Tropical cyclones—continued 
observations, 902 
origin, 894 
precipitation, 890 
pumping, 888 
radar bands, 891, 1275 
rain area, dynamical aspects, 905 
heat transfer, 906 
microstructure, 905 
thermal structure, 904 
upper outflow, 907 
wind distribution near surface, 906 
region of origin, 895 
research needed, 900 
schematic development of swells, 899 
season of origin, 895 
steering currents, 898 
storm swell significance, 899 
storm tide significance, 900 
surface characteristics, 887 
surface indications, 896 
temperature, 889 
theories of formation, 907 
thunderstorms, 892 
tornadoes, 892 
tropopause heights, 893 
upper-air indications, 897 
vertical structure, theory, 892, 904 
wind circulation, 889 
Tropical meteorology, 859 
see also Equatorial meteorology 
air-mass method, 859, 863 
achievements, 873 
analysis methods, 859 
climatological analysis method, 859 
climatological method, 859, 860 
achievements, 872 
tropical storms and, 862 
convergence lines, 874 
cumulus base height, 861 
direct circulation cell, 871 
easterly wave, 868 
equatorial front, 865 
Freeman waves, 870 
frontal surface, 865 
frontal theory, 866 
modifications, 867 
perturbation method, 859, 868 
achievements, 875 
polar trough, 869 
surface air temperature, 860 
temperature discontinuities, 868 
wind persistence, 860 
Tropics, weather observation, 709 
Tropopause, humidity in, 315 
Troposphere, anticyclone in, water vapor 
structure, 316 
chemistry and, 262 
intrusion of moist air tongues into dry 
air, 317 
normal circulation, 553 
ozone conditions, 286 
sound waves through, 371 
subsiding polar air, 315 
upper, jet stream, 604 
vertical distribution of ozone, 7 
water-vapor distribution, 315 
droushs intensitying, flow pattern in, 
temperature pattern in, 458 
Trough formula, Rossby’s, 415 
Trough motion, atmospheric, 563 
Tundra, 953 
maritime, 957 
Turbidity coefficient, correlation be- 
tween maximum polarization 
and, 84 
Turbulence, and diffusion, 492 
aerodynamical background, 492 
boundary layer, 492 
eddy diffusion, 501 
flow near a boundary, 493 
heat transfer, 499, 502 
influence of density gradient on na- 
ture of flow, 506 
INDEX 
Turbulence—continued 
in the general circulation, 502 
Kolmogoroff’s theory, 497 
laminar flow, 492 
large-scale processes, 500 
macroviscosity, 496 
mathematical treatment, 493 
microscale of turbulence, 497 
mixing-length hypothesis, 494 
momentum transfer, 499 
momentum-transport theory, 496 
nature of, 492 
physical features, 498 
humidity field, 499 
temperature field, 498 
velocity field, 498 
power-law profile, 496 
Reynolds stresses, 493 
scale, 497 
small-scale diffusion processes, 503 
statistical theories of, 496 
velocity profile, near a boundary, 495 
near rough surface, 495 
near smooth surface, 495 
vorticity-transport hypothesis, 496 
water-vapor transfer, 499 
Twilight, polarization anomalies during, 
87 
Twilight arch, 73 
Twilight phenomena, 72 
description, 73 
problems, 74 
results of observations, 73 
schematic view, 73 
theories, 74 
Typhoon see Tropical cyclones 
U 
Ultraviolet, solar energy in, 295 
Ultraviolet absorption, temperatures 
based on, 305 
Ultraviolet daylight integrator, for 
measuring atmospheric pollu- 
tion, 1140 
Ultraviolet intensity, sun and sky, 1119 
Ultraviolet radiation, effect of cloudiness 
on, 1119 
solar, effect on upper atmospheric 
gases, 248 
Ultraviolet spectrum, use in studying 
upper atmosphere, 251 
Umkehr curves, 277 
Umkehr effect, 276 
Unifilar electrometer, 144 
Wulf’s, 145 
Upper atmosphere, 245 
absorbing constituents, amounts, 272 
absorbing layers, heights, 271 
anticyclonic shear, 585 
aurorae, 255 
balloon studies, 303 
composition, 7, 251 
absorption-spectral evidence regard- 
ing, 270 
emission-spectral evidence regard- 
ing, 271 
constituents, 270 
diffusion in, 320 
diffusive separation, 256 
dissociation of atomic particles, 268 
emitting constituents, amounts of, 272 
emitting layers, heights of, 271 
extreme ultraviolet radiation, 256 
fast-charged particles in, 255 
illumination by solar rays, 248 
ionization, 254 
meteoric, 257 
atomic particles, 268 
luminescence, 254 
meteor use in research in, 356 
molecular escape, 247 
night-sky radiations from, 341 
origin of structure, 245 
ozone, 275 
amount, 278 
1333 
Upper atmosphere—continued 
ozone—continued 
and constitution of, 287 
vertical distribution, 280 
ozone heating, 305 
phenomena, 245 
photochemical processes, 262 
physical features, 249 
physics, general aspects of, 245 
pressures, 303 
radio exploration, 254 
reactions, 270 
rocket measurements, 306 
solar control, 247 
sound propagation through, 304 
study of meteors, 253 
studying, by V-2 rocket, 250 
direct methods, 250 
indirect methods, 251 
sunrise in, 248 
temperature distribution, 252 
temperatures, 303 
unsolved problems, 256 
water vapor in, 311 
weather and, 256 
winds, 255, 358 
Upper-air analysis, 717 
Upper-air maps, prognosis of, 780 
Uranus, atmosphere, 394 
meteorological parameters, 392 
Vv 
V-2 rockets, use in determining ozone 
distribution, 278 
use in studying upper atmosphere, 250 
Vacuum tube electrometers, use in meas- 
uring atmospheric electricity, 
144 
Vanishing constant, 148 
Venus, atmosphere, 391 
research needed, 397 
meteorological parameters, 392 
Vertical current, atmospheric, measure- 
ment, 149 
recorder, 149 
Vertical-overturning instability, gener- 
alized, 468 
Vertical velocity, large-scale, and diver- 
gence, 639 
adiabatic method of computing, 640 
as a forecast tool, 645 
direct measurement of, 640 
distribution of, 641 
theoretical explanation, 642 
effects of, 648 
advection of temperature, 644 
advection of velocity, 643 
changes in cloudiness, 644 
pressure changes, 644 
influence of seale on, 639 
kinematic method of determining, 640 
Virga, appearance of, 192 
Visibility, in meteorology, 91 
research needed, 95 
Visual range, calculation, 93 
in practice, 95 
instruments for measuring, 94 
Volcanic dust, effect on skylight pol- 
arization, 79 
role in climatic changes, 1015 
Volcanic eruptions, effect on Grosswetter, 
815 
Vortex, circular, atmospheric flow and, 
455 
permanent circular, application to 
tropical cyclones, 448 
thermometer, 1224 
Vorticity, absolute, for mean zonal flow, 
461 
isolines for vertical component of, 
460, 
analysis of extratropical cyclones, 582 
conservation, 461 
equation, 458 
