Quick Q About Systems

[sammie]

Large scale synopic systems exist in geostrophic ballence, but smaller mesoscale systems exist in cyclostrophic ballence. What is the major diffrences between the two?

And is a Meso-low and Meso-cyclone interchangable terms or are they diffrent things?

[J07]

Cyclostrophic balance is a balance between centrifugal and pressure gradient forces. There is no coriolis force.

Geostrophic balance is a balance between coriolis and pressure gradience forces. There is no curvature of the pressure field.

Geostrophic balance is usually ruined at the surface by friction (which is the prime ageostrophic component of the wind), but in the upper atmosphere it works pretty well. In fact, I believe NWP models themselves tend towards geostrophic balance above the surface.

The reason small scale systems such as tornadoes can be approximated to cyclostrophic balance is that they exist on such a small scale that the rotation of the earth can be neglected- hence no coriolis force.

If you add coriolis force into the cyclostrophic formulation you have the gradient wind- which basically is also geostrophy with curved isobars. The solutions to this are slightly more complicated and allows for "anomalous" highs and lows, which are mathematically allowed solutions that do not exist in reality.

Hope I've not made any catastrophic errors in the above- not had breakfast yet :lol:

[sammie]

Thank you very much! Missed the damn lecture on this *headdesk* I just know its going to come up in the exam (sods law ain't it?) Thank you very much again <3