Resumen
We study the modulation of atmospheric nonisothermality and wind shears on the propagation of seismic tsunami-excited gravity waves by virtue of the vertical wavenumber, m (with its imaginary and real parts, ????
m
i
and ????
m
r
, respectively), within a correlated characteristic range of tsunami wave periods in tens of minutes. A generalized dispersion relation of inertio-acoustic-gravity (IAG) waves is obtained by relaxing constraints on Hines? idealized locally-isothermal, shear-free and rotation-free model to accommodate a realistic atmosphere featured by altitude-dependent nonisothermality (up to 100 K/km) and wind shears (up to 100 m/s per km). The obtained solutions recover all of the known wave modes below the 200-km altitude where dissipative terms are assumed negligible. Results include: (1) nonisothermality and wind shears divide the atmosphere into a sandwich-like structure of five layers within the 200-km altitude in view of the wave growth in amplitudes: Layer I (0?18) km, Layer II (18?87) km, Layer III (87?125) km, Layer IV (125?175) km and Layer V (175?200) km; (2) in Layers I, III and V, the magnitude of ????
m
i
is smaller than Hines? imaginary vertical wavenumber (??????
m
i
H
), referring to an attenuated growth in the amplitudes of upward propagating waves; on the contrary, in Layers II and IV, the magnitude of ????
m
i
is larger than that of ??????
m
i
H
, providing a pumped growth from Hines? model; (3) nonisothermality and wind shears enhance ????
m
r
substantially at an ~100-km altitude for a tsunami wave period ??????
T
t
s
longer than 30 min. While Hines? model provides that the maximal value of ??2??
m
r
2
is ~0.05 (1/km2
2
), this magnitude is doubled by the nonisothermal effect and quadrupled by the joint nonisothermal and wind shear effect. The modulations are weaker at altitudes outside 80?140-km heights; (4) nonisothermality and wind shears expand the definition of the observation-defined ?damping factor?, ß: relative to Hines? classical wave growth with ??=0
ß
=
0
, waves are ?damped? from Hines? result if ??>0
ß
>
0
and ?pumped? if ??<0
ß
<
0
. The polarization of ß is determined by the angle ? between the wind velocity and wave vector.