Search found 19 matches

by ryanxia
December 16th, 2019, 12:11 pm
Forum: Trajectory Model
Topic: Eddy diffusion in back trajectory?
Replies: 3
Views: 3178

Re: Eddy diffusion in back trajectory?

Thank you. I have a general technical question. I am interested in knowing the source of moisture for rainfall. For mid-latitude regions, rainfall has mainly caused by transient eddy rather than advection, but eddy is also embedded in advection. If I run back-trajectory for such region, does the sin...
by ryanxia
December 16th, 2019, 2:03 am
Forum: Trajectory Model
Topic: Eddy diffusion in back trajectory?
Replies: 3
Views: 3178

Eddy diffusion in back trajectory?

There are two mechanisms in transporting water vapor in atmosphere, one is advection and one is eddy diffusion. I do not quite understand the numerical way HYSPLIT is modeling the back-trajectory, but it seems to me the most important are wind velocity and direction fields if I am right. If I modele...
by ryanxia
September 4th, 2019, 3:26 pm
Forum: Users
Topic: GDAS terrain height?
Replies: 3
Views: 3040

Re: GDAS terrain height?

Hello, Thanks for your answer. I notice that the TERR_MSL field in trajectory file is very variable. For example, in one of my trajectory file generated from GDAS 1 degree gridded dataset, TERR_MSL was 91.5, 124.3, 188.3, 267.1, 269.9, 269.7... at 0h, -1h, -2h, -3h, -4h, -5h... even the coordinates ...
by ryanxia
July 18th, 2019, 8:52 pm
Forum: Users
Topic: GDAS terrain height?
Replies: 3
Views: 3040

GDAS terrain height?

Hello, I am using GDAS 1 deg resolution data for HYSPLIT back trajectory modeling. In the traj output, there is a column of terrain height asl. What's the resolution of this "terrain" height data? Is it also 1 deg? If so, finer scale peaks or mountains might be smoothed out. Is the elevation the sam...
by ryanxia
October 27th, 2017, 4:54 pm
Forum: Trajectory Model
Topic: Along-trajectory rainfall rate
Replies: 1
Views: 2704

Along-trajectory rainfall rate

Hi HYSPLITers I am interested in along-trajectory meteorological parameter: rainfall rate I displayed GDAS data text profile and found in 2D field of each 3h interval, there is a "TPP6" (mm): I think it is the accumulated precipitation in the last 3h. Is that right? Is this interpolated from station...
by ryanxia
July 23rd, 2017, 12:16 pm
Forum: Trajectory Model
Topic: trajectory runs get stuck for ERA-interim meteo files
Replies: 17
Views: 17032

Re: trajectory runs get stuck for ERA-interim meteo files

Hi Alice, I am so sorry for that I found new problems about my ERA meteo files. As I posted above, I use 2D data from 0/12 hour and 6/12 step (2m temp, 10m U/V wind, total precip). The converted ERA meteo files have missing parts. For example, for the ERA meteo file covering Nov 2016 week 4 (11/22-1...
by ryanxia
July 21st, 2017, 4:21 pm
Forum: Trajectory Model
Topic: trajectory runs get stuck for ERA-interim meteo files
Replies: 17
Views: 17032

Re: trajectory runs get stuck for ERA-interim meteo files

Hi Alice, I am successful to do this. I download the 2D file at hour 0/12 and step 6/12 and selected 2m temp, 10m u/v wind and total precipitation. I should not select step 0. It looks like the "forecast" file also include the analysis field data. Stream:Atmospheric model Type:Forecast Dataset:inter...
by ryanxia
July 16th, 2017, 11:55 am
Forum: Trajectory Model
Topic: trajectory runs get stuck for ERA-interim meteo files
Replies: 17
Views: 17032

Re: trajectory runs get stuck for ERA-interim meteo files

Here are something I tried: I downloaded 2D data (2m Temp, 10m U V wind, and total precipitation): Time 0h 6h 12h 18h and Step 0 3 6. I converted to ARL meteo files. However, I could not run the trajectory generation model. The error information is below: Model started ... HYSPLIT4 - Initialization ...
by ryanxia
July 14th, 2017, 6:24 pm
Forum: Trajectory Model
Topic: trajectory runs get stuck for ERA-interim meteo files
Replies: 17
Views: 17032

Re: trajectory runs get stuck for ERA-interim meteo files

Hi Alice, I downloaded ERA files in weekly interval and not it works in trajectory generation!!! Thank you !!! Also, I have another question, which it looks like you answered before. If I include total precipitation (forecast field) when downloading 2D files, then if I checked meteorology output alo...
by ryanxia
July 11th, 2017, 5:28 pm
Forum: Trajectory Model
Topic: trajectory runs get stuck for ERA-interim meteo files
Replies: 17
Views: 17032

Re: trajectory runs get stuck for ERA-interim meteo files

Hi Alice, Indeed, the text profile showed that everything is 0 after the day when the trajectory generation got terminated. You mentioned using files less than 2GB. But my 1-degree ERA dataset was only 1.1 GB after conversion. You recommended "decomposing" the monthly dataset into smaller ones, e.g....

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