Re: [CF-metadata] new standard_name needed for cloud_phase (an enumeration type) - GOES-R
On 7 July 2015 - Reply by Mike Carlomusto: Alison, I agree with your assessment - the proposed standard name cloud_phase_category and the existing standard name thermodynamic_phase_of_cloud_water_particles_at_cloud_top are redundant. Your proposed addition of three values - clear_sky, super_cooled_liquid_water and unknown - to thermodynamic_phase_of_cloud_water_particles_at_cloud_top is an excellent solution and acceptable for the GOES-R Cloud Top Phase product. Mike On 3 July 2015 Alison Pamment wrote: Thread new standard_name needed for cloud_phase (an enumeration type) (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2013/056424.html) Current status: Under discussion. cloud_phase_category (canonical units: 1) 'Cloud phase category is a string, taking one of the following standardised values: clear_sky, liquid_water, super_cooled_liquid_water, mixed_phase, ice, unknown. For a data variable it is encoded as an integer using flag_values and flag_meanings.' This name received some brief discussion on the mailing list and was agreed at the time. However, I was looking through existing names whose definitions also refer to flag_values and flag_meanings because I wanted to check that the wording of the proposed definition is broadly consistent. In doing so I came across the name thermodynamic_phase_of_cloud_water_particles_at_cloud_top, introduced into the standard name table at Version 24 (June 2013), for use with Meteosat Second Generation (MSG) data. The existing name is defined as follows: ' cloud_top refers to the top of the highest cloud. Water means water in all phases. A variable with the standard name of thermodynamic_phase_of_cloud_water_particles_at_cloud_top contains integers which can be translated to strings using flag_values and flag_meanings attributes. Alternatively, the data variable may contain strings which indicate the thermodynamic phase. These strings are standardised. Values must be chosen from the following list: liquid; ice; mixed.' Although the list of standardised values is not the same as proposed for GOES-R, I think the existing name is basically the same quantity as the one requested. My suggestion is that, instead of adding the new name, we expand the definition of the existing name to allow for all the strings needed for both MSG and GOES-R data, as follows: ' cloud_top refers to the top of the highest cloud. Water means water in all phases. A variable with the standard name of thermodynamic_phase_of_cloud_water_particles_at_cloud_top contains integers which can be translated to strings using flag_values and flag_meanings attributes. Alternatively, the data variable may contain strings which indicate the thermodynamic phase. These strings are standardised. Values must be chosen from the following list: liquid; ice; mixed; clear_sky; super_cooled_liquid_water; unknown.' The standardised strings for liquid_water and mixed_phase would be slightly different from those agreed in the discussion of the current proposal, but if the names are to be combined I think we would need to stick with the earlier strings so as not to invalidate existing MSG data. Expanding the list of standardised strings would not affect existing data as I don't think there is any requirement to use all possible values of flag_values and flag_meanings within a particular data variable. One of the reasons for using standard names in CF is to avoid accidental duplication of quantities with the same meaning but different names, so I think that expanding the existing definition is the right way to go. Do you agree? Michael Carlomusto mcarl...@harris.commailto:mcarl...@harris.com Harris Corp. Government Communications Systems Division (GCSD), GOES-R Ground System Melbourne, FL, USA (321) 309-7905 ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] Proposed Standard Name: dvorak_tropical_cyclone_current_intensity_number
Thread: Proposed Standard Name: dvorak_tropical_cyclone_current_intensity_number (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2014/057271.html) Alison Pamment wrote on 2 July 2015: Current status: under discussion dvorak_tropical_cyclone_current_intensity_number (canonical units: 1) ' Dvorak current intensity number means the ranking (1 to 8) of tropical cyclone strength derived using the Advanced Dvorak Technique based on satellite observations, which has been empirically related to maximum sustained 1-minute wind speed and mean sea level atmospheric pressure.' No comments were received on this name following the original proposal. Having done some reading around the subject, it appears that the Current Intensity (CI) number relates cyclone intensity to maximum wind speed in particular, rather than mean sea level pressure (MSLP). The relationship between intensity and MSLP seems to be summarized in the Tropical (T) number which I think is the subject of proposal 6b (standard name proposal of dvorak_tropical_number). Please can you confirm whether this is correct? The definitions of 6a and 6b should make clear the difference between the two names and a reference to the Advanced Dvorak Technique should be added. The name itself and the canonical units are fine. Reply by Michael Carlomusto on 3 July 2015: You are correct, Alison. CI number and T number have similar definitions and the CI number does map to a maximum wind speed. It is derived though by applying a series of intensity constraints based on previous Dvorak T number trends. For weakening storms, for example, the CI number will remain higher since its source data spans a longer period of time than the T number. I would like to submit the following revised proposal to further distinguish this standard name from dvorak_tropical_number: dvorak_tropical_cyclone_current_intensity_number (canonical units: 1) ' Dvorak current intensity number indicates the ranking of tropical cyclone strength (ranging from 1.0 to 8.0, increasing with storm intensity). The current intensity (CI) number is derived using the Advanced Dvorak Technique based on satellite observations over time. The CI number maps to a maximum sustained 1-minute wind speed and is derived by applying a series of intensity constraints to previous Dvorak-calculated trends of the same storm. See Olander, T. L., Velden, C. S., The Advanced Dvorak Technique: Continued Development of an Objective Scheme to Estimate Tropical Cyclone Intensity Using Geostationary Infrared Satellite Imagery (2007). American Meteorological Society Weather and Forecasting, 22, 287-298. ' This information is only intended for the use of the individual or entity named in this email. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the contents of this information is strictly prohibited. If you have received this email in error, please notify me and delete it immediately. Michael Carlomusto mcarl...@harris.commailto:mcarl...@harris.com Harris Corp. Government Communications Systems Division (GCSD) Melbourne, FL (321) 309-7905 ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] new standard name: automated_tropical_cyclone_forecasting_system_storm_identifier
Thread: new standard name: automated_tropical_cyclone_forecasting_system_storm_identifier (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2014/057390.html) Current status: Under discussion. automated_tropical_cyclone_forecasting_system_storm_identifier (canonical units: 1) ' Definition: Contains an 8 character string, BBCC which identifies a tropical cyclone. A string type variable should not normally have a units attribute. BB is the ocean basin, specifically: AL - North Atlantic basin; north of the Equator SL - South Atlantic basin; south of the Equator EP - North East Pacific basin; eastward of 140 degrees west longitude CP - North Central Pacific basin; between the dateline and 140 degrees west longitude WP -North West Pacific basin; westward of the dateline IO - North Indian Ocean basin; north of the Equator between 40 and 100 degrees east longitude SH - South Pacific Ocean basin and South Indian Ocean basin CC is the cyclone number. Numbers 01 through 49 are reserved for tropical and subtropical cyclones. A cyclone number is assigned to each tropical or subtropical cyclone in each basin as it develops. Numbers are assigned in chronological order. Numbers 50 through 79 are reserved for internal use by operational forecast centers. Numbers 80 through 89 are reserved for training, exercises and testing. Numbers 90 through 99 are reserved for tropical disturbances having the potential to become tropical or subtropical cyclones. The 90's are assigned sequentially and reused throughout the calendar year. is the four-digit year Calendar year for the northern hemisphere. For the southern hemisphere, the year begins July 1, with calendar year plus one.' Alison Pamment wrote on 2 July 2015: No comments were received on this name following the original proposal. We have existing standard names for string valued variables such as region, area_type, platform_name and sensor_band_identifier. The values of the first two are standardised while the second two are not. The proposed name would be another example of a standardised string valued variable and the possible values are described in the definition, so that is fine. A string type variable should not normally have a units attribute so the canonical units should be left blank. (I've added a sentence to the definition regarding units). As for the name itself, is there only one automated tropical cyclone forecasting system in existence? I.e. is the naming convention referred to in this name universally recognised or are there any competitor names that could be assigned to the same cyclone by a different forecasting system? Reply by Michael Carlomusto on 3 July 2015: To answer Alison's questions - 1) There is only one Automated Tropical Cyclone Forecasting System (ATCF) which was first defined in an American Meteorological Society journal - Miller, R.J., Schrader, A.J., Sampson, C.R., Tsui, T.L. (1990). The Automated Tropical Cyclone Forecasting System (ATCF), Computer Techniques, 5, 653-660. 2) There are many tropical cyclone naming conventions, both current and deprecated, but only one ATCF storm identifier. I would like to submit the following revised proposal (Alison - please edit/delete the canonical units according to the convention. I literally just left it blank. Thanks): automated_tropical_cyclone_forecasting_system_storm_identifier (canonical units: ) ' Definition: The Automated Tropical Cyclone Forecasting System (ATCF) storm identifier is an 8 character string which identifies a tropical cyclone. A string type variable should not normally have a units attribute. The storm identifier has the form BBCC, where BB is the ocean basin, specifically: AL - North Atlantic basin, north of the Equator; SL - South Atlantic basin, south of the Equator; EP - North East Pacific basin, eastward of 140 degrees west longitude; CP - North Central Pacific basin, between the dateline and 140 degrees west longitude; WP -North West Pacific basin, westward of the dateline; IO - North Indian Ocean basin, north of the Equator between 40 and 100 degrees east longitude; SH - South Pacific Ocean basin and South Indian Ocean basin. CC is the cyclone number. Numbers 01 through 49 are reserved for tropical and subtropical cyclones. A cyclone number is assigned to each tropical or subtropical cyclone in each basin as it develops. Numbers are assigned in chronological order. Numbers 50 through 79 are reserved for internal use by operational forecast centers. Numbers 80 through 89 are reserved for training, exercises and testing. Numbers 90 through 99 are reserved for tropical disturbances having the potential to become tropical or subtropical cyclones. The 90's are assigned sequentially and reused throughout the calendar year. is the four-digit year. This is calendar year for the northern hemisphere. For the southern hemisphere, the year begins July 1, with calendar year plus one. See
Re: [CF-metadata] Proposed Standard Name: dvorak_tropical_number
Thread: Proposed Standard Name: dvorak_tropical_number (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2014/057272.html) Current status: under discussion dvorak_tropical_number (canonical units: 1) ' dvorak_tropical_number means the tropical number derived using the Advanced Dvorak Technique based on satellite observations, which has been empirically related to maximum sustained 1-minute wind speed and mean sea level atmospheric pressure.' Alison Pamment wrote on 2 July 2015: No comments were received on this name following the original proposal. Please can you confirm whether my interpretation of 6a and 6b is correct (see 6a). I suggest that this name should be dvorak_tropical_cyclone_number for consistency of wording with 6a and to make clear that it relates to cyclones. The units are fine. On the related dvorak_tropical_cyclone_intensity_number proposal (aka 6a), Alison wrote: Having done some reading around the subject, it appears that the Current Intensity (CI) number relates cyclone intensity to maximum wind speed in particular, rather than mean sea level pressure (MSLP). The relationship between intensity and MSLP seems to be summarized in the Tropical (T) number which I think is the subject of proposal 6b. Please can you confirm whether this is correct? The definitions of 6a and 6b should make clear the difference between the two names and a reference to the Advanced Dvorak Technique should be added. Reply by Mike Carlomusto 3 July 2015: Alison, you are correct. The calculation of the Dvorak T number (proposed standard name dvorak_tropical_number) uses maximum wind speeds and mean sea level pressure. The GOES-R Hurricane Intensity Estimate product will contain variables raw_T_number, adjusted_raw_T_number and final_T_number which will all use the same standard name (dvorak_tropical_number). I disagree that the proposed standard name should change from dvorak_tropical_number to dvorak_tropical_cyclone_number. The latter looks more like a cyclone identifier, which it is not. I would like to submit the following revised proposal: dvorak_tropical_number (canonical units: 1) ' Definition: The Advanced Dvorak Technique (ADT) is used to derive a set of Dvorak Tropical numbers using an objective pattern recognition algorithm to determine the intensity of a tropical cyclone by matching observed brightness temperature patterns, maximum sustained winds and minimum sea level pressure to a set of pre-defined tropical cyclone structures. Dvorak Tropical numbers range from 1.0 to 8.0, increasing with storm intensity. See Olander, T. L., Velden, C. S., The Advanced Dvorak Technique: Continued Development of an Objective Scheme to Estimate Tropical Cyclone Intensity Using Geostationary Infrared Satellite Imagery (2007). American Meterorological Society Weather and Forecasting, 22, 287-298. ' This information is only intended for the use of the individual or entity named in this email. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the contents of this information is strictly prohibited. If you have received this email in error, please notify me and delete it immediately. Michael Carlomusto mcarl...@harris.commailto:mcarl...@harris.com Harris Corp. Government Communications Systems Division (GCSD) Melbourne, FL (321) 309-7905 ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] Units for dimensionless quantities
Good day. As a data producer I am seeking a resolution on the use of units=1 for dimensionless quantities. Page 10 of CF Metadata Conventions version 1.6 states: Units are not required for dimensionless quantities. A variable with no units attribute is assumed to be dimensionless. However, a units attribute specifying a dimensionless unit may optionally be included. The Udunits package defines a few dimensionless units, such as percent, but is lacking commonly used units such as ppm (parts per million). This convention does not support the addition of new dimensionless units that are not udunits compatible. The conforming unit for quantities that represent fractions, or parts of a whole, is 1. This clearly states that units=1 should be used for fractions or parts of a whole. However, in the standard name table, units=1 is used for dimensionless quantities that are not fractions. See for example, land_binary_mask or sea_ice_classification. Is units=1 valid for dimensionless quantities that are not fractions? Or is units=1 simply used as the default for all standard names that are dimensionless? What units if any should be used for a variable named number_of_cloud_pixels in a dataset containing a satellite image of the earth? Thank you. Michael Carlomusto mcarl...@harris.com Harris Corp. GOES-R Ground System Melbourne, FL, USA +1-321-309-7905 ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
[CF-metadata] Reflectance channel satellite imagery units
We're producing a satellite imagery product where the pixel values are reflectance factors which is unitless. What unit definition should we be using to comply with CF? Mike Carlomusto Michael Carlomusto mcarl...@harris.commailto:mcarl...@harris.com Harris Corp. Government Communications Systems Division (GCSD) Melbourne, FL (321) 309-7905 ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] Reflectance channel satellite imagery units
Jonathan, We thought about using 1', but Paragraph 3.1 in CF 1.6 states 1 can be used for fractions or parts of a whole. Reflectance factor is neither a fraction nor part of a whole so I think the better option is Jim's suggestion - no units attribute, unless we're missing something about the uses of 1. Mike -Original Message- From: cf-metadata-boun...@cgd.ucar.edu [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of Jonathan Gregory Sent: Monday, May 14, 2012 9:51 AM To: cf-metadata@cgd.ucar.edu Subject: Re: [CF-metadata] Reflectance channel satellite imagery units Dear Mike We?re producing a satellite imagery product where the pixel values are ?reflectance factors? which is unitless. What unit definition should we be using to comply with CF? Jim is correct that you can omit the units attribute. It is also permissible and may be more informative to code units=1. A dimensionless number is a legal udunit. Best wishes Jonathan ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
[CF-metadata] FW: GOES-R metadata prototype
_ From: Carlomusto, Michael Sent: Wednesday, March 07, 2012 5:20 PM To: 'CF-metadata@cgd.ucar.edu' Subject: GOES-R metadata prototype The attached NcML file has been vetted by a small group of people from the CF metadata list, especially with regard to the representation of the proposed GOES projection. I would like to submit it for comments to the larger group. I encourage a critical evaluation. Thanks. Mike Carlomusto This information is only intended for the use of the individual or entity named in this email. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the contents of this information is strictly prohibited. If you have received this email in error, please notify me and delete it immediately. Michael Carlomusto mcarl...@harris.com Harris Corp. Government Communications Systems Division (GCSD) Melbourne, FL (321) 309-7905 ?xml version='1.0' encoding='UTF-8'? netcdf xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance; xsi:schemaLocation=http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2 http://www.unidata.ucar.edu/schemas/netcdf/ncml-2.2.xsd; xmlns=http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2; !-- Title : Volcanic Ash Product -- !-- Identifier / Metadata Reference -- !-- global attributes -- attribute name=id value=ef175830-cc1c-11e0-bfd6-0800200c9a66 type=string/ attribute name=dataset_name value=OR_ABI-L2-VAAF-M3_G16_s2011177060530_e2011177062030_c2011177080607.nc type=string/ attribute name=naming_authority value=gov.noaa.goes-r, SE-21_GS_8021130_Metadata_Model_Rev-A_Final.docx type=string/ attribute name=iso_series_metadata_id value=a70be540-c38b-11e0-962b-0800200c9a66/ attribute name=Conventions value=CF-1.6 type=string/ attribute name=Metadata_Conventions value=Unidata Dataset Discovery v1.0, CF-1.6 type=string/ attribute name=standard_name type=string value=volcanic_ash_detection_and_height/ attribute name=standard_name_vocabulary value=CF Standard Name Table (v18, 22 July 2011) type=string/ attribute name=title value=Advanced Baseline Imager (ABI) Level 2+ Volcanic Ash: Detection and Height type=string/ attribute name=summary value=The volcanic ash product provides an estimation of cloud height and mass loading (mass per unit area) of volcanic ash clouds observed by the Advanced Baseline Imager (ABI)... type=string/ attribute name=keywords value=Spectral/EngineeringSensor CharacteristicsImager type=string/ attribute name=keywords_vocabulary value=NASA Global Change Master Directory (GCMD) Earth Science Keywords, Version 6.0 type=string/ attribute name=platform value=GOES-16 type=string/ attribute name=sensor value=GOES 16 Imager type=string/ attribute name=license value=Unclassified data. Access is restricted to approved users only. type=string/ attribute name=processing_level value=National Aeronautics and Space Administration (NASA) L2 type=string/ attribute name=institution value=DOC/NOAA/NESDIS U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Services type=string/ attribute name=date_created value=2016-09-09T14:45:00Z type=string/ attribute name=processing_site value=NSOF type=string/ attribute name=satellite_position_flag type=string value=G16/ attribute name=spatial_resolution type=string value=2km at nadir/ attribute name=scene_id value=Full Disk type=string/ attribute name=cdm_data_type value=Grid type=string/ attribute name=project value=GOES type=string/ attribute name=time_coverage_start value=2016-09-09T14:30:00Z type=string/ attribute name=time_coverage_end value=2016-09-09T14:35:00Z type=string/ attribute name=timeline_id value=ABI Mode 3 type=string/ attribute name=platform_ID value=G16 type=string/ attribute name=instrument_ID value=ABI-1 type=string/ attribute name=percent_uncorrectable_L0_errors type=float value=3.45/ attribute name=nominal_satellite_subpoint_lat type=float value=0.0/ attribute name=nominal_satellite_subpoint_long type=float value=75.0/ attribute name=nominal_satellite_height type=string value=35000 km/ !-- Dimension Statements -- dimension name=y length= 5424 isUnlimited =false/ dimension name=x length= 5424 isUnlimited =false/ dimension name=t length=1 isUnlimited=false/ dimension name=number_of_time_values length=2 isUnlimited=false/ !-- GOES Projection Coordinates y and x -- variable name=y type=short shape=y attribute name=scale_factor value=0.56 type=float/ attribute name=offset value=-0.151844 type=float/ attribute name=units value=radians type=string/ attribute name=axis value=Y type=string/ attribute name=long_name value=GOES Projection y-Coordinate type=string/ attribute name=standard_name
