But how much exactly?

The Flying Rivers project is attempting to quantify the amount of water vapour transported by these invisible rivers passing over our heads. They may well account for a volume of water on a par with discharge of the mighty Amazon River itself – estimated at 200,000 cubic metres per second – the most powerful discharge of any single river in the world.

The lower half of Brazil, essentially its agricultural and industrial heartland, depends entirely on its hereto reliable and abundant rainfall. Brazil receives more rain that any other country in the world (estimated at over 15,000 cubic kilometers per year – almost double the next best, Russia) and has, until recently, relied on hydro power for up to 90% of its energy requirements.

But is this all set to change?

In the face of the uncertainty about the ultimate impact of global warming, the search is on for further explanations and new data. By following the same westerly direction as the trade winds and collecting samples of airborne water vapour from the Amazon delta to the westernmost borders of Brazil, it is hoped to establish how often the humidity is returned to the atmosphere by evapotranspiration from the rainforest. And, by the same token, demonstrate to the Brazilian people as a whole the importance of maintaining the forest alive and well, so that the whole process may continue indefinitely.

The Flying Rivers project has been idealized by Gérard Moss, who will undertake all the active flying and collecting of samples. The analyses of these samples, interpretation of the results and final conclusions are in the capable hands of a renowned team of Brazilian scientists, spearheaded by the eminent Prof. Eneas Salati who, back in the 70s, first brought forward a theory on the correlation between the evapotranspiration of humidity from the rainforest in the Amazon basin and the rainfall in the southern half of the country. (See Pesquisas for information about the scientists).

COULD THE SOUTHEAST OF BRAZIL EVER BECOME A DESERT?

If we carefully examine a map of the southern hemisphere, it soon becomes apparent that landmasses between the 20th and 30th parallels are largely covered by deserts… Namib, Kalahari, southern Madagascar, Great Sandy and most of Australia, Atacama, going eastbound. When we cross the Andes, however, we come to the vast greenness and lushness of Paraguay, Brazil and Northern Argentina. So how come?

It is a complex question and there is no easy reply, but part of the answer lies in Amazonia, in the moisture-laden trade winds that initially bring humidity off the ocean to the mouth of the giant river, carry it all across the continent in an on-going process of rainfall/evapotranspiration/rainfall until hitting the wall of the Andes. The Cordillera forces the winds downwards, so they continue to carry this very same moisture in a southerly direction, greening the continent.

But what might happen in the south if the rainforest is ultimately destroyed to make way for pasture, soya and sugarcane? If the hydrological cycle stops continually pumping out humidity?

In a continuation of the ‘Brasil das Águas’ (Waters of Brazil) project, Gérard e Margi Moss have now taken on this new, urgent project. During the course of 2007 and 2008, they will monitor the trajectory of the Flying Rivers in a bid to understand the consequences of deforestation and slash-and-burn operations in the Amazon region on Brazil’s hydrological balance, and the impact of climate change on the forest itself.

OBJECTIVES

To try to ascertain the origin of the water vapour, rainwater and river water in the areas crossed by the flying rivers.

Through the results obtained from the analyses of the samples collected, further a better scientific understanding of these processes and their importance in collective rainfall patterns in central and southern Brazil.

To help Brazil’s large urban population – the man in the street – understand the importance of protecting the true source of the water resources upon which they depend for drinking, domestic and industrial usage, energy and agriculture.

To raise awareness of the key role played by the Amazon rainforest in generating the water that turns the great powerhouse of Brazil’s economic activities, and put a value on its preservation.

The term “Rios Voadores” or Flying Rivers was coined by Dr. José Marengo to describe the low level jets or air currents that carry water vapour down the eastern flank of the Andes, from Amazonia to Northern Argentina. In this project, the expression is being used in a broader sense to include the complete movement of water vapour from that region towards Southern Brazil.

Gérard and Margi Moss – Exploring the environment

Ever since the mid-80s, Gérard and Margi have travelled all over Brazil and around the world in light aircraft, at low altitude, attune with the land, seas, forests and deserts that pass beneath their wings.

Watching the landscape go by, they noticed the precarious state of so many rivers, the stubborn march of desertification, the open wounds left in the forests by slashing-and-burning, villagers and native peoples becoming environmental refugees – and they decided to act.

They specifically chose “water” as their theme. Ironically, it’s from the air that they can “explore” the environment in a different way, using innovative technology on a geographical scale.

Thus, in recent years, they have used light aviation’s strong points – access to remote locations, low-level flight, moving observation deck and photograph platform – in the service of the environmental cause, working together with prominent Brazilian scientists.

Gérard is totally at home in the sky. A private pilot with almost 5,000 hours in command, he reconciles a passion for flying with his engineer’s technical curiosity of how things work to put together environmental projects where an aircraft can do the job more efficiently than a person on the ground. This is of particular advantage in a country as vast as Brazil.

With the rare experience under his belt of having twice piloted around the world, encountering the most adverse and diverse conditions, a calm and methodical presence of spirit is vital for those difficult moments when he has to creep up on cumulus-nimbus clouds or collect samples skimming the water from narrow tree-lined riverbeds. Upon landing at the end of a long day like that, he frequently comes out with “Ah well, didn’t kill ourselves today, did we?”

Margi, pen and camera at hand, accompanies him on these challenging and often grueling flights. A nature-lover ever since her childhood growing up in Kenya, she is perfectly used to sleeping rough or riding the storms that come their way.

She takes photos that can at times be shocking or enigmatic, or more often simply beautiful and touching. “Nature paints the pictures, I just press the button,” she says, but nevertheless transforms those visual images into written ones that also invite us to climb aboard.

Having lived in Rio de Janeiro for over a quarter of a century, Brazil is their true home and they are naturalized Brazilians. They recently moved from the lushness of the Atlantic rainforest to the drier cerrado biome that surrounds Brasilia, in the very heart of the country.