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Meteorology

Inside the rain clouds

A new hydro-meteorological system is going to forecast rain with up to threehours of anticipation

MIGUEL BOYAYANNext summer, if all goes well, the inhabitants of the Metropolitan Region of São Paulo, which covers thirty nine municipalities, will have at their disposal an information service concerning rainfall that will avoid lots of damages and even save lives. Tropical storms, like those that flooded, at the start of January, the streets of São Paulo, São Caetano do Sul and São Bernardo do Campo, where landslides killed nine people,  will be forecast with anticipation after the implementation of a new meteorological system that is going to identify and analyze the formation and the movements of clouds in the region. The idea is to forecast the dangers of heavy rains and to relay alerts at very short notice (with up to three hours of anticipation) to the Civil Defense, government organs and also to all of the population by all means of communication.

The project is part of a wide science and innovative technology program funded by FAPESP, in partnership with the Hydro-Meteorological Board of the State Secretariat of Science and Technology, which is beginning to be implemented and carries the name of Integrated System of Hydro-Meteorology of the State of São Paulo (Sihesp). The first phase of the program was implemented in December of 2004 and is composed of four projects approved by a team of specialists from abroad.

At a cost of R$ 4 million, this stage is dedicated to the implementation of an equipment network that includes the installation of ground meteorological stations and the building of a mobile radar, followed by the modernization of the two radars already in existence in the cities of Bauru and Presidente Prudente, which mainly serve the farming community in forecasting rain. With new sensors and new software, they will be of fundamental importance for the weather forecasts that identify and quantify the rain in the cloud cover. Besides providing a service to society, the Sihesp program is going to initiate an advance in meteorological scientific knowledge in the state of São Paulo and will boost the technological development of the country in this area.

“The program is paradigmatic as it brings together scientific research activities of current actuality, permitting the generation of information that is of socio-economic relevance and, with strategic financing, will contribute to technological innovation in precision instrumentation”, says José Fernando Perez, FAPESP’s scientific director. “With the radars and the meteorological stations network, which are currently being implanted, we are going to amplify our capacity for observation and the diagnosis of the physical and dynamic processes in cloud formation and of tropical storms, as well as sampling data of better quality that will be inserted into the numerical models for forecasting weather, climate and hydrological models (the analysis of the quantity of rain that falls on the ground and into the rivers)”, explains Oswaldo Massambani, from the Astronomy, Geophysics and Atmospheric Sciences Institute (IAG) of the University of São Paulo and the coordinator of the Sihesp program.

An unprecedented tool for the researchers is the acquisition of the new radar, which will perform in conjunction with that existing at the Ponte Nova dam, in the municipality of Biritiba Mirim (the eastern region of Greater São Paulo) and which will be installed in a truck, allowing for greater mobility in the detection of rains, including those on the coast. The radar unit will be produced by a small São Paulo company, Atmos, the only Brazilian company that presented a proposal along with four other companies from abroad. Although they had promised better prices (up to 30% cheaper) and a faster delivery time, the foreign companies were excluded by FAPESP because, in an agreement with the researchers, they decided to invest in Brazilian capability in the manufacturing of meteorological radars. “We used our purchasing power to spur technological development in this area within the country”, explains Perez.

“We demonstrated that in this case fast delivery and price are not the only criteria and not even the most appropriate when one intends to make a technological impact on the capability of Brazilian companies.” In the agreement between the company, FAPESP and the researchers responsible for the IAG radars and the Meteorological Research Institute (IPMet) of the Paulista State University (Unesp) in São Paulo, it was established that Atmos, in order to attend to the specifications formulated by the researchers, as yet not mastered by the company, would import some technology packages in order to have the equipment ready for the summer of 2006.

The technology of the new radar is based on the X-band, an electromagnetic frequency that works at 9.5 gigahertz, while  the so called S-band, still in use by the IPMet’s radars (Bauru and Presidente Prudente) and at Ponte Nova, run by the Foundation for Hydraulic Technology Center (FCTH), operates at a frequency of 2.8 gigahertz. The difference is that the S-band has a range of 200 kilometers (km) and the-X band, of up to 100 km. “But the X, as well as being of Doppler Effect (electronic procedure that measures the velocity of the displacement of the echo – reflection of the electromagnetic waves – coming from the clouds in relation to the radar), will have the capacity to detect the clouds with greater resolution and precision”, explains engineer Fábio Haruo Fukuda, responsible for the projects at Atmos. “We are going to carry out the projects of the radar’s electronics and mechanical assemblages and import the software along with some electronic modules. However, all of the engineering for the integration will be carried out here in São Paulo.”

The company is also looking after the project on the control pedestal of the radar’s antenna, which has built into it rotational movement and that of azimuth (the angle of direction in relation to the ground). All the equipment will be installed in a truck that will be acquired for the project and adapted for the functioning of the radar. “We will have the conditions to develop here the majority of the modules that we are going to purchase abroad, but this would imply a longer delivery date, which is just not viable for this project”, says engineer Paulo Eduardo Martins, from Atmos.

Founded in July of 2004, Atmos is a company that was nurtured at the innovation incubator of the Critical Technology Applications Foundation, which runs under the commercial name of Atech, an organization with private rights and is non-profit, established in 1997 in order to integrate the System for the Vigilance of the Amazon (Sivam), implemented by the Brazilian Air Force, the company’s main client. In October of 2004, Atech, which designs schemes and provides consultation on air traffic control systems, radar and satellite image processing for the Armed Forces as well as for companies, closed a contract worth US$ 1 million with the Venezuelan government to provide consulting services and to participate in the process of transference and the absorption of the technology of Program System Modernization of Hydro-Meteorological Prognostication of that country.

Atmos was also set up with the participation of Omnisys, a company also founded in 1997 to develop systems applicable in aeronautics, the navy, meteorology and telecommunications. In order to solidify its knowledge about radars, Atech, and afterwards Atmos, developed a meteorological radar, of S-band type, which is installed in the city of Mogi das Cruzes. “With the experience that we acquired on the Sivam Project, we projected all of the S-band equipment, including the software for the radar control, and we installed it at Mogi. Now we are in the testing phase, making use of German meteorological software”, says engineer Fukuda. “In the future we also intend to develop this type of software, which is the only part of the equipment produced outside of the country.”

On the scientific side, the meteorologist Augusto José Pereira Filho, from IAG, who coordinated the project on the development of the new radar, stated that the X-band, as is in the approved project, caters to the technical demands of the researchers. “It will allow for an analysis at the moment of the formation of the system (clouds) and to verify if the said system is a candidate for a tropical storm”, says Pereira Filho, who has been studying the forecasting of flooding since 1986. For four years now he has been analyzing the data collected by the radar at Ponte Nova along with flooding. “Through the media I make a comparison of the consequences of flooding with what was shown on the radar.

The victims during this period, including those at the start of January of this year in São Bernardo, have already passed thirty dead, the majority of them being children.””In 70% of the cases, the strong rains, which can reach beyond 100 millimeters (mm) of water in only three hours, occur due to the localized formation of air circulation generated by super heating within the metropolitan region”, explains Pereira Filho. “Since within this large area is lots of concrete and pavement, in summer a warming up occurs that transforms the air into very hot air that rises in the direction of the atmosphere.

When this bubble of air meets up with the breeze that comes from the coast a mixture of the hot air with the much colder and more humid air occurs. In general, the winds change direction from the northwest to the southeast and make the air rise (beyond twelve kilometers it is possible to find temperatures of -60°C), expand and cool down, having as a consequence the transformation of water vapor and the formation of raindrops and of hailstones.” All of this happens in a very short period of time. From the formation of the clouds until the end of the rainstorm, only three hours might have gone by. “The major goal f the X-band radar will be to detect the formation of rain while still in the development stage within the clouds. It will function as a complement to the radar at Ponte Nova, which detects the rain when it is actually falling.”

Coastal vision
In summer, the mobile radar could be positioned to monitor cloud formations at the top of the Mar ridge (which separates the plateau where the city of São Paulo is located and the region around the port of Santos). Thus the researchers would mount an immediate forecast system of at the maximum three hours with a resolution in the order of 200 meters on the ground. “It’s not possible to avoid tropical storms, but it is possible to anticipate the formation of the system and where it is going to rain more heavily. In this way we could alert the Civil Defense and governmental entities, so that they could remove people from the hillsides before landslides occur, for example, and even close tunnels and avenues, or that is to say, take the people out of the rainfall’s pathway.” Communication between the mobile radar, the IAG and Ponte Nova would be done via radio or cellular telephone. The work of meteorologist Augusto and a further thirteen researchers also includes accompanying the rising of the rivers that circumvent the metropolitan region and make up part of the basin of the upper Tietê river. “We are going to analyze the quantity of rain that runs into the river and how much remains in the basin. In some case we have had measurements that show the inflow to the Tietê river rising from 100 m3 of water per second to 600 m3 per second in less than three hours, a situation that also contributes to flooding.”

In order to process all of the data involved in forecasting rain and other forecasts, the researchers will also count on a network of ground meteorological stations. Initially, ten new automated stations will be purchased (that will measure and send information via land telephone, cellular phone and the internet) in the metropolitan region that are going to measure temperature, winds, relative humidity and the amount of rainfall. “They will be interlinked to a network already in existence of eighty (80) stations spread throughout the state and maintained by the State’s Secretary of Agriculture and Provision and under the responsibility of the State Fund of Water Resources (Fehidro)”, informs Orivaldo Brunini, a researcher at the Agronomy Institute of Campinas (IAC), who coordinates the network of ground meteorological stations in the Sihesp program. “These eighty are also going to be modernized”, says Brunini. For him, the implementation of the Sihesp program is of extreme importance not only to avoid flooding but also for agriculture. “The weather forecasting and the alert systems could help the farmer in his choice of the correct time for harvesting, planting, and principally, in the management of agrochemicals, because it would be possible to cancel a spraying before a heavy rainfall. If it rains right after a spraying ,the job is lost.”

Benefits for agriculture are were also forecast by Lourival Mônaco, the executive secretary for Science and Technology in the São Paulo  government. For him, if the efficiency of the Sihesp program attains 40%, the state’s farmers could save US$ 160 million per year with herbicide and pesticide spraying. In the sugarcane industry, if 40% for the plantations use the weather forecasting for spraying and 30% are successful, the savings would reach US$ 42 million. “Furthermore, weather forecasting allows for a better development of agricultural policies”, says Mônaco.

Agriculture will also benefit from the modernization of the Bauru and Presidente Prudente radar stations to be carried out by Atmos. “In the first phase the system of reception and signal processing will be modernized”, says engineer Fukuda, from Atmos. In this case the equipment and software will come from the United States. The Brazilian company will manage the modifications and carry out the adaptation of the radar’s circuits for the installation of the new equipment. Afterwards Atmos will be responsible for maintenance. “With the new hardware and software we will have more parameters and we hope to make forecasts more quickly”, says Gerhard Held, the project coordinator within the Sihesp program. The modernization of the radars will also benefit the monitoring of the flood alert system in the urban areas of Bauru, for example, as well as the identification of other severe atmospheric events such as tornados, whirlwinds and hailstorms.

Both the information from the radars and the meteorological stations are going to inter-react with the fourth and final project approved within this phase of the Sihesp program, under the coordination of Tércio Ambrizzi, from IAG. This will be the formation of a computer network that is going to house a climatic model for the state. To this end, the project is setting up a network of sixteen computers that will work in parallel to generate close to 140 billion pieces of information per second. “This project has the objective of carrying out climatic simulations using new mathematical models for the forecast and for the studies on the climatic variability of the state. Our interest is to provide information for a better seasonal climatic forecast in this region”, explains Massambani. For him, the data obtained in real time by the networks of observational platforms and the products of extremely short time forecasting, of period forecasting and of climate, are of fundamental importance for the lowering of the impact of extreme events in the state of São Paulo, such as severe tropical storms, inundations, gale force winds, severe droughts and frosts.

The Project
Implantation of observational platforms (4 projects); Modality Integrated System of Hydro-Meteorology of the State of São Paulo (Sihesp); Coordinator Oswaldo Massambani – IAG-USP; Investment R$ 4 million (FAPESP)

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