Friday, January 11, 2013

Science Discussion: Our first event!

We saw our first event the other day on BARREL, and actually the first 4 now. They have all been small, but it's still something to look at , and who knows, maybe we'll still see something interesting with it.

We've also started to receive data from a few other sources which also saw some of the events and we thought it might be neat to have a science discussion on the blog. If you have other data to add, please feel free to contact me with it! If you have something quick to say, write a comment below. If it's longer, again, feel free to contact us!

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With that all taken care of, here is the day with our first events.

We saw a small spike ~0430 UT, a small longer duration event around ~0930 UT - 11:00 and another small longer duration event at ~2330 UT all on January 9th 2013.

The four light curves from BARREL created by Leslie at Dartmouth College

Leslie has graciously made a zoomed in plot of the 0430 UT event. It's tiny, but we see something out at the Van Allen Satellites as well. (See below). When we zoom in it looks like there is possibly a modulation of the precipitation. Leslie says "Look Mary- ULF modulations???" 

If we look to see where we were for the three events we have

The first event at 0430

The second event starting at ~930

The third event at ~2330

Carol Weaver from UNH who works with the Halley Bay magnetometer data contacted me almost immediately saying that they had observed something and could I please share it. (Sorry it's taken me a while to get this conversation started)

Here's the quick look data she sent me where we see a bursty wave ~0430UT and possibly some Pc3 or Pc4 waves during the first longer duration event.
The induction coil magnetometer, located in Halley Bay, shows bursty wave activity in the Pi1 range from about 0422 UT to 0450 UT.  The signal appears to have ducted through the ionospheric wave guide due to the location of the coils and balloons being separated by such a distance. -Carol 

and some nice spectrograms from GOES 13 which had a magnetic footprint close to I think 1D.

I also plotted GOES 13 magnetometer data (attached).  GOES 13 has a geomagnetic foot point near the balloon "that saw something" that is over land.  The bursty wave activity on GOES and when it begins at Halley occurs at nearly the same time.  Particles must be coming from at least geosynchronous orbit. -Carol

We have some great data from Joe Fennell from the MagEIS instrument showing a enhancement in the flux around the loss cone only in the lower energy bands, which are in the same band that we see the enhancements in! It's always nice when things agree. They can do so much more with their data than what shown here, but this is a quick look of what we might find once everything is processed. As Joe says, "It is clear that the 'loss cone region' is fairly empty at the higher energies" So I've tried to show where I think the loss cone may be in the plot (the black circles), but correct me if I'm wrong. I've also put lines around the time when we saw the first event at 1D and 1J.

If we look at some of the quick look data around the web:

First place to look... Was there any geophysical activity... Sort of. It looks like for the second event there was some auroral activity, possibly a substorm.

However there was nothing really in Dst. Xinlin Li provides a really nice prediction of the real time Dst, and as his plots scale, I've been looking at his lately to see if there is anything, anything at all.

Cluster quick look plots 

There is a lot of data available on line and this is just a smattering, but it looks like there is some interesting stuff.

Any comments/ additions? I'll add more as we go. Just think how excited we'll be once we get a much larger actual event involving relativistic precipitation!