# Netcdf layer question

**URL:** <https://forum.generic-mapping-tools.org/t/netcdf-layer-question/1266>\
**Category:** Q&A\
**Created:** [January 26, 2021, 3:48pm UTC](https://forum.generic-mapping-tools.org/t/netcdf-layer-question/1266 "2021-01-26T15:48:42Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![yangleir](https://avatars.discourse-cdn.com/v4/letter/y/a8b319/32.png) [@yangleir](https://forum.generic-mapping-tools.org/u/yangleir)\
**Post date:** [January 26, 2021, 3:48pm UTC](https://forum.generic-mapping-tools.org/t/netcdf-layer-question/1266/1 "2021-01-26T15:48:42Z")

</div>

Hi, all  
I have a Netcdf file from ERA5 model. It contains 37 levels, and 24 hours each day, and parameters of temperature, geopotential , etc.  
Can the GMT `grdinfo` show the info of the specific parameter at specific level and time?  
According to help documents, I have tried:

```auto
$ gmt grdinfo "download.nc?z[1]"

```

But the output information dose not change.

Here is the data link: [https://www.jianguoyun.com/p/DQ9wKWYQ2PCQBxjuid0D](https://www.jianguoyun.com/p/DQ9wKWYQ2PCQBxjuid0D)  
And the data content:

```auto
Source:
           .\era5\data\download.nc
Format:
           64bit
Global Attributes:
           Conventions = 'CF-1.6'
           history = '2021-01-25 12:29:12 GMT by grib_to_netcdf-2.16.0: /opt/ecmwf/eccodes/bin/grib_to_netcdf -S param -o /cache/data1/adaptor.mars.internal-1611577635.3646965-31867-15-c8a30075-33b0-4e6e-bd80-aa66400794d9.nc /cache/tmp/c8a30075-33b0-4e6e-bd80-aa66400794d9-adaptor.mars.internal-1611577635.3652627-31867-2-tmp.grib'
Dimensions:
           longitude = 5
           latitude = 5
           level = 37
           time = 24
Variables:
    longitude
           Size: 5x1
           Dimensions: longitude
           Datatype: single
           Attributes:
                       units = 'degrees_east'
                       long_name = 'longitude'
    latitude 
           Size: 5x1
           Dimensions: latitude
           Datatype: single
           Attributes:
                       units = 'degrees_north'
                       long_name = 'latitude'
    level    
           Size: 37x1
           Dimensions: level
           Datatype: int32
           Attributes:
                       units = 'millibars'
                       long_name = 'pressure_level'
    time     
           Size: 24x1
           Dimensions: time
           Datatype: int32
           Attributes:
                       units = 'hours since 1900-01-01 00:00:00.0'
                       long_name = 'time'
                       calendar = 'gregorian'
    z        
           Size: 5x5x37x24
           Dimensions: longitude,latitude,level,time
           Datatype: int16
           Attributes:
                       scale_factor = 7.0901
                       add_offset = 233961.4879
                       _FillValue = -32767
                       missing_value = -32767
                       units = 'm **2 s** -2'
                       long_name = 'Geopotential'
                       standard_name = 'geopotential'
    q        
           Size: 5x5x37x24
           Dimensions: longitude,latitude,level,time
           Datatype: int16
           Attributes:
                       scale_factor = 2.1534e-07
                       add_offset = 0.007058
                       _FillValue = -32767
                       missing_value = -32767
                       units = 'kg kg**-1'
                       long_name = 'Specific humidity'
                       standard_name = 'specific_humidity'
    t        
           Size: 5x5x37x24
           Dimensions: longitude,latitude,level,time
           Datatype: int16
           Attributes:
                       scale_factor = 0.001659
                       add_offset = 245.7435
                       _FillValue = -32767
                       missing_value = -32767
                       units = 'K'
                       long_name = 'Temperature'
                       standard_name = 'air_temperature'

```

---

<div class="post-metadata">

**Author:** ![Joaquim](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/joaquim/32/16_2.png) [@Joaquim](https://forum.generic-mapping-tools.org/u/Joaquim)\
**Post date:** [January 26, 2021, 4:06pm UTC](https://forum.generic-mapping-tools.org/t/netcdf-layer-question/1266/2 "2021-01-26T16:06:34Z")

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It looks we need a permanent link to this

> **[3. General Features — GMT 6.1.1 documentation](https://docs.generic-mapping-tools.org/latest/cookbook/features.html?highlight=ndvi#reading-more-complex-multi-band-images-or-grids)**

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<div class="post-metadata">

**Author:** ![yangleir](https://avatars.discourse-cdn.com/v4/letter/y/a8b319/32.png) [@yangleir](https://forum.generic-mapping-tools.org/u/yangleir)\
**Post date:** [January 27, 2021, 1:22am UTC](https://forum.generic-mapping-tools.org/t/netcdf-layer-question/1266/3 "2021-01-27T01:22:07Z")

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Thanks for your reply.  
But that is link for images. It dose not work for nc files.  
Should I look this link?[Modifiers for COARDS-compliant netCDF files](https://docs.generic-mapping-tools.org/latest/cookbook/features.html?highlight=ndvi#modifiers-for-coards-compliant-netcdf-files).

---

<div class="post-metadata">

**Author:** ![Joaquim](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/joaquim/32/16_2.png) [@Joaquim](https://forum.generic-mapping-tools.org/u/Joaquim)\
**Post date:** [January 27, 2021, 1:32am UTC](https://forum.generic-mapping-tools.org/t/netcdf-layer-question/1266/4 "2021-01-27T01:32:50Z")

</div>

It says **Reading more complex multi-band IMAGES or GRIDS** and the example provided is to read SST.