. (R) over cap (WWLLN) > 1 suggests significant LGW effects in the inner belt.

Plain Language Summary Lightning flashes strongly emit electromagnetic lightning-generated waves (LGW). This radiation propagates inside the Earth-Ionosphere waveguide and escapes into the magnetosphere. Trapped electrons originating from solar eruptions bounce and drift around Earth magnetic field lines. They can be scattered into the atmosphere by any resonant interactions with surrounding LGW that causes diffusion of the electron velocity. Computing accurately the electron diffusion is critical for space weather. This diffusion is proportional to the LGW drift intensity, that is, the LGW intensity affecting the electron along its drift around the Earth, which is not directly measurable since many satellites would be required. Here, we propose a new method that uses the ground-based World-Wide Lightning Location Network (WWLLN) to estimate both the local and the drift lightning power density at the Van Allen Probes (RBSP) footprints. Their ratio defines a time-resolved WWLLN-based LGW power density ratio, R-WWLLN, which multiplied by the local LGW intensity measured by RBSP allows direct computation of LGW diffusion required in space weather codes. Statistical maps of power density and ratios are discussed. We conclude that the large geographical and seasonal variability is important to keep in assessing effects in space and that R-WWLLN > 1 suggests significant LGW effects in the inner belt.