Sealoc - a multivariable forecast and visualization engine for Mediterranean Sea phenomena and variables

1. Operational function of a forecasting system providing sea
characteristics and other support services on high local
resolution, entitled sealoc
G. Kalantzi1*, I. Hatzopoulos1, A. Partozis1, K. Karystinakis1 and S. Kotsopoulos2
1OMIKRON Environmental Consultants SA, 15th klm of Thessaloniki-Moudania Nat. Rd., Thermi, 57001, GREECE
2DRAXIS Environmental SA, Themistokli Sofouli 54-56, Thessaloniki, 54566, GREECE
*Corresponding author: georgiak@omikron-sa.gr, +30 2310 863216
Sealoc system (sealoc.gr) has been operationally active online since the end of 2020. It has been developed, as a pilot system, by two Greek SMEs through funding from the
Operational Program “Competitiveness, Entrepreneurship and Innovation” (EPAnEK), Intervention I, of the NSRF 2014-2020 (project ID T1EDK-03595). The system combines
four core building blocks: (1) interconnected in-house forecast models for wind and sea waves, (2) automated processes for marine forecasts’ acquisition and storage from
Copernicus Marine Service (various parameters), (3) calculation and visualization engine for all associated datasets and (4) an interactive web interface and a mobile
application. All four building blocks have been structured into an automated chain of processes which is functioning on a daily operationally basis without external interaction.
The system provides every day a three-day length marine forecast of various parameters for the Mediterranean and the Greek Seas, in increasing height of spatial resolution.
The visualizations and color scales, for every parameter, have been carefully developed so as to provide users all the necessary information “at an eye’s glance”. Moreover, both
the web interface and the mobile app avail users a logon/ login capability in order for them to be further informed by statistically developed “experience parameters” focusing
specifically to swimming and sailing activities. So far the operational activity of sealoc has been proven to be a success and its web interface and mobile app have gathered
interest from the targeted users.
High resolution and user-friendly forecasts in form of data-as-services for the sea,
are a prerequisite for many applications both professional and recreational.
Whereas, scientific and research developments in the field of ocean forecasting are
remarkable today, only few of these breakthroughs reach users outside the
scientific community.
The problem SeaLoc project, which is now in its final stage, consists of a pilot forecasting
platform providing sea characteristics and other support services on high local
resolution for the Mediterranean and the Greek seas. It serves forecasting data
comprising results from in-house models, Copernicus Marine Service (CMS)
datasets and “experience parameters” resulting from the original forecasts. The
system is fully customizable and can provide the base of a wide range of tailor-
made services (i.e. APIs, visualizations, data flows, charts, consultancy etc.)
necessary to a wide range of near-shore and offshore applications.
1. In-house forecast models and validation
There are three forecasting domains with descending spatial resolutions: (a)
Mediterranean (18,5x18,5 km), (b) Greek Seas (3,68x3,68 Km) and Aegean
(1,84x1,84 km). For the weather forecast the system uses the numerical weather
model WRF-ARW (WRF4.0.1) [5] which runs daily and produces wind (m/sec) at
10m height, every day at 12.00 am with a forecasting span of the order of three
days and hourly time steps. For the sea wave forecast the system uses the
numerical third generation sea wave model WAVEWATCH III® (v. 5.16) [6] which
runs daily by using the above mentioned winds as input, and produces significant
wave height (m) and wave direction (degrees) every day at approximately 2.00 am
with a forecasting span of the order of three days and hourly time steps. The wave
model set-up has been validated through comparisons with altimetry data
(collocated Jason 2 data) in the framework of WaveForUs project [3] and in the
framework of SeaLoc project; i.e. comparisons with collocated Sentinel 3A data.
The comparisons showed an acceptably good fit.
2. CMS products
The relevant research for open access and reliable data led to the widely used data
base of European Data, i.e. Copernicus and specifically Copernicus Marine Service.
All datasets used correspond to the whole Mediterranean region and have a spatial
resolution of the order of 4,6x4,6 km. The forecasting time step is hourly, except of
the Biochemistry dataset which is daily, and the forecasting time span is three days.
The three datasets used are: (a) Mediterranean Sea Physical Analysis and
Forecasting Product, (b) Mediterranean Sea Biogeochemistry Analysis and
Forecasting Product and (c) Mediterranean Sea Waves Analysis and Forecast
Product.
3. Experience parameters
Apart from the forecasting parameters themselves, a set of “experience
parameters” have been developed and integrated currently concerning sailing and
swimming activities. For sailing activities, the internally produced wind velocity/
direction and significant wave height forecasts are used to estimate two scales,
namely Beaufort [4] for wind and Douglas [2] for waves. These two scales when
estimated from valid data and visualized in appropriate color scales can give “easy-
to-comprehend” information to the general, non-scientific, public. Additionally, the
wind direction is also denoted with common wind names popular amongst the
marine community. For the swimming activities, the CMS product corresponding to
sea surface temperature forecasts is used to estimate two experience scales,
namely sea temperature feeling and swimming performance. Specifically, based on
the work of Alexiou [1] the water temperature is expressed in “easy-to-
comprehend” thematic maps, where each scale value explains (a) the way the
human body approximately feels when a person swims in certain temperature
ranges and (b) the way the human body can perform when a person swims in
certain temperature ranges. The estimation of these additional layers concerning
“experience parameters” can be extended to include other activities such as
fishing, aquaculturing, surfing, diving, infrastructure design, etc.
Materials and Methods
Sealoc web and mobile
interfaces/
applications
Daily operational cycle
All structural components of the system are conjoined into a prototype operational
chain of processes. The two in-house models interoperate with internally
developed background processes (linux and ftp services), so as to support (a) data
input from the weather model into the sea wave model in daily forecast runs and
(b) output of the produced forecast parameters as conduit/ input on back-end
estimations of the experience scale/ parameters and area filtering (isolines
produced by applying the Marching Squares algorithm) and visualization processes.
Also, the CMS products are acquired with the use of an internally developed
software (Visual Studio VB.net) which automatically downloads and stores the
data, daily. These CMS data are also managed in a similar way to all the internally
produced forecasts. Each daily operational cycle is concluded at approximately
02.00 am.
1. Web user interface
The sealoc web user interface includes a wide map window with all widely used
functionalities such as zoom in and out, dragging and click for info. The web-
interface also presents a login and layer column on the right, and an animation/
color scale bar on the bottom. On the far right corner there is a button designed to
collect feedback from users.
2. Mobile application user interface
In the same rationale as in the web interface, the stand alone sealoc mobile app
presents all the functionalities, information, parameters and thematic maps as
presented previously, in mobile friendly views. The application is available on
google play and is updated on a frequent basis.
3. Conclusions
Sealoc aspires to be a point of reference for the provision of reliable ocean
forecasts for Greece and the Mediterranean on a commercial B2C and B2B level. It
aims in bridging the gap between oceanographic forecasting datasets and marine
end-users’ needs, while integrating scientific, technical and technological
innovations in an interdisciplinary manner. It is addressed to a wide range of end-
users, performing many activities with various needs.
Results and Conclusions
Visit sealoc applications by following
these two QR codes and don’t forget
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Literature
1. Alexiou, S., 2014. The effect of water temperature on the human body and the swimming effort. Biology of Exercise, 10:2.
2. Brittanica, 2018. Douglas scale. Encyclopaedia Britannica, 22 Jun. 2018.
3. Krestenitis, Y.N., Kombiadou, K.D., Androulidakis, Y.S., Makris, C.V., Baltikas, V., Skoulikaris, Ch., Kontos, Y., Kalantzi, G., 2015.
Operational Oceanographic Platform in Thermaikos Gulf (Greece): Forecasting and Emergency Alert System for Public Use.
E-Proceedings of the 36th IAHR World Congress, 28 June – 3 July, 2015, The Hague, the Netherlands, 12p.
4. The Met Office, 2011. The Beaufort Scale. National Meteorological Library and Archive Fact Sheet 6.
5. MMML, 2019. ARW Version 4 Modeling System User's Guide. NCAR-MMM 411.
6. WW3DG, 2016. User manual and system documentation of WAVEWATCH III® version 5.16. Tech. Note 329,
NOAA/NWS/NCEP/MMAB, College Park, MD, USA, 326 pp. + Appendices.