9. Nocturnal Thunderstorms: Midnight Blue Illuminations
Some of the most impressive shows of blue lightning come from nighttime thunderstorms. A mesmerising show results from the more noticeable contrast between the night sky and the electric blue flashes as darkness descends. Especially at the lower altitudes, the atmosphere typically stabilises and gets drier over night. This variation in atmospheric conditions can cause elevated thunderstorms to develop whereby the main storm activity takes place higher in the atmosphere. Often travelling through drier air, the lightning in these higher storms makes the blue wavelengths more apparent. The cooler nighttime temperatures also help to produce this effect since colder air is usually drier and lets light go farther without spreading. Nightfall blue lightning can seem to light the whole sky for onlookers, producing fleeting periods when the terrain is covered in an alien blue glow. With blue lightning acting as a fundamental signal of atmospheric conditions, meteorologists and atmospheric scientists research nocturnal thunderstorms to better understand how the diurnal cycle affects storm dynamics and lightning generation.