Hailstorms, effect of cloud seeding on, 
232 
Half-life, 267 
Halo phenomena, genetic features, 70 
schematic view, 69 
Halos, before rain, 1168 
Harmonic analysis, generalized, use in 
times-series prediction, 851 
Haze, 1179 
radiation by, 42 
Haze content, effect on downcoming 
radiation, 40 
Heat, radiation to space, 42 
Heat conduction, at cloud edges, 200 
in interior of cloud, 200 
Heat conductivity, of different ma- 
terials, 1116 
Heat exchange, at Earth’s surface, 50 
Heat flux, due to atmospheric turbu- 
lence, 536 
equation, 506 
Heat gain, of atmosphere, through con- 
vection, 1065 
Heat lightning, 141 
Heat loss, from ocean, through con- 
vection, 1064 
Heating, radiational, of stratosphere, 47 
Heating degree days, 983 
Height, absolute, 772 
relative, 772 
associated with transisobaric mo- 
tion, 783 
local changes associated with dia- 
batie processes, 784 
Heiligenschein, 71 
Helium, content of atmosphere, 5 
isotopic variation in atmosphere, 8 
Helium escape, problem of, 247 
Helmholtz instability, fluid motion and, 
468 
Helmholtz waves, 469 
Heterostatic circuit, for electrometers, 
Hoar crystals, 208 
Hobbs’ theory of glacial anticyclone, 
942, 943, 961 
Hochtroposhdre, 287 
Horizon, looming, 66 
sinking, 66 
Horse latitudes, air motion, 862 
Housing design, and applied climatology, 
982 
Hudson Bay, freeze-up, 959 
Human bioclimatology see Bioclimato- 
logy, human 
Humidity, and temperature patterns, 
small-scale, in free air, 318 
effect on condensation, 169 
effect on electrostatic charge of con- 
densation nuclei, 188 
effect on growth of condensation 
nuclei, 184 
effect on growth of various nuclei, 185 
in thunderstorm, 686 
at tropopause, 315 
measurement by aircraft, 1225 
measurement, future research, 319 
Humidity field, turbulent air flow, 
499 
Humphrey’s volcanic dust theory, 1015 
Hurricane rings, characteristics, 432 
Hurricane tide, 892 
Hurricane wave, 892 
Hurricanes, formation, 907 
see also Tropical cyclones, 
convection theory, 907 
frontal theory, 908 
hypothesis of Riehl, 909 
hypothesis of Sawyer, 909 
synoptic conditions during, 908 
frontal analyses, 866 
movement, 910 
recurvature, 911 
INDEX 
Hurricanes—continued 
movement—continued 
steering method, 910 
steering principle, 911 
radarscope photographs, 1275 
Hydration order, importance for mode 
of charging nuclei, 1133 
Hydraulic jumps, in atmosphere, early 
work on, 421 
Hydrodynamic equations, 404 
atmospheric flow, 454 
boundary conditions, 406 
physical, 403 
systems of, 403 
Hydrodynamic equilibrium, 446 
Hydrodynamic instability, 434 
and theory of atmospheric perturba- 
tions, 444 
as function of latitude, 438 
cyclogenesis in extratropical latitudes 
and, 442 
in lower latitudes, 440 
quadratic form of Kleinschmidt, 437 
Hydrogen, isotopic variation, in atmos- 
phere, 8 
Hydrogen content of atmosphere, 6 
Hydrogen lines, in spectrum of aurorae, 
351 
Hydrogen sulfide, atmospheric, deter- 
mining, 1127 
Hydrologic cycle, relation to meteor- 
ology, 1048 
schematic diagram, 1049 
Hydrology, design problems and, 1050 
evaporation factor, 1049 
fields, 1048 
precipitation factor, 1048 
relation to meteorology, 1048 
snow factor, 1050 
Hydrometeorology, depth-duration-area 
data, 1033 
empiricism and theory, 1034 
future of, 1045 
in United States, 1033 
moisture, equations of, 1037 
physical background, 1034 
precipitable water, 1035 
rainfall, nonorographic, 1039 
orographic, 1038 
recurrence interval, 1043 
seasonal distribution, 1043 
space distribution, 1042 
storage equation, 1037 
time distribution, 1042 
rainfall depth, 1033 
rainfall intensity, 1033 
rainfall probabilities, 1042 
rainfall volume, 1033 
research needed, 1046 
reservoirs, wind tides and waves, 1045 
scope, 1033 
snow melt, 1044 
special problems, 1042 
vertical motion, 1037 
water resources, estimating, 1045 
Hydrometeors, cold air-mass, forecast- 
ing, 789 
general, forecasting, 788 
warm air-mass, forecasting, 789 
Hygrometer, frost-point, design of, 312 
Hypsography, relative, 773 
geometrical extrapolation, 780 
prognosis by advective-adiabatic ex- 
trapolation, 782 
prognosis by nonadvective and dia- 
batic extrapolation, 784 
I 
Ice ages, climate during, 1004 
early, climate during, 1006 
Ice caps, polar, effect in climatic changes, 
1014 
1325 
Ice clouds, appearance of, 192 
growth, 197 
physics of, 192 
relation ie condensation mechanisms, 
9 
Ice conditions, effect on Grosswetter, 815 
Ice crystals, formation, 207 
by sublimation, 207 
physics, 177 
in cirrus clouds, 222 
size, aircraft measurement, 1229 
Ice fogs, 193, 1183 
Ice nuclei, behavior of, 192 
concentration, 224 
effect of expansion-chamber experi- 
ments on, 193 
effect of temperature on, 192 
foreign-particle, temperature depend- 
ence, 224 
in high-level clouds, 196 
in medium-level clouds, 196 
in upper troposphere, 193 
spectrum, 193 
Ice particles, charging, 1134 
collision, 116 
Ice phase, development in clouds, 194 
Ice splinters, rate of formation, 195 
Icing, aircraft see Aircraft icing 
-rate meter, 1227 
Idiostatic circuit, for electrometers, 144 
Impact-chemistry, 262 
Index cycle, 560, 561 
circulation patterns, 560 
primary, 561 
variations, 561 
winter’s primary, 561 
Indian summer anticyclones, 626 
Industry, and microclimatology, 1001 
Infrared absorption, pressure effects on, 
298 
Infrared light, 265 
Infrared spectra, of ozone, 296 
Insects, exchange between earth and 
atmosphere, 1107 
Instability, dynamic, 584 
centrifugal, 467 
energy, 436 
gravitational, 467 
hydrodynamic, 434 
Instability lines, 647; see also Squall lines 
and airline operations, 647 
and cyclonic wind shear, 649 
and pressure gradient, 649 
and pseudo-cold front, 650 
and thunderstorms, 689 
and tornadoes, 647, 651 
associated physical factors, 648 
cyclone with, 648 
general features, 647 
physical processes, 650 
future research needed, 652 
recent studies, 651 
synoptic aspects, 648 
Thunderstorm Project, 652 
Instruments see Meteorological instru- 
ments 
Insulation, wood, use in lightning pro- 
tection, 142 
Insulator, open-air, 145 
Inversion, compression waves under, 425 
expansion waves under, 425 
flow, time-dependent under an, 424 
flow under, 424 
height, transmission of energy by 
means of finite disturbances in, 
429 
simple waves under, 425 
steady-state flow equations under, 430 
lodine, atmospheric, 1128 
effect on condensation nuclei forma 
tion, 186 
Jon-capture, 116 
Ton clouds, 255 
