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Posted: August 1st, 2013, 5:00 pm
I would like to use Trajstat Version 22.214.171.124 to look at source region impact on ten day air mass back trajectories (generated by Hysplit) from an ambient air sampling source.
I am having difficulties with TrajStat because when I go to do the trajectory calculation and I combine the .tigs files that are generated (into CTUIR 4_24) and then try to convert to a shape file but there is nothing in the document to convert to a shape and I do not get a meaningful output.
We use GDAS met files (which are also supported by Hysplit) because they are easy files to acquire and I was wondering if this was the problem or if I was inputting something incorrectly into the command window? I have attached a screen shot of what I was inputting.
I also have a question about the start and end day that need to be inputted into the calculation. If we are interested in ten day back trajectories and if we sample ambient air on April 24 2011 and I want to take ten day air mass trajectories to determine where the air we sampled would be coming from, would my start date be the 24th or the 14th and consequently what would run time be in TrajStat?
I have also determined the trajectories for the times we are interested in on Hysplit. Is there a way I can use TrajStat on these Gis .shp files or do I need to use TrajStat to calculate the trajectories again? Because I am able to add the .shp file as a layer in TrajStat
All the help anyone could give me on this issue would be much appreciated!
Re: TrajStat Help
Posted: August 5th, 2013, 12:32 pm
Thank you for your reply.
The HYSPLIT model online yields a .shp file. Am I able to use this file or do I need another file type initially and go through this process with TrajStat?
I have also attached the screen shot I was talking about in the original post. I guess the previous file I had was to big.
Re: TrajStat Help
Posted: August 6th, 2013, 1:47 pm
So I have tried to increase the resolution of the screen shot. Hopefully this image is a bit better. The trajectory that you saw in the last screen shot was from a .shp file that was generated via the online version of Hysplit and added as a layer in TrajStat.
The problem that I am finding is that this .shp is reported in 1 column and not lat/long data points as can be seen in the attribute table in the screen shot posted in this message.
Is there an easy way to find information out about this .shp file? I know in the GIS output zipped folder that is generated there is a .txt file with alt., lat., lon. points but I would not know how to use this.
I've also tired an alternative method
I tried the PC version of Hysplit to determine trajectories. Then I have converted the .txt files generated into .tigs files and joined the .tgs files together. But when I go to turn this joined .tigs file into a .shp file I get this error message.
Thank you again for the help and your response
See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.
************** Exception Text **************
System.FormatException: String was not recognized as a valid DateTime.
at System.DateTimeParse.Parse(String s, DateTimeFormatInfo dtfi, DateTimeStyles styles)
at System.Convert.ToDateTime(String value)
at .(String , String )
at . (Object , EventArgs )
at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e)
at System.Windows.Forms.ToolStripMenuItem.OnClick(EventArgs e)
at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
at System.Windows.Forms.ToolStripItem.FireEventInteractive(EventArgs e, ToolStripItemEventType met)
at System.Windows.Forms.ToolStripItem.FireEvent(EventArgs e, ToolStripItemEventType met)
at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)
at System.Windows.Forms.ToolStripDropDown.OnMouseUp(MouseEventArgs mea)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ToolStrip.WndProc(Message& m)
at System.Windows.Forms.ToolStripDropDown.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
************** Loaded Assemblies **************
Assembly Version: 126.96.36.199
Win32 Version: 2.0.50727.5472 (Win7SP1GDR.050727-5400)
Assembly Version: 188.8.131.52
Win32 Version: 184.108.40.206
Re: TrajStat Help
Posted: August 7th, 2013, 6:15 pm
Thank you for that last response, I have been able to upload the trajectory to Trajstat using the endpoint file.
Now that I have the trajectory uploaded I have a few questions about the PSCF and CWT calculations.
As I've stated before In my lab we have used source region impact factors (SRIFs) in the past, in which we use the percentage of the time an air mass has spent in a given source region in the days before arriving at the collection site to determine a source region. The higher the SRIF the more time the sampled air mass spent in a given source region.
Am I able to do a similar calculation with the PSCF and CWT calculations?
--- If so, Would the field that I should select be? (Hour?)
--- and what should I / would be appropriate to input for the pollution Criterion and the Null data.
I was also wondering if you could point me in the direction of how to determine or find the accepted spatial resolution for this model (or Hysplit). Does it depend on the plot resolution I selected for the calculation in Hysplit?
I ask because I want to make sure I define acceptable Grid sizes.
Again I thank you for you help and continuing support with my questions. It is much appreciated.
Re: TrajStat Help
Posted: January 5th, 2015, 5:32 am
I don't understand anymore
can you explain clearly