AERMOD View – Common Upper Air Data Errors in AERMET
October 2014
Several air dispersion models require measurements of vertical meteorological parameters or “upper air data”. This data is recorded from weather balloons launched simultaneously around the globe at 00Z and 12Z each day. Data is made available from several resources including the NOAA/ESRL Radiosonde Database. Users can look up and download data for worldwide locations as far back as the mid-1940s. The Forecast Systems Laboratory format, or FSL format, is used by several meteorological data preprocessors including READ62, the upper air data pre-processor for the CALPUFF modeling system, and AERMET.
When running AERMET, fatal errors can stop the model from successfully completing its processing. One problem can occur while downloading data. After a user submits a request for data, the information will be printed to the screen of their internet browser. Users can right-click and use the Save As context menu to save the data to a text file, or they can copy and paste the data from the browser into a blank text file. When using the former method, some internet browsers will save the file as an encoded text file which AERMET cannot read. The error message in the AERMET Message file will appear to contain an invalid date:
The first characters in the error message should report a date in YYMMDD format. The string of unexpected values there indicates that the file encoding is invalid for AERMET. Changing the encoding is simple:
When running AERMET, fatal errors can stop the model from successfully completing its processing. One problem can occur while downloading data. After a user submits a request for data, the information will be printed to the screen of their internet browser. Users can right-click and use the Save As context menu to save the data to a text file, or they can copy and paste the data from the browser into a blank text file. When using the former method, some internet browsers will save the file as an encoded text file which AERMET cannot read. The error message in the AERMET Message file will appear to contain an invalid date:
21068088 UPPERAIR E33 GETFSL : ERROR READING 1st RECORD OF FSL SDG # 1
The first characters in the error message should report a date in YYMMDD format. The string of unexpected values there indicates that the file encoding is invalid for AERMET. Changing the encoding is simple:
- Open the FSL file in Notepad
- Select File | Save As
- Change the Encoding drop-down menu to "ANSI"
Below is another example of the E33 error code which contains valid date information but still reports an error in reading sounding data.
This message can appear when there is an extra carriage return (e.g., blank line) at the end of the file. You can identify such issues by referring to the date (e.g., 111231 is December 31, 2011). Since the file used in this example ended at 31/12/11, it indicates that the extra line exists at the end of the file. Once the extra line is removed and the file saved, AERMET should run without any issue.
If you’ve encountered an error message while processing data and need assistance in understanding the problem, you can contact our technical support team via email (support@weblakes.com). Our dedicated team of specialists will help you quickly analyze and fix the problem.
111231 UPPERAIR E33 GETFSL : ERROR READING 1st RECORD OF FSL SDG # 5861
This message can appear when there is an extra carriage return (e.g., blank line) at the end of the file. You can identify such issues by referring to the date (e.g., 111231 is December 31, 2011). Since the file used in this example ended at 31/12/11, it indicates that the extra line exists at the end of the file. Once the extra line is removed and the file saved, AERMET should run without any issue.
If you’ve encountered an error message while processing data and need assistance in understanding the problem, you can contact our technical support team via email (support@weblakes.com). Our dedicated team of specialists will help you quickly analyze and fix the problem.
