Draft Minutes of the ESEAS Research Infrastructure (ESEAS-RI) Kick-Off Meeting and Third Meeting of the ESEAS Technical Committee
Place and date: Crystal Hotel, Istanbul, Turkey, 11-12 November 2002.
1. Opening and Welcome 2. General Overview of the ESEAS-RI Project 2.1 Objectives, Tasks, and Organisation of the ESEAS-RI Project 2.2 WP1 - Quality Control of the Sea-Level Observations 2.3 WP2 - Absolute Sea Level Variations 2.4 WP3 - Decadal to Inter-Decadal Sea Level Variations 2.5 WP4 - Improving the Sea Level Observing System 2.6 WP5 - Management of the Project 2.7 General Discussion of the WPs and the Work for the Next Six/Twelve Months 3. Detailed Discussion of the WPs 3.1 WP1 3.2 WP2 3.3 WP3 3.4 WP4 3.5 Other Aspects of the ESEAS-RI Project 4. Accepting Minutes of the second TEC meeting 5. Open and Uncovered ESEAS TEC Action Items 5.1 The Combined ESEAS/ESEAS-RI Web Page 5.2 Altimetry Web Pages 5.3 Tide Gauge Operation Document 5.4 Tide Gauge Quality Control Document 5.5 Specifications and Classification of ESEAS Observing Sites 5.6 Modelling Issues 5.7 ESEAS TEC Action Items not addressed to date 6. Advices for ESEAS-RI from the TEC 7. List of Action Items for the Next Six/Twelve Months 8. Date and Place of Meetings (WPs, Project Team, TEC)
Coscun Demir opened the meeting and welcomed all participants.
The Turkish General Commander welcomed the participants and wished a successful meeting (in Turkish, with translation by Hasan Yildiz).
Hans-Peter Plag, Coordinator of the ESEAS-RI project and director of the ESEAS Central Bureau, gave a brief overview of the objectives, tasks, and status of the ESEAS, summarised the objectives of the ESEAS-RI project, reviewed the participants, work packages and deliverables of this project, addressed some management issues and discussed the expected impact of the project (see the pdf file of the presentation for the full details or down-load the postscript file).
Starting off, H.-P. Plag mentioned that there is a large European tide gauge database consisting of more than 10000 station years. However, the data is distributed over more than 50 operators and databases, is of heterogeous quality and access is governed by different data policies. To a large extent, the hourly data is difficult or virtually not accessible.
The main objectives of the ESEAS are to provide sea level and sea level related information for European users, and strive to guarantee and coordinate long-term monitoring and data exchange. In order to achieve this, the ESEAS has the tasks to integrate its activities into strategies of relevant programs, coordinate sea-level observations, set standards, provide data and other products for users, and establish and maintain a web site for this. The list of anticipated products includes but is not limitted near-real time access to tide gauge data, hourly and monthly mean values, estimates of extreme sea levels and secular trends as well as crustal motion and gravity changes at tide gauges.
H.-P. Plag emphasised the need for standardisation of the measurement techniques and the processing of data in order to create a homogeneous quality-controlled data base. Moreover, provision of an European inventory in order to make the data more easily accessible needs to be focussed on.
The organisational structure of the ESEAS is based on a physical network of observational sites and data centres, an application network comprising analysis and supporting centres as well as the ESEAS web site, and an institutional network consisting of the decision-making and advisory bodies being composed of representatives of the member organisations. The physical network was to a large extent in place prior to the establishment of the ESEAS in 2001. Most of the institutional network has been established in 2001 and is operational. However, the implementation of the application network has just started and is a key task for the coming years.
The main components of the institutional network of the ESEAS are the Governing Board (GB) with representatives of the institutional members of the ESEAS, which is the decision-making body, the Central Bureau (CB), which provides the daily administration and operation, and the Technical Committee (TEC) with experts coverning all scientific fields relevant for the ESEAS, which gives advice to the GB.
The goal of the ESEAS-Reseacrh Infrastructure (ESEAS-RI) project is to support the research infrastructure of the ESEAS. The project, which started on 1 November 2002 will receive a total funding of 2.3 MEuro and has 21 Partners and 5 subcontractors from a total of 17 countries. The coordination and management of the project rests with the CB, which is hosted by the Norwegian Mapping Authority. The project has both scientific and technological objectives.
Technologically, the project aims to support the ESEAS infrastructure, to support the upgrading of the network of observing sites, to promote standardisation of the network, operational routines, databases and quality control. Moreover, the project will also facilitate transnational coordination.
Scientifically, the goal is to study sea level variations at inter-annual to century time scales and to quantify future changes in mean sea level. A key result will be an empirical model of the sea level variations in European waters over the last hundred years.
The project is organised in a total of five WPs:
The expected impacts of the projects are
2.2 WP1 - Quality Control of the Sea-Level Observations
Lesley Rickards, British Oceanographic Data Centre, the leader of Work Package 1, gave an overview of the work content of WP1 (see the Powerpoint presentation for the full details). The main objectives of WP1 are to povide standardized access to a large part of the European tide gauge data bases and to quality-control the tide gauge data made thus available.
Concerning the contributors, she emphasised that most of the partners in the ESEAS-RI consortium are involved in one or more of the tasks in WP1.
Describing the background, she pointed out that for a significant fraction of the tide gauges, data are today available as monthly values through the PSMSL, where also a certain quality control is carried out. However, hourly values are accessible for a very small part only. Moreover, there is no standardised and very minor external quality control carried out for the hourly data. In the frame of WP1, an attempt will also be made to digitise a significant amount of analogue records hitherto not available in digital form.
More than 150 tide gauges are proposed as ESEAS Observing Sites, and these sites will be classified for one or more of the four main applications identified by EOSS, i.e. absolute sea-level changes, ocean circulation, calibration of satellite altimetry, and storm surge warning.
The tasks, deliverables and milestones discribed in the ESEAS-RI Description of Work (PDF) (p.32) were presented. The tasks of this WP are:
Lesley Rickards made clear that most of the WP1 milestones are expected within the first 12 months:
T1.2 and T1.4 will start at the KOM. T1.3 has also already started and the web site is available at http://www.eseas.org/. Before T1.5 can started, the work in T1.2 needs to be carried out. She then suggested to have a workshop for WP1 at POL, UK, early in 2003, where the quality control procedures and step towards data archaeology would be in focus.
Action item KOM-2: The WP1 leader organises a WP1 workshop at POL, UK, early in 2003.2.3 WP2 - Absolute Sea Level Variations
WP2 was presented by the WP leader, Richard Bingley of the University of Nottingham (UNOTT), see the Powerpoint presentation for the full details).Describing the Mmain objectives of WP2, he emphasised the development of appropriate processing and analysis strategy for CGPS at tide gauges, the processing and analysis of data from CGPS stations co-located with (ESEAS) obs. sites, and the study of pysical processes causing vertical land movements as the key issues.
In an overview of tasks, deliverables and miltestones, as given in ESEAS-RI Description of Work (p. 35) he pointed out that there are eight tasks in WP2 as well as an equal number of corresponding deliverables and milestones. Partners contributing the WP are P1, P2, P3, P4, P7, P9, P11, P12, P16, P18 and P20.
The tasks are:
With respect to the milestones of WP 2, which are
Related to Tasks 2.1 and 2.2, the question was raised whether ESEAS-RI really needs to "invent" a new analysis strategy rather than using the strategy used for the EUREF European Permanent Network (EPN) In the subsequent discussions, the following points were emphasised:
With respect to T2.6, Richard Bingley pointed out that expect for measurements at two sites no further absolute gravity measurements will be included in WP2. The contribution of P3 will be a compilation of results from previous absolute gravity measurements at tide gauges.
2.4 WP3 - Decadal to Inter-Decadal Sea Level Variations
The WP leader for WP3, Per Knudsen, KMS presented the key points related to this WP (see the Powerpoint presentation for full details.The main objectives of WP3 are to study the sea-level variation at inter-annual to century time scales and to quantify potential future changes in sea level. The main goals are to set up an empirical model for sea level variations and to determine secualr trends at tide gauges decontaminated for decadal variations.
Studies will use the tide gauge data made available in WP1 and also the vertical velocities provided by WP2. Moreover data available at PSMSL and satellite altimetry products will be used. High temporal resolution from long time series at tide gauges will be combined with high spatial resolution from global coverage of satellite altimetry in order to arrive at an empirical model of sea level variations over the last hundred years.
The records available at PSMSL are mostly shorter than 50 years and most of them cover mainly the last 50 years, while some records have a length of up to 200 years.
Using the relationship between record length and local sea level trend as well as the geographical pattern of sea level trends determined from eight years of Topex/POSEIDON satellite altimetry, Per Knudsen pointed out that there are large and spatially variable interannual to decadal sea-level variations.
The tasks, deliverables, milestones, and timetable for the WP, as given in the ESEAS-RI Description of Work (PDF) (p. 38) were presented. The tasks are:
Partners contributing to WP3 are P1, P2, P3 , P5, P10, P13, P14, P16, P18, P19, and P21. The first milestones and deliverables are
2.5 WP4 - Improving the Sea Level Observing System
WP4 was presented by Dov Rosen, IOLR, who leads this WP together with Hans-Peter Plag, NMA (for the full details of the presentation, see the Powerpoint presentation).Dov Rosen started with an overview and brief status with respect to the stations around the Mediterranean and connected seas. He then stated that WP4 focuses on improving the European sea level observing system by upgrading sites which are either important for long-term recording, or located at straits or in low-resolution areas. The sites will have to be selected on the basis of the classification carried out in WP1. However, a problem arise from the fact that upgrading should be performed as early as possible, while tasks T1.1 and the related milestones M1.1 and M1.5 are not expected to be completed before 6 months after project start.
He continued with a review of the tasks, deliverables and milestones as given in ESEAS-RI Description of Work (PDF) (p. 41). The tasks are:
With respect to the tide gauges to be upgraded (T4.2), he gave the following list of stations:
The milestones of WP4, which are
In the subsequent discussion, the following points were raised:
2.6 WP5 - Management of the Project
WP5 is leaded by Hans-Peter Plag, NMA, who summarised key issues related to the project managment (see pdf file of the presentation for the full details or down-load the postscript file).
Hans-Peter Plag pointed out that most partners are involved in more than one WP and vice versa, and therefore, coordination, cooperation, interaction, and communication is crucial for the success of the project.
In the DoW, time tables for milestones and deliverables are included. All WP leaders are asked to check if these time tables are realistic, and update, if necessary, within a month.
Action item KOM-4: All WP leader check the time tables given in the DoW and report necessary updates back to the coordinator within 15 December.One task in WP5 is to establish the Project Team within 3 days of the KOM. According to the DoW, the PT consists of:
Hans-Peter Plag discussed the meetings and reports which are requested in the contract. The following meetings, which are also related to reports, are required according to the DoW:
| M.-No. | Month | Key Elements for Discussion | Date |
| 1 | 00 | Start-up of project | 11-12/11/2002 |
| 2 | 06 | Project Team/Steering Committee | 15-16/05/2003 |
| 3 | 12 | Project Team/Steering Committee, Annual review meeting | 06-07/11/2003 |
| 4 | 15 | 1st workshop, presentation of project results and review of plan | 29-30/01/2004 |
| 5 | 18 | Project Team/Steering Committee | 06-07/05/2004 |
| 6 | 24 | Project Team/Steering Committee, Annual review meeting | 04-05/11/2003 |
| 7 | 30 | Project Team/Steering Committee | Mai/2005 |
| 8 | 35 | Final project workshop | Sep or Oct/2005 |
All meeting participants are asked to check these dates and give immediate feedback to the coordinator if participation is not possible. It was pointed out that participation in the PT meetings is mandatory for WP leaders.
The following table summarises the deadlines for reports:
| Project Months | Deadline | Title of report | Deadline input to Coordinator |
|---|---|---|---|
| 6 | 31/05/2003 | Management Report | 30/04/2003 |
| 12 | 30/11/2003 | Management Report | 31/10/2003 |
| 12 | 31/12/2003 | Annual Scientific and Technical Report | 31/10/2003 |
| 12 | '' | Draft TIP | 31/10/2003 |
| 12 | '' | Cost Statements | 15/11/2003 |
| 18 | 31/05/2004 | Management Report | 30/04/2004 |
| 24 | 30/11/2004 | Management Report | 31/10/2004 |
| 24 | 31/12/2004 | Annual Scientific and Technical Report | 31/10/2004 |
| 24 | '' | Draft TIP | 31/10/2004 |
| 24 | '' | Cost Statements | 15/11/2004 |
| 30 | 31/05/2005 | Management Report | 30/04/2005 |
| 36 | 30/11/2005 | Management Report | 31/10/2005 |
| 36 | 31/12/2005 | Final Report | 31/10/2005 |
| 36 | '' | Actual TIP | 31/10/2005 |
| 36 | '' | Final Cost Statements | 15/11/2005 |
It was emphasised that all partners need to meet the deadlines for their input to the coordinator. Due to the start of the project at 1 November, the actual time slot available for finalising the reports is reduced to about six weeks before Christmas, which requires that all partners respond in a timely manner to the deadlines for input and to requested revision of the draft reports and documents.
The following specifications for the reports and cost statements were given:
It was emphasised that the Bank Information for some partners was not yet available and all partners were asked to send the bank information to Reidun Khalayli at NMA, with
Hans-Peter Plag then discussed the Technical Implementation Plan (TIP). All partners were asked to keep the TIP in mind, and to update and improve the plan as the project progresses.
It was pointed out that the ESEAS-RI project lasts for three years only. Therefore, it should be considered how funding can be continue, e.g. through projects under the FP6.Stimulated by this comment, Hans-Peter Plag informed that the ESEAS CB has been active in preparation of Letters of Interest for the FP6 and made sure that the ESEAS is included. Moreover, within the GMES programme, it is expected that the ESEAS can be included in EuroGOOS proposals. This would result in reasonable chance to get funding in the development phase of GMES as well as in the operational phase after 2008.
Another question was related to how detailed the cost statements will have to be. Here, Hans-Peter Plag explained that the form for the cost statement, which will be distributed in due time, ask for the sums spend in the reporting period for the different cost categories as they appear in the CPFs and in the contract, e.g. personnel costs, travel and subsistence, consumables, durable equipment cost, overhead.
It was also askes what happesn if not all the costs planned for the first year are really spend. Hans-Peter Plag emphasised that it is important that any underspending is not too large. In the case of significant underspending of one or more partners, most likely, the pre-payments for the second and third years will be reduced accordingly for all partners. This could cause problems for some of the partners.
Finally, the coordinator pointed out that it is important to identify task leaders for each of the Tasks, with the task leaders being responsible for the timely delivery of the deliverables originating from that task. As mentioned earlier, for each WP, the WP leaders and the task leaders form the WP team.
2.7 General Discussion of the WPs and the Work for the Next Six/Twelve Months
Hans-Peter Plag pointed out that the ESEAS-RI needs a midterm review, i.e. after about 18 months. He emphasised that TEC members, who are not part of the ESEAS-RI consortium are welcome to criticially follow the progress in the project. Moreover, the three "external" experts in the Project Team will also provide some reviewing. It is, however, not clear, whether the EC will request some other midterm reviewing.
An ESEAS-RI mailing list will be set up. All ESEAS-RI members are requested to provide to the ESEAS CB e-mail addresses of participants that should be included in the e-mail list. For each WP, specific e-mail lists will be set up. Here, too, e-mail addresses for the WP members have to be submitted to the ESEAS CB. The ESEAS CB will include tools for sending e-mails to these list on the ESEAS-RI web page.
Action item KOM-5: All partners are asked to send via the responsible person e-mail addresses of all person they want to include in the full ESEAS-RI e-mail list to the ESEAS CB.The coordinator then pointed out that meeting plans for the individual WPs need to be established. Therefore, dates and places should be suggested and as far as possible coordinated between WPs and Project Team in order to keep travel costs as low as possible.
Action item KOM-7: The WP leaders are asked to plan their WP meeting schedule in coordination with the other WPs and to inform the ESEAS CB about the meeting plan.3.1 WP1
Lesley Rickards, BODC, (see Powerpoint for the full presentation) presented the contributions from BODC and POL to WP1. 45 station as an example, she elaborated key points related to quality control and addressed the extent of required with respect to information accompany the data. She also pointed out the need to compile metadata for the ESEAS Observing Sites. With respect to data archaeology, she informed that this work has started at GLOSS sites and a questionnaire is available on POL/BODC GLOSS web pages. She suggested to collate the response from ESEAS partners. The priority for digitisation need to be assessed and POL/BODC can also assist in the digitisation.
Lesley Rickards also addressed a list of items to be discussed, which include
Dov Rosen, IOLR, introduced a software package based on Microsoft Excel for storing and filtering data. The program checks for errors, may send error messages, and has a filtered display, with many options. It also has an automatic preliminary quality control for: Rate of change of sea level data hourly, sea water temperatures, and atmospheric pressure. Other parameters may be added.
Laurent Roblou LEGOS, France (the full presentation is available as Powerpoint) described aspects of the sea-level research of LEGOS. One focus is on ocena tides, where tidal constants from observations and model are compared. High-frequency signals (time scales shorter than 20 days) are also studied in order to detect erroneous data. LEGOS high quality products include harmoci constants, non-tidal residual time series, and global and regional model outputs. LEGOS is also involved in the Albicocca project, which provides regional calibration for the Jason altimeter. Potential contributions to ESEAS might come via the french network, SONEL, and could include
Fabio Raicich, CNR-ITT (for the full presentation, see the Word document,html document) addressed tide gauge data quality control, and he focused on delivery time line, quality control, data corrections, data extraction and concluded with a list of discussion items. The presentation is based on a document prepared for the ESEAS TEC and revised for the KOM (see the Word document).
Based on a number of examples, he suggested the following definitions for the ESEAS delivery timeline:
The question was raised whether 1 cm in height was in agreement with 1 mm/yr required for the long-term stability and vertical crustal motion. This was further discussed under point 5.3 (see below).
Fabio Raicich then stated that the goal of quality control is to detect and, if possible, correct errors and fill gaps. For that, emphasis is on
Based on what other relevant groups use, he suggested a set of quality control levels for data:
For the ESEAS data quality control, he suggested a distinction according to the delivery timeline, with NRT data undergoing a fast automatic procedure and the delayed-mode data receivind a full control.
With respect to data correction, Fabio Racich pointed out that data corrections and filling of gaps should only be carried out if really necessary. Filling of gaps should preferably done with quality-controlled data from neigbouring tide gauges linked to the same datum. Short gaps can be interpolated in the resiudal time series if weather conditions are not too severe. Gaps longer than 6-7 hours should not be filled. Data should not be corrected for certain effects such as seiches or other weather-induced effects, but when going to longer smapling intervals, data needs to be filtered appropriately to avoid aliasing. Thus, when producing hourly data, all oscillations with periods less tham 2 to 3 hours meed to be removed.
It is assumed that the data of e.g. water level height after full quality control has a sample rate of ten minutes. Additonal filtering is required to produce hourly values, daily, monthly or annual means and mean tidal levels.
Finally, he presented a list of items to be discussed in the ESEAS-RI WP:
Ivica Vilibic, HHI (for the full presentation, see Powerpoint; note that the file also include the overheads related to WP2 and WP4), gave a detailed description of the HHI's contribution to T1.1 WP1. With respect to T1.4 he emphasised that HHI has approximately 200 years of charts which are still not digitised. He illustrated the processing used in the digitasation of data at HHI.
Hans-Peter Plag, NMA, described the ESEAS web page, which is currently under development (see http://www.eseas.org). Among others, this page will provide access to sea-level data from the European national archives. The ESEAS web page may be a distributed site with links to the different sites, which may be hosted by ESEAS members.
Concerning the tide gauge data, he suggested that
A comment was made (Andrew Shaw) pointing out that the software netCDF may be useful program especially made for creating, accessing and sharing scientific data (array-oriented data access).
In the subsequent discussion, it became obvious that the set of essential parameters for the data is not clear and an agreement on the minimum parameters must be reached.
3.2 WP2Richard Bingley, UNOTT (for the full presentation, see the Powerpoint) addressed the individual tasks, deliverables and milestones of WP2 in detail.
For T2.1 (i.e. 1 mm/yr analysis strategy), he addressed the alternatives for the tracking network (global or regional) as well as the processing strategy (double-differences or ppp, combing solutions from different ACs) and software (GIPSY, Bernese or others). He also raised the questions of how to analyse the dual-CGPS sites and the GPS campaigns. In order to achieve the milestone of having the analysis strategy defined after 6 months (i.e. 30 April 2003), he suggested a WP meeting.
Hans-Peter Plag remarked that the realisation of a homogeneous reference frame is a prerequisite for the 1 mm/yr agenda and even more so for the 0.5 mm/yr agenda, which can only be achieved if a almost homogeneous tracking network can be identified. Attention needs to be on changes at stations (e.g. receivers, antennas, radoms, ...) but also on long-period effects (seasonal, interannual) on stations on the one side and and satellite orbits and clocks on the other side.
For T2.2 (i.e. 0.5 mm/yr analysis strategy), Richard Bingley focused on the treatment of noise, periodic variations and steps in the time series. He questioned the availablility of analysis software and restated the question of combining solutions from different analysis centres. For achieving the milestone connected to this task, he again suggested a WP meeting.
In the discussion it was pointed out that tide gauge data should be corrected by the (non-linear) vertical movement observed by the CGPS receiver. However, for that it is important to have CGPS close to the tide gauge, in order to avoid effects of spatially variable noise in CGPS.
Related to T2.3 (i.e. coherent processing of all CGPS observations from ESEAS Observing Sites), Richard Bingley pointed out that this will be based on the strategy derived in T2.1. This task requires the archive of CGPS data that will be established through the ESEAS.
Guy Wöppelmann from University of la Rochelle described the structure of the SONEL ftp server, which will host the TIGA CGPS data archive. He explained that no distinction between TIGA and ESEAS data is planned for the SONEL server. It was discussed whether ESEAS and TIGA data should be mixed in the present situation, where the relation between ESEAS and TIGA still remains undefined. The issue was expected to be taken up by the GB in its meeting (see Point 4 in the minutes of the 3rd GB meeting for the outcome).
For T2.4 (i.e. primary assemble information on loading), Richard Bingley pointed out that NMA host the IERS GGFC Special Bureau for Loading (SBL). Hans-Peter Plag clarified that
For T2.5 (i.e. coherent analysis with the most accurate strategy), the same considerations as for T2.3.
For T2.6 (which is related to abs. gravity measurements at selected observing sites), Richard Bingely pointed out that P3 will carry out abs. gravity measurements at selected ESEAS Observing sites in the U.K. Moreover, in the frame of the ESEAS-RI project, P20 will sub-contract repeated abs. gravity measurements to be carried out by the Finnish Geodetic Institute.
Roger Flather, POL, presented the following plan at POL:
T2.7 (i.e. assemble of information on precise levelling at all ESEAS Observings Sites collocated with CGPS) was only briefly addressed.
T3.1 (i.e. empirical determination of inter-annual to decadal sea level variations) has to be finished within the first 12 months. Overall task leader is Michael Tsimplis, P19, while the work with the tide gauge data will by coordinated by Igor Strojan, P10, and the satellite altimetry work by Ole Andersen, P2. As the next steps, Per Knudsen identified for
He also presented a suggestion of regions for regional analysis to be carried out by the different ESEAS partners (see the map in the full presentation with the link given above). Briefly, the following list applies
It was asked how post-glacial rebound should be treated. This signal is only important in some regions (e.g. Baltic Sea and adjacent areas) and there most models agree on the 1-2 mm/yr level. Therefore, use of models is acceptable.
The following comments were made:
Per Knudsen then reviewed more briefly the other tasks of WP3, which all (except T3.5) start after the first year. T3.2 (estimation of dominating spatial and temporal signals) runs from month 13-18 and will be led by Lucian Fenoglio Marc, P14. T3.3 (set up empirical model) runs from month 13 to 24 and will be led by Ole Andersen, P2. T3.4 (secular trend determination) runs from months 22-34 and will be led by Hans-Peter Plag, P1. Finally, T3.5 runs from month 1 to 36 and will be led by Phillip Woodworth, P3.
Michael Tsimplis, SOC (no copy of overheads available yet), gave a presentation related to the sea level variability. He presented a map of the global sea level pointed out that sea-level models do not agree with each other as the models represent forces differently. A conclusion was that the basically correct information obtained from satellite altimetry may be interpreted wrongly.
Focusing on the Mediterranean, he also mentioned that a bounce in sea level has been observed for the last 10 years for Lagos, Marseille, and Genova.
Ole Andersen, KMS (for the full presentation, see Powerpoint), addressed
He reported a high correlation (> 0.9) between tide gauge recordings and Topex/POSEIDON observations t/p in many places, thus promising a very good agreement between satellite altimetry and tide gauges For ERS 1+2, correlation was slightly lower (between 0.7 and 0.9) but still rather high.
Based on a wave-length analysis of the Topex/POSEIDON sea surface height time series he discussed that the amplitude of the annual variation appears to have increased over the last ten years while the phase shows some interannual variability.
Using a global map of the sea level trends as determined from TOPEX/POSEIDON altimetry data of the interval 1993-2001, he emphasised the regional variation in the decadal trend as well as the interannual variations. Based on latitudinal averages, he further elucidated these spatial variations.
Luciana Fenoglio-Marc, TUD (for the full presentation, see Powerpoint), revied Task 3.2 and its relation to T3.3 and T3.4, She then described the EOF analysis techniques and showed examples of EOF empirical orthogonal functions and addressed the question of how to use EOFs derived from satellite altimetry for the interpolation of spatially sparse tide gauge data to grids.
The question whether the work should be carried out regionally and, if so, how large the regions should be was asked. According to Luciana Fenoglio-Marc, it is currently to early to answer this question.
In a short note, Hans-Peter Plag pointed out that it is often stated that due to the large decadal and inter-decadal sea level variability reliable secular sea level trends can only be determined from very long records of 40 to 60 years. This is correct if a single station is considered. However, he pointed out that using a high-quality and long record in the same oceanographic region as base record, then the difference between a given shorter record and the base record will be largely free of the decadal to inter-decadal variations, which can be assumed to be the same at both sites. Using some examples from the Baltic Sea, he compared the resulting trends from the difference method to those of the simple local linear trends:
| Tide gauge | linear trend | differential | decontaminated |
|---|---|---|---|
| Stockholm | -3.91 +/- 0.13 | ||
| Tallinn | -4.48 +/- 4.47 | 2.86 +/- 1.71 | -6.77 +/- 1.84 |
| Salgrund | -10.74 +/- 5.46 | 7.23 +/- 1.43 | -11.14 +/- 1.56 |
| Spikarna | -6.27 +/- 1.02 | 4.08 +/- 0.18 | -7.99 +/- 0.31 |
In another brief note, Svetlana Jevrejeva, POL, addressed the North Atlantic Oscillation and pointed out that the correlation of the NAO index with sea level at different places changes throughout time.
Alexander Kuznetsov, Ukraine (for the full presentation, see Powerpoint), reported on the status of the long-term sea level observations in the Black Sea (translation by Eugen Lemeshko). He considered the different factors contributing to the Black Sea water balance and compared the long-period content of long sea level records from several Black Sea gauges.
Dov Rosen, IOLR (for the full presentation, see Powerpoint), summarised again the objectives and tasks of WP4. For T4.1 (Comparison of tige gauges), Begona Perez, P6, is the task leader. T4.2 (Upgrading of tide gauges) will be led by Dov Rosen, P18. T4.3 (Co-location of tide gauges with CGPS) is under the lead of Emin Ayhan, P9. Finally, T4.4 (GPS Campaigns) will be led by Ryszard Zdunek, P20.'
Concerning T4.1, Begona Perez pointed out that the site will be ready after 2 months (M4.1), not after 1 months as as scheduled in the DoW.
It was emphasised that information for the preferable "best" tide guage intruments and optimal location/local conditions should be provided in a report within the next year in order to allow to base the decision for the stations to be upgraded on T4.1 results.
Begona Pérez, PE (for the full presentation see Powerpoint) described the contribution of PE to WP4 and included also some information on contributions to WP1.
With respect to WP1, she described the software and procedures used for quality control and outlined future studies and improvements. The latter will include the variability of harmonic constants, filter effects and algorithms for the computation of mean sea level.
With respect to WP4, she mentioned that PE contributes with two ESEAS Observing Sites at Barcelona and Bilbao. A gauge in Ibiza will be upgraded and equiped with CGPS. The pilot station for testing of different sensors (T4.1) is at Villagarcia. The sensors include SONAR acustic sensor, Aquatrak acoustic sensor, several radar sensors, float gauges, and a pressure sensor. Moreover, PE is involved in 48-h sea level forecasting for the ESEAS stations within the NIVMAR region.
In a brief note, Hans-Peter Plag, NMA reported some results related to the Dual-CGPS concept, which is implemented at the ESEAS Observing Site on Andøya, Northern Norway. More than one year of GPS data from a reference station (which has actually already six years of CGPS data) at optimal GPS conditions and a receiver directly at the tide gauge, which is approximately 7 km away from the reference station, show that the two receivers show similar long-period behaviour, while data quality at the tide gauge is worst than at the reference station. In conclusion, he stated that for tide gauges on stable rock and with good GPS conditions, the CGPS receiver can be directly on the tide gauge. However, for tide gauges not known to be very stable and in areas with poor GPS conditions (like it is often the case in harbours), the optimal solution is the dual receivers method, which connects the tide gauge to the global reference frame and at the same time gives reliable estimates of the vertical crustal motion.
Marzenna Sztobryn, IMGW, gave a brief description of the polish tide gauges, and discussed the locations. She also described the quality control procedures used by them.
Jose Martin Davila, ROA, briefly described the contribution of ROA to WP4 but also to WP2. A particular problem for the Spanish tide gauges is the tectonics, which require frequent measurements. Several GPS campaigns with long baselines are planed.
Ivica Vilibic, HHI (for the full: presentation, see Powerpoint; note that this file is identical to the one under WP1 and contains also the contribution to WP1 and WP2), pointed out that HHI will co-locate the tide gauge at Split with CGPS: However, there are considerable problems to find a suitable location. The harbour with considerable boats traffic close to station in Split is expected to causes problems both due to distortions of the horizon, changes in the multipath and electro-magnetic emission from the ship.
Viorel Malciu, Romania (for the full presentation, see Powerpoint), described the Romanian network of recorders in the Black Sea and addressed the maintainence routines, location, and equipment used.
Roger Flather, POL, presented Philip Woodworths comments on WP4. He suggested a WP4 meeting in Paris in 2003 in conjunction with GLOSS meeting, which will be held during the Sea Level Week at IOC, 13-17 October. The workshop will concentrate on technical developments in observation systems and is ideally suited for WP4.
E. Lemeshko, Ukraina (for the full presentation, see Powerpoint), reported work on the steric heights method in the Black Sea, which gives independent estimates of sea surface heights, and a comparison between altimeter and tide gauge data. Tide gauges and satellite altimetry results are in reasonable to good agreement for several aspects such as trends, seasonal cycles and intra-annual variations.
3.5 Other Aspects of the ESEAS-RI Project
The coordinator, Hans-Peter Plag took up again the meeting plan (given in a table above) and emphasised the need that all potential participants in the meetings should comment on this plan.
He also pointed out that the Project Management Plan has to be set up and this includes also a diagram giving for all tasks all names of those contributing to the tasks.
He then summarised the WP and Task Leaders:
WP1 POL/BODC, Lesley Rickards
T1.1 UNOTT, Richard Bingley
T1.2 IEO, Maria-Jesus Garcia
T1.3 NMA, Hanne Heiberg
T1.4 POL/BODC, Lesley Rickards
T1.5 RIKZ, Douwe Dillingh
WP2 UNOTT, Richard Bingley
T2.1 NMA, Halfdan Kierulf
T2.2 UNOTT, Norman Teferle; OR POL, Simon Williams ??
T2.3 NMA, Halfdan Kierulf
T2.4 NMA, Hans-Peter Plag
T2.5 UNOTT, Norman Teferle; OR POL, Simon Williams ??
T2.6 POL, Simon Williams
T2.7 GCM, Coskun Demir
T2.8 UNOTT, Richard Bingley
WP3 KMS, Per Knudsen
T3.1 NERC-SOC, Mikis Tsimplis
T3.2 TUD, Luciana Fenoglio Marc
T3.3 KMS, Ole Andersen
T3.4 NMA, Hans-Peter Plag
T3.5 POL, Philip Woodworth
WP4 IOLR, Dov Rosen/Hans-Peter Plag
T4.1 PE, Begona Perez
T4.2 IOLR, Dov Rosen
T4.3 GCM, M. Emir Ayhan
T4.4 SRC/DPG, Ryszard Zdunek
He emphasised the importance of having one task responsible
for each task and asked to clarify the question marks i the above list
as soon as possible.
With respect to the Consortium Agreement, he mentioned that there still is a need to get this Agreememt set up and signed by the participants. An attempt will be made to provide a draft in the near future. However, most of the aspects related to data and software exchange are already included in the DoW and therefore, the urgency for the Consortium Agreement is not very high.
Concerning the ESEAS-RI web page, it was concluded that for the time being no parts of the pages have to be excluded from the public. Offical project e-mails send out to the Consortium will be included in the web page. However, communications between WP members will normally not be included there.
Eimuntas Parseliunas inform that publications related to ESEAS-RI are very welcome for publication in the Journal of Geodesy and Cartography at the Vilnius Technical University.
4. Accepting Minutes of the second TEC meeting
The minutes of the Second TEC meeting were accepted with a correction of one mispelling.
5. Open and Uncovered ESEAS TEC Action Items
Richard Bingely, the chair of the TEC, presented the List of TEC members and discussed their relation to the different fields of experties (for more details, see Powerpoint). In addition to the 12 members, there are currently also 4 observers. He then addressed the question of which of the TEC members could be the three experts in the Project Team. These should not be involved in the ESEAS-RI Project team and not part of a WP Team. This leaves very few choise. Moreover, the TEC is also the Scientific Advisory Committee for the ESEAS-RI project and therefore, it was questioned whether the experts should come from the TEC. It was again suggested that this should be taken up by the ESEAS GB.
5.1 The Combined ESEAS/ESEAS-RI Web Page
This refers to TEC Action Items 1-17, 1-18 and 2-14. The ESEAS/ESEAS-RI web pages were presented by Hanne Heiberg and Hans-Peter Plag, NMA. Most of the overall structure is in place and for the ESEAS page, a website map is available allowing for very fast navigation to any desired location. The development of the pages is as far as possible based on simple html code. The original pages at NMA are behind a firewall. Thus, in case of problems, the pages can be restored in very short time.
All participants are asked to visit the pages and comment on them to the ESEAS CB. The ESEAS web pages are a key deliverable of the ESEAS-RI project and this requires active participation from all. The overall concept is that single pages or subsets of the pages can be hosted by other institutes and the ESEAS CB awaits volunteers.
The ESEAS Web page also include a dummy Newsletter. It is expected that a first real issue of the Newsletter will be announced in January 2003.
It was suggested to consider whether the use of certain tools could inmprove the web pages. However, Hans-Peter Plag strongly emphasised that the pages should be as far as possible platform independent and based on generally available software. Therefore, the ESEAS CB will continue to use html directly whereever possible. More advanced pages, will be developed using Python.
The related TEC items are considered to be closed as the web page development will now be done within the frame of the ESEAS-RI project.
5.2 Altimetry Web PagesThis refers to TEC Action Item 1-13. The Altimetry Web Pages were presented by Per Knudsen, KMS. Currently, the pages are hosted by KMS and give an initial overview of satellite altimetry related topics. They also include links to related sites. The TEC Action Item 1-13 is considered to be closed.
5.3 Tide Gauge Operation Document
This is related to TEC Action Items 1-4 and 2-5 as well as 2-3. Begona Perez, PE, gave an overview of the state-of-the-art instrumentation for tide gauge sites (for the full presentation, see Powerpoint). She discussed the advantages and disadvantages of counter balanced float gauges, pressure sensors, acoustic sensors and radar sensors. For such pressure sensors, different alternatives are single tranducer, bubbler pressure gauges, and multiple pressure transducers, all with different problems and advantages. Acoustic gauges (sea level derived from the time of travel of ultrasonic pulses) can be with or without sounding tubes. For radar sensors, amplitude (pulse) and frequency modulation is in use.
She also suggested a list of Minimum requirements for the tide gauges (TEC Action Item 2-3), which is now open for comments:
Again, the question was raised whether 1 cm in height was in agreement with 1 mm/yr required for the long-term stability and vertical crustal motion. It was clarified that the 1 cm accuracy refers to each single sample of the water level, and this requires over long time a very high stability (much better than 1mm/yr) for the tide gauge level and calibration. Doubts were raised whether the 2 minutes accuracy requirement for time was sufficient. It was pointed out that technically, a much better accuracy is possible and ESEAS shoudl consider to increase the requirement to a few seconds or even less.
5.4 Tide Gauge Quality Control Document
This is related to TEC Action Items 1-5 and 2-6. The document produced by Fabio Raicich (see the Word document) was discussed as part of "Detailed Discussion of the WP1", see point 3.1 above.
5.5 Specifications and Classification of Observing Sites
This is related to TEC Action Items 1-2, 2-4 as well as 1-3. Richard Bingley presented the draft specifications and classification of observing sites, which are available as the following documents:
He pointed out that there is a need for (updated) documentation of sites, calibration, levelling, benchmarking and asked all operators of ESEAS Observing Sites to provide this to the ESEAS CB.
He also identified the need for information about the data sources for the ESEAS web portal to tide gauge data. It has to be clarified which sites can be used for the different applications. For that,
Requirements for the benchmark network must be discussed and it should be specified which height system should be adopted.
The structure and content of the site documentation (TEC Action Item 1-7) should be specified by a TEC group.
5.6 Modelling Issues
This is related to TEC Action Items 1-16, 2-10, 2-11, 2-12, 2-13. R. Flather, POL, described a draft questionnaire related to modelling of sea level variations (see Word document), which was circulated to GB for comment. The final questionnaire will be distributed by the ESEAS CB to an address list.
It is suggested to include links to other operational oceanography web sites on www.eseas.org.
5.7 ESEAS TEC Action Items not addressed to date
Richard Bingley reviewed the status of all the TEC Action Items (see Powerpoint; but note that a more complete status was given under Point 5 during the subsequent ESEAS GB meeting, see the minutes of the 3rd GB meeting for more details).
Following a proposal of Nico Kaajk, it was discussed whether the four ESEAS-RI WP groups should be established as formal ESEAS Working Groups. This would, on the one hand, allow non-ESEAS-RI partners to become members in the WGs and thus contribute in a formally correct way to the progress of ESEAS and ESEAS-RI, and, on the other hand, these WG could continue the work after the three years of the ESEAS-RI project and thus ensure continuity. The discussion resulted in the Action Item:
Action item TEC-3-1: The TEC suggests to the GB to establish four working groups parallell to the four WPs of the ESEAS-RI project. The ESEAS-RI WP leaders should also be the leaders for the ESEAS WGs.6. Advices for ESEAS-RI from the TEC
A list of advices from the TEC to the ESEAS-RI project was presented by Richard Bingley (see Powerpoint). All advices were related to the TEC Action Items.
7. List of Action Items for the Next Six/Twelve Months
7. Date and Place of Meetings (WPs, Project Team, TEC)
A ESEAS-RI WP1 meeting is suggested for early 2003 at POL, UK. The date is still t.b.d.
A ESEAS-RI WP2 meeting is suggested for early 2003. Place and date are still t.b.d.
The next ESEAS-RI Project Team meeting will be held on 15-16 May 2003. The place is still t.b.d.
A meeting of the ESEAS-RI WP4 is suggested to be held in conjunction with the Sea Level Week at the IOC in Paris, 13-17 October 2003.
The date and place of the next ESEAS TEC meeting are still t.b.d. Is has to be considered whether a TEC meeting in conjunction with one of the WP meetings or the Project Team meeting is appropriate.
Minutes written by Hanne Heiberg and Hans-Peter Plag
Hønefoss, 12 January 2003.