CLEVELAND, Miss. -- Don’t ask Charles Wax, an assistant state climatologist and head of Mississippi State University’s geosciences department, exactly what kind of weather Mother Nature will wield. He doesn’t have a crystal ball, after all.
But he can tell you, based on trends and cycles and cause and effect, what is likely to happen and why.
“Why was 2005 hurricane season so active? Everybody is thinking, ‘Oh my, it’s global warming. It’s changed. Life will never be the same thing again,’” he said during a presentation at the annual Delta Ag Expo in Cleveland, Miss. on Jan. 18.
“I can tell you with some assurance that none of those assumptions are true.”
While residents along the Gulf Coast, and particularly New Orleans, continue to rebuild homes and entire communities, farmers of all kinds are also wishing the harshest tempests endured will not reoccur anytime soon.
Don’t get your hopes up, Wax conveyed.
Since 1995, he said, meteorologists have noted that the amount of seasonal hurricane activity in the Atlantic Ocean, technically referred to as the Atlantic Multidecadal Oscillation, has been locked in on high mode.
“We had a most active hurricane season and we are most likely going to have another one next year (2006),” he predicted. “And I think that is pretty good science and not in the realm of magic. It’s something that has been measured and mapped out the past few years.”
Weather trends in the Atlantic Ocean, Wax explained, generally last several decades in either low or high modes of activity.
“There are decades-long — 20, 30, 40 years — natural cycles in cyclone activity. When it is in high phase we have a lot of hurricane activity in the Atlantic; when it is in a low phase we have very little activity.”
He said charting the AMO over the years indicates a cyclical pattern that climbs up, falls down, climbs up and falls down again.
Wax said there are about six variables that combined influence phases of high or low activity. One critical factor involves vertical wind shears.
“In a year where we are having a lot of shear in the upper atmosphere in the tropical region, it will destroy the storm. You won’t have hurricanes. In a year where there is low or no shear in that part of the world, that storm is going to blossom up and become a Category Five hurricane over and over again. That was the case last year.”
A second critical factor concerns oceanic temperatures.
“When ocean temperatures are high, the AMO is high and conversely, when temperatures are low, the AMO is low.” Such was the case last year.
In recent years, scientists have mapped out what’s known as the Global Ocean Circulation Current, which ties large currents of water together around most of the world. Within these connected currents, Wax said, there are layers of warm water and cold water, which periodically flip flop. Whichever water conditions are on top also affect the AMO activity level.
Better detection, same patterns
While scientists have been well aware of some kinds of weather patterns for many decades or centuries, such as El Niño (since 1540), many people believe that severe weather has increased in recent memory and hold global warming accountable.
He’s skeptical, at best, asserting that weather patterns have stayed consistent.
Thanks to technology advancements, scientists have only in recent history had a better chance of identifying storms, he observed.
Citing an example, he said 1933 stands behind 2005 as having the most hurricane activity recorded. However, 1933 was prior to the development of radar and satellites, meaning many more storms probably went undetected.
While many countries have made efforts to track temperatures in recent years, there have been errors made in methods, leading to climate discrepancies, as well as political arguments.
Many scientists and others contend that one climate anomaly, such as Arctic glacial warming, is a reflection of the entire globe. But, he said, since 1880, weather patterns have undergone colder than normal periods, followed by warmer than normal periods, and one region’s weather conditions are contradicted by another region’s at any point in time, called geographic non-uniformity.
He said while urban sprawl and carbon emissions do affect the atmosphere, during the decades 1940 and 1970 — when the level of carbon oxide emissions in America skyrocketed — climate temperatures stayed relatively low.
“Remember the ‘now’ is just the end of a very long story of ups and downs,” he said.