By Dr.Satish Shetye, National Institute of Oceanography, Goa, India

1. Introduction

IOC-UNEP-WMO Pilot Activity on Sea-Level Changes and Associated Coastal Impacts was implemented in the Indian Ocean (Ref. 1) in 1993 with two primary objectives:

(i) To improve understanding of the processes that control sea-level variability at sites where sea-level is monitored in the Indian Ocean.

(ii) To enhance capabilities of countries of the Indian Ocean to monitor and analyze sea-level data.

The purpose of this report is to provide an overview of the evolution of the pilot activity so far and suggest possible paths it might follow in the future.

The Pilot Activity envisaged setting up of a network of Cells for Monitoring and Analysis of Sea-Level (CMAS). The tasks of the scientists associated with each CMAS were to secure high quality sea-level data, to analyze these data to identify important features of variability, and to undertake research to understand the causes behind these features.

In response to the appeal from the IOC to participate in the Pilot Activity, the following countries established CMAS: Bangladesh, India, Kenya, Madagascar, Malaysia, Maldives, Mauritius, and Mozambique. In addition, Tanzania participated in the activities of the Pilot Activity, Seychelles offered to support it by making sea-level data from its stations available to interested researchers, and Australia, through its National Tidal Facility, provided support to the Pilot Activity.

2. Planning Workshop at Zanzibar

Scientists associated with implementation of the Pilot Activity met at a planning workshop in Zanzibar, Tanzania, 17-21 January 1994. The workshop concluded that the most important challenge for the Pilot Activity is to enhance the expertise available in participating countries through training programmes, both short-term (training in routine data analysis and maintenance of tidal installations), and long-term (graduate studies in physical oceanography). The workshop provided an opportunity to get an overview of the work that was going
on in the participating countries (see Ref. 2).

3. IOC/GLOSS-GOOS Training Workshop on Sea-Level Data Analysis

A specific recommendation from the Zanzibar workshop was to organize a hands-on training workshop on microcomputer-based analysis of sea-level data. The proposal was discussed and supported by the Meeting of the IOC Group of Experts on Global Sea Level Observing System (GE-GLOSS) at Bordeaux, France, 31 January -3 February 1995. GE-GLOSS also helped in prescribing the syllabus and the programme of the workshop.

The IOC/GLOSS-GOOS Training Workshop on Sea-Level data Analysis was held at the Geodetic & Research Branch, Survey of India, Dehra Dun, India during 21 November-1 December, 1995 (Ref. 3). The Department of Ocean Development, Government of India, New Delhi, provided financial assistance towards local organization of the workshop.

The trainees in the workshop were invitees, one each, from the CMAS of the following countries: Bangladesh, India, Kenya, Madagascar, Malaysia, Republic of Maldives, Mauritius, and United Republic of Tanzania. The invited lecturers were: Mr. P. Caldwell, TOGA Sea-Level Centre, University of Hawaii, USA; Dr. T. Murty, National Tidal
Facility, Australia; Brig. B.S. Rajal, Survey of India, India; Dr. S. Shetye, National Institute of Oceanography, India; and, Dr. P. Woodworth, Proudman Oceanographic Laboratory, UK.

Each trainee in the workshop was exposed to general principles of sea-level variability, and was given specific hands-on training on using the PC-based TOGA Sea-Level Centre Package for analyzing tide-gauge data. Subsequently the trainees were also sent the PC-based TASK package for tide-gauge data analysis developed at the Proudman
Oceanographic Laboratory, UK. To a large extent, the workshop met the short-term training goals set by the Zanzibar workshop: each participant received the the training needed to do routine sea-level analysis (usual quality checks, tidal prediction, etc.) and to examine low-frequency variability.

4. Other Activities

The two workshops were the only activities that involved all the CMAS and were carried out primarily with financial support from the IOC. For other activities, each CMAS was expected to determine its own agenda and find resources to implement it. This approach was necessitated due to CMAS-to-CMAS variations in access to: funds, expertise, and infrastructure to collect sea level data. A country like Malaysia that had recently established a new tide-gauge network and had good financial support, used CMAS to enhance its expertise. In
most other countries lack of financial support was a major constraint. Efforts of the CMAS in Madagascar to gain expertise in tidal modelling were frustrated due to lack to resources. What was desired was a fellowship to visit a suitable centre for learning mathematical modelling. Difficulties similar to these were also noted in other CMAS (see Ref. 3 for an overview of activities in CMAS). An exception was the CMAS in India which was fortunate to pull together funds, expertise and infrastructure to help the research effort.

5. Activities in Indian CMAS

In India the Department of Ocean Development, Government of India, New Delhi took the initiative to bring together the resources available in the country and to provide incentives for sea level research. The department provided financial resources to establish a CMAS at the Geodetic and Reseach Branch (G&RB), Survey of India, Dehra Dun. The
department also helped to bring together G&RB, traditionally a service organization that operates the tide-gauge network in India, and the National Institute of Oceanography (NIO), Goa, a research organization. G&RB made hourly tidal data available to the researchers at NIO to stimulate research in issues related sea-level variability. The major research areas that have been addressed under the above programme are:

- Documenting low-frequency (with periods ranging from days to months) variability along the coast of India and identifying the underlying dynamics.
- Modelling of tidal circulation along the coast of India.
- Assembling a database on tidal constituents along the coast of India.
- Documenting signatures of storm surges in the Bay of Bengal in tide-gauge data.

Though quite a bit of work in these areas is under way, some publications (see Refs. 4-7) are available describing the results.

6. What next?

This pilot activity now needs to evolve into a new initiative that builds on the experience of the pilot activity. The suggestions below are made with this in mind:

- Two new proposals - one on establishing a sea level network in the Indian Ocean, and the other on establishing a storm surge prediction system in the Bay of Bengal - have been made recently. These need to be encouraged.

- In order to sustain productive effort under these new proposals, it is necessary to address the issue of capacity building in the region. Lack of expertise in the field of physical oceanography has been the major handicap with the Pilot Activity. Linked to the new proposals should be a programme of providing fellowships for training in physical oceanography at the level of masters degree to provide a well rounded education to those who will be operating the new network/prediction system.

The Indian Ocean offers exciting possibilities in the study of sea level variability: the large scale variability can be used to monitor the seasonal monsoon-driven currents of this region; a storm-surge prediction system would be a boon in restricting damage from the storms that the Bay of Bengal breeds. To turn these possibilities into operational systems it is necessary to take a long-term view and plan creation of manpower that can operate these systems effectively.

References

IOC-UNEP-WMO Pilot Activity on sea-level changes and associated coastal impacts. IOC/INF-908, Paris, 18 November 1992.

IOC-UNEP-WMO-SAREC Planning Workshop on an Integrated Approach to Coastal Erosion, Sea Level Changes and their Impacts. Zanzibar, United Republic of Tanzania, 17-21 January 1994. Submitted Papers. IOC Workshop Report No. 96- Supplement 2.

IOC/GLOSS-GOOS Training Workshop on Sea-Level data Analysis, Dehra Dun, India, 21 November-1 December 1995. IOC Training Course Report No. 39.

Shankar, D., and S. Shetye (1997) On dynamics of Lakshadweep High/Low. Journal of Geophysical Research, vol. 102, C6, 12,551-12,562.
Shankar, D (1999) Low frequency sea level variability along the coast of India. Doctoral Thesis submitted to Goa University.

Unnikrishana, A.S., A.D. Gouveia, and P. Vethomony (1999) Tidal regime in the Gulf of Kutch, West Coast of India by a 2-D model.

Journal of Waterways, Port and Harbour Engg., ASCE. (in press)

Unnikrishnan, A.S., S.R. Shetye and G.S. Michael (1999) Tidal
propagation in the Gulf of Khambat, Bombay High, and surrounding areas. (submitted to Proc. Indian Acad. Sci. - Earth and Planetary Sci.)