This Thursday, I will be flying to Alaska. For this trip, I have three objectives. The ULF coils at Poker Flat are having the same type of noise as the ones in Ny-Alesund had this summer. We think it is probably the main sensor cable that was cut during brush clearing earlier this summer. I will also be changing out the data acquisition system. There is a specific type of aurora called pulsating aurora which pulsates around 7 Hz. We want to determine if there is a ground signature from the aurora. Our current DAQ samples at 10 Hz, which with a nyquist frequency means that events in the less than 5 Hz range will be observed. The new DAQ samples at 40 Hz, putting the nyquist at 20 Hz and the 7 Hz is well within observable parameters.
My next objective is to install an ELF system. The ULF coils (ultra low frequency) generally measure pulsations to only a few Hz. The ELF coil (extremely low frequency) will measure pulsations in the range of 10 - 250 hertz. I spent last week testing the coil and contending with the ever present 60 Hz. Hopefully when I am in a less electromagnetic saturated environment, I will be able to turn off the active 60 Hz filter and the noise it creates.
My last objective is to take images of the aurora. It will be the first time I have seen aurora. The sun appears pretty active right now with a coronal hole and two active regions. I am hoping to image a substorm. A substorm generally occurs when the magnetic tail of the earth is stretched to the point of "breaking" and the released energy and particles flow from the tail back towards the earth. The energetic particles will then interact with the ionosphere causing the aurora, roughly speaking.
I am excited to not be going alone this time. Two guys from Dartmouth College will also be at Poker repairing their instruments. It'll be good to have other people around.
I'll be updating as interesting things happen, or when interesting things should be happening, but aren't.