BUFR TABLES RELATIVE TO SECTION 3 (Version 13) (updated 11 July 2007)
(For full operational use on 7 November 2007)
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(1) Where a code table or flag table is appropriate, "code table" or "flag table" respectively is entered in the UNITS column.
(2) The code tables and flag tables associated with Table B are numbered to correspond with the F, X and Y part of the table reference.
(3) To encode values into BUFR, the data (with units as specified in the UNITS column) must be multiplied by 10 to the power SCALE. Then subtract the REFERENCE VALUE to give the coded value found in Section 4 of the BUFR message. For example, a measured latitude is -45.76 degrees. The coarse accuracy descriptor is 0 05 002 and the encoded value is -45.76 x 102 - (-9000) = 4424.
(4) Where UNITS are given as CCITT IA5, data shall be coded as character data left justified within the field width indicated using CCITT International Alphabet No. 5, and blank filled to the full field width indicated.
(5) Classes 48 to 63 are reserved for local use; all other classes are reserved for future development.
(6) Entries 192 to 255 within all classes are reserved for local use.
(7) The use of local descriptors, as defined in Notes (5) and (6), in messages intended for non-local or international exchange is strongly discouraged. They should be kept to the barest minimum possible and must also be by-passed by the use of descriptor 2 06 YYY.
(8) First-order statistics are included in Table B only when they are produced, as such, by the observing system.
(9) In all flag tables within the BUFR specification, bits are numbered from 1 to N from the most significant to least significant within a data width of N bits, i.e. bit No.1 is the leftmost and bit No. N is the rightmost bit within the data width. The bit No. N (the least significant bit) is set to 1 only if all the bits are set to 1 within the data width of the flag table to represent a missing value.
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(1) For CREX descriptors F = B, not 0.
(2) Master Tables are described in Note (2) to Section 1 of the BUFR regulations.
(3) BUFR Master Table Version Numbers are described in Notes (2) and (4) to Section 1 of the BUFR regulations for edition 3, and in Notes (2) and (5) to Section 1 of the BUFR regulations for edition 4.
(4) CREX Master Table Version Numbers are described in Note (1) to Section 1 of the CREX regulations.
(5) Local Table version number (see Note (2) to Section 1 of the BUFR regulations.
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(1) The storm identifier (descriptor 0 01 025) has the following meaning: the first two characters shall be a numeric sequence number assigned by the originator of the message; the third character is a letter indicating the ocean basin where the storm is located, as follows:
W | >
NW Pacific Ocean |
E |
NE Pacific Ocean to 140°W |
C |
NE Pacific Ocean 140°W - 180°W |
L |
N Atlantic Ocean, including Caribbean and Gulf of Mexico |
A |
N Arabian Sea |
B |
Bay of Bengal |
S |
S Indian Ocean |
P |
S Pacific Ocean |
F |
RSMC Nadi's zone in South Pacific |
U |
Australia |
O |
South China Sea |
T |
East China Sea |
There is no requirement that differing observers coordinate sequence numbers even though they both may be reporting the same storm.
(2) WMO storm name (descriptor 0 01 027): the storm name NAMELESS shall be used in those cases where an identifiable tropical disturbance has not reached tropical storm strength and has not been assigned an official name.
(3) Where a centre other than the originating centre generates quality information, replacement or substitute values, and/or statistical information, the centre may be indicated by using 0 01 033.
(4) A generating centre may wish to indicate a reference to the application that generated quality information, etc.; it may use descriptor 0 01 032 for this purpose. However, the corresponding code tables will vary from centre to centre.
(5) Code table 0 01 032 is to be generated by each centre.
(6) The components of absolute platform velocity (0 01 041, 0 01 042, 0 01 043) are defined as follows:
First component: |
From the Earths centre to 0 degree longitude at the Equator: velocity of the platform along this line relative to the Earths centre. |
Second component: |
From the Earths centre to 90 degrees East longitude at the Equator: velocity of the platform along this line relative to the Earths centre. |
Third component: |
From the Earths centre to the North Pole: velocity of the platform along this line relative to the Earths centre. |
(7) The values for descriptors 0 01 041, 0 01 042 and 0 01 043 have been chosen to be suitable for polar orbiting satellites in approximately Sun-synchronous orbits. Geostationary orbits would require greater data widths for distance and slightly less for speed.
(8) Left handed xyz axes have been chosen for descriptors 0 01 041, 0 01 042 and 0 01 043.
(9) Descriptor 0 01 020 should be used instead of 0 01 004 for encoding this element.
(10) Descriptor 0 01 033 shall be used instead of descriptor 0 01 031 for encoding originating/generating centre. Code table 0 01 034 is to be established by the associated originating/generating centre identified by descriptor 0 01 033 and provided to the Secretariat for publication.
(11) For 0 01 022, the character string representing the "Name of feature" should be of the form: "Type of phenomenon" - "Location or geographical name" (e.g.: "volcano - Popocatepetl", "oil fire - Kuwait")
(12) Descriptor 0-01-082 is to be used for reporting the sequential number of the current radiosonde reporting period (e.g. synoptic cycle) within a given year or other similar locally-defined length of time. Descriptor 0-01-083 is to be used in the case of multiple sequential radiosonde releases during a single reporting period (e.g. synoptic cycle), in order to indicate which particular release generated the corresponding data values.
(13) The value of this feature could be a string of characters, which contains the name of the model and other useful elements such as the model mesh.
(14) Descriptor 0 01 027 should be used instead of 0 01 026 to encode this element.
(15) Descriptors 0 01 012 and 0 01 013 may relate to parameters of various meanings and the corresponding values may be integrated on different periods.
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(1) This class shall contain elements to describe the instrumentation used to obtain the meteorological elements reported.
(2) This class may also contain elements relating to observational procedures.
(3) Some indication of expected accuracy may be implied in conjunction with certain elements in this class.
(4) Note that descriptor 0 02 140 is the Azimuth angle measured anticlockwise from satellite heading vector.
(5) In descriptor 0 02 142: Ozone instrument serial number/identification is four characters long. For Japanese Dobsons instruments, omit the leading digit(s).
(6) Descriptor 0 02 019 should be used instead of descriptor 0 02 152 for single satellite instrument identification.
(7) Note missing (0 02 73)
(8) Descriptor 0 02 152 should be used instead of 0 02 021 for encoding this element.
(9) This constant is defined as follows: Z = P + radar constant where Z = the reflectivity of target in beam direction (dBZ); P = the input receiver power above 1 mW (dBm).
This constant is used to normalize the signal to the equivalent 100 km range.
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(1) The significance of time periods or displacements may be indicated using the time significance code corresponding to table reference 0 08 021.
(2) Where more than one time period or displacement is required to define complex time structures, they shall be defined in immediate succession, and the following ordering shall apply: ensemble period (if required), followed by forecast period (if required), followed by period for averaging or accumulation (if required).
(3) Time periods or displacements and time increments require an initial time location to be defined prior to their use, followed where appropriate by a time significance definition.
(4) The time location, when used with forecast values, shall indicate the time of the initial state for the forecast, or the beginning of the forecast period; when used with ensemble means of forecast values, the time location shall indicate the initial state or the beginning of the first forecast over which ensemble means are derived.
(5) Negative time periods or displacements shall be used to indicate time periods or displacements preceding the currently defined time.
(6) Descriptor 0 04 041 has been replaced by the combination of 0 08 025 and 0 26 003 and should not be used for encoding this element.
(7) All times are Universal Time Coordinated (UTC) unless otherwise noted.
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(1) Values of latitude and latitude increments are limited to the range -90 degrees to +90 degrees.
(2) South latitude shall be assigned negative values.
(3) North to south increments shall be assigned negative values.
(4) Bearing or azimuth shall only be used with respect to a stated location, and shall not redefine that location.
(5) The Pixel size on horizontal - 1 is given at location where map scale factor is unity.
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(1) Values of longitude are limited to the range -180 degrees to +180 degrees.
(2) West longitude shall be assigned negative values.
(3) East to west increments shall be assigned negative values.
(4) Distance shall only be used with respect to a stated location and a bearing, azimuth or elevation; it shall not redefine that location.
(5) The Pixel size on horizontal - 2 is given at location where map scale factor is unity.
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(1) Regarding data from ground based stations, this descriptor should be used for archived data only. Descriptors 0 07 030 and 0 07 031 should be used and preferred to represent ground elevation and elevation of barometer, respectively, as defined in Observing Stations, WMO Publication No. 9, Volume A1. Regarding marine stations, this descriptor refers to the height above mean sea level of the deck of marine platform where the instruments stand.
(2) Elevation shall only be used with respect to a stated location and a bearing, azimuth or distance; it shall not redefine that location.
(3) Height of station ground above mean sea level is defined as the height above mean sea-level of the ground on which the raingauge stands or, if there is no raingauge, the ground beneath the thermometer screen. If there is neither raingauge nor screen, it is the average level of terrain in the vicinity of the station (Reference: Guide to Meteorological Instruments and Methods of Observation, WMO-No. 8. 1996).
(4) Height of barometer above mean sea level, referring to the location of barometer of a station, does not redefine the descriptor 0 07 030.
(5) Height of sensor above local ground (or deck of marine platform) is the actual height of sensor above ground (or deck of marine platform) at the point where the sensor is located. This descriptor does not redefine the descriptor either 0 07 030 or 0 07 033. Previously defined value of 0 07 032 may be cancelled by setting 0 07 032 to a "missing value".
(6) Height of sensor above water surface is the height of sensor above water surface of sea or lake. This descriptor does not redefine the descriptor either 0 07 030 or 0 07 032. Previously defined value of 0 07 033 may be cancelled by setting 0 07 033 to a "missing value".
(7) Representative height of sensor above station is the standard height of a sensor required by WMO documentation. Value of the following meteorological element should be adjusted using a formula. For example, standard height recommended in WMO documentation for surface wind sensors is 10 metres. If the sensor is placed at different height, the wind speed may be adjusted using a formula.
(8) For an atmospheric limb sounder, the "impact parameter" is the distance between the ray asymptote and the centre of curvature of the Earths surface at the tangent point.
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(1) Where values are accumulated or averaged (for example over a time period), the total number of values from which the accumulated or averaged values are obtained may be represented using reference 0 08 022.
(2) A previously defined significance may be cancelled by transmitting a "missing" from the appropriate code or flag table.
(3) First order statistics have values with a similar range and the same dimensions as the corresponding reported values (e.g., maxima, minima, means, etc.).
(4) Difference statistics are difference values; they have dimensions similar to the corresponding reported values with respect to units, but assume a range centred on zero (e.g., the difference between reported and analysed values, the difference between reported and forecast values, etc.).
(5) Descriptor 0 08 025 is to be used with 0 26 003 (time difference).
(6) Descriptor 0 08 033 is to be used by preceding the element 0 33 007 as part of quality control information in order to specify the method used to calculate the percentage confidence.
(7) When descriptor 008043 is used to specify particulate matter under a given size threshold, descriptor 008045 may also be used to further specify a subset of the PM population on the basis of ion composition. (Missing reference)
(8) Descriptor 0 08 090 is to be used to establish the decimal scale of one or more subsequent numerical element descriptors requiring a large dynamic range of values. The numerical element descriptor(s) will contain the scaled value of the measurement(s) with the required number of significant digits. The actual value will be obtained, at the application level, by multiplying the scaled value by the given decimal scale : (scaled value * 10decimal scale). (Missing Reference)
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(1) Vertical elements and pressure shall be used to define values of these elements independent of the element or variable denoting the vertical coordinate.
(2) The value for descriptor 0 10 031 has been chosen to be suitable for polar orbiting satellites in approximately sun-synchronous orbits. Geostationary orbits would require greater data widths for distance and slightly less for speed.
(3) Left handed xyz axes have been chosen for descriptor 0 10 031.
(4) The "geoid undulation" is the difference between the reference ellipsoid (WGS-84) and the geoid height (EGM96) at the geographic location of the observation, both referenced to the centre of mass of the Earth.
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(1) West to east u-components shall be assigned positive values.
(2) South to north v-components shall be assigned positive values.
(3) Upward w-components shall be assigned positive values where units are m s-1.
(4) Downward w-components shall be assigned positive values where units are Pa s-1.
(5) Wind reporting standards:
Speed |
Direction |
|
No observation |
Missing |
Missing |
Calm |
0 |
0 |
Normal observation |
> 0 |
1° - 360° |
Speed only |
> 0 |
Missing |
Direction only |
Missing |
1° - 360° |
"Light and variable" |
> 0 |
0 |
(6) The steadiness factor (descriptor 0 11 019) is the ratio of speed of the monthly mean vector wind to the speed of the monthly mean scalar wind expressed as a percentage. It is reported to the nearest one percent.
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(1) Where the expression "at height and over period specified" is entered under ELEMENT NAME, an appropriate vertical location shall be specified using descriptors from class 07, together with an appropriate period using descriptors from class 04.
(2) Descriptor 0 12 076 should be used instead of descriptor 0 12 072 to encode radiance.
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(1) A precipitation value of -0.1kg m-2 before scaling (-1 after scaling or in CREX) shall indicate a "trace" (non-measurable, less than 0.05 kg m-2).
(2) A snow depth value of -0.01 m before scaling (-1 after scaling or in CREX) shall indicate a little (less than 0.005 m) snow. A value of -0.02 m (-2 after scaling or in CREX) shall indicate "snow cover not continuous".
(3) The "parcel lifted index" (as defined in the International Meteorological Vocabulary (WMO-No. 182) under the listing "lifted index") is defined as the temperature difference between the ambient 500 hPa temperature (T500) and that of a parcel of air lifted from the surface (Tparcel) following the dry and moist adiabatic process. Negative values of (T500 - Tparcel) suggest instability. The "best lifted index" is defined as the most unstable of a collection of parcel lifted indices, with parcel initial conditions defined for a collection of 30 hPa thick layers stacked one upon the other with the lowest resting on the ground. Commonly four to six such layers are used in the calculation.
(4) Since the two lifted indices (042 and 043) are defined as temperature differences, they may take on negative values, even though the units are kelvin; hence the non-zero reference value.
(5) Descriptor 0 13 033 should be used instead of descriptor 0 13 032 to encode evaporation/evapotranspiration.
(6) Concerning descriptor 0 13 009, the originators of these data want to be able to retain the raw (i.e. unprocessed) relative humidity value reported by the sensor in order to be able to track, among other things, when a sensor begins to malfunction. The latter case is when a negative value might occur. For world-wide exchange with other countries, it is possible that only the processed data would ever be sent.
(7) The "Modified Showalter stability index" is defined as the temperature difference between the ambient 500 hPa temperature and the temperature a parcel of air, initially at a selected base level, would have if brought from its condensation level to the 500 hPa surface by a moist adiabatic process. Positive values denote stable conditions, while negative values denote unstable conditions. The base level is 850 hPa, 800hPa or 750 hPa if the station elevation is less than 1000, 1000 to 1400 or 1401 to 2000 gpm above mean sea level, respectively.
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(1) Downward radiation shall be assigned negative values.
(2) Upward radiation shall be assigned positive values.
(3) Where the expression "period specified" is entered under ELEMENT NAME, an appropriate period shall be specified using descriptors from class 04.
(4) Channel radiance (014045) uses cm to represent the wave number.
(5) Emissivity is the ratio of the amount of energy emitted from a particular object compared to the amount that would be emitted by a blackbody at the same temperature (I.e. the Planck function). Multiplying by 100 gives a percent (and provides 2 digits of precision at the same time).
(6) An offset has been introduced for the scaled IASI radiances (0-14-046). This is to accommodate the negative radiances which can be measured at some wave numbers, either due to effects of noise or remaining after apodisation. The offset is an order of magnitude larger than the expected maximum negative excursion based on instrument noise, and so would leave sufficient margin. At the same time the dynamic range is not significantly degraded.
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(1) 0 15 003 is partial pressur of ozone, measured at the pressure level identified by 0 07 004.
(2) 0 15 004 (CF) is defined as:
CF = TOI/TOS
where TOI is the integrated ozone value obtained "simultaneously to a sounding" from a Dobson or Brewer spectrophotometer at the site or "nearby" and TOS is the total ozone obtained from the sounding. TOS is sum of the integrated ozone below the lowest pressure level reached by the sounding and the estimate of the amount above. In the absence of any spectrophotometer measurement, CF = Missing value.
(3) 0 15 005 is the value obtained as the result of the vertical integration of the sounding values (0 15 003) measured below the lowest pressure level reached by the sonde, multiplied by 0 15 004.
(4) DU = Dobson unit.
(5) The refractivity, N, is related to the refractive index, n by the formula N = 106 (n - 1). N is therefore dimensionless but values computed by the formula are by convention described as being in N-units.
(6) Scaled descriptors should be preceded by descriptor 008090 which indicates the decimal magnitude of the scaled value. See note concerning descriptor 0 08 090 for further details.
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(1) The effective radius of feature shall be defined with respect to the radius of the 1000-hPa isobars at mean sea level.
(2) Maximum wind and effective radius of maximum wind shall be indicated by means of the 0 19 003 and 0 19 004 entries.
(3) For a stationary feature, both 019005 (Direction of motion of feature) and 019006 (Speed of motion of feature) shall be reported 0.
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(1) When encoding present weather reported from an automatic weather station, the appropriate combination of descriptors 0-20-021, 0-20-022, 0-20-023, 0-20-024, 0-20-025, 0-20-026 and 0-20-027 should be used and preferred. A descriptor 0-20-003 should be used only when descriptors mentioned above are not applicable.
(2) When encoding past weather reported from an automatic weather station, the appropriate combination of descriptors 0-20-021, 0-20-022, 0-20-023, 0-20-024, 0-20-025, 0-20-026 and 0-20-027 should be used and preferred. Descriptors 0-20-004 or 0-20-005 should be used only when descriptors mentioned above are not applicable.
(3) The data width for descriptor 0 20 038 originally defined to be 12 is wrong. Nine bits are sufficient as for all the other "degree true" quantities. However, the 12-bit width is maintained for historical consistency. Also: A bearing of ice edge value 0 shall indicate "Ship in shore or flaw lead".
(4) Snow cover will be reported for each satellite pixel as a percentage of coverage of the pixel. It does not seem feasible to try to use existing descriptor 0 20 062 for such a purpose because the use of that descriptor additionally implies details on, e.g. snow drifts, wet compared to dry snow, etc. that a satellite obviously cannot accurately detect.
(5) A cloud cover (total) value 113 shall indicate "Sky obscured by fog and/other meteorological phenomena.
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Note 1 NOF = Normalized Objective Function
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(1) 0 25 014 nominal input range 0 - 2300
(2) The actual meaning may be obtained from the originator of the data.
(3) Descriptor 0 25 143 is intended for numerical, non-dimensional values to be used as coefficients in statistical or linear processing. Each instance of 025143 should be characterized by using an appropriate significance qualifier, such as 008026. Descriptor 143 is to be found in CREX document only
(4) Descriptor 0 25 009 is deprecated. 0 25 029 should be used instead
(5) The meaning of these quantities should be obtained from the originator of the data.
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Note 1 Descriptor 0 26 003 is to be used with 0 08 025 (time difference qualifier).
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(1) The alternate latitude may be used when the computation of the position yields multiple solutions and there is no a priori way to distinguish between them.
(2) The satellite location counter is calculated as:
counter = superswath no. x 1000 + box no. x 10 + minibox no.
(3) The satellite sublocation dimension is calculated as:
dimension = minibox dimension + box dimension
where: |
minibox dimension |
= lines x 1000 |
+ spots x 100 |
box dimension |
= lines x 10 |
+ spots |
(4) The value for descriptor 0 27 031 has been chosen to be suitable for polar orbiting satellites in approximately sun-synchronous orbits. Geostationary orbits would require greater data widths for distance and slightly less for speed.
(5) Left handed xyz axes have been chosen for descriptor 0 27 031.
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(1) The alternate longitude may be used when the computation of the position yields multiple solutions and there is no a priori way to distinguish between them.
(2) The value for descriptor 0 28 031 has been chosen to be suitable for polar orbiting satellites in approximately sun-synchronous orbits. Geostationary orbits would require greater data widths for distance and slightly less for speed.
(3) Left handed xyz axes have been chosen for descriptor 0 28 031.
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(1) Pixel data width can be changed with descriptor 2 01 YYY.
(2) In order to distinguish unambiguously the cases of missing data and saturated pixels, n-bit image data should be encoded using a data width of n+1. Where such a descriptor is not already available in Class 30, operator descriptor 2 01 YYY should be used to modify the data width of the existing entry as required.
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(1) The "delayed descriptor and data repetition factor" is intended for run-length encoding (e.g. scanning an image). It specifies a count N which applies to both descriptor and data, i.e. the value of the single element defined by the following descriptor is repeated N times (at intervals already specified).
(2) Descriptor 0 31 031, used in conjunction with quality control or statistics operators 2 22 YYY through 2 32 YYY, shall indicate the presence of quality control information when the indicator value is set to zero. It may be used, in conjunction with the replication operator 1 01 YYY, to construct a table of data present/not present indicators, forming a data present bit-map as defined in Regulation 94.5.5.3. This makes it possible to present quality control information and statistical information for selected data corresponding to element descriptors which precede the 2 22 to 32 YYY operators.
(3) Other applications of the data present indicator may be developed.
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(1) When using descriptor 0-33-045 or 0-33-046, operator 2-41-000 shall be used in order to define the following event to which the reported probability value applies.
(2) When using descriptor 0-33-046, operator 2-42-000 shall precede the occurrence of this descriptor in order to define the event upon which the reported probability value is conditioned.
(3) When defining an event for use with descriptor 0-33-045 or 0-33-046, descriptor 0-33-042 may be employed in order to indicate that the following value is actually a bound for a range of values.
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