Reading some of the Conspiratorial Cr*p on the gossip/fear mongering webpages, the HAARP thing is going to warm up the ionosphere by focussing the power from all those antennas (antennae?) - they look a lot like wire HF discones but with a central metal mast - but seeing as most of the atmosphere has gone by 60,000ft how do they warm up the odd few rare gas molecules? The ionospheric D region starts around 70km (210,000ft) and the F2 is way up at 400km (1,200,000ft) - there's not even gas up there - it's just free electrons. You may be able to re-ionise the upper layers with sufficient power and produce a reflective layer temporarily, but when you turn off the power, does the layer de-ionise and dissappear? Don't know, but it may be interesting to find out. One good thing from my point of view is that the transmitter is in Alaska, thats'a long way from here! (All data from my old RSGB handbook!)
Oh-oh - I see the conspiracy theorists now reckon that HAARP was responsible for the Christchurch NZ earthquake.....hmm....
Yes, the conspiracy stuff associated with HAARP is indeed interesting. I also like it how now any large antenna complex has taken on the name "HAARP" in certain circles.
The HAARP antennas are not discones, but rather enhanced dipoles, 4 per tower, two each for low and high band. The "enhanced" part is pretty simple, HAARP needs a broad bandwidth antenna, and one of the easiest ways to broaden the bandwidth of a dipole is to increase the diameter of the element in relationship to the wavelength. Make the dipole element bigger around, if you will. For example the "bird cage dipole" or "cage dipole".
As far as the altitudes for the different layers....if there is any heating associated, why assume it would be limited to one layer (although it might be larger in one area over another)? The RF would have to pass through everything on its way to a specific layer...shedding energy along the way (space loss). This would cause heating along the way, "burning" a path if you will.
Hmmmm...if that is the case then how much energy would go into heating the atmosphere before your quoted layers? To get to 70 km and assuming the lowest loss frequency HAARP operates at (about 2.8 MHz) space loss would take up 78 dB of the energy transmitted before the signal even got to that layer (10 MHz would have about 89 dB across the same 70 km path). Now, that means that by the time the 2.8 MHz signal got to 70 km altitude (assuming straight up and no path lengthening due to slant range) only a very small fraction of energy would be left, about 1/63097000. Or, if it launches with 3.6 million Watts, and it has 20 dB of gain at 2.8 MHz (it has 30 dB at 10 MHz, but as shown above the path loss is higher, so 2.8 MHz is the worse case), for an ERP at 2.8 MHz of 115.5 dBm (85.5 dBW), or about 360 million Watts, by the time it gets to 70 km altitude it is down to about 37.5 dBm (7.5 dBW). Or about 5.6 Watts, distributed more or less evenly across the area and depth of the entire illumination cell in the sky. I am not going to bother with that math, but it probably means you are getting a much higher power density, and more heating, in your head with your bluetooth device stuck in your ear. And, the other 359,999,994.4 Watts went into heating the lower atmosphere before it got to that altitude.
HAARP itself claims that the most intense regions of the upper atmosphere are on a power density level of less than 3 microwatts per square cm, and I would say that is somewhat optimistic under all but the most favorable conditions.
My math above was just some quick back of the envelope stuff (OK, really I did it on spreadsheet I had previously written for radar world applications on my iPad) and may have missed a few points, but should be pretty close in theory.
As far as the ionosphere returning to it's normal state after you turn the transmitter off, I would expect it would, but over time. Not just like flipping a switch. How much time that would take I can not even guess, but I would not be surprised if it was measure in hours. And I have no idea what the curve would look like.
T!
