Eyjafjallajökull's volcanic ash cloud in Google Earth
How to turn a volcano-ruined vacation into a programming opportunity :-)
Forecast of ash cloud extent ( copyright Norwegian Meteorological Service)
Volcanic ash advisory bulletins are given in plain text using a conventional format which is probably typical of the aeronautics world. I am no expert in the field, nor did I have much time to devote to this small project: yet, I wanted to get something kinda working asap. So a few manual steps are required to run my application, and there is almost no exception management and logging. So, as the old saying goes: a word to the wise is enough, please do not take it as a shining programming example :-). Anyway, please feel free to make any comments and/or report any bugs!
Here are the steps to follow:
0. Please make sure you have a working installation of the Java run time environment (version 1.5 or later).
1. Download the application jar file from the link that can be found at the bottom of this page, and save it to a temporary directory.
2. Go the latest text advisory available at the following link:
http://www.metoffice.gov.uk/aviation/vaac/vaacuk.html
If necessary, scroll down to the section that you want to display in Google Earth. The advisory issue date field is contained in the DTG field (date in YYYYMMDD format; times refer to Zulu, or UTC, timezone). Then come the sections which contain the observed cloud boundaries (as lat/long pairs) and the boundary forecasts for +6, ("FCST VA CLD +6HR:" +12 ("FCST VA CLD +12HR:" and +18 hours ("FCST VA CLD +18HR:") relative to the time of observation. The boundaries are available for two altitude ranges: "SFC/FL200" (0-20000 feet, i.e. ground level up to about 6000 m) and "FL200/FL350" (20000-35000 feet, i.e. 6000-10500 m).
3. Choose one section that you want to view in Google Earth. Select the data from the start of the "SFC" marker up to the last coordinate pair before the next section, as shown below:
4. Copy and paste the selection into a plain text editor, and save it as a plain text file (e.g. "volcano.txt").
5. Open a command shell, cd to the directory where the Jar file is, and type in the following command:
java -jar MetOfficeToKML.jar volcano.txt volcano.kml
of course, the above is just an example, and you can use any valid combination of input and output files. It is important that the output file have the .kml extension.
6. Open the resulting KML file in Google Earth. You will have something like the following:
Forecast volcano ash cloud extent for April 20th, 2010 at 0:00 UT:
The ash cloud boundary is rendered as a colored extruded polygon (elevations not to scale) with both layers: 0-6000 m elevation (blue) and 6000-10500 m elevation (red). You can even choose which layers to show in GE's left-hand side menu bar:
Download the Jar File
Disclaimer: this application is provided as is, with no warranties whatsoever, of suitability for any kind of purposes. Use it at your known risk. Distribution is prohibited without the author's written consent. By clicking on the link (s) below you agree to fully comply with the terms and conditions set out in this disclaimer.
JAR File
Full NetBeans 8.0 project
Conclusions
Ok, my holidays are gone. More "friendly" winds could have blown the ash away instead of bringing it right above us. However, we are witnessing yet another example of Mother Nature's power: that's why I personally just can't help but admire this dramatic event in all its power.
Disclaimer: this application is provided as is, with no warranties whatsoever, of suitability for any kind of purposes. Use it at your known risk. Distribution is prohibited without the author's written consent. By clicking on the link (s) below you agree to fully comply with the terms and conditions set out in this disclaimer.
JAR File
Full NetBeans 8.0 project
Conclusions
Ok, my holidays are gone. More "friendly" winds could have blown the ash away instead of bringing it right above us. However, we are witnessing yet another example of Mother Nature's power: that's why I personally just can't help but admire this dramatic event in all its power.