H2Otown_WX Posted March 28, 2012 Share Posted March 28, 2012 Just looking for some clarification of confluence and diffluence..the definitions on wiki are kind of sketchy. Also, why does confluence tend to suppress cyclones? Link to comment Share on other sites More sharing options...
am19psu Posted March 28, 2012 Share Posted March 28, 2012 Confluence (diffluence) means streamlines - the path an air parcel takes through the atmosphere - are coming together (moving apart). Confluence by itself does not tend to suppress cyclones, but confluence is often a sign of convergence, which does. The unscientific way of explaining why confluence suppresses cyclones is that convergence aloft increases mass in the column and raises surface pressure, "blocking" the cyclone from gaining latitude. That's not exactly what happens, but it's close enough for the layperson. Link to comment Share on other sites More sharing options...
H2Otown_WX Posted March 28, 2012 Author Share Posted March 28, 2012 Confluence (diffluence) means streamlines - the path an air parcel takes through the atmosphere - are coming together (moving apart). Confluence by itself does not tend to suppress cyclones, but confluence is often a sign of convergence, which does. The unscientific way of explaining why confluence suppresses cyclones is that convergence aloft increases mass in the column and raises surface pressure, "blocking" the cyclone from gaining latitude. That's not exactly what happens, but it's close enough for the layperson. Duh, I knew that, lol. Thanks for the explanation though..you could go in some more depth, I am a met. student, believe it or not. Link to comment Share on other sites More sharing options...
H2Otown_WX Posted March 30, 2012 Author Share Posted March 30, 2012 Bump..LocoAko, where's my mathematical representation? Link to comment Share on other sites More sharing options...
LocoAko Posted April 1, 2012 Share Posted April 1, 2012 Bump..LocoAko, where's my mathematical representation? I just saw this. What were you looking for? I guess I'm a bit unsure of what you're unsure of. Could you be more specific? As for the difference between confluence/diffluence and convergence/divergence, this graphic from The Weather Prediction is good. Link to comment Share on other sites More sharing options...
heavy_wx Posted April 2, 2012 Share Posted April 2, 2012 It is useful to represent confluence and diffluence using the normal coordinate system, in which the axes are orthogonal to the streamlines. The axis parallel to the streamline is called S and the axis perpendicular is called N. Confluence can be expressed mathematically using these coordinates as CON = -V*(dA/dN), where dA/dN is the change in the angle of the wind and the S axis, with respect to N, and V is the wind magnitude. So having an increase in the angle as N increases means that the wind is spreading apart, which is diffluence. Since the confluence term ends up being negative as a whole according to the formula, we get negative confluence which is diffluence. Link to comment Share on other sites More sharing options...
GreatLakesWxMan Posted April 21, 2012 Share Posted April 21, 2012 Difluence and divergence are different mathematically in that divergence represents the change in area of a fluid parcel...while difluence will change the shape of an air parcel but not necessarily its area. This has obvious implications as to why, for example, a parcel's vorticity changes due to convergence/divergence. Link to comment Share on other sites More sharing options...
H2Otown_WX Posted May 21, 2012 Author Share Posted May 21, 2012 I just saw this. What were you looking for? I guess I'm a bit unsure of what you're unsure of. Could you be more specific? As for the difference between confluence/diffluence and convergence/divergence, this graphic from The Weather Prediction is good. This is way late, lol. I was looking for an equation more than diagrams..I've seen this on habyhints, good stuff. P.S. Congrats on your red tag! Link to comment Share on other sites More sharing options...
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