Hi Emily,

Yes we can estimate that. For instance, if by solar storm you mean a coronal mass ejection (a CME), we can calculate the kinetic energy (=mass*velocity², if you have gotten that far in school). We can estimatte the velocity
(see http://www-istp.gsfc.nasa...poster/measure.html) and it turns out you can estimate the mass by how bright the CME is in the coronagraph images (like those in the page I just mentioned).

I think that when you do that you get a range of values (there are big and small CMEs) but they get as high as 10³² ergs or so. that is a 1 with 32 zeros after it. That is really huge!
I just looked up how much energy is in a volcano and found an estimate of about 10²⁴ ergs, so a CME can have 100,000,000 (one hundred million) times more energy. 10³² ergs is also 25,000 times more that the amount of energy humans consumed in the year 2000 (I had to look that up once :-)).

Terry

Hi Emily,

In Terry Kucera's answer to your question, she said that the energy released in a CME was about 10³² ergs. By doing a few unit conversions, we can compare this energy to the electrical energy you use every month. An erg is a unit scientists use to measure energy in the cgs system of units, where distance is measured in centimeters (cm), mass is measured in grams (g), and time is measured in seconds (s). Another useful system of units used by scientists is the SI system, in which masses are measured in kilograms (kg), distances in meters (m), and time in seconds (s). The unit of energy in the SI system is called the Joule (J). Both the erg and the Joule can be written in terms of other units:

1 erg = 1 g-cm²/s² = 1/10,000,000 J = 1/10⁷ J

1 J = 1 kg-m²/s² = 10,000,000 ergs = 10⁷ ergs

In the SI system the energy released by a CME is about 10³² ergs x 1/10⁷ = 10²⁵ J

In the SI system, the unit used to describe the rate of energy release per unit time (or power), is the Watt (W). You may have noticed that the lightbulbs we use give their power consumption in Watts on the package. If you take a look at your parent's electric bill, you will see that the power company charges you for the amount of electrical energy you used in kWh, or kilowatt-hours. To get the electrical energy you use in kWh, they just take the power consumption in kW x the amount of time.

A kilowatt is just 1kW= 1000 W = 1000 J/s.

A kilowatt-hour 1 kWh=1000 J/s x 60 minutes/hour x 60 seconds/minute = 3,600,000 J = 3.6x10⁶ J

If we take the CME energy of 10²⁵ J divided by the conversion factor, 3.6x10⁶ J/kWh, we find that the energy released by the CME is 2.8 x 10¹⁸ kWh.

For comparison, your refrigerator probably uses about 180 kWh of energy every month. A typical CME releases enough energy to power 1.6 x 10¹⁶ (that's 16,000,000,000,000,000) refrigerators for 1 month, or 1 refrigerator for 1.3 x 10¹⁵ years. That's a lot of refrigerators!

A fun thing to do when you go home tonight is to ask your parents for an old electric bill and try comparing the energy released by a CME to the amount of energy you use in one month.

Kris