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BUFR edition 4
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BUFR table D and B, new entries for ground-based microwave radiometer data #162

Closed SibylleK closed 1 year ago

SibylleK commented 1 year ago

Initial request

DWD is requesting on behalve of E-PROFILE new entries for ground-based microwave radiometer brightness temperature data and derived thermodynomic procfile data.

A microwave radiometer (MWR) is a passive ground based remote sensing instrument exploiting the microwave region of the spectrum to measure vertical profiles of temperature and humidity. There are a few MWR networks worldwide, but data are not exchanged internationally over the GTS and a BUFR sequence for such data does not yet exist. However, EUMETNET is in the process to connect MWRs in Europe to form a network and plans to exchange data over the GTS beginning of 2024. The purpose of this document is to define two BUFR sequences for the exchange of Level 1 (brightness temperatures) and level 2 (meteorological products) data.

Experts from E-PROFILE and the COST action PROBE have jointly elaborated this proposal.

We propose creating the following new BUFR sequences: • 3 09 072 Ground based microwave radiometer brightness temperature observations (Lv1) • 3 09 073 Ground based microwave radiometer retrieval products (Lv2) • 3 03 100 Forecast indexes The new sequences will require the following new BUFR descriptors: • 0 12 190 Brightness temperature error covariance • 0 03 031 Channel bandwidth, full width half maximum (FWHM) • 0 03 032 Channel centre frequency • 0 03 033 Channel band width • 0 03 034 Channel wavelength • 0 13 165 CAPE (convective available potential energy) • 0 13 166 Total totals index • 0 13 167 S index (STT) • 0 13 168 Fog threat index • 0 13 169 MDPI (microburst day potential index) • 0 13 170 TQ index • 0 13 171 CIN (convective inhibition) The new sequences will require the following new code/flag table: • 0 20 143 ~139~ Liquid cloud flag The new sequences will require extending the following existing code table: • 0 02 006 Upper Air Remote Sensing Instrument Type

In addition the new sequences will require extending common code table C-13 (see wmo-im/CCT#132)

Amendment details

Add new entries to BUFR table B:

ClassNo ClassName_en FXY ElementName_en BUFR_Unit BUFR_Scale BUFR_ReferenceValue BUFR_DataWidth_Bits CREX_Unit CREX_Scale CREX_DataWidth_Char Note_en noteIDs Status
03 Instrumentation 003031 Channel bandwidth, full width half maximum (FWHM) m 11 0 16 m 11 13
03 Instrumentation 003032 Channel centre frequency Hz -6 0 26 Hz -6 10
03 Instrumentation 003033 Channel band width Hz -6 0 26 Hz -6 10
03 Instrumentation 003034 Channel wavelength m 9 0 16 m 9 5
12 Temperature 012190 Brightness temperature error covariance K2 3 -15000 15 K2 3 8
13 Hydrographic and hydrological elements 013165 CAPE (convective available potential energy) Jkg-1 0 0 14 Jkg-1 0 5 (see Note 11)
13 Hydrographic and hydrological elements 013166 Total totals index K 1 0 10 °C 0 5 (see Note 12)
13 Hydrographic and hydrological elements 013167 S index (STT) K 1 -1000 11 °C 0 6 (see Note 13)
13 Hydrographic and hydrological elements 013168 Fog threat index K 1 -100 8 °C 0 5 (see Note 14)
13 Hydrographic and hydrological elements 013169 MDPI (microburst day potential index) K/K 1 -100 8 K/K 0 5 (see Note 15)
13 Hydrographic and hydrological elements 013170 TQ index K 1 -1000 11 °C 0 6 (see Note 16)
13 Hydrographic and hydrological elements 013171 CIN (convective inhibition) Jkg-1 0 -1000 10 Jkg-1 0 5 (see Note 17)
20 Observed phenomena 020143 Liquid cloud Code table 0 0 2 Code table 0 1

Notes: (11) The convective available potential energy (CAPE) defines the maximum energy available to an ascending air parcel. CAPE is also referred to as positive buoyancy.

(12) The total totals (TT) index is defined by the combination of the vertical totals ($VT = T{850}*T{500}$) and the cross totals ($CT = Td{850} - T{500}$), resulting in $TT = T{850} + Td{850} - 2 * T_{500}$.

(13) The S index (STT) is defined as $STT = TT - (T{700} + Td{700}) - A$, where TT indicates total totals index and A depends on the vertical totals ($VT = T{850}*T{500}$) such that it penalizes cases with low values of VT (i.e. low vertical temperature gradients): $A = 0 (if\ VT > 25); 2 (if\ 22 <= VT <= 25); 6 (if\ VT < 22)$.

(14) The fog threat (FT) index indicates the potential for radiation fog and is based on the definition of fog point (FP), which is the temperature at which radiation fog will form. The fog point is determined by following the saturation mixing ratio line from the dew point curve at the lifting condensation level (LCL) to the surface temperature. Then, the fog threat is given by the difference of the wet bulb potential temperature at 850 mb ($\theta{WB850}$) and the fog point: $FT = \theta{WB850} - FP$ The potential for radiation fog is low for FT>3, while it becomes high for FT<0.

(15) The microburst day potential index (MDPI) is based on the vertical profiles of equivalent potential temperature and is defined follows: $MDPI = (Max \theta e - Min \theta e_{aloft})/ CT$

MDPI was designed to determine likely and unlikely environments for downbursts. For MDPI values greater than or equal to 1, microbursts are likely.

(16) The TQ index (TQ) is used to assess the potential for lowtopped convection. It is defined as $TQ = (T{850} + Td{850}) - 1.7 * (T_{700})$

(17) The convective inhibition (CIN) indicates the amount of energy required to overcome the negatively buoyant energy the environment exerts on an air parcel. Conceptually, CIN is the opposite of CAPE and is also referred to as negative buoyancy.

Add new entires in existing code table:

FXY ElementName_en CodeFigure EntryName_en EntryName_sub1_en EntryName_sub2_en Note_en noteIDs Status
002006 Upper Air Remote Sensing Instrument Type 0 Reserved Operational
002006 Upper Air Remote Sensing Instrument Type 1 Elastic backscatter lidar Operational
002006 Upper Air Remote Sensing Instrument Type 2 Raman backscatter lidar Operational
002006 Upper Air Remote Sensing Instrument Type 3 Radar wind profiler Operational
002006 Upper Air Remote Sensing Instrument Type 4 Lidar wind profiler Operational
002006 Upper Air Remote Sensing Instrument Type 5 Sodar wind profiler Operational
002006 Upper Air Remote Sensing Instrument Type 6 Wind profiler Operational
002006 Upper Air Remote Sensing Instrument Type 7 Lidar Operational
002006 Upper Air Remote Sensing Instrument Type 8 Ground-based microwave radiometer
002006 Upper Air Remote Sensing Instrument Type 9 Differential absorbtion lidar
002006 Upper Air Remote Sensing Instrument Type 10-62 Reserved Operational
002006 Upper Air Remote Sensing Instrument Type 63 Missing value Operational

Add new code table 020143 ~020139~ - Liquid cloud

FXY ElementName_en CodeFigure EntryName_en EntryName_sub1_en EntryName_sub2_en Note_en noteIDs Status
020143 Liquid cloud 0 No liquid cloud
020143 Liquid cloud 1 Liquid cloud present
020143 Liquid cloud 2 Reserved
020143 Liquid cloud 3 Missing

Add new sequence to BUFR table D, category 3 - Meteorological sequences common to vertical soundings data

Sequence 3 03 100 - Forecast indices (see Note 4)

FXY2 ElementName_en ElementDescription_en
013165 CAPE (convective available potential energy)
013045 KO index
013166 Total totals index
013044 K index
013042 Parcel lifted index (to 500 hPa)
013167 S index (STT)
013168 Fog threat index
013169 MDPI (microburst day potential index)
013170 TQ index
013171 CIN (convective inhibition)

Notes: (4) For a discussion of "Forecast indices from ground-based microwave radiometers for operational meteorology" see: https://doi.org/10.5194/amt-8-315-2015

Add new sequence to BUFR table D, category 9 - Vertical sounding sequences (conventional data)

Sequence 3 09 072 - Ground-based microwave radiometer brightness temperature observations (Lv 1)

FXY2 ElementName_en ElementDescription_en
301132 Common header sequence
107000 Delyed eplication of 7 descriptors
031001 Delayed descriptor replication factor
003032 Channel centre frequency
003033 Channel band width
002106 3dB beam width
102000 Delayed replication of 2 descriptors
031001 Delayed descriptor replication factor
003032 Channel centre frequency
012190 Brightness temperature error covariance
113000 Delayed replication of 13 descriptors
031001 Delayed descriptor replication factor Number of microwave radiometer measurements
008021 Time Significance = 29 End of scan or time of ending
301011 Year, month, day
301013 Hour, minute, second
008021 Time significance = 2 Time averaged
004026 Time period or displacement
002134 Antenna beam azimuth
002135 Antenna elevation
020143 Liquid cloud
103000 Delayed replication of 3 descriptors
031001 Delayed descriptor replication factor
003032 Channel centre frequency
033021 Quality of following value
012063 Brightness temperature
114000 Delayed replication of 14 descriptors
031001 Delayed descriptor replication factor Number of infrared radiometer measurements
008021 Time Significance = 29 End of scan or time of ending
301011 Year, month, day
301013 Hour, minute, second
008021 Time significance = 2 Time averaged
004026 Time period or displacement
002134 Antenna beam azimuth
002135 Antenna elevation
105000 delayed replication of 5 descriptors
031001 Delayed descriptor replication factor
003034 Channel wavelength
003031 Channel bandwidth, full width half maximum (FWHM)
002106 3dB beam width
033021 Quality of following value
012063 Brightness temperature

Sequence 3 09 073 - Ground based microwave radiometer retrieval products (Lv2)

FXY2 ElementName_en ElementDescription_en
301132 Common header sequence
008021 Time significance = 2 Time averaged
004026 Time period or displacement
013095 Total column water vapour
013109 Ice/liquid water path Ground based MWR are only sensitive to liquid water
020013 Height of base of cloud
008092 Measurement uncertainty expression = 0 Standard uncertainty
008093 Measurement uncertainty significance
013095 Total column water vapour
013109 Ice/liquid water path
020013 Height of base of cloud
008092 Measurement uncertainty expression Set to missing (cancel)
008093 Measurement uncertainty significance Set to missing (cancel)
303100 Forecast Indexes
117000 Delayed replication of 17 descriptors
031002 Extended delayed replication factor
007007 Height
301021 Latitude/longitude (high accuracy)
033021 Quality of following value
012001 Temperature
033021 Quality of following value
013002 Mixing ratio
033021 Quality of following value
013003 Relative Humidity
008092 Measurement uncertainty expression = 0 Standard uncertainty
008093 Measurement uncertainty significance
012001 Temperature
013002 Mixing ratio
013003 Relative Humidity
008092 Measurement uncertainty expression Set to missing (cancel)
008093 Measurement uncertainty significance Set to missing (cancel)
010071 Vertical resolution
027079 Horizontal width of sampled volume

Comments

No response

Requestor(s)

Alexander Häfele (E-PROFILE, MeteoSwiss) Moritz Löffler (E-PROFILE, DWD) Sibylle Krebber (DWD)

Stakeholder(s)

E-PROFILE

Publication(s)

Manual on Codes (WMO-No. 306), Volume I.2

Expected impact of change

MEDIUM

Collaborators

E-PROFILE COST action PROBE

References

A discussion of the forecast indices from ground-based microwave radiometers for operational meteorology can be found here: https://doi.org/10.5194/amt-8-315-2015

Validation

No response

amilan17 commented 1 year ago

https://github.com/wmo-im/CCT/wiki/Teleconference.2&3May.2023 notes: Sibylle presented the proposal; discussion about using satellite channel frequency for this ground-based data; to continue tomorrow;

amilan17 commented 1 year ago

https://github.com/wmo-im/CCT/wiki/Teleconference.2&3May.2023 notes:

Team decided to add notes, even though it's verbose; Team decided to not rename 'Satellite centre frequency'; Jeff noted that there are some "$"s in the note text.

almost ready for branch; @antoinemerle and @marijanacrepulja will validate.

SibylleK commented 1 year ago

I have updated the proposal and just double-checked. I suppose it is now ready for branch. @amilan17 could you please create a branch for this issue? Thanks a lot!

SibylleK commented 1 year ago

Branch is updated.

BUFR examples for validation are included in example.groundBasedMWR.zip example.groundBasedMWR.zip

amilan17 commented 1 year ago

https://github.com/wmo-im/CCT/wiki/Teleconference.13.July.2023 notes:

@marijanacrepulja will provide samples;

SibylleK commented 1 year ago

@amilan17 , I have added the notes for this issue. I keep the markup notation for the formula, as e.g. "pandoc" is able to convert this in proper formula for e.g. Word (.docx). But I don't know, how to handle line breaks in the notes.

amilan17 commented 1 year ago

@SibylleK Branch looks good. I just have a couple questions in the PR #173. 

Regarding line breaks -- I can address them when putting together the word/pdf.

SibylleK commented 1 year ago

Thank you @amilan17. I answered in the PR. And thank you too for the "minor editorial" changes!

amilan17 commented 1 year ago

@marijanacrepulja I think I'm just waiting for you to validate the samples that Sibylle provided in a comment above.

marijanacrepulja commented 1 year ago

AachenMWR02_MWR_validated.tar.zip

Hi, @SibylleK and @amilan17

I was able to successfully decode samples provided, using ECMWF software and tables created from the branch. Values look identical. Output of decoding is attached.

amilan17 commented 1 year ago

@SibylleK I changed 020139 to 020143 due to conflicts.

SibylleK commented 1 year ago

Thanks @amilan17, it also has to be changed in table D sequence 309072. I updated the FT2023-2 accordingly.

amilan17 commented 1 year ago

Thanks!