iL 7/ AIR MASS ANALYSIS 
Examples of Upper-Air Cross-Sections Showing Interpretations 
of the Tropopause, etc. 
GMT M1300 T.700 U7 L.6% J.8:8 K.700 S922 M700 
; 7m 
hl I -55" 55" kn 
Ypyy J 
ZL . O° —} 
Madrid Trappes Uccle Lindenberg Jeplonnan ae Sloutzk Moscow 
Fic. 1. Vertical cross-section from Madrid to Moscow, A.M. of Feb. 17, 
1935. Isotherms in °C, fronts and tropopauses heavy black lines; dashed lines 
for subsidence inversions (troposphere) and for indefinite tropopauses (being 
formed or dissolved). The overlapping of the multiple tropopauses is called 
for by the theory of Palmén, that the adiabatic cooling or heating from the 
pumping effect of passing disturbances and highs in the troposphere causes 
the tropopause to be destroyed at one level and reform at higher or lower 
levels as the case may be. Only a few soundings (vertical ordinates) were 
available for this analysis by Bjerknes and Palmén (Geofys. Publ., v. 12, no. 
2, 1987, p. 52) but experience from other cases analyzed permits the interpo- 
lations. The fronts are drawn double-lined, indicating top and bottom of the 
frontal zone of inversion or relative stability which is typical of soundings 
through fronts. 
The stratosphere is low and warm over the surface cold-air dome (“‘high’’) but high and 
cold over the surface low pressure. Note that the warm front connects with the tropopause in 
this case, but the cold air is shallow. The surface weather chart and streamlines of the tropical 
air flow in the warm sector above the friction layer and at the slopes of the fronts is shown in 
Fig. 2. Fig. 8 shows the tropopause and frontal at the same synoptic hour. 
TT 
V] 
if 
ZN 
es 
saual 
S (et tt OA 
Fic. 2. Fronts and warm-air streamlines, Feb. 17, 1935, 07h. he tropical 
air has been far to the north over the Atlantic and is returning into the 
cyclone as a NW wind descending over the cold front. 
