[CF-metadata] CF standard_name irradiation ?
Dear colleagues, I am trying to clean up some data files and make them CF compliant. But I am confused about the standard name that I could use for (measured) irradiation. There is an entry "downwelling_spectral_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics." This definition explicitly mentions "irradiance", so I guess I am close to the solution. However, the irradiance measurement data I have are not "spectral". I did not find a standard_name entry "downwelling_radiative_flux_in_air" which I would have expected to be the integral flux. There are only various variants of "surface_net..." or "surface_spectral..." fluxes. These don't help, or am I wrong here? Unless I am mistaken or have overlooked something obvious, I therefore propose to add a standard_name tabel entry: "downwelling_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. For spectrally resolved radiative flux or net radiative flux see downwelling_spectral_radiative_flux_in_air or surface_net_downward_radiative_flux, respectively." Best regards, Martin Schultz = Dr. Martin G. Schultz, IEK-8, Forschungszentrum Jülich = = D-52425 Jülich, Germany = = ph: +49 (0)2461 61 2831, fax: +49 (0)2461 61 8131 = = email: m.schu...@fz-juelich.de = = web: http://www.fz-juelich.de/icg/icg-2/m_schultz = Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] CF standard_name irradiation ?
Hi Martin, There are two Standard Names 'downwelling_shortwave_flux_in_air' and 'downwelling_longwave_flux_in_air'. Do either of these fit your data. I have associated the former with downwelling irradiance data from PAR cosine-collector light meters. Cheers, Roy. -Original Message- From: cf-metadata-boun...@cgd.ucar.edu [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of Schultz, Martin Sent: 18 February 2011 13:28 To: cf-metadata@cgd.ucar.edu Subject: [CF-metadata] CF standard_name irradiation ? Dear colleagues, I am trying to clean up some data files and make them CF compliant. But I am confused about the standard name that I could use for (measured) irradiation. There is an entry "downwelling_spectral_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics." This definition explicitly mentions "irradiance", so I guess I am close to the solution. However, the irradiance measurement data I have are not "spectral". I did not find a standard_name entry "downwelling_radiative_flux_in_air" which I would have expected to be the integral flux. There are only various variants of "surface_net..." or "surface_spectral..." fluxes. These don't help, or am I wrong here? Unless I am mistaken or have overlooked something obvious, I therefore propose to add a standard_name tabel entry: "downwelling_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. For spectrally resolved radiative flux or net radiative flux see downwelling_spectral_radiative_flux_in_air or surface_net_downward_radiative_flux, respectively." Best regards, Martin Schultz = Dr. Martin G. Schultz, IEK-8, Forschungszentrum Jülich = = D-52425 Jülich, Germany = = ph: +49 (0)2461 61 2831, fax: +49 (0)2461 61 8131 = = email: m.schu...@fz-juelich.de = = web: http://www.fz-juelich.de/icg/icg-2/m_schultz = Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- This message (and any attachments) is for the recipient only NERC is subject to the Freedom of Information Act 2000 and the contents of this email and any reply you make may be disclosed by NERC unless it is exempt from release under the Act. Any material supplied to NERC may be stored in an electronic records management system. ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] CF standard_name irradiation ?
Hello - It would be useful to know what type of measurement you're working with. Is it an observed variable? What kind instrument made the measurement, and at what position - i.e is it on a surface buoy? We use surface_downwelling_shortwave_flux_in_air for swr measured by an Eppley PSP (Precision Spectral Pyranometer) on a surface buoy. - Nan On 2/18/11 8:27 AM, Schultz, Martin wrote: Dear colleagues, I am trying to clean up some data files and make them CF compliant. But I am confused about the standard name that I could use for (measured) irradiation. There is an entry "downwelling_spectral_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics." This definition explicitly mentions "irradiance", so I guess I am close to the solution. However, the irradiance measurement data I have are not "spectral". I did not find a standard_name entry "downwelling_radiative_flux_in_air" which I would have expected to be the integral flux. There are only various variants of "surface_net..." or "surface_spectral..." fluxes. These don't help, or am I wrong here? Unless I am mistaken or have overlooked something obvious, I therefore propose to add a standard_name tabel entry: "downwelling_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. For spectrally resolved radiative flux or net radiative flux see downwelling_spectral_radiative_flux_in_air or surface_net_downward_radiative_flux, respectively." Best regards, Martin Schultz = Dr. Martin G. Schultz, IEK-8, Forschungszentrum Jülich = = D-52425 Jülich, Germany = = ph: +49 (0)2461 61 2831, fax: +49 (0)2461 61 8131 = = email: m.schu...@fz-juelich.de = = web: http://www.fz-juelich.de/icg/icg-2/m_schultz = Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- *** * Nan Galbraith(508) 289-2444 * * Upper Ocean Processes GroupMail Stop 29 * * Woods Hole Oceanographic Institution* * Woods Hole, MA 02543* *** ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] CF standard_name irradiation ?
Hi Roy, thanks - yes: I think that would do. I am not an expert in this field and don't know if the light meter spectral response is close enough to what models generally consider "shortwave flux", but this might be a rather fine point. In any case it would be good if a search for "irradiance" or "radiation" would turn up something that points to "shortwave" and "longwave" as well. "downwelling_shortwave_*radiation*_flux_in_air" would be more precise, but also redundant for a human being... Cheers, Martin > -Original Message- > From: Lowry, Roy K. [mailto:r...@bodc.ac.uk] > Sent: Friday, February 18, 2011 2:38 PM > To: Schultz, Martin; cf-metadata@cgd.ucar.edu > Subject: RE: CF standard_name irradiation ? > > Hi Martin, > > There are two Standard Names > 'downwelling_shortwave_flux_in_air' and > 'downwelling_longwave_flux_in_air'. Do either of these fit > your data. I have associated the former with downwelling > irradiance data from PAR cosine-collector light meters. > > Cheers, Roy. Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] CF standard_name irradiation ?
Nan, unfortunately I don't know the instrument type. I am dealing with the CASTNET data http://java.epa.gov/castnet/ and I am primarily interested in ozone. A brief search didn't turn up any info on the instrument type. But "downwelling_shortwave_flux_in_air" or "surface_downwelling_shortwave_flux_in_air" both seem to be good options. Thanks, Martin > -Original Message- > From: Nan Galbraith [mailto:ngalbra...@whoi.edu] > Sent: Friday, February 18, 2011 2:40 PM > To: Schultz, Martin; cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] CF standard_name irradiation ? > > Hello - > > It would be useful to know what type of measurement you're > working with. Is it an observed variable? What kind > instrument made the measurement, and at what position - i.e > is it on a surface buoy? > > We use surface_downwelling_shortwave_flux_in_air for swr > measured by an Eppley PSP (Precision Spectral Pyranometer) on > a surface buoy. > > - Nan Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
[CF-metadata] ... wind speed
Hi again, more on the CASTNET data. They provide 15,WINDSPEED,m/sec,"Vector wind speed; m/sec.",NUMBER,"16,4", and 23,WINDSPEED_SCALAR,m/sec,"Scalar wind speed; m/sec.",NUMBER,"16,4", The first appears to be a vector average = sqrt( mean(u)**2 + mean(v)**2 ) the second is = mean( sqrt(u**2 + v**2) ) Are both tied to "wind_speed" as standard_name and should they differ in the cell_method attribute? Cheers, Martin Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] CF standard_name irradiation ?
Martin, this is a bit more complicated the radiative fluxes used in climate studies are usually spectrally integrated and usually for these bradband fluxes there is a distinction between solar broadband and IR broadband fluxes. now for these broadband fluxes we also like to distinguish between clear-sky and all-sky fluxes and for the clear-sky downward fluxes there is a difference if these are based on observations under clear-sky conditions or if they are based on simulations where clouds were simply removed (but not the higher water vapor compared to clear-sky) I would look if there are some definitions for radiative fluxes in the radiation or climate section ...? Stefan On 2/18/2011 2:27 PM, Schultz, Martin wrote: Dear colleagues, I am trying to clean up some data files and make them CF compliant. But I am confused about the standard name that I could use for (measured) irradiation. There is an entry "downwelling_spectral_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics." This definition explicitly mentions "irradiance", so I guess I am close to the solution. However, the irradiance measurement data I have are not "spectral". I did not find a standard_name entry "downwelling_radiative_flux_in_air" which I would have expected to be the integral flux. There are only various variants of "surface_net..." or "surface_spectral..." fluxes. These don't help, or am I wrong here? Unless I am mistaken or have overlooked something obvious, I therefore propose to add a standard_name tabel entry: "downwelling_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. For spectrally resolved radiative flux or net radiative flux see downwelling_spectral_radiative_flux_in_air or surface_net_downward_radiative_flux, respectively." Best regards, Martin Schultz = Dr. Martin G. Schultz, IEK-8, Forschungszentrum Jülich = = D-52425 Jülich, Germany = = ph: +49 (0)2461 61 2831, fax: +49 (0)2461 61 8131 = = email: m.schu...@fz-juelich.de = = web: http://www.fz-juelich.de/icg/icg-2/m_schultz = Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- Stefan Kinne MPI-Meteorology Bundesstrasse 53 20146 Hamburg stefan.ki...@zmaw.de tel +49 40 41173 383 fax +49 40 41173 298 ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] handling time in a CF compliant fashion
Janine,
The data model envisioned by CF requires that the time coordinate
variable be fully enumerated. In other words, your scenario
requires "a time dimension at the highest rate", including a time
coordinate value for every time step. time(:) = 0.00, 0.04, 0.08
seconds, etc. I am not aware of any construct in CF that would
support the automatic division of one step on the time dimension
into multiple time intervals.
To answer your first question, the software that I know of today
would not automatically know how to interpret your sps dimensions.
As a programmer I understand your encoding, and know how to make a
customized program to reassemble the time series as intended, but
that is not what you asked.
A straightforward way under CF (the only way?) to handle these data
is to have only 1-D variables, and a separate time dimension and
time coordinate for each data variable. Also you must switch from
integer to float or double for the time2 and time3 coordinates,
because you need fractions of one second.
dimensions:
time1 = 16081 ;
time2 = 160801 ;
time3 = 402001 ;
variables:
float time1(time1) ;
time1:units = "seconds since 2007-11-07 17:54:00 +" ;
float time2(time2) ;
time2:units = "seconds since 2007-11-07 17:54:00 +" ;
float time3(time3) ;
time3:units = "seconds since 2007-11-07 17:54:00 +" ;
float VAR1(time1) ;
float VAR2(time2) ;
float VAR3(time3) ;
By this scheme, software written for CF and COARDS should easily be
able to read these time series. Note also that there is no padding
of the lower rate variables. Will this be sufficient?
--Dave
On Jan 4 2011, Janine Goldstein Aquino wrote:
Hi all,
I have multiple rates of data (1sps, 10sps, 25sps, or higher) in a
single file and am trying to handle this in a CF compliant way without
having to resort to a time dimension at the highest rate, leading to
inordinate amounts of padding in lower rate variables. As far as I can
tell, CF does not address this case directly.
We have been using something like the following. My question is, if
reading this file in an automated fashion, would you know to interpret
the sps dimensions as additional time information? If not, is this
something that should be addressed within CF? Is there a better way to
do this?
Any and all feedback appreciated! Thanks so much,
Janine Aquino
NCAR/EOL/RAF
netcdf ICE-Lrf01h {
dimensions:
Time = 16081 ;
sps1 = 1 ;
sps25 = 25 ;
sps10 = 10 ;
variables:
int Time(Time) ;
Time:long_name = "time of measurement" ;
Time:standard_name = "time" ;
Time:units = "seconds since 2007-11-07 17:54:00 +" ;
Time:strptime_format = "seconds since %F %T %z" ;
float VAR1(Time, sps1) ;
VAR1:_FillValue = -32767.f ;
VAR1:units = "count" ;
VAR1:long_name = "Fred" ;
VAR1:SampledRate = 1 ;
float VAR2(Time, sps10) ;
VAR2:_FillValue = -32767.f ;
VAR2:units = "msec" ;
VAR2:long_name = "Wilma" ;
VAR2:SampledRate = 10 ;
float VAR3(Time, sps25) ;
VAR3:_FillValue = -32767.f ;
VAR3:units = "degree" ;
VAR3:long_name = "Barney" ;
VAR3:SampledRate = 25 ;
// global attributes:
:Source = "NCAR Research Aviation Facility" ;
:Address = "P.O. Box 3000, Boulder, CO 80307-3000" ;
:Phone = "(303) 497-1030" ;
:Conventions = "NCAR-RAF/nimbus" ;
:ConventionsURL =
"http://www.eol.ucar.edu/raf/Software/netCDF.html"; ;
:ConventionsVersion = "1.3" ;
:ProcessorRevision = "4453" ;
:ProcessorURL = "http://svn/svn/raf/trunk/nimbus"; ;
:DateProcessed = "2009-06-11 22:01:28 +" ;
:ProjectName = "ICE-L" ;
:Platform = "N130AR" ;
:ProjectNumber = "ICE-L" ;
:FlightNumber = "rf01" ;
:FlightDate = "11/07/2007" ;
:InterpolationMethod = "Linear" ;
:coordinates = "LONC LATC GGALT Time" ;
:wind_field = "WSC WDC WIC" ;
:landmarks = "39.191 -106.817 Aspen,36.407 -105.573 Taos,37.275
-107.879 Durango,40.7858 -111.979 Alta,38.573 -109.549 Moab,39.9088
-105.117 BJC
,39.5701 -104.849 Centl,41.1556 -104.811 CYS,38.8058 -104.7 COS,38.9697
-104.813
AFF,38.2891 -104.497 PUB,35.0402 -106.609 ABQ,41.312 -105.675
LAR,39.8584 -104.
667 DEN,40.2333 -103.667 FtMpp,40.8667 -105.033 RawHpp,40.8712 -104.715
Pawnee,4
2.908 -106.464 CPR,43.0642 -108.46 RIW,42.8375 -103.095 CDR,42.0532
-102.804 AIA
,41.1013 -102.985 SNY,41.874 -103.596 BFF,40.4518 -105.011 FNL,40.4374
-104.633
GXY,42.0555 -104.929 EAN,42.7972 -105.386 DGW,44.0453 -103.057
RAP,42.7538 -104.
405 LSK,42.0645 -104.153 TOR,41.1881 -103.677 IBM" ;
:TimeInterval = "17:54:00-22:22:00" ;
:Categories = "Position,Thermodynamic,Aircraft State,Atmos.
State,Liquid Water,Uncorr\'d Raw,Wind,PMS
Probe,Housekeeping,Chemistry,Radiation,Non-Stan
