From aeb955e9e61ddcfb39e931b915840064f1f6984c Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Fri, 6 Feb 2026 16:06:30 +0000 Subject: [PATCH 01/13] ADR for ldas --- MARS language/ADR-004-ldas.md | 47 +++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 MARS language/ADR-004-ldas.md diff --git a/MARS language/ADR-004-ldas.md b/MARS language/ADR-004-ldas.md new file mode 100644 index 0000000..e857067 --- /dev/null +++ b/MARS language/ADR-004-ldas.md @@ -0,0 +1,47 @@ +# Architectural Decision Record 001: CEMS and C3S hydrology data in MARS + +## Status +[**Proposed** | Accepted | Deprecated | Superseded by [ADR-XXX]] + +## Last Updated +2026-02-05 + +## Context +The Land Data Assimilation (LDAS) system provides initial conditions of land surface parameters for the different forecasting systems which run on different time scales and model resolutions. + +LDAS will run in research as well as operationally. Target forecasting systems which need LDAS initial conditions are the medium-range (MR), the sub-seasonal to seasonal (s2s) and the seasonal forecasting (SEAS) systems. In operational and some research configurations, LDAS data are produced as a near-real-time (NRT) product as well as a behind-real-time-product (BRT), which need to be distinguished. Data are needed in the FDB and will be archived in MARS. + +Data from LDAS include analysis values and forecast values (e.g. surface fluxes). Analysis and forecast values for a given valid time will exist for the NRT time and for the BRT at multiple lead times, since the BRT will typically run each day covering the period from 5 days previous. Additionally, diagnostic statistics such as monthly means will be produced at the end of each calendar month. + +Operational configurations will run in parallel for each of MR, S2S and SEAS. The BRT component will include a reanalysis covering at least the previous 20 years. Different IFS cycles will typically (but not always) require a new reanalysis, so we need to distinguish re-analysis data produced with the same valid date for different IFS cycles as well as the different target forecast configurations. Upgrades of LDAS do not necessarily follow the release timeline of IFS cycles meaning that a newer IFS cycle still might use the LDAS system from the previous cycle/s. However, data volumes are very small and it would be possible to re-archive the data from a previous cycle with revised metadata to be consistent with a new cycle, this would be a matter for those configuring and running the operational suites and does not affect the design of the archive. + + +### Options Considered +1. Data go under class od for the operational data and class rd for research data. This allows to have the same data layout in MARS for operational and for research data. Stream ldas will be created and is used for the instantaneous / high-frequency output and stream ldst for derived statistics. The distinction of behind-real-time (BRT) and near-real-time (NRT) is done using a new mars keyword mode, and data with different lead times in BRT mode will be distinguished using anoffset. The different target forecasting systems and the analysis producing cycle of the LDAS system are indexed in the mars key configuration which will be introduced for the hydrological data as well. The value of this key will be a concatenated string with first the model cycle of the LDAS analysis system and then the target model with MR for medium range, s2s for the extended range, and seas for the seasonal system. +An example of the configuration is “50r1_s2s”. + +2. Basically, the same approach as 1., but instead of labelling the target forecasting system with MR, s2s and seas, the MARS stream to which the target forecasting system belongs is used. So enfo for the medium-range, eefo for the sub-seasonal and mmsf for the seasonal system. Examples are configuration=50r1_enfo / 50r1_eefo / 50r1_mmsf. + +3. This option is to create a new class ld for ldas, and to use the same stream as that of the target forecasting system (enfo/eefo/mmsf). + +### Analysis +It was discussed to include a new class ld for ldas operational data, but we would need either a different solution for research data, which complicates life for everyone, or else a complicated solution for safely separating operational and research data in class=ld. Using new streams for the instantaneous and derived ldas / ldst statistics allows to have the same layout under class od and rd, and even member state classes should that be required in the future. It avoids relying on specific expver ranges reserved for research experiments, and allows a clean introduction of the required mars keywords under the new streams. + +For hydrology data, a similar need for distinguishing different model configurations exists and it was agreed to introduce a new mars key configuration for this purpose. +The configuration key is ideally suited for the present use case as well and re-using it will enhance the consistency of mars. + +It was considered that using the names of the streams (enfo/eefo/mmsf) in the configuration string might be more stable and less ambiguous than a “name” of the relevant forecast configuration (such as mr/s2s/seas), since the preferred names of our forecast systems have been changed several times in recent years (e.g. ENS>MR, EXT>SUBS>S2S) and may change again. + + +## Decision + + + +### Related Decisions + +## Consequences +The data will be completely new in MARS. SEAS6 will require LDAS data to provide land initial conditions, so a prompt implementation is needed to avoid delays. + +## References + +## Authors From 9ea9c33e58fdab486d2fa4d9ba18ca13631a8296 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Fri, 6 Feb 2026 16:08:18 +0000 Subject: [PATCH 02/13] title --- MARS language/ADR-004-ldas.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/MARS language/ADR-004-ldas.md b/MARS language/ADR-004-ldas.md index e857067..9563eb8 100644 --- a/MARS language/ADR-004-ldas.md +++ b/MARS language/ADR-004-ldas.md @@ -1,4 +1,4 @@ -# Architectural Decision Record 001: CEMS and C3S hydrology data in MARS +# Architectural Decision Record 004: Land Data Assimilation System (LDAS) ## Status [**Proposed** | Accepted | Deprecated | Superseded by [ADR-XXX]] From 99a2f1e5e682062f53d04860bee15e8217ab3561 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Mon, 9 Feb 2026 14:52:42 +0000 Subject: [PATCH 03/13] small changes description --- MARS language/ADR-004-ldas.md | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/MARS language/ADR-004-ldas.md b/MARS language/ADR-004-ldas.md index 9563eb8..68912ae 100644 --- a/MARS language/ADR-004-ldas.md +++ b/MARS language/ADR-004-ldas.md @@ -11,14 +11,13 @@ The Land Data Assimilation (LDAS) system provides initial conditions of land sur LDAS will run in research as well as operationally. Target forecasting systems which need LDAS initial conditions are the medium-range (MR), the sub-seasonal to seasonal (s2s) and the seasonal forecasting (SEAS) systems. In operational and some research configurations, LDAS data are produced as a near-real-time (NRT) product as well as a behind-real-time-product (BRT), which need to be distinguished. Data are needed in the FDB and will be archived in MARS. -Data from LDAS include analysis values and forecast values (e.g. surface fluxes). Analysis and forecast values for a given valid time will exist for the NRT time and for the BRT at multiple lead times, since the BRT will typically run each day covering the period from 5 days previous. Additionally, diagnostic statistics such as monthly means will be produced at the end of each calendar month. +Data from LDAS include analysis values and forecast values (e.g. surface fluxes). Analysis and forecast values for a given valid time will exist for the BRT and for the NRT at multiple lead times. The BRT will typically run each day covering the period up to 3 days previous. The NRT will run daily with a 5-day spinup and will be intialized from the BRT product. Additionally, diagnostic statistics such as monthly means will be produced at the end of each calendar month. Operational configurations will run in parallel for each of MR, S2S and SEAS. The BRT component will include a reanalysis covering at least the previous 20 years. Different IFS cycles will typically (but not always) require a new reanalysis, so we need to distinguish re-analysis data produced with the same valid date for different IFS cycles as well as the different target forecast configurations. Upgrades of LDAS do not necessarily follow the release timeline of IFS cycles meaning that a newer IFS cycle still might use the LDAS system from the previous cycle/s. However, data volumes are very small and it would be possible to re-archive the data from a previous cycle with revised metadata to be consistent with a new cycle, this would be a matter for those configuring and running the operational suites and does not affect the design of the archive. ### Options Considered -1. Data go under class od for the operational data and class rd for research data. This allows to have the same data layout in MARS for operational and for research data. Stream ldas will be created and is used for the instantaneous / high-frequency output and stream ldst for derived statistics. The distinction of behind-real-time (BRT) and near-real-time (NRT) is done using a new mars keyword mode, and data with different lead times in BRT mode will be distinguished using anoffset. The different target forecasting systems and the analysis producing cycle of the LDAS system are indexed in the mars key configuration which will be introduced for the hydrological data as well. The value of this key will be a concatenated string with first the model cycle of the LDAS analysis system and then the target model with MR for medium range, s2s for the extended range, and seas for the seasonal system. -An example of the configuration is “50r1_s2s”. +1. Data go under class od for the operational data and class rd for research data. This allows to have the same data layout in MARS for operational and for research data. Stream ldas will be created and is used for the instantaneous / high-frequency output and stream ldst for derived statistics. The distinction of behind-real-time (BRT) and near-real-time (NRT) is done using a new mars keyword mode, and data with different lead times in NRT mode will be distinguished using anoffset. The different target forecasting systems and the analysis producing cycle of the LDAS system are indexed in the mars key configuration which will be introduced for the hydrological data as well. The value of this key will be a concatenated string with first the model cycle of the LDAS analysis system and then the target model with MR for medium range, s2s for the extended range, and seas for the seasonal system. An example of the configuration is “50r1_s2s”. 2. Basically, the same approach as 1., but instead of labelling the target forecasting system with MR, s2s and seas, the MARS stream to which the target forecasting system belongs is used. So enfo for the medium-range, eefo for the sub-seasonal and mmsf for the seasonal system. Examples are configuration=50r1_enfo / 50r1_eefo / 50r1_mmsf. From 03d383b0eb7685d8ba7087dcd56ad79b9d5c2b10 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 13:37:05 +0000 Subject: [PATCH 04/13] rename ldas ADR file --- .../{ADR-004-ldas.md => ADR-004-land-data-assimilation-system.md} | 0 1 file changed, 0 insertions(+), 0 deletions(-) rename MARS language/{ADR-004-ldas.md => ADR-004-land-data-assimilation-system.md} (100%) diff --git a/MARS language/ADR-004-ldas.md b/MARS language/ADR-004-land-data-assimilation-system.md similarity index 100% rename from MARS language/ADR-004-ldas.md rename to MARS language/ADR-004-land-data-assimilation-system.md From 35e6562cfbe955a4394ee7cff56238359f018862 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 13:46:22 +0000 Subject: [PATCH 05/13] rename ADR MARS document --- ...lation-system.md => MARS-004-land-data-assimilation-system.md} | 0 1 file changed, 0 insertions(+), 0 deletions(-) rename MARS language/{ADR-004-land-data-assimilation-system.md => MARS-004-land-data-assimilation-system.md} (100%) diff --git a/MARS language/ADR-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md similarity index 100% rename from MARS language/ADR-004-land-data-assimilation-system.md rename to MARS language/MARS-004-land-data-assimilation-system.md From 0d36c239e8de76d55a983b01b5f355317a15f6b2 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 13:54:34 +0000 Subject: [PATCH 06/13] adapt title --- MARS language/MARS-004-land-data-assimilation-system.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index 68912ae..7cf9f5c 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -1,4 +1,4 @@ -# Architectural Decision Record 004: Land Data Assimilation System (LDAS) +# MARS Language Decision Record 004: Land Data Assimilation System (LDAS) ## Status [**Proposed** | Accepted | Deprecated | Superseded by [ADR-XXX]] From 1af13cbd279bec1788dee3d46529ac770a02ca30 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 14:07:10 +0000 Subject: [PATCH 07/13] change to accepted --- MARS language/MARS-004-land-data-assimilation-system.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index 7cf9f5c..381c2fa 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -1,10 +1,10 @@ # MARS Language Decision Record 004: Land Data Assimilation System (LDAS) ## Status -[**Proposed** | Accepted | Deprecated | Superseded by [ADR-XXX]] +[~~Proposed~~ | **Accepted** | ~~Deprecated~~ | ~~Superseded by [ADR-XXX]~~] ## Last Updated -2026-02-05 +2026-05-19 ## Context The Land Data Assimilation (LDAS) system provides initial conditions of land surface parameters for the different forecasting systems which run on different time scales and model resolutions. From bc1f5a6596c7fd5cb25814c8dbee5e8f8f88544d Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 14:17:48 +0000 Subject: [PATCH 08/13] table with streams --- MARS language/MARS-004-land-data-assimilation-system.md | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index 381c2fa..85c300e 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -33,6 +33,15 @@ It was considered that using the names of the streams (enfo/eefo/mmsf) in the co ## Decision +Four new mars streams will be created for the Land Data assimilation system. As there is a the moment only a distinction in near real time and behind real time and as it is also unlikely that there will be more options, the stream name include this distinction. Two streams will be created for the statistics of the near real time and behind real time ldas data. The four streams are the following ones: + +| Stream mars abbreviation | Stream name | +|:------------:|:-------------:| +| ldas | Land data-assimilation system (near real time)| +| ldbt | Land data-assimilation system behind real time | +| ldst | Land data-assimilation system statistics (near real time) | +| ldsb | Land data-assimilation system statistics behind real time | + From 88fc43f19b9ef0a862da287e30b45e8e97b0aebe Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 14:30:38 +0000 Subject: [PATCH 09/13] finalising decision part --- .../MARS-004-land-data-assimilation-system.md | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index 85c300e..eb6b56f 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -42,10 +42,19 @@ Four new mars streams will be created for the Land Data assimilation system. As | ldst | Land data-assimilation system statistics (near real time) | | ldsb | Land data-assimilation system statistics behind real time | +The target forecasting system as well as the cycle of the LDAS system will be specified in the MARS key configuration. It will contain entries like + - 49r2-sfdd + - 50r1-oper + - 50r1-enfo + - 50r1-sfdd + - 50r2-oper + - 50r2-enfo + - 50r2-sfdd - +anoffset is included in the mars namespace of the near-real-time case and absent in the behind-real-time case. The mars key timespan is used and additionally in the statistical streams ldst and ldsb the mars key stattype. ### Related Decisions +This decisision is in line with the implementation done for the hydrological data. ## Consequences The data will be completely new in MARS. SEAS6 will require LDAS data to provide land initial conditions, so a prompt implementation is needed to avoid delays. @@ -53,3 +62,8 @@ The data will be completely new in MARS. SEAS6 will require LDAS data to provide ## References ## Authors +David Fairbairn +Jonathan Day +Robert Osinski +Sebastien Villaume +Tim Stockdale From b3fdde0d6b4b3c36ec0c0f85e4a6b8965ebd2ee7 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 14:38:52 +0000 Subject: [PATCH 10/13] correct spelling --- .../MARS-004-land-data-assimilation-system.md | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index eb6b56f..2187401 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -33,7 +33,7 @@ It was considered that using the names of the streams (enfo/eefo/mmsf) in the co ## Decision -Four new mars streams will be created for the Land Data assimilation system. As there is a the moment only a distinction in near real time and behind real time and as it is also unlikely that there will be more options, the stream name include this distinction. Two streams will be created for the statistics of the near real time and behind real time ldas data. The four streams are the following ones: +Four new mars streams will be created for the land data assimilation system. As there is at the moment only a distinction needed into a near-real-time and a behind-real-time configuration and as it is also unlikely that there will be more options, the stream names include this distinction rather adding an additional key in MARS with only two possible options. Two streams will be created for the statistics of the near-real-time and behind-real-time ldas data. The four streams will be the following ones: | Stream mars abbreviation | Stream name | |:------------:|:-------------:| @@ -42,14 +42,14 @@ Four new mars streams will be created for the Land Data assimilation system. As | ldst | Land data-assimilation system statistics (near real time) | | ldsb | Land data-assimilation system statistics behind real time | -The target forecasting system as well as the cycle of the LDAS system will be specified in the MARS key configuration. It will contain entries like - - 49r2-sfdd - - 50r1-oper - - 50r1-enfo - - 50r1-sfdd - - 50r2-oper - - 50r2-enfo - - 50r2-sfdd +The target forecasting system as well as the cycle of the LDAS system will be specified in the MARS key configuration using the cycle dash mars stream of the target system. It will contain entries like + * 49r2-sfdd + * 50r1-oper + * 50r1-enfo + * 50r1-sfdd + * 50r2-oper + * 50r2-enfo + * 50r2-sfdd anoffset is included in the mars namespace of the near-real-time case and absent in the behind-real-time case. The mars key timespan is used and additionally in the statistical streams ldst and ldsb the mars key stattype. From 0a621d869a4c4e3dcc3216a1d07172f069a090a5 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 14:39:30 +0000 Subject: [PATCH 11/13] formatting table --- MARS language/MARS-004-land-data-assimilation-system.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index 2187401..88c78ff 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -36,7 +36,7 @@ It was considered that using the names of the streams (enfo/eefo/mmsf) in the co Four new mars streams will be created for the land data assimilation system. As there is at the moment only a distinction needed into a near-real-time and a behind-real-time configuration and as it is also unlikely that there will be more options, the stream names include this distinction rather adding an additional key in MARS with only two possible options. Two streams will be created for the statistics of the near-real-time and behind-real-time ldas data. The four streams will be the following ones: | Stream mars abbreviation | Stream name | -|:------------:|:-------------:| +|:------------:|:-------------| | ldas | Land data-assimilation system (near real time)| | ldbt | Land data-assimilation system behind real time | | ldst | Land data-assimilation system statistics (near real time) | From ab430fae29ea42f305d85aed66961b09e0bfc370 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 14:40:42 +0000 Subject: [PATCH 12/13] formatting of the table --- .../MARS-004-land-data-assimilation-system.md | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index 88c78ff..1634621 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -43,13 +43,13 @@ Four new mars streams will be created for the land data assimilation system. As | ldsb | Land data-assimilation system statistics behind real time | The target forecasting system as well as the cycle of the LDAS system will be specified in the MARS key configuration using the cycle dash mars stream of the target system. It will contain entries like - * 49r2-sfdd - * 50r1-oper - * 50r1-enfo - * 50r1-sfdd - * 50r2-oper - * 50r2-enfo - * 50r2-sfdd +* 49r2-sfdd +* 50r1-oper +* 50r1-enfo +* 50r1-sfdd +* 50r2-oper +* 50r2-enfo +* 50r2-sfdd anoffset is included in the mars namespace of the near-real-time case and absent in the behind-real-time case. The mars key timespan is used and additionally in the statistical streams ldst and ldsb the mars key stattype. From 3bb8625a0aa44465df70bccba0f4a115f6d52c95 Mon Sep 17 00:00:00 2001 From: Robert Osinski Date: Tue, 19 May 2026 14:42:16 +0000 Subject: [PATCH 13/13] author list --- .../MARS-004-land-data-assimilation-system.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/MARS language/MARS-004-land-data-assimilation-system.md b/MARS language/MARS-004-land-data-assimilation-system.md index 1634621..abb7396 100644 --- a/MARS language/MARS-004-land-data-assimilation-system.md +++ b/MARS language/MARS-004-land-data-assimilation-system.md @@ -62,8 +62,8 @@ The data will be completely new in MARS. SEAS6 will require LDAS data to provide ## References ## Authors -David Fairbairn -Jonathan Day -Robert Osinski -Sebastien Villaume -Tim Stockdale +- David Fairbairn +- Jonathan Day +- Robert Osinski +- Sebastien Villaume +- Tim Stockdale