Divergence (meteorology)

Areas of convergence and divergence in the emergence of a hurricane in the Caribbean

When air masses sink towards the earth's surface and finally flow apart, one speaks of divergence . To compensate for this, air must flow in from higher layers, which in turn is replaced by air flowing together ( converging ) there . The air heats up as it sinks, which increases its water vapor capacity and consequently causes the cloud cover to dissolve . This process can be observed in the core of high pressure areas, which is why these also have a fair weather character.

The formula for the divergence is:

${\displaystyle \operatorname {div} {\vec {V}}_{2}={\frac {\partial u}{\partial x}}+{\frac {\partial v}{\partial y}}>0}$

With

• the divergence operator ${\displaystyle \operatorname {div} }$
• the Nabla operator ${\displaystyle \nabla }$
• the 2D wind vector ${\displaystyle {\vec {V}}_{2}}$
• the zonal wind component and ${\displaystyle u}$
• the meridional wind component . ${\displaystyle v}$

Divergences and convergences also arise in the area of ​​the extra-tropical west wind zone ( jet stream), when the jet stream forms Rossby waves , when flowing around obstacles (mountains) or as a result of speed differences due to different ground friction (e.g. over sea and land). You are responsible for creating dynamic pressure areas .

See also

• Ryd-Scherhag effect