Radio atmospheric a distance where luminosity is visible and thunder can be heard (typically about 10 km), these electromagnetic impulses are the only sources of direct information about thunderstorm activity on the ground. Transients electric currents during return strokes (R strokes) or intracloud strokes (K strokes) are the main sources for the generation of impulse-type electromagnetic radiation known as sferics (sometimes called atmospherics). While this impulsive radiation dominates at frequencies less than about 100 kHz, (loosely called long waves), a continuous noise component becomes increasingly important at higher frequencies. The longwave electromagnetic propagation of sferics takes place within the Earth-ionosphere waveguide between
Atmospheric Circulation Reconstructions over the Earth and for teaching. The 20CR dataset has already been utilized in several significant research projects, CLIWOC's efforts culminated in the creation of this historical document, namely "A Dictionary of Nautical Meteorological Terms: CLIWOC Multilingual Dictionary of Meteorological Terms; An English/Spanish/French/Dutch Dictionary of Windforce Terms Used by Mariners from 1750 to 1850". Atmospheric Circulation Reconstructions over the Earth The Atmospheric Circulation Reconstructions over the Earth, ACRE, is an international science project, began in 2008, that recovers historical weather observations to reconstruct past global and local weather patterns and so support meteorological reanalysis. The project aims to collect weather data from the