New evidence for the brightness and ionization of blue starters and blue jets

Blue jets and blue starters are partially ionized luminous cones of primari ly blue light that propagate upward out of the top of thunderstorms at spee ds of order 100 km s(-1). Blue jets propagate up similar to 40 km, but blue starters, which resemble blue jets, terminate abruptly after only a few ki lometers of upward travel. Theories on the origin of blue jets have propose d that they are due to either positive or negative streamers or runaway ele ctrons. Quantitative analysis of new multi-instrument observations of a blu e starter from an aircraft during the Energetics of Upper Atmospheric Excit ation by Lightning, 1998 (EXL98) campaign of July 1998, shows that the ioni zation accounts for similar to3 % of the observed intensity. Quantitative a nalysis of a remarkable color photograph of a blue jet taken from Reunion I sland in the Indian Ocean shows that the minimum optical energy deposition was similar to0.5 MJ. The same photograph shows details of streamers never before seen.