Space Weather
1.Check this out: https://en.wikipedia.org/wiki/Geomagnetic_storm … …find me something on this Wikipedia page that is cool and important!
2.We ran into “magnetic reconnection” in several places. Where? And why is it important?
3.Are there any sunspots right now? How about Coronal holes??
4.Put these in order of lowest to highest energy per photon: Visible Light, Gamma Rays, Microwaves, Cosmic Ray, Ultraviolet, Infrared, X-raysPut these in order from sparsest to densest: thermosphere at 400 km, photosphere, air density in your parent’s basement, solar wind.
5.Check out this old Dst data. What’s it a measure of? What’s happening on 6 Nov.?
6.Where is the L1 Lagrange point (no, not the one near the moon!) relative to the magnetopause(e.g. ratio of distances from center of Earth)? Does this relationship ever change?
7.Archimedes was an old Greek dude. Trace the track a typical CME takes on its way here. (assume we are looking down onto the solar system from the “north”)
8.Once things are moving faster than about 10% light speed, we consider them relativistic. Approximately what minimum energy does an alpha particle need to be to be considered relativistic? How about an electron? Compare these energies to a “typical” cosmic rayas well as a “typical” SEP.
9.Earth’s magnetic field flips on occasion. How often? How quickly can it happen? Does the Sun’s magnetic field ever flip in a similar way?
10.How close will the Parker Solar probe eventually get to the “surface” of the sun (in units of solar radii)?
11.A CME and associated shockwave traveled to the outer solar system in the mid-1980s. Was there any good music in the 80s? Anywho, Voyager picked up a radio hiss(~2 to 3 kHz) when this packet hit interstellar wind (an indication that the CME had reached the heliopause?) about 13 months after it flopped out of the sun. Assuming it was traveling a wee bit faster than typical solar wind, how far away is the heliopause?
12.WIND (https://wind.nasa.gov/) data (solar wind stuff) is shown:What is being measured?What time(s) might you expect some geomagnetic storm activity here on Earth??
13.You’ve built a rocket in your parents’ basement that you’re sending to Mars. Where (if anywhere) should you launch from to avoid the Van Allen radiation belts on your trip?
14.An alpha particle in the solar wind approaches Earth. If it weren’t for our magnetic field, this particular beastie would be heading straight towards State College PA!! Thankfully, it is deflected… towards the East coast or the West coast??? Note: assume Vernal Equinox (basically a few days from now)
15.What isF 10.7 ? Why do we care? What frequency does it operate at? .
16.What parameter do we measure to define the strength of solar flares?
17.The Super-K facility seems neat! But I wonder why they built it so far underground? It’s located about 36 degrees North latitude; wait, what is its magnetic latitude? … Quite often it detects neutrinos from underneath itself! Whiskey Tango Foxtrot???
18.Consider differential rotation of our sun … how long does it take for the low latitudes to “lap” high latitude portions of the sun? Do we see SW effects on these time scales? Compare your answer to the 11-year solar cycle… btw, what was the Carrington rotation number when you were born?
19.What’s the ratio between typical solar wind speed and typical wind speed in a tornado?
20.The IMF sometimes points north, sometimes south… why does it change?21.SDO Image of sun. Where might you expect fast solar wind to be originating from? …Oh, and btw, what wavelength was this image taken at?
22.If you were tasked with putting a permanent solar observing station at L5 or L4, which would you choose, and why? btw, w here are the STEREO satellites right about now?
23.What wavelength does SDO’s Helioseismic and Magnetic Imager operate at? What does it measure, and why do we care?24.Why is Sansa important to understanding Space Weather? True, she is Queen in the Northand married to a Jonas brother, but that might simply all be a distraction…
25.What (if any) are the connections between these solar abnormalities: Prominences, Flares, Sunspots, and CMEs ?
Sample Solution
Space Weather
A geomagnetic storm (commonly referred to as solar storm) is a temporary disturbance of the Earth`s magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth`s magnetic field. A geomagnetic storm is defined by changes in the Dst (disturbance-storm time) index. The Dst index estimates the globally averaged change of the horizontal component of the Earth`s magnetic field at the magnetic equator based on measurements from a few magnetometer stations. Dst is computed once per hour and reported in near-real-time. During quiet times, Dst is between +20 and -20 nano-Tesla (nT). A geomagnetic storm has three phases: initial, main and recovery. The initial phase is characterized by Dst increasing by 20 to 50 nT in tens of minutes. The main phase is defined by Dst decreasing to less than -50 nT. The recovery phase is when Dst changes from its minimum value to its quiet time value.
