New Study, Recent Atlantic Hurricane Activity might have been Highest in 1,000 Years

New research on the history of tropical cyclone activity in the Atlantic has found that the Atlantic tropical cyclone activity, in terms of frequency and strength over recent decades, may have been greater than any period going back a thousand years.

Reply: No doubt, the 1990s and a good chunk of this decade have been active, but the most active in 1,000 years? For instance, is the author overlooking the active period from the 1930s through the 1950s?

The link below (Thanks Mark B.) to this graph says he is not, but is it an accurate representation?

http://www.nature.com/nature/journal/v460/n7257/fig_tab/nature08219_F3.html#figure-title

Evidence from sediment samples from landfalling hurricanes going back 1,500 years indicated that there was a period of enhanced Atlantic tropical cyclone activity between AD 900 and 1100 followed by a lull. That medieval period of enhancement was perhaps even more active than what we have seen over the past couple of decades.

"We are at levels now that are about as high as anything we have seen in the past 1,000 years," said Michael Mann, director of the Earth System Science Center at Pennsylvania State University and the lead author of the paper.

"Hurricane activity since the mid-1990s is the highest in the historical record, but that only goes back a little more than a century and is most accurate since the advent of air travel and satellites in recent decades," said Mann. "It is therefore difficult to assess if the recent increase in hurricane activity is in fact unusual."

According to the EurekAlert release, the study also adds validity to the theory that two factors fuel higher hurricane activity, namely the La Nina effect and high surface temperatures over the ocean. If climate change continues to warm ocean waters, Mann said, it could lead to more active hurricane seasons.

You can read a more detailed look at the study right here.

The National Science Foundation (NSF) also interviewed Dr. Mann about the results of this study. You can watch that video here.

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Our own Hurricane expert Joe Bastardi disagrees with Mann on this...........

What is it with Dr. Michael Mann? His latest "findings" on hurricanes , that we are at some mythical high is nonsense. And if he understood how the energy budget actually worked, he should be making the argument that the low we are in is more of support of his argument of warming... fake as it is, as it would mean a distortion of the energy budget of the earth because of warming in coldest places. Again using the absolute temp of the earth is not the way to look at this, its to look at the measure of energy of the earth, and understanding that a 1 degree drop where the wet bulb is 80 is equal in energy consideration to a 32 degree rise where its -30 degrees.

So Dr Mann, you should be using the record LOW ACTIVITY for your argument, except that of course would run into the true argument as to what cyclones represent..energy, in which case it falls apart.

http://www.coaps.fsu.edu/~maue/tropical/global_running_ace2.jpg

(From his Accuweather.com Professional column)

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Chris Landsea via the Houston Chronicle......

"The paper comes to very erroneous conclusions because of using improper data and illogical techniques," said Chris Landsea, science and operations officer at the National Hurricane Center.

In his criticism, Landsea notes that the paper begins by saying that Atlantic tropical activity has "reached anomalous levels over the past decade."

This ignores recent work by Landsea and a number of other hurricane scientists who found that storm counts in the early 1900's -- in an era without satellites and fewer seaborne observers -- likely missed three or four storms a year. The addition of these storms to the historical record, he said, causes the long-term trend over the last century to disappear.

"This isn't a small quibble,"he said. "It's the difference between a massive trend with doubling in the last 100 years, versus no trend."

A Hurricane in Los Angeles?

Here is the current Pacific satellite image, note the lower right.

Click for a larger image

I might add that the likelihood of a hurricane strength storm striking Southern California is low. Since 1900, only four tropical cyclones have brought gale-force winds to the Southwestern United States. They are an unnamed tropical storm that made landfall near San Pedro in 1939, the remnants of Hurricane Joanne in 1972, the remnants of Hurricane Kathleen in 1976, and Hurricane Nora in 1997 which entered California as a tropical storm.

The storms that do make it close enough to be a threat are often weakened by two facts: cold sea surface temperatures and upper level steering winds that tend to take them away for SoCal. But it’s a fun exercise to discuss the possibility. – Anthony

Hurricanes in Los Angeles?

Guest post by Roger Sowell

A hurricane hitting Los Angeles. No, it hasn’t happened yet, but it could. I am using the same reasoning as the Carbon Is Going to Kill Us crowd, where it is deemed prudent and even mandatory that we take action now to prevent a future catastrophe. AGW believers insist that all mankind (well, except for developing countries, of course!) curtail or stop altogether emitting carbon dioxide, as that may cause ice caps to melt and oceans to rise and population disruption.

There is a hurricane in the Pacific Ocean, headed directly toward Los Angeles. It’s name is Jimena (pronounced him -ay – nuh, accent on the ay). Jimema currently has winds of 135 miles per hour, and is just south of the tip of Baja, California. Its course is to the northwest, up the Baja peninsula.

Judging from the mass confusion a couple of years ago when Houston evacuated ahead of hurricane Rita, Los Angeles might want to start packing and driving today. Houston only had around 1 million people exiting the city, and had at least five freeways on which to do it. Los Angeles has approximately 3 million people, probably closer to 4 million, but the metropolitan area has 18 million, and only three ways out. There is the Interstate 10, going due East; Interstate 5 going North; and highway 101, also going north. I-5 also goes south, but little good that will do since one runs into San Diego and the hurricane.

A hurricane hitting Los Angeles. We must take prudent steps to avoid the certain disaster and destruction from a hurricane. We will not be required to wait 100 years for the results to be in. This hurricane will be here in less than 10 days. We must act today, while there is still time. The science is settled. Hurricanes hitting major population centers are a serious threat. Remember New Orleans and Hurricane Katrina. Houston and Hurricane Rita. We must mobilize FEMA so they can get their red tape all in order, ready to send trailers and water and food packs to Los Angeles.

The low-lying areas of Southern California are at risk of inundation from the storm surge. Ports and river basins will be swamped with seawater, causing un-told devastation to precious seashore that is a national treasure, as the California Coastal Commission regularly reminds us. A storm surge from a hurricane can be several feet. The California Coastal Commission was in a tizzy recently over the prospect of the ocean rising just one foot, in the next century. Where is the alarm, the hysterical and frantic activity, over a storm surge of 5 to 10 feet in the space of 24 hours?

Where is the clarion call to action from our state and city leaders? Governor Schwarzenegger, Mayor Villaraigosa, are you watching this hurricane? Have you prepared the state and city and county to deal with this?

Or, are you hoping the hurricane does arrive, and right away, so that the wildfires will finally be put out and the firefighters get some much-needed rest?
Stay tuned, sports fans. This is about to get interesting.