1. Where can I find the US Standard Atmosphere?
USA Today
"Understanging Density Altitude"
USA Today
Table
UCSD
Diagram
Stanford Calculator
Another Table
An
Interesting Story
Handbook
of Space Astronomy and Astrophysics
Handbook
of Space Astronomy and Astrophysics (part II)
2. What is the difference between "mass mixing ratio" and "mixing ratio"? For that matter, what's a mixing ratio?
The mixing ratio of anything is the amount of that something divided by the total amount of everything. For example, in a "normal" population of people, the mixing ratio of women is 0.50 (50%, or darned close to it). The mixing ratio of people with cellular phones might be 0.10. In dry air, the mixing ratio of oxygen is 0.21, nitrogen 0.78, argon 0.1, CO2 is 0.000365, etc, all expressed as a number fraction, i.e. number of N2 divided by total number of air molecules. We like mixing ratios to be expressed in numbers that are reasonable to write and easy to state, without all the zeros that follow the decimal place, as in the case of CO2. So we multiply up the ratio by the factor of 1000 (a "mil"), 10^6 (a "million"), 10^9 (a "billion"), or 10^12 (a "trillion"), and call the result "parts per mil (or thousand)", "parts per million" (or ppm), "parts per billion" (or ppb), and "parts per trillion" (or ppt). So, for example, CO2 is 365 ppm.
It's easy to get the number mixing ratio, which we call the "mixing ratio by volume". It's a little bit (not much, though) harder to get the "mass mixing ratio". For this, you have to convert the numbers of molecules into mass, and then divide by the total mass of the air. The easiest way to do this is to multiply the mixing ratio by volume (assuming you have it already) by the molecular mass of the specie of interest (28 g/mole for N2, 32 g/mole for O2, 44 g,/mole for CO2, etc.) and divide by the molecular mass of air (28.8 g/mole, the weighted averages of the masses of the individual components of air). So the mass mixing ratio of CO2 is 365 ppb x 44/28.8 = 558 ppm by mass.
4. I can't get the "meridional winds" plot to work. Help!
Try this:
[1] In the "visualize NCEP data" window select the button "no difference processing".
http://www.cdc.noaa.gov/cgi-bin/DataIntro.pl?dataset=NCEP
[2] In the subsequent window, select "meridional wind" as your variable below, and click on the "monthly longterm mean" statistic link above. Click "continue image specification" box. This should take you to a new window that will allow you to fill in the appropriate "blanks" to get the months you need.
[3] In the next window, for "dimension 1" pick
"level" (this means altitude), and for "dimension 2" pick
"latitude". This should give you the next window
that allows you to pick the plot limits.
[4] In the last window, leave the axis defaults alone and pick longitude "0.0" an again on "357.5" (this will average over all longitudes, at least it did for me) and pick "JAN" and "JAN" in the other boxes (this will then only give January average). Click on the select button, wait a minute or two, and voila...image! My understanding of the way they are plotting this is that a negative wind ("v" means in the N-S direction, not "vertical") is one that is a mean flow southward, and a positive number is a mean flow northward.
Please note that by averaging over all longitudes,
you can only discuss "global" features, not individual regions, like California.
To do a particular region, you will have to limit your averaging to a smaller
range of longitudes.
3. What is a "sounding diagram" and how do I read (construct) one?
4. Where can I find GOES realtime Images?
5. What is the molecular weight of "X"?
The Periodic Table of the Elements
6. What does "^&$(#*" mean?
