TrajStat Help

Topics about the HYSPLIT trajectory model.

TrajStat Help

Postby lafontas » August 1st, 2013, 5:00 pm

I would like to use Trajstat Version 1.2.2.6 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!
lafontas
 
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Re: TrajStat Help

Postby yaqiang » August 3rd, 2013, 10:37 pm

1. Your input screen shot can't be found. For trajectory calculation, TrajStat uses HYSPLIT model, so the calculated trajectories should be same, and the input interface forms are also similar. GADS data is not the problem. But you should notice that the paths of meteorological data and trajectory output must have no space or special characters.

2. The start time should be same as your sample time.

3. It's not necessary to calculate the trajectories again in TrajStat if they have been calculated using HYSPLIT. They can be converted to .tgs files firstly (using the menu Trajectory -> Convert To TGS File) and then combine them into one .tgs file (Trajectory -> Join TGS Files) and convert it to a shape file (Trajectory -> Convert To Shape file).
yaqiang
 
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Re: TrajStat Help

Postby lafontas » 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.
Attachments
Doc1.docx
(217.66 KiB) Downloaded 42 times
lafontas
 
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Re: TrajStat Help

Postby yaqiang » August 6th, 2013, 2:23 am

The shape file created from HYSPLIT may not suitable for TrajStat, you can convert trajectory end point files calculated from HYSPLIT to shape file using TrajStat (the steps haved beed described in the previous reply).

The resolution of the screen shot figure is too low to identify the details. But I can see the trajectory shape layer has been plotted in TrajStat, so if it means you have solved the problem?
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Re: TrajStat Help

Postby lafontas » 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 **************
mscorlib
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.5472 (Win7SP1GDR.050727-5400)
CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
TrajStat
Assembly Version: 1.2.2.6
Win32 Version: 1.2.2.6
CodeBase: file:///C:/Users/lafontas/Desktop/TrajStat_1.2.2.6_Files/TrajStat/TrajStat.exe
----------------------------------------
System.Windows.Forms
Attachments
Screen Shot.png
lafontas
 
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Re: TrajStat Help

Postby yaqiang » August 6th, 2013, 9:37 pm

Do not use GIS output files from HYSPLIT. Use the output trajectory end point file. The content of the trajectory end point file look like:

6 1
GDAS 11 1 22 0 0
GDAS 11 2 8 0 0
GDAS 11 2 15 0 0
GDAS 11 2 22 0 0
GDAS 11 2 1 0 0
GDAS 11 1 29 0 0
1 BACKWARD OMEGA
11 2 19 6 36.160 117.150 1500.0
2 PRESSURE RAINFALL
1 1 11 2 19 6 0 0 0.0 36.160 117.150 1500.0 833.7 0.0
1 1 11 2 19 5 0 1 -1.0 36.136 117.065 1504.0 834.5 0.0
1 1 11 2 19 4 0 2 -2.0 36.105 116.991 1505.8 835.3 0.0
1 1 11 2 19 3 0 3 -3.0 36.068 116.929 1505.1 835.9 0.0
1 1 11 2 19 2 0 2 -4.0 36.032 116.887 1505.8 836.0 0.0
1 1 11 2 19 1 0 1 -5.0 36.006 116.874 1509.6 835.2 0.0
1 1 11 2 19 0 0 0 -6.0 35.990 116.890 1515.9 834.2 0.0
1 1 11 2 18 23 0 1 -7.0 35.986 116.920 1524.4 832.7 0.0
1 1 11 2 18 22 0 2 -8.0 35.995 116.949 1535.2 830.7 0.0
1 1 11 2 18 21 0 3 -9.0 36.019 116.979 1547.9 828.9 0.0
1 1 11 2 18 20 0 2 -10.0 36.046 117.005 1553.7 827.7 0.0
1 1 11 2 18 19 0 1 -11.0 36.065 117.021 1545.0 829.1 0.0
1 1 11 2 18 18 0 0 -12.0 36.076 117.025 1523.0 831.9 0.0
1 1 11 2 18 17 0 1 -13.0 36.083 117.022 1500.8 835.9 0.0
1 1 11 2 18 16 0 2 -14.0 36.092 117.019 1491.1 837.2 0.0
1 1 11 2 18 15 0 3 -15.0 36.104 117.016 1493.0 837.2 0.0
1 1 11 2 18 14 0 2 -16.0 36.116 117.020 1502.5 835.8 0.0
1 1 11 2 18 13 0 1 -17.0 36.126 117.035 1517.2 834.1 0.0
yaqiang
 
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Re: TrajStat Help

Postby lafontas » 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.
lafontas
 
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Joined: January 23rd, 2013, 7:28 pm

Re: TrajStat Help

Postby yaqiang » August 9th, 2013, 1:00 am

PSCF or CWT method is more reasonable then SRIFs method, because in-situ air pollution measurement data are used. Please look at the help document of the TrajStat software to understant the methods. The first calculated Nij is similar with SRIFs value.
yaqiang
 
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