Doppler (HF) Radar Facility for Monitoring Dynamic Processes in Geospace

Doppler (HF) radar for probing the dynamics of the ionosphere (between 100 and 400 km altitude) is briefly described. Analysis of the observations of the dynamic processes in the atmosphere and geospace that accompany the dawn and dusk terminators, solar eclipses, geospace storms, and heavy rocket engine burns during solar cycle 24 (2009–2020) is presented. The basic parameters of the dynamic processes in geospace, which resulted from the terminators, solar eclipses, geospace storms, heavy-lift rocket engine burns, have been determined to vary over a wide range of scales. The dusk terminator effects are observed to occur during an
$\sim4-6-\mathbf{h}$
time interval when the Doppler shift,
$\boldsymbol{f}_{\boldsymbol{D}}$
, becomes negative,-(0.2-0.4) Hz, its amplitude,
$\boldsymbol{f}_{\boldsymbol{Da}}$
, increases to 0.3-0.5 Hz, and the period, T, to 20–25 min. Near the dawn terminator,
$\boldsymbol{f}_{\boldsymbol{D}}=\boldsymbol{\sim 0.3-}$
0.4 Hz, the amplitude attains 0.3-0.4 Hz, and
$\boldsymbol{T\approx 11-20}$
min, which persist for up to 6 h. The solar eclipse of March 20, 2015, was accompanied by an enhancement in wave activity
$\boldsymbol{(f_{Da\max}\approx 0.3}$
Hz,
$\boldsymbol{T\approx 12}$
min) against undisturbed values of
$\boldsymbol{f_{Da}\approx 0.1-0.2}$
Hz,
$\boldsymbol{T\approx 5-6}$
min. The ionospheric storms were also accompanied by an enhancement in wave activity:
$\boldsymbol{f_{Da}}$
, increased from 0.10-0.15 Hz to 0.15-0.25 Hz,
$T$
from 5–10 min to 12–20 min, and the relative amplitude,
$\boldsymbol{\delta}_{\boldsymbol{N}}$
, of disturbances in the electron density,
$\boldsymbol{N}$
, reached 0.10-0.15. Rocket launches excite waves with the following characteristics: the amplitude
$\boldsymbol{f_{Da}\approx}$
0.1-0.3 Hz, the period
$\boldsymbol{T\approx}$
5–20 min, and
$\boldsymbol{\delta}_{\boldsymbol{N}}\approx$
0.01-0.12.