HYSPLIT for Mixed Layer Height Calculations

Topics about the HYSPLIT trajectory model.
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yunlec
Posts: 3
Joined: May 5th, 2021, 9:55 am
Registered HYSPLIT User: Yes

HYSPLIT for Mixed Layer Height Calculations

Post by yunlec »

Hello, I'm a new HYSPLIT user. I need hourly mixed layer height data for a single location, and I tried to do this using HYSPLIT's multiple trajectories in time feature. I tested it with the example file (oct1618.BIN) but couldn't understand the output (attached). Some details about my settings:
  • MULTIPLE trajectories in time
    Restart interval (hr): 1
    Restart duration (hrs):12
    Number of multiple levels: 0
  • Trajectory Setup:
    Starting time: 95 10 16 12
    Starting location: 40.0 -90.0 500.0
    Total run time: -12 (back trajectory)
In the output file, I had 12 trajectories for the starting time, all at my set location with the same MLH, then 1 trajectory for the hour before, at a different location and different MLH, then 2 trajectories for 2 hours before...., which is not what I expected.

Moreover, I wonder if there's any easier way to calculate MLH time series for a single location. Is there a way to do this without having to calculate each trajectory individually? Do we need to set up a batch file to do a series of individual trajectories? I have a very large number of these calculations and need to find a way to make it as simple to do as possible... Thanks for your help.
Attachments
example_output.txt
(9.77 KiB) Downloaded 199 times
yunlec
Posts: 3
Joined: May 5th, 2021, 9:55 am
Registered HYSPLIT User: Yes

Re: HYSPLIT for Mixed Layer Height Calculations

Post by yunlec »

Some updates to my post:
I just found that as I used the default trajectory points output frequency (60 min), the air parcel positions seem to be saved at the beginning of each hour. What I want is the MLH data when an air parcel arrived at my set location, which is at the end of an hour. By increasing output frequency I can almost get what I need, but this is too calculative expensive. I wonder if I can change saving settings instead of increasing output frequency to achieve the same goal? Thanks.
alicec
Posts: 411
Joined: February 8th, 2016, 12:56 pm
Registered HYSPLIT User: Yes

Re: HYSPLIT for Mixed Layer Height Calculations

Post by alicec »

Do you just want to get the PBL height at a certain location?
You can use one of the utilities that extracts information from the meteorological data.
vmixing or xtrct_stn would work.
https://www.ready.noaa.gov/HYSPLIT_vmixing.php
yunlec
Posts: 3
Joined: May 5th, 2021, 9:55 am
Registered HYSPLIT User: Yes

Re: HYSPLIT for Mixed Layer Height Calculations

Post by yunlec »

alicec wrote:
May 6th, 2021, 3:54 pm
Do you just want to get the PBL height at a certain location?
You can use one of the utilities that extracts information from the meteorological data.
vmixing or xtrct_stn would work.
https://www.ready.noaa.gov/HYSPLIT_vmixing.php
Exactly! Thanks for your help!
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