Value chain · CLM-1068
In plain terms
The 1979-80 heating experiments warmed the lower ionosphere's electrons by a factor of up to about two to two and a half. Theory predicted it would thin by up to half low down and thicken by up to a fifth higher up. The navigation and broadcast signals passing through showed nothing anyone could measure.
The claim as recorded
The April 1980 ionospheric session states the measurements the December 1980 sizing paper later summarised as "a factor of 2 or 3": Arecibo 430 MHz heating at SPS-scaled "~50 mW/cm2" gave "Te/Ti values of ~1.5 at 95 km"; D-region heating "peaked near Te/Ti = 2.5 +/- .5 at an altitude of 72 km"; HF heating at 5.1 MHz and scaled "~5 mW/cm2" gave "Te/Ti was found to be 2.1 +/- .5" near 75 km; Rice and Los Alamos reported "Electron-temperature increases of up to a factor of two were observed at 75-km altitude, in general agreement with current theoretical models" and "For the underdense heating, no short-scale plasma striations were detected at either E- or F-region heights"; theory (fluid and kinetic) "predict a factor of 2-3 increase in electron temperature" with "electron density decreases of up to 50 percent ... below 80 km and increases of up to 20% ... in the E-layer"; the 40 MHz experiment, "equivalent, after the frequency squared correction, to 225 W/M2 at the SPS frequency", gave "a measured electron temperature increase of 100 K - a 50% increase of the ambient 200 K temperature" with relaxation "about 4 msec at 100 km"; Platteville cross-modulation on 60 kHz to 5 MHz paths was "typically .01 to 0.1%", and OMEGA 11.8 kHz phase and amplitude at Brush, Colorado on 16 August 1979 were "3.82 +/- 1.54 us with the Facility ON and 5.82 +/- 1.45 us with it OFF" and "14.9 +/- 1.30 dB ... ON and 15.1 +/- 0.90 dB ... OFF", so "no change in the performance of VLF, LF, and MF systems that can be associated with operation of the Satellite Power System".
Evidence behind this: T3, five ionospheric-heating abstracts reporting measured electron heating, irregularity limits and telecommunication effects from 1979-80 experiments.
Scope and limits
Arecibo's HF facility was "only partially completed" and pulsed at 50 per cent duty; the OMEGA test is one day and one path; the F-region self-focusing threshold was not measured (Le-Cong's laboratory phase shift of "75 deg" is a bench analogue, PDF p.433 / printed 412).
What it assumes
The 1/f^2 ohmic scaling (CLM-1011) for the "SPS-equivalent" fluxes; Djuth's HF estimate "assumes a 100% radiating efficiency for the HF transmitter".
Where it comes from
PDF p.429 / printed 408, normalised: "power densities of ~ 1.5 mW/cm2 at the center of the radar beam (SPS frequency scaled ~ 50 mW/cm2) at 100 km altitude"; "Typically 100 K increases in electron temperature were observed yielding Te/Ti values of ~ 1.5 at 95 km altitude"; "values of Te/Ti for D-region heating that peaked near Te/Ti = 2.5 +/- .5 at an altitude of 72 km"; "SPS frequency-scaled power densities of ~ 5 mW/cm2 near the center of a 5.1 MHz beam at an altitude of 75 km"; "maximum heating was observed near 75 km altitude, where Te/Ti was found to be 2.1 +/- .5". PDF p.430 / printed 409: "An upper limit for heater-induced irregularities was experimentally set at 5% in amplitude for irregularities having spacial scale sizes greater than 5 km"; "an upper limit of 1 m2 has been set for the total scattering cross section". PDF p.428 / printed 407: the sentences quoted; "Density variations as large as 2% were observed within the irregularities" (nighttime underdense); "Radio scintillations at 430 MHz were easily detected in association with overdense ionospheric-heating striations, but no effect was seen at 1410 MHz". PDF p.426 / printed 405: conclusions (1) to (4) as quoted; "Platteville, operating at 5 MHz X-mode simulates or exceeds SPS effects over most of the D-layer"; PDF p.424 / printed 403: "the microwave absorption is almost one-half of the solar heating". PDF p.421 / printed 400: the 225 W/M2, 100 K, 4 msec and cross-modulation sentences; PDF p.422 / printed 401: "no effects have been observed that would indicate significant impact on telecommunications services". PDF p.139-140 / printed 116-117, render read: the OMEGA numbers (the page prints a plus-or-minus sign in all four places; the amplitude sentence runs over the page break) and "no change" sentence as quoted.
Basis: Te/Ti and K of electron heating; per cent density change; microseconds of OMEGA phase; per cent cross-modulation
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-1068
CLM-1068, Energy Aperture, as of 1980-04.
Connected records
Other published records linked to this one. A list, not a judgement.
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