Recent rains splash into El Niño theories
By Jeyling Chou
Jan. 20, 2005 9:00 p.m.
Soggy shoes were traded for short skirts and scarves were
swapped for sunglasses.
Relentless rains last Wednesday suddenly gave way to sunshine on
Thursday, much to the relief of students and their umbrellas. So
far this week, the forecast has been clear.
Even without another drop of rain this month, rainfall levels
this January are record-setting for the campus area, said James
Murakami, the staff meteorologist for the Department of Atmospheric
Sciences.
UCLA researchers say the shift in weather from last week is not
anything out of the ordinary, and was caused by regularly occuring
weather phenomena.
An area of warming water off the South American coast, otherwise
known as El Niño, often causes heavy rains throughout the
winter season. This year, however, El Niño has come with a
twist.
“It’s not a typical El Niño year,”
Murakami said. “The pool of warm water is lying much farther
west ““ it’s not in it’s usual
position.”
This shifted position can cause colder rains, and may explain
the episodes of snow experienced in some areas of Southern
California, Murakami said.
Much remains unknown about the El Niño phenomenon and the
mechanisms that cause it to return every four to five years.
The current theories about the phenomenon were established in
the 1940s by former UCLA Professor Jacob Bjerknes, the founder of
what is now the Department of Atmospheric and Oceanic Sciences.
“UCLA has traditionally had a tremendous impact in the
atmospheric science and climate fields ““ both in developing
these computer models of climate, and the understanding of El
Niño,” said Professor Carlos Mechoso, who has been with
the department since 1979, shortly after Bjerknes’ death.
The warm waters in the Pacific Ocean characteristic of El
Niño cause increased rates of evaporation, carrying ocean
storms to higher latitudes.
UCLA researchers presently receive data via satellite from buoys
around the equator that measure ocean temperature and currents to
gather more information about the nature of the weather and to
potentially predict how it may behave.
“We still do not understand how we can use El Niño
for predicting the next season, so we are constantly monitoring the
situation in the tropical Pacific,” Mechoso said.
Mechoso’s own research deals with the computer
representations and simulations of weather phenomena such as cloud
movement and the absorption of the sun’s energy waves.
This research can ultimately be applied to a better
understanding of weather and forecasts.
Current technology has improved forecast accuracy, but more
improvements can be made.
“I don’t believe we have any predictable skill
beyond five days,” said Robert Fovell, an associate professor
of atmospheric and oceanic sciences, who studies the simulation of
thunderstorms.
Because of their rarity in Southern California, Fovell looks
mainly to the Midwest for his storm material.
“I’m interested in the forces that trigger
thunderstorms,” Fovell said. “Thunderstorms tend to
appear in clusters or groups ““ when you find a thunderstorm,
you tend to find more in the immediate environment.”
It is currently unknown how one thunderstorm may assist in the
formation of a subsequent one.
The current warm weather conditions can also be attributed to
the Santa Ana winds which blow in from the desert, Fovell said.
The air in the desert starts out cold, but rises in temperature
and speed as it squeezes through passes and canyons. These winds
are common throughout the winter season until March, increasing the
danger of wildfires.
Globally speaking, however, climate change is an undeniable fact
increasing at a rate of four degrees centigrade every 100
years.
“There is practically a unanimous consensus in the science
world that the atmosphere is going to be warming, and the only
debate is on the magnitude,” Mechoso said.
The changes in the last 100 years or so in temperature have been
much larger than the ones that we saw before in a comparable
period. That is giving us the confidence to say we’re seeing
the fastest rate of the global warming,” he added.
If the trend continues, Mechoso said, something ““ such as
an agreement to reduce the emissions of fossil fuels ““ will
have to be done.
