Karl,
I've wondered about this 'gust' question myself, with respect to wind_speed_of_gust, and to many other names with statistical components (mean, st_dev, minimum, etc.). I've always assumed that this either reflected (a) convenience, or (b) the reality that many sensors return data that is already parameterized (?), and so the characteristics required for cell methods might not be readily captured.
I would appreciate hearing further clarification of the CF principles in these cases. (Can be added to the FAQ!)
John
On May 22, 2014, at 09:48, Karl Taylor <taylor13 at llnl.gov> wrote:
>
> Hi Heiko et al.,
>
> I agree that if we include the "gust" name, it should include "speed" as in x_wind_speed_of_gust (for consistency with previous name).
>
> Alternatively, I'm not sure wind_speed_of _gust should ever be used when referring to observations or in many models, since it's just the maximum wind speed occurring during an interval, and it's not a different quantity from wind speed itself. If the x_wind_speed_of_gust is some parameterized quantity and can't be obtained from the x_wind time series (sampled at model time-step), then there might be an argument for defining a new standard_name.
>
> best regards,
> Karl
>
>
> On 5/22/14, 9:27 AM, John Graybeal wrote:
>> Hello Heiko, thanks for the requests.
>>
>> Re x|y_wind_gust, for consistency with existing names would x_wind_speed_of_gust and y_wind_speed_of_gust be OK, for consistency with the existing name wind_speed_of_gust?
>>
>> The description of graupel should be included in this definition. For example "Graupel is precipitation that forms when supercooled droplets of water are collected and freeze on a falling snowflake, forming a 2?5 mm (0.079?0.197 in) ball of rime." Stolen from wikipedia, you may have better/preferred language.
>>
>> Re the name graupelfall_amount, my web search found only uses that treat graupel as a separate word (except in German), so is graupel_fall_amount acceptable? I know it doesn't match the existing snowfall/rainfall etc., but those are common English words.
>>
>> For inland_water_area_fraction, I don't know how to interpret 'inland water ... is all water-surfaces which are not "sea" '. Are bays, fjords, etc. inland water? Is there a clear transition at the river delta of which part is inland and which is not? For CF this may not be essential, but if the answers are well known it would be helpful to state them. (And if not, maybe just say something like 'inland water does not include any ocean or sea'.)
>>
>> John
>>
>> On May 22, 2014, at 01:10, Heiko Klein <Heiko.Klein at met.no> wrote:
>>
>>> Hi,
>>>
>>> we're currently converting the AROME model output to netcdf and have problems finding good standard_names for some of the parameters. Therefore, we would like to request the following new standard_names:
>>>
>>> x_wind_gust:
>>> definition: "x" indicates a vector component along the grid x-axis, positive with increasing x. Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.)
>>> A gust is a sudden brief period of high wind speed. In an observed timeseries of wind speed, the gust wind speed can be indicated by a cell_methods of maximum for the time-interval. In an atmospheric model which has a parametrised calculation of gustiness, the gust wind speed may be separately diagnosed from the wind speed.
>>> units: m/s
>>>
>>> y_wind_gust:
>>> (see x_wind_gust. The definition is taken from the existing x_wind and wind_speed_of_gust)
>>>
>>>
>>>
>>> graupelfall_amount:
>>> definition: "Amount" means mass per unit area.
>>> units: kg m-2
>>>
>>>
>>> inland_water_area_fraction:
>>> definition: "X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" means the horizontal area occupied by X within the grid cell. "inland_water" is water surrounded by land-masses like rivers and lakes, and is all water-surfaces which are not "sea".
>>>
>>>
>>> Best regards,
>>>
>>> Heiko
>>> (on behalf of the MET Norway Arome team)
>>>
>>>
>>>
>>> --
>>> Dr. Heiko Klein Tel. + 47 22 96 32 58
>>> Development Section / IT Department Fax. + 47 22 69 63 55
>>> Norwegian Meteorological Institute http://www.met.no
>>> P.O. Box 43 Blindern 0313 Oslo NORWAY
>>> _______________________________________________
>>> CF-metadata mailing list
>>> CF-metadata at cgd.ucar.edu
>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>> ------------------------------------
>> John Graybeal
>> Marine Data Manager
>>
>> M +1 408 675-5445
>> skype: graybealski
>> Marinexplore
>> 920 Stewart Drive
>> Sunnyvale 94085
>> California, USA
>> www.marinexplore.com
>>
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>
>
>
> _______________________________________________
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------------------------------------
John Graybeal
Marine Data Manager
M +1 408 675-5445
skype: graybealski
Marinexplore
920 Stewart Drive
Sunnyvale 94085
California, USA
www.marinexplore.com
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