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Warning
The following MARS retrieval is provided only  as an example of the sort of change that users will need to make once the data are provided in GRIB2.  If this request is run at the moment, it will return data encoded in GRIB1.


Retrieval of U-component of 10m wind in GRIB1Retrieval of U-component of 10m wind in GRIB2


HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=sfc,
  <b><font color="red">param=165.128</font></b>,
  target="output_10u.grib1"
<pre>



HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=sfc,
  <b><font color="red">param=165</font></b>,
  target="output_10u.grib2"
<pre>


Changes for parameters archived with levtype=sol

...

Warning

The levtype=sol keyword for multi-layer snow depth parameters in GRIB2 has been introduced with the Implementation of IFS Cycle 48r1. 


Retrieval of snow depth in GRIB1Retrieval of snow depth in GRIB2


HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  <b><font color="red">levtype=sfc</font></b>,
  <b><font color="red">param=141.128</font></b>,
  target="output_sd.grib1"
<pre>



HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  <b><font color="red">levtype=sol</font></b>,
  <b><font color="red">levelist=1/2/3/4/5</font></b>,
  <b><font color="red">param=228141</font></b>,
  target="output_sd.grib2"
<pre>


Changes for parameters archived with levtype=hl

...

Warning

The following MARS retrieval is provided only  as an example of the sort of change that users will need to make once the data are provided in GRIB2. 


Retrieval of 100m wind components and speed in GRIB1Retrieval of 100m wind components and speed in GRIB2


HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  <b><font color="red">levtype=sfc</font></b>,
  <b><font color="red">param=228246/228247/228249</font></b>,   <b><font color="red"># 100u/100v/100si</font></b>
  target="output_100m_winds.grib1"
<pre>



HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  <b><font color="red">levtype=hl</font></b>,
  <b><font color="red">levelist=100</font></b>,
  <b><font color="red">param=131/132/10</font></b>,   <b><font color="red"># u/v/ws</font></b> 
  target="output_100m_winds.grib2"
<pre>


Addition of new MARS keyword timespan for parameters processed statistically over a time interval

In GRIB1, parameters processed statistically over a time interval, such as maximum or minimum temperature in the last 3 hours or last 6 hours or since previous post-processing, have their own distinct paramIds.  In GRIB2, there will be a single paramId to identify, e.g., maximum 2m temperature and a new MARS keyword, timespan, to specify the period over which the maximum or minium minimum or average, etc, has been taken.  Typically, timespan=1h for "previous hour",  timespan=3h for "previous 3 hours" and timespan=6h for "previous 6 hours", etc. 

Warning

The following MARS retrieval is provided only  as an example of the sort of change that users will need to make once the data are provided in GRIB2. 


Retrieval of maximum and minimum 2m temperature in GRIB1Retrieval of maximum and minimum 2m temperature in GRIB2


HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  levtype=sfc,
  <b><font color="red">param=201/202</font></b>,       <b><font color="red"># mx2t/mn2t</font></b>
  step=1/2/3/4/5/6,
  target="output_max_min_2t.grib1"
retrieve,
  <b><font color="red">param=228026/228027</font></b>, <b><font color="red"># mx2t3/mn2t3</font></b>
  step=3/6,
  target="output_max_min_2t.grib1"
retrieve,
  <b><font color="red">param=121/122</font></b>,       <b><font color="red"># mx2t6/mn2t6</font></b>
  step=6,
  target="output_max_min_2t.grib1"

<pre>



HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  levtype=sfc,
  <b><font color="red">param=237167/238167</font></b>, <b><font color="red"># max_2t/min_2t</font></b> 
  <b><font color="red">timespan=1h</font></b>,         <b><font color="red"># previous hour</font></b> 
  step=1/2/3/4/5/6,
  target="output_max_min_2t.grib2"
retrieve,
  <b><font color="red">param=237167/238167</font></b>, <b><font color="red"># max_2t/min_2t</font></b>
  <b><font color="red">timespan=3h</font></b>,         <b><font color="red"># previous 3 hours</font></b> 
  step=3/6,
  target="output_max_min_2t.grib2"
retrieve,
  <b><font color="red">param=237167/238167</font></b>,  <b><font color="red"># max_2t/min_2t</font></b>
  <b><font color="red">timespan=6h</font></b>,          <b><font color="red"># previous 6 hours</font></b>
  step=6,
  target="output_max_min_2t.grib2"
<pre>

Addition of new MARS keyword chem for retrieval of chemical species


Tip

There is no need to re-specify the param keyword in the second and third retrieve blocks as it will be inherited from the first block.  It is included here only to illustrate the changes needed.


The timespan keyword is also needed for parameters accumulated from the start of the forecast, such as precipitation or and radiation parameters .  For such parameters, set timespan=fs for "from start",  e.g:

Warning

The following MARS retrieval is provided only  as an example of the sort of change that users will need to make once the data are provided in GRIB2. 


Retrieval of maximum and minimum 2m temperature in GRIB1Retrieval of maximum and minimum 2m temperature in GRIB2


HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  levtype=sfc,
  param=169,       # ssrd - surface solar radiation downwards
  step=6/to/360/by/6,
  target="output_ssrd.grib1"
<pre>



HTML
<pre>
retrieve,
  class=od,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  levtype=sfc,
  param=169, # ssrd - surface solar radiation downwards
  <b><font color="red">timespan=fc</font></b>,         <b><font color="red"># from start of forecast</font></b> 
  step=6/to/360/by/6,
  target="output_ssrd.grib2"
<pre>


Addition of new MARS keyword chem for retrieval of chemical species

Another example are chemical parameters. Besides using the MARS keyword param in the request to specify the parameter type, e.g., mass mixing ratio, an additional MARS keyword chem will be used to specify the chemical substance(s), e.g., nitrogen dioxide.

Warning

The following MARS retrieval is provided only  as an example of the sort of change that users will need to make once the data are provided in GRIB2.  The values taken by the chem keyword are not yet finalised.


Retrieval of NO2 mass-mixing ratio in GRIB2 - currentRetrieval of NO2 mass-mixing ratio in GRIB2 - new


HTML
<pre>
retrieve,
  class=mc,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=ml,
  levelist=1/to/137,
  <b><font color="red">param=210121</font></b>,
  target="output_no2.grib1"
<pre>



HTML
<pre>
retrieve,
  class=mc,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=ml,
  levelist=1/to/137,
  <b><font color="red">param=402000</font></b>,      <b><font color="red"># Mass mixing ratio</font></b>
  <b><font color="red">chem=no2</font></b>,          <b><font color="red"># Nitrogen dioxide</font></b>
  target="output_no2.grib2"
<pre>


Addition of new MARS keywords chem and wavelength for retrieval of chemical species with optical properties

Other chemical parameters, such as aerosol optical depths and absorption aerosol optical, are available for different wavelengths.  Besides using the MARS keywords param and chem in the request to specify the parameter type and chemical substance, e.g., "aerosol optical depth" and "sea salt", an additional MARS keyword wavelength will be used to specify the wavelength.Another example are chemical parameters. Besides using the MARS keyword param in the request to specify the parameter type, e.g., mass mixing ratio, an additional MARS keyword chem will be used to specify the chemical substance(s), e.g., nitrogen dioxide.

Warning

The following MARS retrieval is provided only  as an example of the sort of change that users will need to make once the data are provided in GRIB2.  The values taken by the chem keyword are not yet finalised.


Retrieval of
NO2 mass-mixing ratio in GRIB2 - current
sea salt aerosol optical depth at 550nm in GRIB1Retrieval of sea salt aerosol optical depth at 550nm in GRIB2
Retrieval of NO2 mass-mixing ratio in GRIB2 - new


HTML
<pre>
retrieve,
  class=mc,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=
ml
sfc,
levelist=1/to/137, 
<b><font color="red">param
=210121<
=208.210</font></b>,
  target="output
_no2
_sea_salt_aerosol_550.grib1"
<pre>



HTML
<pre>
retrieve,
  class=mc,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=ml,
  levelist=1/to/137,
  <b><font color="red">param=
402000<
</font></b>,      <b><font color="red">#
Mass mixing ratio<
 Aerosol optical depth</font></b>
  <b><font color="red">chem=no2</font></b>,          <b><font color="red"># Sea salt</font></b>
 <b><font
<b><font color="red"
>chem
>wavelength=
no2<
</font></b>,
       
<b><font color="red">#
Nitrogen dioxide</font></b>
At 550nm
  target="output
_no2
_sea_salt_aerosol_550.grib2"
<pre>



Change of GRIB packing for GRIB2 parameters retrieved from MARS on a grid

...

Warning

The following MARS retrieval is provided only  as an example of the sort of change that users will need to make once the data are provided in GRIB2.  The values taken by the chem keyword are not yet finalised.


<b><fontfont></b><b><fontfont></b><b><fontfont></b> <b><fontfont></b><b><fontfont></b>
Retrieval of NO2 mass-mixing ratio in GRIB2 - currentRetrieval of NO2 mass-mixing ratio in GRIB2 - new with simple packing


HTML
<pre>
retrieve,
  class=mc,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=ml,
  levelist=1/to/137,
  
<font color="red">param=210121</
font>,
  target="output_no2.grib1"
<pre>



HTML
<pre>
retrieve,
  class=mc,
  stream=oper,
  expver=1,
  date=-2,
  time=00:00:00,
  type=fc,
  step=0,
  levtype=ml,
  levelist=1/to/137,
  
<font color="red">param=402000</
font>,      
<<font color="red"># Mass mixing ratio</
font>
 
 <font color="red">chem=no2</
font>,          
<font color="red"># Nitrogen dioxide</
font>
  <b><font color="red">packing=simple</font></b>,    <b><font color="red"># Simple packing</font></b>
  target="output_no2.grib2"
<pre>