Background:
Today’s weather forecasts are based on modeling mathematical quantities that affect the weather, in other words, taking measurements and using those measurements to infer tomorrow’s or next week’s weather. If you looked to the sky right now, you would be able to predict the weather, although your prediction would be limited to a short term prediction that would be accurate only for your immediate location. Around the world are thousands of stations taking ground and air data, and by compiling these readings, we can predict weather world-wide with reasonable accuracy.
Important things to know at a weather station might be temperature, wind speed and direction, barometric pressure and it’s upward or downward trend, humidity (or dew point) and even the date and season. Space weather is analogous since we take measurements and attempt to reasonably predict what is going to happen.

Space weather involves carefully observing three things:

• What’s happening at the Sun
  
• What’s happening between the Sun and Earth
  
• What is or will be happening on Earth as a result
  
  

Consider the following images:

Since you probably are not familiar with how we measure important space weather quantities, here is a brief, down-to-Earth explanation:

• We observe what’s happening on the Sun with ground and space based observation platforms like ACE (the Advanced Composition Explorer) and SOHO.
  
  

• Solar wind density measures the amount of stuff (particles) moving toward Earth per unit volume (similar to air pressure).
  
  
• Solar wind speed is how fast this stuff is moving. Technically, it is the average bulk speed of the solar wind. (similar to wind speed on Earth).
  
  
• Interplanetary Magnetic Field Magnitude and Angle tells us how much magnetic force is produced. Technically, it is the strength of the interplanetary magnetic field as measured by ACE.
  
  

• Voltage across the polar cap / convection potential tells us the amount that the solar wind affects our own magnetic field. This is what has most to do with understand effects on Earth. Technically this quantity measures the solar wind energy input to the magnetosphere. It shows itself as an electric potential appearing across the upper atmosphere at the poles. The quantity shown here is an estimate of the convection potential based on ACE/SWEPAM and ACE/MAG measurements.
  

Relevant links:

• http://www.srl.caltech.edu/ACE/ASC/browse/view_browse_data.html
  
• http://space.rice.edu/ISTP/dials.html
  

Procedure:

ALSO: Please separate investigations so that each is individually accessible, but one can move freely from one to the other.
Investigation 1 - How fast is fast?
This exercise requires a simple understanding of velocity and computing conversions/ratios.
It may be most convenient to print out this portion of the investigation since you will be going to different internet sites.
1. Look up, or indicate from memory, the speed of light in km/sec. __________________

2. Calculate the amount of time it takes light to travel from the Sun to the Earth (use the distance from Sun to Earth as 150 million km.):



YOUR ANSWER: _________________________

Examine the process for a moment: Events occur in the Sun (Fusion), these events caused particles and radiation to be emitted into space at a certain velocity, and if headed toward Earth, the light and other electromagnetic radiation arrives here approximately ____________(how long?) later.

3. Particles travel more slowly - for one thing, they have mass, therefore inertia.
ACE measures how fast many particles travel in space.

• Go to http://www.srl.caltech.edu/ACE/ASC/view_browse_data.html
  
• Click on “ACE fixed browse data plots.” in the middle of the page.
  
• You have arrived at the ACE browse data page. At the very top right of the page, click on “SWEPAM”. SWEPAM stands for Solar Wind Electron Proton Alpha Monitor. It monitors and provides detailed information about the solar wind on a real time basis.
  
• Scroll down the page to the fifth graph entitled: “ACE/SWEPAM Solar Wind Proton Speed” (hourly averages)
  
• Let’s take a minute to figure out what we’re looking at:
  

•First, on the y axis, you’ll note that the speed is in km/sec. The x axis represents time in days of the year in universal time universal time. Universal time is a method of describing the day of the year by starting on January 1 and counting forward. For example, Feb. 15 is the 46th day of the year, and would be referred to as “day 46” on the graph.).
•Identify the range of values for the solar wind speed (represented by the speed of the protons ejected from the Sun:

•How might you calculate the average for this data set? Describe your method below:

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

•Calculate the average for the solar wind proton speed in km/sec:








YOUR ANSWER:_________________________
•Calculate, at that speed, the amount of time it will take for protons to travel from the Sun to the Earth:




YOUR ANSWER:______________________
•Calculate, at that speed, the amount of time it will take for protons to travel from ACE to the Earth:




YOUR ANSWER:_________________________
•This time is how much advanced warning we get from 1.5 million km from Earth.





Investigation 2: Forecasting

1. Go to the following link: http://space.rice.edu/ISTP/dials.html

2. Note that the page is divided into two parts. In the top area are three different ways of measuring and predicting space weather: The Kp index, solar wind observations, and the NOAA/SEC forecast.

1. The Kp index relates to the Earth and its magnetosphere, observed at locations around the globe. where changes in the magnetic field are generated by increased or decreased activity. The scale that Kp is measured on ranges from 0 to 9, with a reading of 4 indicating a significant disturbance, and 7 indicating imminent disruptions on many scales.
   
2. The solar wind observations are keyed to two measurements: the data from ACE and the electrical energy dumped across the poles due to the solar wind. You’ll note that the measurement is in units of voltage. “Solar wind observations” measure both interplanetary and near Earth phenomena.
   
3. The NOAA/SEC forecast uses measurements from a variety of ground and space-based observations to predict future activity, usually up to 48 hours in advance.
   
   

In the lower area of the page are important variables relating to space weather, with measurements on dials (much like wind dials). It is divided into three sections as well, and the first set deals with solar wind, the second set with the interplanetary magnetic field, and the third with the response of the Earth’s magnetosphere.

You’ll note that the most important of these quantities are discussed in the background

3. Fill in the following table based on the readings on the dials (include units):

Investigation 3 - The real thing!!!

1. Please read “Storms in Space: A Fictionalized Account of ‘The Big One’” by John W. Freeman Jr.

2. To reinforce your reading, answer the following questions from the article. Try to answer them without looking at the article first, but if you must, refer to the article to answer the questions:

1. List 10 effects that were observed and out of the ordinary that were caused by the space storm.
   
2. The storm is not caused by a matter striking the Earth’s surface. What does cause most of the effects that we feel on Earth?
   
3. In the section “Chalk It Up to a Space Storm,” list the phrase of sentence that most closely describes the picture found at the beginning of the investigation.
   
4. What particles make up the solar wind?
   
5. What are scientists attempting to do at Rice University?
   
   

3. Now your job is to compose an essay or short story about a fictional space weather event. The time frame for your writing should be from the birth of the event on the Sun, through the effects on our planet. Include effects here on Earth that affect the daily lives of individuals as well as groups of people. Feel free to email your story if you feel that it is exceptional. (Your teacher may provide you with my email address.).

Investigation 4: Assessment

* Space weather is a function of which three areas or regions of study:

1. ________________

2. ________________

3. ________________

* The average speed of the solar wind is approximately 450 km/sec. It passes the ACE spacecraft which is 1.6 million km from Earth. How long will it take for the storm to reach and affect Earth?






What is the ratio of the speed of a proton to the speed of light?





* Correctly express the following:
The speed of light is _____________ times as fast as the speed of the
average proton in the solar wind.
Explain in a sentence or two why the average proton is so much
slower than light or other radiation:

List the most important measured variables associated with space weather:

1. ________________

2. ________________

3. ________________

4. ________________

5. ________________




Coding:
Maryland Core Learning Goals (Science): 2.1.2, 2.3.1
National Standards (Science): B.1, B.2, C.5, D.1, E.2, F.5, F.6
National Standards (Geography): 7.2, 8.2
National Standards (Mathematics): 1.2, 4.4,

Questions found in procedure.

Extension:
1. Go to http://space.rice.edu/ISTP/dials.html. Record readings for a week (or a fixed period of time) during fixed intervals (at least once a day!
Graph your results and draw conclusions!



Credits:
Pat Keeney GESSEP Program
queen3@access.digex.net

Daniel Hortert GESSEP Program
howard6@access.digex.net

Dr. Eric R. Christian
ACE Deputy Project Scientist
cosmicopia@cosmicra.gsfc.nasa.gov

Dr. John Krizmanic
Astroparticle Physicist
cosmicopia@cosmicra.gsfc.nasa.gov

Beth Barbier
ACE Outreach Specialist
High Energy Astrophysics
cosmicopia@cosmicra.gsfc.nasa.gov