Airstream Boundaries vs. Fronts: A Comparison

Robert Cohen
East Stroudsburg University
East Stroudsburg, PA

David Schultz
NOAA/National Severe Storms Laboratory
Norman, OK

In this talk, I will compare the structure of cyclones in terms of the airstream boundaries and fronts. Fronts are usually defined as sharp boundaries in the density of air masses (typically revealed in temperature contrasts) although in regions where the temperature boundary is not distinct, some analyses use moisture (moist potential temperature, usually) or winds (wind shear or pressure trough, usually). Airstream boundaries, on the other hand, are strictly defined on contrasts in air mass source region. An analysis of various parts of the cyclone (e.g., surface cold front, upper cold front, warm front, bent-back warm front, trowal, occluded front, trop fold, etc.) will be examined to distinguish between the two analysis techniques. If time allows, I will also discuss the question of which came first: the airstream boundary or the front? In other words, does the front form an airstream boundary or visa-versa?