New Models of Weather Pattern

For a mathematician, Joseph Biello spends a lot of time thinking about the weather. But the UC Davis assistant professor isn't looking out the office window. He is using mathematical theory to build a model of the Madden-Julian Oscillation, a tropical weather pattern that influences drought and rainfall in the western U.S.

The Madden-Julian Oscillation was discovered in 1972 when researchers looked closely at meteorological data. It lasts 30 to 60 days and appears as clusters of tropical thunderstorms over the Indian Ocean before sweeping eastward into the Pacific, where it dissipates.

Measured in weeks, the Madden-Julian Oscillation lies in a gray area between short-term weather forecasts and long-term climate studies, said Bryan Weare, a professor of meteorology at UC Davis who also studies the phenomenon. A better understanding of the weather pattern would help with medium-range weather and climate forecasting.

Weare is trying to understand, for example, the conditions that cause the oscillation to begin over the Indian Ocean. Once the oscillation is under way, you can use it to make predictions about weather phenomena over a month or so, he said. But how it occurs in the first place is not well understood. So far, his work supports theories that link surface moisture over the ocean to thunderstorms, he said.

The phenomenon has subtle effects on weather in the U.S. There is a link between days of very intense rainfall on the West Coast and rainfall associated with a Madden-Julian Oscillation near the equator, Weare said. On the other hand, Biello said that there also seems to be a link between a strong oscillation and a general drought on the West Coast.

So far this winter, the Madden-Julian Oscillation appears to be weak, according to data from the National Weather Service. But the oscillation can occur several times over the winter months.

To understand the weather, you have to look at processes at vastly different scales of space and time, Biello said.

"To understand the Earth, you have to understand raindrops," he said. Biello's specialty is to build mathematical models that incorporate these different scales. Often, weather and climate models divide the planet into a grid of squares, kilometers across, and look at how those squares interact. But that means making assumptions about what is going on within the squares, Biello said.

Source: UC Davis

Related stories:

Salmon-tracking network challenges conventional wisdom
They were two of the 1,000 juvenile salmon implanted with almond-sized transmitters as they headed out of the Rocky Mountains, down the Snake River bound for the sea.
The Good Vibrations of Nearby Stars
Some of the first data collected by the CoRoT space telescope mission, launched in December 2006, provides valuable information about the physical vibrations and surface characteristics of nearby stars that are similar to our Sun, researchers say. This novel information illustrates the great value of space-based observations, and provides astronomers with insights into the interior of our Sun, other stars, and the overall evolution of our galaxy.
Brainy genes, not brawn, key to success on mussel beach
It's hard being a mussel: you have to worry about hungry starfish and even hungrier humans, not to mention an environment that can change your body temperature 50 degrees Fahrenheit in just a few hours.
Penguins setting off sirens over health of world's oceans
Like the proverbial canary in the coal mine, penguins are sounding the alarm for potentially catastrophic changes in the world's oceans, and the culprit isn't only climate change, says a University of Washington conservation biologist.
World's first space telescope to discover near-Earth objects
Canada is building the world's first space telescope designed to detect and track asteroids as well as satellites. Called NEOSSat (Near Earth Object Surveillance Satellite), this spacecraft will provide a significant improvement in surveillance of asteroids that pose a collision hazard with Earth and innovative technologies for tracking satellites in orbit high above our planet.
Understanding autumn rain decline in SE Australia
According to a report from a CSIRO Wealth From Oceans Flagship study – published this week in the science journal Geophysical Research Letters – since 1950 Victoria has suffered a 40 per cent decline in autumn rainfall (March to May) compared to the average recorded between 1961–90.
Larger Pacific Climate Event Helps Current La Nina Linger
Boosted by the influence of a larger climate event in the Pacific, one of the strongest La Niñas in many years is slowly weakening but continues to blanket the Pacific Ocean near the equator, as shown by new sea-level height data collected by the U.S.-French Jason oceanographic satellite.
El Nino at Play as Source of More Intense Regional U.S. Wintertime Storms
The next time you have to raise your umbrella against torrents of cold winter rain, you may have a remote weather phenomenon to thank that many may know by name as El Nino, but may not well understand.

News discussion:

General Science news