The lack of marine observations and the need of the society of marine engineers have forced the Ports and Maritime Organization (PMO) to act as the main patron of marine affairs alongside its governmental authority to over come this problem. One of major efforts in this regard is to study and establish an observational network in Iranian seas. Coastal and offshore marine observational networks, such as buoys, provide an essential input to meteorological and oceanographic warning and forecast services. The purpose of such networks is typically multi-fold:
• General data collection to develop an improved understanding of coastal climatology.
• Real-time data provision to important water users, such as fishers, boaters and commercial vessel traffic. These data can provide warning with respect to the existence of hazardous conditions.
• For assimilation into meteorological and oceanographic forecasting systems and obtaining a better understanding
• To aid in calibration and verification of atmospheric and wave models used in both hindcasting (historical predictions) and forecasting (future predictions).
Development of a nearshore wave climate monitoring system will allow coastal engineers and planners to make more rational design decisions. Distribution of the results will help to promote public safety and the responsible use and enjoyment of coastal resources. This section summarizes a brief summary of the studies and actions performed in Iranian Ports and Maritime Organization (PMO) to establish an ideal marine observational network in Iranian seas.
Final Proposed Marine Observational Network
There are two fundamental components of any marine observation network which are meteorological measurements and wave measurements. The meteorological measurements, in particular wind observations, form an important driving force for numerical models of wave growth and propagation that are the basic of hindcasting and forecasting systems. Most of the error and uncertainty in wave prediction is associated with the wind field definition. The proposed network, as detailed below, would provide a complete coverage of the Iranian coastline, and give an excellent data source for wave model validation. In water bodies such as the Persian Gulf, Oman Sea and Caspian Sea that are surrounded by mountains and similar elevated terrain, there can be considerable orographic effects, and the winds near the coastline may differ from those measured offshore. On the other hand, It is the offshore winds that can be of greatest importance with respect to wave generation. Thus, where practical, we have recommended the implementation of offshore meteorological stations.
A network of 11 wave buoys is proposed as shown in Fig. 1 and described in the following. The wave buoys should be capable of measuring winds as well. The proposed network is designed to provide complete information coverage and the associated cost of deployment was not considered as a contributing factor.
The Caspian Sea
Based on ISWM results, three wave buoys are sufficient to define wave conditions along this coastline. Similar to the met stations, the proposed locations are at Anzali, Nowshahr and Amirabad.
The Oman Sea
Three wave buoys are proposed to define wave and wind conditions along this coastline. The proposed locations are at Chabahar, Jask and a location near the border of Hormozgan and Baluchestan provinces (East Gooksar) as shown in Figure 1. The buoy at Chabahar would provide critical data regarding both the local seas generated on the Oman Sea as well as the long-period swells that propagate to this region from the Indian Ocean. The buoy at Jask provides an indication of waves and meteorological conditions in the western Oman Sea, which is sheltered by the Arabian Peninsula, as well as those waves propagating into the Strait of Hormoz. The buoy East of Gooksar is proposed to provide wave information in an area where west and SSE waves are equally important.
The Persian Gulf
Four wave buoys are proposed to define wind conditions in the Persian Gulf. The proposed locations are at Bushehr, Asaluyeh, Nasr V and AB platforms as shown in Fig. 1. The buoys at Bushehr and Asaluyeh will help to define wave conditions in the northern and central portions of the Persian Gulf coastline which include very important economical zones. Bushehr buoy could be eliminated in case of budget limitations. The buoy at NASR V Platform provides an indication of wave conditions in the southern Persian Gulf, and is particularly important in helping to define conditions during Shamal events. Due to the long fetches in the Gulf, large wave conditions would be measured at this buoy from time to time. The AB platform buoy will help to define wave conditions in the northern Persian Gulf, and is particularly important in helping to define conditions during southeast storm events (Sharji). Due to the long fetches in the Gulf, large wave conditions would be measured at this buoy from time to time. In the Strait of Hormuz it is recommended that one wave buoy be deployed at a location southeast of Queshm, which is exposed to both east and west parts of the Strait of Hormuz, in order to best define waves in this region.
Establishing An Ideal Marine Observational Network
To establish the ideal marine observational network, PMO has performed the following items:
• To purchase and set up three wave buoys which were made in Iran in 1998
• To purchase and set up three wave buoys which were made in foreign countries in 2006
• Primary negotiations with Iranian Offshore Oil Company (IOOC) to obtain the required permission for using oil platforms in the Persian Gulf for installing measuring instruments
• Cooperation with Iranian Meteorological Organization in this field
It is hoped that completing the described marine observational network results in more navigation safety and decrease of losses due to marine events.
Figure 2 shows the proposed meteorological stations network.
Figure 1 Proposed Wave Buoy Network
Figure 2 Proposed Meteorological Stations