This example shows
- A single sounding plot in red
- The Standard Atmosphere profile in blue
A large number of soundings contain at least one unknown height (value = -9999).
These normally occur when the temperature reaches a minimum at the top of the troposphere
(near 12,500 meters in this example).
In order to display these points, I have used a linear interpolation (which produces a small error) to determine a value
from the provided pressure.
The following sample datasets contain all the available data for 2006 at the associated site.
It is fairly common for some data to be missing.
| DataSet (file)
| Comment
|
|---|
| Anchorage 2006.html
| Near the pole, the tropopause is lower and warmer than the standard
|
| Denver 2006.html
| High altitude, surface at 1,612 meters, about 10°C diurnal range at the surface,
morning inversions are rare
|
| Jacksonville 2006.html
| Notice that the tropopause is higher and colder than the standard
|
| Key West 2006.html
| Island beside the Gulf Stream - The surface temperature changes very little
|
| SouthPole 2006.html
| Data from AMUNDSEN-SCOTT (id 89009) -90°N 0°W 2,835 m. The upper troposphere temperature
is frequently below -80°C and the tropopause is occasionally below -90°C.
There appears to be a problem computing wind speed - 391 m/s - greater than 870 mph.
I assume that this is a problem related to gps accuracy near the south pole.
All the books say that the tropopause is about 17 km at the equator and 7 km at the poles.
However, on 08-16-2008, the polar tropopause was over 20 km.
|
| Tucson 2006.html
| The surface temperature changes a lot between day and night
|
| YUMA 2006.html
| Almost no stratosphere data .. no idea why.
It is also missing a lot more days than the other files.
|
Notice that between 5,000 and 10,000 meters, the temperature of the
troposphere
changes very little between
day and night. This is the primary evidence that this part of the atmosphere
does not radiate IR energy directly to the surface.
The longer term changes are usually produced by wind and/or weather fronts.
Operation
- The entire window can be resized
- Some colors can be changed by clicking the colored squares
- See Lapse Rate Overview for information on DALR, ELR, and SALR
- The graph has pan/zoom capabilities
| Zoom
| Left click and drag the mouse from the upper left to the lower right
|
| Restore
| Left click and drag the mouse from the lower left to the upper right
|
| Pan
| Once the graph is zoomed, right click and drag the mouse to change the displayed data
|
Displaying Additional Data
The data in the zip file is representative - coastal, desert, polar.
Since I don't want anyone to accuse me of cherry picking the examples,
the program allows you to retrieve any dataset available from the
Integrated Global Radiosonde Archive (IGRA)
and display it yourself.
Unfortunately, the procedure is manual.
As of 07-13-11 (and still down 07-31-11), the NOAA site has a problem and the
method described in this section no longer works.
Please see
the next section
for a technique which still works.
I am leaving the following because it may just be a temporary problem.
Currently not Functional
The basic procedure is to select a sounding site and some number of soundings.
(I have tested the software with 3 years of data and it seems to work fine.)
Starting from
the station selection page,
select United States and one of the available stations.
I have tried many times, but so far I have not been able to get data for locations outside the United States.
It appears that the data is available, but a bug in their software blocks filtered access.
The next section describes how to download the compressed data
and process it with Process_Raw_Data.exe
so that non-US data can be displayed.
The rest of this section applies to US data only.
On the next page, be sure to select Multiple Soundings, the default returns only a single set of measurements.
The other setting on this page (the date range) is not particularly important.
On the next page,
you need to select the start and end dates - I find it easier to just type them in.
For my program to work, be sure that the following options are selected
(I may fix this later).
| Property
| Value
|
|---|
| Vertical Coordinate
| Height
|
| Sort Order
| Ascending
|
| Output Format
| HTML Table
|
When you click Continue, an html page will be displayed in a new window.
This file contains the data and must be saved on your local machine.
With IE, I select View Source and then save the file in the same directory as the program.
Warning - be sure to wait for the file to finish downloading before saving a local copy.
In the program, just click the Read File button and select the file you saved. The extension does not matter.
Warning - Because there is limited error checking, if you give it the wrong type of data file
the results are not predictable.
Using Process_Raw_Data.exe
LapseRateAnimation.exe
works by processing
the html files produced by NOAA.
Unfortunately, of the 1,500 global sites available via ftp,
the NOAA web interface provides the data in an html format
for only the US sites.
(As of 07-13-11, none of the html files are currently available ..
their server produces an Internal Server Error .. which I reported.)
In order to view the data from those additional sites, I wrote
Process_Raw_Data.exe to make the conversions.
Unfortunately, the procedure is still fairly manual.
- First, locate and download the appropriate data file .. gz format
- Uncompress the file
- Since the file contains unix line terminations, open the file in an appropriate text editor .. I use WordPad (free with Windows)
- Save the data you want as a text file (*.txt) - there might be 50 years of data, but you only want one
- Run Process_Raw_Data.exe to convert the data to html and save it
I know that this is a poor way to write software, and someday I might fix it.
But at least it works.
The main problem is file size - the raw files are very large.
My procedure is to edit the raw file and to save
one or two years worth of data in a separate txt file
which is then processed.
Example file sizes for one year at the south pole
89009 - AMUNDSEN-SCOTT
|
| File | Size
| Comment
|
|---|
| 89009.dat.gz | 6,506 KB
| Original file from NOAA
|
| 89009.dat.txt | 32,367 KB
| Uncompressed file - has unix line endings
|
| 89009.dat.2006.txt | 1,995 KB
| One year's worth of data, still in raw format but with DOS line endings
|
| 89009.dat.2006.html | 1,519 KB
| html file read by LapseRateAnimation.exe
Renamed as SouthPole 2006.html in the provided zip file
|
This is not a good (or user friendly) design ... but it works.
The main ASCII text edit program I use for this is MS WordPad
(because it reads unix terminated data files).
You must save the selected data as a *.txt file
and not an rtf.
Process_Raw_Data.exe reads the selected *.txt file and
defaults the output filename to have an *.html extension.
The data is accessed in LapseRateAnimation.exe by using the Read File... button.
Download Process_Raw_Data.exe
Archive Details
The Integrated Global Radiosonde Archive (IGRA) provides the following
Important Data Fields
Since this procedure requires manually editing the raw data,
it is necessary to understand the format.
This is a sample of the raw data
#8900920060101002116 111
21 69000B 2835 -245B 37 310 56
30 68100 -9999 -9999 -9999 320 66
30 66700 -9999 -9999 -9999 315 77
|
Each sounding starts with a header that contains the site ID and a date/time stamp.
// #7220620060101002304 63
// #7220620060101121116 76
// yyyymmddhh
// 2006-01-01 00:00
// 2006-01-01 12:00
// 72206 - JACKSONVILLE
|
Understanding the data.
// 10 92500 799B 166B 43 250 92
col field
1 flag 10, 20, 30
3 press_mb 925.00
10 geo_hgt_m 799
15 Height_Flag A, B, or blank
16 temp_C 16.6000
22 dpdiff_C 4.3000
27 wind_dir 250
36 wind_spd_ms 9.2000
-9999 means unknown
|
I have identified only those fields you need to make the necessary edits ..
a full description
is available.
ini File
Version 1.0.1.2 allows the user (that means YOU) to add data files
to the combo box. You can also set the initial delay between frames.
The provided file contains the details.
Analysis
It is a little weird that the maximum jet stream speed is typically at the same level as
the minimum troposphere temperature. I assume that this is a measurement artifact
because the balloon
is about 85 feet above the sensor package.
Since the wind speed is determined by tracking the balloon from the ground,
my interpretation of this anomaly is that the balloon is in the jet stream while the sensor
package is still in the troposphere.
Data Access
Since this page was first produced (03-06-09), NOAA has changed their interface.
Unfortunately, it is no longer possible to access the sounding data
in an html format.
Of note,
this site
indicates that
these airports
provide soundings every hour for the last 2 weeks.
I have not tried to use this data.
Author:
Robert Clemenzi