Science Facts - Lapse Rate Animations

Twice every day, radiosonde and pilot balloon observations are made at over 1500 locations world wide (though only about 700 are really useful, the rest don't have enough data). That data is archived by NOAA in the Integrated Global Radiosonde Archive (IGRA).

I have produced a few Flash based graphs to view temperature vs altitude plots (Lapse Rate plots). Unfortunately, Flash programs are too slow for anything more complicated.

LapseRateAnimation.zip provides the program and several sample data sets. Unfortunately, this software runs under Microsoft Windows XP only. However, it is a stand-alone exe-file and it does not make any registry changes. (This will not work with Vista.)

Overview

Most of the Lapse Rate Animation program is self explanatory. The zip file also comes with several datasets - just select one from the combobox.

Screen shot of the Lapse Rate Animation program

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
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
Tucson 2006.html	The surface temperature changes a lot between day and night
SouthPole 2006.html	Data from AMUNDSEN-SCOTT (id 89009) -90°N 0°W 2,835 m. The troposphere temperature is frequently below -80°C and 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 tropoause was over 20 km.

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.

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. At a future time, I might try writing my own program to process the non-US data.

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).

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.

Analysis

It is a little weird that the maximum jet stream speed is typically at the same level as the minimum troposphere temperature. I assmue 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 anomoly is that the balloon is in the jet stream while the sensor package is still in the troposphere.

Author: Robert Clemenzi