Scientific E Notation and conversion to decimal I am working with satellite data and having fits understanding how to work with it because of the way the data is written (scientific E notation?). My math skills, unfortunately, are not where they should be for a programmer. I hope to find an answer here but I will give a small backstory to hopefully explain this better:
The data I am working on is lightning data, measured in units of 'Joules per Flash'. The  US National Weather Service can display this data on their systems, and there is a legend that shows which color corresponds to the level of energy: 

I managed to get ahold of the raw data, but it is in scientific notation and not on the 0-1500 scale as seen in the image. What is going on here?
For example, one value is $3.657199E-16$.
I figured I could convert that number to the nearest whole integer so I tried some converters online. (With my unfortunate math skills, this is what I resorted to).
I used  this calculator  and the result was a very tiny number in decimal form - $0.0000000000000003657199$


*

*any number out of the data values I have are like this. Does anyone have any idea, or could give me guidance on how to convert this number? I don't understand why this could be. 


PS - If anyone finds this question to be unfitting or unsuitable to ask here, please tell me in the comments rather than downvote. I will happily delete the question if needed rather than lose reputation, I am just not sure where to ask but first, it would be helpful to know if the problem is math-related before moving on to other things.
 A: The conversion is very simple: simply shift the decimal dot 16 places to the left. Complete with zeroes if necessary. The meaning of the notation is
\begin{equation}
3.657199\times 10^{-16} = \frac{3.657199}{10^{16}}
\end{equation}
hence $3.657199$ divided by 10 million billions.
Of course with $6.02E23$ you would shift the dot 23 places to the right!
Edit I want to add that a value such as 3.65E-16 in numerical data may sometimes simply mean zero if it is the result of a computation in typical 64 bits floating precision. For example on my computer, if I compute
>>> 3 * 0.1 - 0.3
5.551115123125783e-17

This value simply means an error due to the limited precision of the computation. It doesn't have another meaning, let it be Joules or femto Joules!
A: You are on the right lines.  It's a reporting error due to inadequately-programmed automatic calculations.
I.e this energy is far too small to be a lightning strike.  I think it might correspond to a just-about visible spark from a model railway.
The energy is roughly equivalent to one (!) electron at 2kV.     Under easiest-breakdown conditions (high humidity, helpful geometry, etc.), 2kV would still not be enough to break down across more than about 10-cm, and "breakdown" implies very many electrons.
A: Scientific E notation is used in displaying big or small numbers with some characters. 'E' notation is used in raw data, calculators, computers, etc. But mathematic notation is widely used by mathematicians. Let me show first the math notation:
Mathematicians write such big or small numbers on this way:
$$3000000000 = 3 × 10^9$$
$$0.000000003 = 3 × 10^{-9}$$
Or simply: If you have number $x$ and $n$ zeroes, then written number is $\overline{x000...000} = x × 10^n$
(Notation $n=\overline{xxxxx}$ means that these are the digits of the number n. For example, if $x=1$, then $n=\overline{xxxxx}=11111$)
In another direction: If you have $n$ zeroes and number $x$ (including this before coma), then the number is written as $\overline{0.000...0000x} = x * 10 ^ {-n}$
But scientific E notation writes numbers on this way:
$$n × 10 ^ {x} = nEx$$
because computers can't easily store the data in exponents, but with 'E' is everything easier.
You should know also what are the metric prefixes.
The definition of the metric prefix is:
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit. While all metric prefixes in common use today are decadic, historically there have been a number of binary metric prefixes as well. (Wikipedia)
Prefixes are defined nowadays in the decadic system. In fact, you should keep in mind, that k in kg means $×10^3$, so:
$$1 kg = 1 × 10^3 g$$
Every prefix means the exponent of ten. You will convert it in the best way if you will use femto. So look at the table at Wikipedia and you will find the prefix femto at the value $×10^{-15}$, so we can write the result as:
$$3.657199E-16J=3.657199 × 10^{-16}J=3.657199 × 10 ^ {-1} fJ = 3.657199 × 0.1 fJ = 0.3657199 fJ$$
The prefix femto (f) destroyed $×10^{-15}$ in the second step (when we got $×10^{-1}$), so it stays only $×10^{-1}$, which is equal to $×1/10^1=×1/10=0.1$
Hope that this helped and if you still have any question, ask me in the comments.
P.S. Thank you for the awesome question. Now you will know a lot about the metric prefixes. And sorry for the extra long question.
