Solar Observations in Bulgaria

Jet streams are fast flowing, narrow air currents found at the tropopause, the transition between the troposphere (where temperature decreases with height) and the stratosphere (where temperature increases with height),[1] and are located at 10-15 kilometers above the surface of the Earth. They form near boundaries of adjacent air masses with significant differences in temperature, such as the polar region and the warmer air to the south.[2] The path of the jet typically has a meandering shape, and these meanders are one manifestation of Rossby waves. Rossby waves propagate westward with respect to the flow in which they are embedded, which translates to a slower eastward migration across the globe than smaller scale short wave troughs. The major jet streams are westerly winds (flowing west to east) in the Northern Hemisphere. During the summer, easterly jets can form in tropical regions, typically in a region where dry air encounters more humid air at high altitudes. Low level jets can form wherever low level winds are squeezed.

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