Shortwave radio

Shortwave radio is radio transmission using shortwave frequencies, generally 1.6–30 MHz (187.4–10.0 m), just above the medium wave AM broadcast band.

Shortwave radio is used for long distance communication by means of skywave or skip propagation, in which the radio waves are reflected or refracted back to Earth from the ionosphere, allowing communication around the curve of the Earth. Shortwave radio is used for broadcasting of voice and music, and long-distance communication to ships and aircraft, or to remote areas out of reach of wired communication or other radio services. Additionally, it is used for two-way international communication by amateur radio enthusiasts for hobby, educational and emergency purposes.

Frequency classifications

The widest popular definition of the shortwave frequency interval is the ITU Region 1 (EU+Africa+Russia...) definition, and is the span 1.6–30 MHz, just above the medium wave band, which ends approximately at 1.6 MHz.

There are also other definitions of the shortwave frequency interval:

Shortwave (disambiguation)

Shartwave can refer to:

Shortwave (meteorology)

A shortwave or shortwave trough is an embedded kink in the trough / ridge pattern. Its length scale is much smaller than that of longwaves, which are responsible for synoptic scale systems, although shortwaves may be contained within or found ahead of longwaves and range from the mesoscale to the synoptic scale. Shortwaves are most frequently caused by either a cold pool or an upper level front.

Corresponding weather and effects

Shortwaves are often associated with warm (WAA) or cold air advection (CAA), which influence temperature. Due to the way they curve the air that moves around them and the way air moves away from them, shortwaves produce positive curvature vorticity and positive shear vorticity, respectively. Ahead of a shortwave there is large-scale lift due to divergence from positive vorticity advection (PVA). This lift often sparks precipitation. In a capped environment, the lift generated by a shortwave may cool the inversion layer through adiabatic cooling, allowing for deep, moist convection.