New BUFR Template for Snow Surface Temperature

rzhangwmo commented 2 months ago

Initial request

I'm submitting the request expressed by the Expert Team on Snow Watch of AG-GCW, for the generation of a new BUFR Template for Snow Surface Temperature (or expansion of an existing sequence, as the case may be). The scientific lead of the issue is Dr Charles Fierz (fierz@slf.ch), who will connect with MeteoSwiss on the data exchange aspects. Ran Zhang (rzhang@wmo.int) will support Charles, from the Secretariat. Thank you.

Amendment details

1. Add a new elements in table B F X Y	ELEMENT NAME	UNIT	SCALE	REFERENCE VALUE	DATA WITH (bits)
0-12-133	Ice temperature	Numeric	2	0	16

2. Add a new BUFR template in table D

Table reference	Table references	Element name
3-07 - 104		Snow temperature profile
3 01 150	WIGOS identifier
0 01 019	Long station or site name
0 02 001	Type of station
3 01 011	Year, month, day
3 01 013	Hour, minute, second
3 01 021	Latitude/longitude (high accuracy)
0 07 030	Height of station ground above mean sea level
0 02 177	Method of snow depth measurement
0 20 062	State of the ground (with or without snow)
0 13 013	Total snow depth
0 08 029	Surface type
0 12 161	Skin temperature
0 08 029	Surface type	Cancel
1 04 000	Delayed replication of 4 descriptors
0 31 001	Delayed replication factor
0 07 032	Height of sensor above local ground (or deck of marine platform)
0 12 101	Temperature/air temperature
0 12 131	Snow temperature
0 12 133	Ice temperature	New
1 02 000	Delayed replication of 2 descriptors
0 31 001	Delayed replication factor
0 07 061	Depth below land surface
0 12 133	Soil temperature
1 03 000	Delayed replication of 2 descriptors
0 31 001	Delayed replication factor
0 07 062	Depth below sea/water surface
0 13 082	Water temperature
0 12 133	Ice temperature	New

Comments

No response

Requestor(s)

Ran Zhang, rzhang@wmo.int Rodica Nitu, rnitu@wmo.int

Stakeholder(s)

Charles Fierz (fierz@slf.ch)

Publication(s)

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

Expected impact of change

None

Collaborators

No response

References

No response

Validation

No response

amilan17 commented 2 months ago

2024-05-02 notes:

Charles Fierz introduced the request; see PPT: ttTDCF-20240502_issue198-CF2.pptx
Marijana noted that perhaps there needs to be a sm all group to discuss these requests;
Antoine noted that we could use surface flag in BUFR, e.g. 0-08-010 or 0-08-029, and then also maybe 0-02-096 to specify the type of sensor;
Jeff noted that snow temperature is 0-12-131 with scale 2 (there is no corresponding 0-12-031 with scale 1); the generic profile as described might not work as described but the code approach could work;

Team to look at snow surface temperature template as well as the generic profile template: @antoinemerle, @jbathegit, @marijanacrepulja, and @SibylleK

jbathegit commented 2 months ago

It would also be good to consider how or whether this proposed new template and content would relate to existing GTS snow reports which use the templates 3-07-103, 3-07-101, etc, since I know that Switzerland in particular is already reporting such data.

fierz commented 2 months ago

It would also be good to consider how or whether this proposed new template and content would relate to existing GTS snow reports which use the templates 3-07-103, 3-07-101, etc, since I know that Switzerland in particular is already reporting such data.

@jbathegit @antoinemerle @marijanacrepulja @SibylleK @rzhangwmo: The two templates above refer to properties of the snow cover (as a whole): snow depth, water equivalent of snow cover, and bulk snow density. Snow surface temperature could or can also be considered as a property of the snow cover (its skin temperature) while snow temperature is measured at multiple levels within the snow cover. Note that the GIMO terminology, used in WMDR, differs sometime a little bit from that of BUFR4 😇

From Antoine's comment above, I think I start to vaguely understand how a template could look like and why it may be difficult to include air in it. Looking forward to our next meeting to learn more.

fierz commented 2 months ago

@all I contacted MeteoSwiss but did not get an answer yet. I also contacted K. Isaksen, with whom you worked on issue#157 about permafrost temperatures. Great work!

I also attachj a few slides that may help better describe the problem from my side. ttTDCF-20240507_issue198-CF.pdf

amilan17 commented 2 months ago

https://github.com/wmo-im/CCT/wiki/Teleconference.14.May.2024 notes: Marijana reported out on the outputs from the meeting last week and presented the updated proposal details; the team discussed the details; points vs profiles; what category/sub-category would this fall under? @fierz @rzhangwmo check with providers/users to see if the generic profile is sufficient;

fierz commented 1 month ago

I did contact some possible players and discussions were very helpful and valuable. I'll report on those in more details (see also attached PDF) but below are the main results.

I would propose to rename the template to "Cryo station temperature profile";
I realised the descriptor Surface qualifier (temperature data) (0 08 010 ) is better appropriate to define the surface as Surface type (0 08 029); on the other hand Surface type can be used to better describe the "ground" on which the station stands;
Total snow depth (0 13 013) would need a change in reference value from -2 to 0 because real negative values could occur, for example on ice sheets;
In addition to snow depth, it may be useful to be able to indicate (sea) ice thickness. A problem arises with the repeated use of Surface type though;
From the discussions with my MeteoSwiss colleague M. Musa and P. Leibersperger, a colleague at SLF, I would now propose the following template ( additions; new elements ):

Table reference	Table references	Element name	Description / comment
3-07-104		Cryo station temperature profile
	3 01 150	WIGOS identifier
	0 01 019	Long station or site name
	0 02 0011	Type of station
	3 01 011	Year, month, day
	3 01 013	Hour, minute, second
	3 01 021	Latitude/longitude (high accuracy)
	0 07 030	Height of station ground above mean sea level
	0 08 029	Surface type	/ Defines on what 'ground' the station stands
	0 02 177	Method of snow depth measurement	/ Not necesssarily needed
	0 20 062	State of the ground (with or without snow)
	2 03 YYY	Change reference values	/ to allow negative values for snow depth
	0 13 013	Total snow depth
	2 03 255	Change reference values
	0 08 029	Surface type	Conflicting w/ definition above / See WMO-No. 306, Vol. I.2, I.2 – BUFR/CREX Table B/13 — 5, note 9 : shall be set to set to 11, 12, 13 or 14 to specify river, lake, sea or glacier, respectively.
	0 13 115	Ice thickness	/ Nice to have
	0 08 029	Surface type	Cancel
	0 08 010	Surface qualifier (for temperature data)
	0 12 161	Skin temperature
	0 08 010	Surface qualifier (for temperature data)	Cancel / Is cancelling necessary?
	1 07 000	Delayed replication of 7 descriptors
	0 31 001	Delayed replication factor
	0 07 034	*Height of sensor relative to* local ground (or deck of marine platform)**
	0 12 101	Temperature/air temperature
	0 12 131	Snow temperature
	0 12 130	Soil temperature
	0 12 133	Ice temperature	New / Needed for sea ice etc.
	0 12 082	Water temperature
	0 12 134	Temperature kelvin	New / Temperature in kelvin as 0 12 023 is in degree Celsius

Add new elements in table B	F X Y	ELEMENT NAME	UNIT	REFERENCE VALUE
0 07 034	Height of sensor relative to local ground (or deck of marine platform)	m	2	16
0 12 133	Ice temperature	K	2	16
0 12 134	Temperature kelvin	K	2	16

MeteoSwiss would need some time to provide BUFR messages with the new templates as BUFR encoding is outsourced (DWD etc.) This would require an agreed upon template;
SLF could provide BUFR messages for cryo stations but not before End July 2024.

ttTDCF-20240605_issue198-CF.pdf

amilan17 commented 1 month ago

https://github.com/wmo-im/CCT/wiki/Teleconference.2024.June.4and5 notes: Charles presented some revisions to the proposal for generic temperature profile for cryosphere stations; there were discussions about "height of sensor relative to local ground", "Temperature Kelvin" descriptor; It was noted that temperature/air temperature == generic temperature OR air temperature;

samples cannot be provided until after the end of July at the soonest;
discussion about proposing only the necessary descriptors, but continue to explore the options for the BUFR sequence;

TO DO: set up an ad hoc meeting to continue discussions in the first week of July; Change to FT2025-1

fierz commented 2 weeks ago

@jbathegit @antoinemerle @marijanacrepulja @SibylleK @rzhangwmo: (and further interested members of TT-TDCF)

Dear all Here is a refined proposal to be discussed next week on 2024-07-01. I added 4 question marks '? N' to elements that I think will need clarification. I also attach a spreadsheet that contains some more info and examples of data mapped to this new template. bufr4-202405_templateSnowTempProfile-v03.xlsx ttTDCF-20240701_issue198-CF.pdf

Table reference	Table references	Element name	Element description	comment
3-07-104		Cryo station temperature profile
	3 01 150	WIGOS identifier
	0 01 019	Long station or site name
	0 02 001	Type of station
	3 01 011	Year, month, day
	3 01 013	Hour, minute, second
	3 01 021	Latitude/longitude (high accuracy)
	0 07 030	Height of station ground above mean sea level
	0 08 029	Surface type		Defines on what 'ground' the station stands
	0 13 115	Ice thickness		? 3 -> See WMO-No. 306. Note to be adapted!
	0 20 062	State of the ground (with or without snow)
	2 03 YYY	Change reference values		? 2 -> How to get rid of -2 ref value
	2 01 131	Change data width		Add 3 bits, see issue https://github.com/wmo-im/BUFR4/issues/157
	2 02 129	Change scale		to allow for mm precision
	0 13 013	Total snow depth
	2 01 000	Change data width	Cancel
	2 02 000	Change scale	Cancel
	2 03 255	Change reference values	Cancel
	0 08 010	Surface qualifier (for temperature data)
	0 12 161	Skin temperature
	0 08 010	Surface qualifier (for temperature data)	Cancel	Is cancelling necessary?
	1 10 000	Delayed replication of 10 descriptors		? 4 -> Is a Time period or displacement (0 04 025) set to zero needed here? See issue #157.
	0 31 001	Delayed replication factor
	0 07 034	Vertical distance of sensor	New	? 1 -> From WIGOS Metadata Standard ID 5-05, Vertical distance of the sensor from a (specified) reference level
	0 12 101	Temperature/air temperature		Generic temperature OR(==/) air temperature
	0 12 131	Snow temperature
	2 01 131	Change data width		Add 3 bits, see issue https://github.com/wmo-im/BUFR4/issues/157
	2 02 129	Change scale		to allow for mK precision
	0 12 130	Soil temperature
	2 01 000	Change data width	Cancel
	2 02 000	Change scale	Cancel
	0 12 133	Ice temperature	New	Needed for sea ice etc.
	0 12 082	Water temperature

Add new elements in table B	F X Y	ELEMENT NAME	UNIT	SCALE	REFERENCE VALUE	DATA WITH (bits)
0 07 034	Vertical distance of sensor	m	2	-65000	17
0 12 133	Ice temperature	K	2	0	16

amilan17 commented 2 weeks ago

https://github.com/wmo-im/CCT/wiki/Teleconference.24and26.June.2024 notes: Proposal is updated and meeting on Monday to discuss further

marijanacrepulja commented 1 week ago

Meeting on 1 July 2024 Decisions:

Define a new descriptor: Snow depth
Define a new descriptor: Ice temperature
There is no need to include time period
Define new a descriptor: Vertical distance of sensor and add a note as defined in WMO No 1192 Chapter 7, WIGOS metadata standard
Adapt WMO-No. 306. Note 5 for Ice thickness
@fierz will update proposal
MeteoSwiss will provide sample BUFR files
Team will validate the samples in November/December 2024
New BUFR template and descriptors for snow temperature profile to be ready for operational use in May-June 2025

amilan17 commented 1 week ago

https://github.com/wmo-im/CCT/wiki/Teleconference.2.July.2024 notes Marijana explained the decisions from meeting yesterday

fierz commented 6 days ago

Following the decisions taken on 2024-07-01, please find below the final proposal for the Cryo station temperature profile template. I'll work with MeteoSwiss and my colleagues at SLF/WSL to provide sample BUFR files for validation the latest by end of October 2024.

Template

Table reference	Table references	Element name	Element description	comment
3-07-104		Cryo station temperature profile
	3 01 150	WIGOS identifier
	0 01 019	Long station or site name
	0 02 001	Type of station
	3 01 011	Year, month, day
	3 01 013	Hour, minute, second
	3 01 021	Latitude/longitude (high accuracy)
	0 07 030	Height of station ground above mean sea level
	0 08 029	Surface type		Defines on what 'ground' the station stands
	0 13 115	Ice thickness		Adapt note 9 to Class 13
	0 20 062	State of the ground (with or without snow)
	0 13 119	Snow depth	New	Add note X to Class 13; millimetre precision is needed
	0 02 177	Method of snow depth measurement
	0 08 010	Surface qualifier (for temperature data)
	0 12 161	Skin temperature
	0 08 010	Surface qualifier (for temperature data)	Cancel
	1 10 000	Delayed replication of 11 descriptors
	0 31 001	Delayed replication factor
	0 07 034	Vertical distance of sensor	New	Positive values are above, negative values below the specified reference level 0 07 030; corresponds to WIGOS Metadata Standard, see added note X to Class 13 below
	0 02 096	Type of temperature sensor		Add three types of sensors to Code Table (see below)
	0 12 101	Temperature/air temperature		Generic temperature OR air temperature
	0 12 131	Snow temperature
	2 01 131	Change data width		Add 3 bits, see issue https://github.com/wmo-im/BUFR4/issues/157
	2 02 129	Change scale		to allow for mK precision
	0 12 130	Soil temperature
	2 01 000	Change data width	Cancel
	2 02 000	Change scale	Cancel
	0 12 133	Ice temperature	New	Needed for temperature of ice bodies
	0 12 082	Water temperature

New elements in table B

F X Y	ELEMENT NAME	UNIT	SCALE	REFERENCE VALUE	DATA WIDTH (bits)
0 07 034	Vertical distance of sensor (see Note X)	m	2	-65000	17
0 12 133	Ice temperature	K	2	0	16
0 13 119	Snow depth (see Note X)	m	3	-10000	15

Notes

Add note X to element 0 07 034: From WIGOS Metadata Standard (WMO-No. 1192), Chapter 7, Category 5, 5-05, Vertical distance of sensor, that is the "Vertical distance of the sensor from a (specified) reference level, such as local ground, deck of a marine platform at the point where the sensor is located, or sea surface".
Add note X to element 0 13 119: In particular on ice sheets and glaciers, snow depth can become negative due to erosion and/or ablation.
Adapt note 9 in Class 13: Ice thickness (0 13 115) shall be preceded by Surface type (0 08 029) set to 11, 12, 13 or 14 to specify whether it is river, lake, sea, or glacier ice, respectively.
Additions to Code Tables

Code figure Code table 0 02 096

8 Platinum resistance thermometer

9 Thermistor

10 Thermocouple

wmo-im / BUFR4