Methane (CH4) variable name

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xolilencipha
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Joined: Sun Dec 06, 2020 10:04 am America/New_York

Methane (CH4) variable name

by xolilencipha » Thu Sep 30, 2021 6:34 pm America/New_York

Hi there,

I have downloaded this file
https://asdc.larc.nasa.gov/data/TES/TL2 ... 015.12.01/. The file is for the month of December 2015 as the label indicate, however when I decode the Time and UT_Hour variable I get a wrong year (1992) in the date:

head(mytime)

[1] "1992-12-01 18:19:29 UTC" "1992-12-01 18:20:02 UTC" "1992-12-01 18:20:47 UTC"

[4] "1992-12-01 18:21:09 UTC" "1992-12-01 18:21:31 UTC" "1992-12-01 18:22:16 UTC"

> head(myUT_Hour)

[1] "1992-12-01 20:19:29 SAST" "1992-12-01 20:20:02 SAST" "1992-12-01 20:20:47 SAST"

[4] "1992-12-01 20:21:09 SAST" "1992-12-01 20:21:31 SAST" "1992-12-01 20:22:16 SAST".

This is not much of the problem because the Date variable/parameter gives a correct year. My issue is that I cannot locate the CH4 profiles data from the file.

Which variable/parameter name represent CH4 profiles data from the list of parameters names provided in the file?

Thanks

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ASDC - ingridgs
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Joined: Fri Apr 23, 2021 9:14 am America/New_York
Answers: 1

Re: Methane (CH4) variable name

by ASDC - ingridgs » Wed Oct 27, 2021 11:25 am America/New_York

Answer from TES science Team:

The "Time" related fields in the .nc file, are:


double Time(Grid_Targets) ;

Time:LongName = "Julian date" ;

Time:Units = "seconds since some reference (1993-01-01 00:00:00)" ;

Time:Calendar = "julian" ;

Time:FillValue = -999.f ;

Time:MissingValue = -999.f ;

float UT_Hour(Grid_Targets) ;

UT_Hour:LongName = "UTC hour at location. fraction corresponds to minutes, seconds" ;

UT_Hour:Units = "hours" ;

UT_Hour:Example = "19.44000" ;

UT_Hour:FillValue = -999.f ;

UT_Hour:MissingValue = -999.f ;

double YearFloat(Grid_Targets) ;

YearFloat:LongName = "year plus fraction of the year" ;

YearFloat:Units = "" ;

YearFloat:FillValue = "-999.00" ;

YearFloat:MissingValue = "-999.00" ;

double YYYYMMDD(Grid_Targets) ;

YYYYMMDD:LongName = "Human readable UTC time at location" ;

YYYYMMDD:Units = "time as YYYYMMDD" ;

YYYYMMDD:Example = "20060805" ;

YYYYMMDD:FillValue = -999.f ;

YYYYMMDD:MissingValue = -999.f ;


Unless some special needs, users normally do not use "Time" (a positive double) in seconds reference to the first day of 1993. All the other time-related fields are self-explanatory.

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