e/Positive vorticity advection

Information
has gloss	eng: Positive vorticity advection, or PVA, is the result of more cyclonic values of vorticity advecting into lower values of vorticity. It is more generally referred to as "Cyclonic Vorticity Advection" (CVA). In the Northern Hemisphere this is positive, whilst in the Southern Hemisphere it is negative.
lexicalization	eng: Positive vorticity advection
instance of	e/Atmospheric physics