This is part 4 of an interview I did with the
Northwest Florida Daily News of Fort Walton Beach, Florida, that was published on Sunday, May 28. The questions were posed to me by Del Stone Jr., Deputy Managing Editor and self-admitted weather nut. I'll be back to live blogging on June 14.
Q. Our nation's first line of defense against hurricanes is the National Hurricane Center. Is NHC adequately funded for such a role?
A. Things have improved considerably, thanks to some increased funding autorized by Congress in the wake of the hurricanes of 2004 and 2005. The Hurricane Center has been understaffed for a number of years, especially since they were tasked with the additional job of writing all the advisories for Eastern Pacific hurricanes. However, NHC just added four new hurricane forecasters last month, thanks to the a special requisition championed by Sen. Bill Nelson (D-Fla). NHC now has ten hurricane forecasters, and this will help greatly. NOAA also got money for a new weather research airplane, which will help out our hurricane reconnaissance needs. An additional $1.4 million has been proposed this year to improved buoys in the Atlantic. The only area where not much money was made available was for hurricane research. We need more dollars to fund development of better hurricane intensity forecasts. NOAA's Hurricane Research Division does fantastic work on this, and could probably significantly improve our hurricane intensity forecasts if they were able to add a few new scientists to research this.
Q. When a hurricane strikes, much of the damage is concentrated along the coastline. Obviously this raises questions about the wisdom of building in vulnerable areas, and materials used in such construction. If you could provide guidance to local governments and contractors about those two issues, what would it be?
A. The level of hurricane activity we experienced in the 1970s and 1980s--when most of the recent coastal development happened--was very low. The high levels of activity we've experienced since 1995 are what we can continue to expect for at least the next 10 or 20 years. Planners better get used to the idea of building for more frequent major hurricanes.
Q. Since 1995, hurricane activity "seems" to have increased. I qualify "seems" because the increase strikes me as more subtle than what might be apparent to somebody who is not a student of tropical meteorology. The 2004 and 2005 seasons were noticeably more active, even to a layman. Is this a result of a natural occurrence, the Atlantic decadal cycle, or is it a portent of things to come?
A. There are a lot of conflicting ideas on this among hurricane scientists. The majority view is that most of the increase since 1995 is due to a natural decades-long cycle called the Atlantic Multidecadal Oscillation (AMO), which is tied to sea surface temperatures and salinity in the Atlantic (the so-called "thermohaline circulation"). The trouble is, there is little observational support for this theory, as there are very few oceanographic measurements going back in time. In fact, ocean measurements taken in the past few years show a 30% slow down of the thermohaline circulation in the North Atlantic, which is the opposite effect one would expect to see if the AMO were truly causing the current upswing in hurricane activity. These measurements had a high potential for error, so more measurements are needed verify this finding. Dr. Kerry Emanuel, who developed much of the theory regarding hurricane intensification, has a
new theory on the AMO--he thinks that this observed decades-long observed change in Atlantic hurricane activity is not a natural cycle. The lower levels of hurricane activity and lower SSTs observed from 1970-1995 were due to increased air pollution over the Atlantic reducing the sunlight. Since 1995, pollution control efforts, plus a significant increase in global warming, have acted to warm the oceans and drive increased hurricane activity. Except for the occasional strong El Nino year, he sees no end to the current pattern of increased hurricane activity in the Atlantic. I believe it is too early to say who's right. Dr. Emanuel hasn't published his findings yet; Nature magazine rejected his paper as being "too esoteric" for its readers.
Q. Lately a debate has sprung up among meteorologists about global warming and its relationship to hurricane formation. In your blog you have made a point of stressing the jury is still out on such a relationship, if I'm reading your blog correctly. The evidence so far seems inconclusive one way or the other. Do you have a personal opinion about such a relationship?
A. There's no doubt that there is an effect. Hurricanes are heat engines, and heating up the oceans makes stronger hurricanes. However, the amount of heating of the oceans we can blame on global warming, about 1 degree Fahrenheit, should (according to Dr. Emanuel's theory) cause at most a 2-3 mph increase in the winds of a storm like Katrina. Is the theory wrong? That's a question that is being seriously considered, and it is possible that global warming has made the strongest hurricanes much stronger than the theory would suggest. My opinion is that it its too early to tell. The database of global hurricane intensities is deeply flawed and doesn't extend over a long enough period of time to determine if there has been a significant increase in Category 4 and 5 hurricanes due to global warming.
Jeff Masters