An operational oceanographic forecasting and - Cyprus ...

An operational oceanographic forecasting and observing system for the Eastern Mediterranean Levantine basin: The Cyprus coastal ocean forecasting and observing system George Zodiatis*, Robin Lardner, Daniel R. Hayes and Georgios Georgiou Oceanography Centre, University of Cyprus, Nicosia, Cyprus

Abstract The Cyprus coastal ocean forecasting and observing system (CYCOFOS) consists of several operational modules: high-resolution coastal–ocean 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 prediction model. All these operational modules provide the following over the internet: daily ocean forecasts for the NE Levantine Basin for the next five days, weekly ocean forecasts for the next 10 days, a three-hourly offshore and near-coast sea state forecast for the Mediterranean, Levantine and Cyprus basins for the next 60 hours, daily single remote sensing SST images with 1 km resolution for the Eastern Mediterranean and the Levantine basin, hourly in situ sea level and water temperature at certain coastal remote stations, and halfhourly temperature and salinity at various depths from the ocean observatory in the SE Levantine Basin. Moreover, CYCOFOS provides daily and weekly forecasting data to end users, necessary for operational applications of the MEDSLIK (Mediterranean oil spill model). The ongoing development and improvement of CYCOFOS include the operational posting of six-hourly ocean forecasts, upgrading of the ocean observatory, expansion of the coastal remote observing stations, and processing in near real time of remote sensing images related to harmful algal blooms.

Keywords: Eastern Mediterranean, ocean forecasting, ocean observation network, wave forecasting, operational oceanography

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), * Corresponding author, email: [email protected]

594

An operational oceanographic forecasting and observing system for the Eastern Mediterranean Levantine basin: The Cyprus coastal ocean forecasting and observing system

to promote the operational oceanographic forecast and monitoring on local and subregional 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 data can be accessed at www.ucy.ac.cy/cyocean. Recently CYCOFOS joined the Mediterranean Operational Oceanography Network (MOON), aimed at sustaining the operational forecasts in the Mediterranean, in collaboration with other basin, sub-basin and coastal forecasting systems. The development and 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 and MFSTEP), the Mediterranean network to access and upgrade monitoring and forecast activities in the region (MAMA), the European sea level service research infrastructure (ESEAS-RI), the Mediterranean network of global sea level observing system (MedGLOSS) and the Marine environment and security in the European areas (MERSEA-Strand 1 and MERSEA-IP). The purpose of this paper is to discuss the current status of CYCOFOS.

2. Description 2.1 Forecasting

Figure 1 New, high-resolution (1.5 km) CYCOM domain. Users can click on any region to display more detailed images.

Operational ocean forecasts of the Levantine Basin (Figure 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 initialised from lower resolution oceanic model forecasts and high frequency atmospheric forecasts. In the past, the MFS basin model has been implemented as the parent model, along with ECMWF forecasts. This mode of operation now allows 10-day forecasts to be completed every week (along with 7-day hindcasts) with a resolution of 2.5 km. Currently, a higher resolution ocean forecast (1.5 km) is produced in which the parent model has been changed to the ALERMO model (www.oc.phys.uoa.gr/), which is in turn nested within the MFS basin model (Figure 2). In addition, the SKIRON (Kallos and SKIRON group, 1998) high-

George Zodiatis*, Robin Lardner, Daniel R. Hayes and Georgios Georgiou

595

frequency (hourly) meteorological forecasts are used (http://forecast.uoa.gr/). This allows a 5-day high resolution ocean forecast to be repeated daily. A variational interpolation method, Variational Initialisation and FOrcing Platform (VIFOP, Auclair, 2000a,b), 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 current field and the high resolution land mask are minimised. It should also be noted that the MFS basin model now includes temperature (XBT) and conductivity–temperature (CTD) profiles into its assimilation scheme, as well as satellite-based sea level anomalies, while the satellite sea surface temperatures are used for correction of the surface heat fluxes. In the near future, six-hourly forecast fields will be posted on the CYCOFOS web page, rather than just daily averages. The CYCOFOS forecasting products will continue to be available for the end users of the Mediterranean oil spill model, MEDSLIK. Use of the six-hourly current fields will certainly improve the accuracy of MEDSLIK predictions, as well as other derived applications.

Figure 2 CYCOFOS model hierarchy. Basin model of 7 km resolution is produced by the Mediterranean Forecasting System — Toward Environmental Prediction (MFSTEP). The regional model, ALERMO, of 3 km resolution is nested within the MFSTEP model. CYCOM is nested within the ALERMO model.

Wave forecasts of the entire Mediterranean and Levantine basins are produced by a WAM model (WAMDI group, 1988). The new extended Levantine wave domain is nested within the Mediterranean wave forecast (Figure 3). The wave forecast is produced every day for the coming 60 hours. Wave height, direction, and the SKIRON wind velocity are available every three hours. The high-frequency SKIRON forecasts provide hourly forcing, rather than the previously used six-hourly ECMWF winds. An even higher resolution wave forecast (Figure 2) based on SWAN (Holthuijsen et al., 1997) has been implemented for simulating waves at the near-coast sea areas around Cyprus.

596


Figure 3 The Cyprus Wave Model forecasts wave height and direction for the entire Mediterranean. Nested within that model is the wave forecast for the Levantine basin (inset 1). Nested within the WAM is a high-resolution SWAN model (inset 2). 2.2 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 XBT short cruises are carried out in the Levantine basin within the framework of the MFSTEP project, in the region south of Cyprus. The data collected from these cruises together with similar data from other parts of the Mediterranean are assimilated into the parent MFS model.

Figure 4 Location and photograph of the CYCOFOS MedGOOS-3 Ocean Observatory.


597

An ocean observatory has been added to CYCOFOS which measures conductivity and temperature at five levels in the open, deep Levantine basin (Figure 4). It is called the MedGOOS-3 Ocean Observatory, and was deployed by Harris Maritime Communication Services, who own and maintain the system. The sensors used 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. Finally, all observatory data will be uploaded every one or two hours rather than every 24 hours. 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 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. Recently, SST images of the Eastern Mediterranean have been posted on the CYCOFOS web page (Figure 5), rather than just the Levantine SST images as previously. Images are currently being produced for the Levantine basin depicting frontal zones based on SST, and these will be posted on the internet too. Also, the capability of producing images of ocean colour to visualise algal blooms will be achieved and made available in the near future.

Figure 5 AVHRR image of the Eastern Mediterranean captured and processed with the CYCOFOS receiving station and processing system.

3. Conclusions CYCOFOS, in close collaboration with other partners in EU promoting the operational oceanography in Europe and the Mediterranean, may contribute to the GMES precursor

598


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 (www.ucy.ac.cy/cyocean). The components are periodically improved by providing higher resolution and more frequent oceanic forecasts, nearcoastal 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’ ability to manage, protect, and enjoy it safely.

Acknowledgements The new developments and improvements of the CYCOFOS modules have been carried out in the framework of European Union and other related international projects including MFSTEP and MERSEA-strand 1. The authors acknowledge the support of: the European Commission’s Marine Science and Technology Programme, contract MAS3– CT98–0171 of the European Commission’s Programme Energy, Environment and Sustainable Development, contracts EVR1–CT–2001–20010, EVK3–CT–2002–0089 and EVK3–CT–2002–00075, the CIESM providing the equipment for the Cyprus MedGLOSS station, the MFS, ALERMO and SKIRON forecasting systems providing access to their forecasting products, Prof. Nadia Pinardi, coordinator of MFSTEP project and of the MFS system, Prof. George Kallos coordinator of SKIRON system, Prof. Alex Lascaratos coordinator of ALERMO system and his scientific team from the University of Athens, Dr. Sarantis Sofianos and Dr. Nicos Skliris. We are also grateful to Dr. Dov Rosen, coordinator of MedGLOSS and his scientific team from IOLR, Dr. Isaac Gertman, Lazar Raskin and Irena Lunin for their valuable support and all CYCOFOS collaborators: Prof. Skevos Paraskeva, Dr. Vladimir Fomin, Dmitry Soloviev, Tommy Eleftheriou, Sotiris Savva, Marinos Ioannou, Marios Papaioannou, Iacovos Kostantinou and Andreas Kasenides for their contributions and to the system’s modules and the system’s operation, and Dr. Andrew Clark of MCS, USA for support of the CYCOFOS MedGOOS 3 Ocean Observatory.

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, thirdgeneration coastal wave model, Conf. Coastal Dynamics ’97, Plymouth, 128–136. Kallos, G. and the 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: Parallelization ISBN 960–8468–18–3; VOL. V: Postprocessing ISBN 960–8468– 19–1; VOL. VI: Procedures 960–8468–20–5.


599

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