State-of-the-art radar set to improve weather forecasts By Patrick Joubert |13 December 2022
The Seychelles Meteorogical Authority (SMA) in collaboration with the University of La Reunion has installed a sophisticated weather and research radar in the vicinity of the Bel Ombre fishing port to collect data on rain pattern in the country.
The collection of data of our precipitating system which started in the last week of October and which will end by the end of January 2023 is part of a project under ‘Espoire’, the study of precipitating systems in the Indian Ocean by radar and satellites funded by European FEDER funds, Reunion Regional Government and the French State.
The sophisticated radar can measure the amount of water vapour in the distant clouds that will allow forecasters to know how much rain will fall and the intensity with which it will hit the islands, hence giving the correct weather forecast and weather warnings.
It is that first time that such a radar is being used to document water vapour in our country’s atmosphere.
SMA is relying on satellite images, among meteorogical attributes, to predict the country’s weather forecast.
Espoire is part of a global scientific strategy, initiated several years by LACY, the University of La Reunion and their regional and national partners. The goal of the project is to improve the understanding of the spatio-temporal variability and the forecasting of extreme weather events and their impacts over the South Western Indian Ocean islands territories, mostly in relation to cyclones.
It is also to better anticipate and characterise the evolution of these events in a context of climate change and territorial resilience, strengthen scientific and technical collaboration, training, and regional expertise in the field of meteorology and remote sensing and to contribute to strengthening the means of meteorological observation in the South Western Indian Ocean region in collaboration with the meteorological research centres of this region.
Apart from the study being conducted here, the continuation of the Espoire project, which started in 2021 in La Reunion in 2021 with the study of the cyclonic band, will move to Tamatave, on the east of Madagascar, in February 2023, for a three-month study on the cyclone band in the area before going back to La Reunion for the continuation of the project which will be completed by end of 2023.
The Espoire project has three actions which include the study of the water vapour field using GPS network, the study of the mechanism of the formation and transformation of intense precipitation at the local scale in interaction with the orography of the different islands using the research radar and steering, training and promotion actions in cooperation with Indian Ocean partners.
Speaking about the project yesterday morning at SMA in the presence of chief executive Vincent Amelie and senior forecasters, the director for of the national research scientific centre (CNRS), Joel Van Baelen, said that our country has been chosen for the project because we are situated in the passage of the Inter-tropical Convergence Zone (ITCZ) associated with deep tropical convection bringing heavy rains in its path during the summer, which could lead to cyclone to regions down south.
Mr Van Baelen explained that the small mobile radar, mounted on a small sea container and turning 360 degrees, can deep scan for atmospheric water vapour at a range of 100km with a 150m resolution in range from very low clouds over the horizon to different cloud elevations higher up.
He added that the volume of data of the very defined images of the precipitation systems, documented on the two computer servers inside the container, are sent to the research lab at the University of La Reunion and at SMA every six minutes to be analysed.
He said that the radar can withstand winds up to 150km per hour.
He said that after touring places on Mahé and on Praslin to install the radar, the site at Bel Ombre was the ideal one for the project, although it doesn’t project the 360 degrees required because of the mountain, given of its logistics with regard to electricity and secure location while overseeing a large ocean view, among others, and the north west monsoon which has started that would bring heavy clouds with lots of water in the area.
Mr Amelie said that in the time of the rainy season, SMA will be in better position, with the use of the radar, to make better impact base forecasting in terms of giving the correct weather information and its impact even hours before the rain is set to pour down.
He noted that the installation of the radar will prepare SMA staff to manage our own weather research radar to be acquired by end of December 2023 or early January 2024, through funds under a regional project. The radar will be installed on Zimbabwe on Praslin.
Mr Amelie said that SMA was very grateful for the expertise being given by the University of La Reunion in relation to the maneuver of the radar and they are looking forward for the continued collaborative relationship to improve our early warning system.
Apart from the radar, SMA has mounted a small automated weather station on the container for its own use to measure the wind, rain, temperature and humidity. There is also a small camera to take photos of the clouds in the area.
Photos by Patrick Joubert
