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The Cyprus Coastal Ocean Forecasting and Observing System, a contribution to GMES Marine services

 

The following description must be refered to:

 

George Zodiatis^*1, Robin Lardner¹, Daniel R. Hayes¹, Georgios Georgiou^1
1Oceanography Centre, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus

Abstract

 

The Cyprus coastal ocean forecasting and observing system (CYCOFOS) consists of several operational modules: high-resolution coastal-ocean flow forecasts in the NE Levantine, offshore and near-coastal wave forecasts for the Mediterranean, Levantine and Cyprus basins, satellite remote sensing for the Eastern Mediterranean, coastal remote monitoring stations, an ocean observatory, and an oil spill and trajectory prediction model. All these operational modules provide through the internet the following: daily high resolution six-hourly flow forecasts for the NE Levantine Basin for the following five days, daily low resolution 24 averaged flow forecasts for the following 10 days, a three-hourly offshore and near-coast sea state forecast for the Mediterranean, Levantine and Cyprus basins for the following 60 hours, daily single remote sensing SST and Chlorophyll-a images for the Eastern Mediterranean and the Levantine basin, hourly in-situ sea level and water temperature at certain coastal remote stations, and half-hourly temperature and salinity at various depths from the ocean observatory in the SE Levantine Basin. Moreover, CYCOFOS provides to end users daily forecasting data necessary for operational applications of the MEDSLIK (Mediterranean oil spill, trajectory and pollutant model).

1. Introduction

 

The development of operational ocean monitoring and forecasting systems on global, regional, sub-regional and local scales will support, among others, a better management of the marine environment and will assist the end users in their decisions for protecting and reducing the environmental problems that may arise from the various economic activities in the marine sector. The Cyprus coastal ocean forecasting and observing system (CYCOFOS) was developed within the broad frame of GOOS (Global Ocean Observing System) and its regional components of EuroGOOS (European GOOS) and MedGOOS (Mediterranean GOOS), to promote the operational oceanographic forecast and monitoring on local and sub-regional scales in the Eastern Mediterranean Levantine Basin. The CYCOFOS has been operational since early 2002 and consists of several forecasting, observing and end user modules. CYCOFOS has been described previously (Zodiatis et al., 2002, 2003a,b), but has been enriched and improved in recent years. CYCOFOS forecasting data are accessible electronically at http://www.ucy.ac.cy/cyocean. CYCOFOS joined the Mediterranean operational oceanography network (MOON), aimed to sustain the operational forecasts in the Mediterranean, in collaboration with other basin, sub-basin and coastal forecasting systems. CYCOFOS is the Cyprus contribution to GMES Marine Services. The development and the continuous improvement of the CYCOFOS modules is carried out following the objectives of several European Union projects, including the Mediterranean forecasting system, both, pilot project and towards environmental predictions (MFSPP & MFSTEP), Mediterranean network to access and upgrade monitoring and forecasts activities in the region (MAMA), European sea level service research infrastructure (ESEAS-RI), Mediterranean network of global sea level observing system (MedGLOSS) and Marine environment and security in the European areas (MERSEA-strand 1 & MERSEA-IP).

2. Description

 

2.1 Forecasting

 

Operational flow forecasts of the Levantine Basin (Fig. 1) are carried out by CYCOM-the Cyprus Coastal Ocean Model (Zodiatis et al., 2003c). CYCOM is based on the Princeton Ocean Model (POM) and is forced and initialized from lower resolution oceanic model forecasts and high frequency atmospheric forecasts. The forecasting data from the MFS-OPA basin model has been implemented directly by the CYCOM along with ECMWF forcing. This mode of operation now is allowing 10-day forecasts to be completed daily with a resolution of 2.5 km. In parallel, a higher resolution flow forecast (1.5 km) is produced by CYCOM in which the parent model has been changed to the ALERMO model, which is in turn nested within the MFS-OPA basin model (Fig. 2). In addition, the SKIRON (Kallos and SKIRON group, 1998) high-frequency (hourly) meteorological forecasts are used. This allows a 5-day high resolution six hourly flow forecast to be repeated daily. A variational interpolation method, Variational Initialization and FOrcing Platform-VIFOP (Auclair, 2000a, 2000b), has been implemented in order to more accurately downscale the ALERMO model fields to the CYCOM grid. In particular, spurious gravity waves due to interaction of the interpolated flow field and the high resolution land mask are minimized. It should also be noted that the MFS-OPA basin model includes temperature (XBT) and conductivity-temperature (CTD) profiles into its assimilation scheme, as well as satellite-based sea level anomaly, while the satellite sea surface temperatures are used for the correction of the surface heat fluxes.

Wave forecasts of the entire Mediterranean and Levantine basins are produced by a WAM model (WAMDI group, 1988). The Levantine wave domain is nested within the CYCOFOS Mediterranean wave forecast (Fig. 3). The three hourly wave forecast is produced every day for the coming 60 hours. Wave height, direction, and the SKIRON wind velocity are provided at the CYCOFOS web page. The high-frequency SKIRON forecasts provide hourly forcing, rather than the previously used six-hourly ECMWF winds. An even higher resolution wave forecast (Fig. 2) based on SWAN (Holthuijsen et al, 1997) has been implemented for simulating waves at the near-coast sea areas around Cyprus. This model is nested with the Levantine wave model. The recommended procedure for responding to marine pollution incidents, that will assist the local and sub-regional decision makers to take the appropriate actions, includes the application of operational models in order to provide predictions of the behaviour and movement of the harmful substances. Additional components of CYCOFOS is the MEDSLIK oil spill, trajectory and pollutant model, that designed to predict the transport, fate and weathering of an oil spill in the Mediterranean Sea. It has been coupled operationally to the MFS-OPA basin model and the CYCOFOS forecasting products, using the hourly SKIRON wind fields. As part of the EU MFSTEP, MERSEA strand-1 and MERSEA-IP projects, CYCOFOS was tasked to apply operationally the MEDSLIK oil spill model in the Levantine Basin, coupled with these project's forecasting products.

2.1 Observing

 

In CYCOFOS, near real time observations consist of two types, periodic short field campaigns and near real time continuous measurements at fixed locations in the Levantine basin. Bi-monthly or monthly XBTs short cruises were carried out in the Levantine basin within the framework of the EU projects (MFSPP, MFSTEP), in the region south of Cyprus. The data collected from these cruises jointly with other similar data from other parts of the Mediterranean were assimilated in the parent MFS-OPA model.

An ocean observatory has been added to CYCOFOS which measures conductivity and temperature at five levels in the open, deep Levantine basin (Fig. 4). It is called the MedGOOS-3 Ocean Observatory, and was deployed by the Harris Maritime Communication Services, who owns and maintains the system. The used sensors are SBE-37 MicroCAT C-T recorders which communicate with the surface using an inductive modem. The deepest sensor also measures pressure. The data are collected every 30 minutes, and retrieved every 24 hours with satellite communication. They are processed and posted on the CYCOFOS web site daily. There are plans to extend the observing depth of this system beyond the current water depths with additional CT sensors. Data on buoy attitude (heave, pitch, roll) will be used to calculate wave height and direction in near real time.

The existing coastal sea level, water temperature, and air pressure MedGLOSS station continues to operate, as it has since 2001 (Zodiatis et al. 2002, 2003a,b). Future similar coastal stations are planned. The CYCOFOS satellite ground receiving station also described in Zodiatis et al. (2002, 2003a,b) has been operating successfully since 2001. It collects images of SST from NOAA AVHRR satellites. Cloud cover is generally not extensive or persistent in the Eastern Mediterranean, so SST images are collected almost daily. SST images of the Eastern Mediterranean have been posted also at the CYCOFOS web page (Fig. 5), rather than just the Levantine SST images. Also, CYCOFOS produces chlorophyll-a images using the NASA MODIS AQUA ocean colour to visualize algal blooms.

3. Conclusions

 

CYCOFOS, in close collaboration with other partners in EU promoting the operational oceanography in Europe and the Mediterranean, contributes to the GMES Marine services, particularly on sub-regional and local scales. CYCOFOS is a well-rounded system consisting of both prediction and observational components. Most components are fully operational, they produce results every day and provide them to the general public via the internet (http://www.ucy.ac.cy/cyocean). The components are periodically improved, by providing higher resolution and more frequent oceanic flow forecasts, near-coastal wave forecasts, more open sea temperature, conductivity, and wave observations from the existing observatory, more coastal sea level/temperature stations, and satellite images of algal blooms and frontal zones. The ongoing developments will increase our knowledge of the Eastern Mediterranean Levantine and the adjacent coastal sea areas, thereby increasing the end users' and the decision makers ability to manage, protect, response and enjoy it safely.

References

 

Auclair, F., P. Marsaleix, and C. Estournel, (2000a). Truncation errors in coastal modelling: evaluation and reduction by an inverse method. J. Atmos. Oceanic Tech., 17, 1348-1367.

Auclair, F., S. Casitas and P. Marsaleix, (2000b). Application of an inverse method to coastal modelling. J. Atmos. Oceanic Tech., 17, 1368-1391.

Holthuijsen, L.H., N. Booij and R. Padilla-Hernandez, (1997). A curvi-linear, third-generation coastal wave model, Conf. Coastal Dynamics '97, Plymouth, 128-136.

Kallos, G. and SKIRON group , 1998: The SKIRON forecasting system: VOL. I: Preprocessing ISBN 960-8468-15-9; VOL. II: Model description ISBN 960-8468-16-7; VOL. III: Numerical techniques ISBN 960-8468-17-5; VOL. IV: Paralellization ISBN 960-8468-18-3; VOL. V: Postprocessing ISBN 960-8468-19-1; VOL. VI: Procedures 960-8468-20-5

WAMDI Group, (1988). The WAM model-a third generation ocean wave prediction model. J. Phys. Oceanogr., 18, 1775-1810.

Zodiatis, G., R. Lardner, G. Georgiou, E. Demirov, and N. Pinardi (2002). Cyprus coastal ocean forecasting and observing system, in Building the European Capacity in Operational Oceanography, Proceedings of 3rd EuroGOOS Conference, Elsevier Oceanography Series, 36-45.

Zodiatis G., Lardner L., Demirov E., Georgiou G., Manzella G. and Pinardi N., (2003a). "An Operational European Global Ocean Observing System for the Eastern Mediterranean Levantine Basin: The Cyprus Coastal Ocean Forecasting and Observing System", Journal of Marine Technology Society, v.37,no.3, 115-123.

Zodiatis G., Lardner R., Georgiou G., Demirov E., Pinardi N., Manzella G. (2003b). The Cyprus coastal ocean forecasting and observing system, a key component in the growing network of European ocean observing systems, Sea Technology, v.44, n.10, 10-15.

Zodiatis G., Lardner R., Lascaratos A., Georgiou G., Korres G., Syrimis M. (2003c). High resolution nested model for the Cyprus, NE Levantine Basin, eastern Mediterranean Sea : implementation and climatological runs, Annales Geophysicae, 21, 221-236.