Wikinews interviews meteorological experts on Cyclone Phalin
Monday, October 14, 2013
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Image: NASA.
Half-a-million people have fled their homes in and around the Indian state of Orissa after Cyclone Phailin made landfall.
Wikinews interviewed specialists in meteorology about the devastation the cyclone has caused.
Interviewees
Wikinews interviewed:
- Michael Richman, Professor in the School of Meteorology at the University of Oklahoma in the United States
- John Snow, Regents' Professor of Meteorology and Dean Emeritus of the College of Atmospheric and Geographic Services at the University of Oklahoma
- Ramalingam Saravanan, Professor of Atmospheric Science at Texas A&M University
- Fuqing Zhang, Professor in the Department of Meteorology at Pennsylvania State University
- David Titley, a Senior Scientist and founding Director of the Center for Solutions to Weather and Climate Risk at Pennsylvania State University
- Paul Knight, a Senior Lecturer in Meteorology at the Pennsylvania State University
- Mark Morrissey, Professor of Meteorology at the University of Oklahoma
Wikinews Q&A
Image: Mark Morrissey.
((Wikinews
)) What is your job role?
- Richman: Professor in the School of Meteorology [at the University of Oklahoma].
- Snow: I am a Regents' Professor of Meteorology and Dean Emeritus of the College of Atmospheric and Geographic Sciences [at the University of Oklahoma].
- Saravanan:I am a professor of atmospheric science at Texas A&M University, specializing in computer modeling of climate and weather phenomena, including hurricanes.
- Zhang: I am a Professor in the Department of Meteorology with a courtesy joint appointment in the Department of Statistics [at Pennsylvania State University]. My current research focuses on the dynamics, prediction and predictability of tropical cyclones.
- Titley: I am a Senior Scientist and founding Director of the Center for Solutions to Weather and Climate Risk at Penn State. I was awarded my Ph.D. in Meteorology from the Naval Postgraduate School in Monterey, California for work in tropical cyclone intensification.
- Knight: I am a senior lecturer in Meteorology [at Pennsylvania State University] and the Pennsylvania State Climatologist.
- Morrissey: I’m a professor of Meteorology at the Univ of Oklahoma. I specialize in tropical meteorology (and teach courses in that too).
Image: David Titley.
((WN)) Cyclone Phailin has winds that have been measured at 200km/h, as it surges over land will it begin to lose strength?
- Richman: Yes, all tropical cyclones are driven by high heat content waters. Once a storm moves over any appreciably sized piece of land, the moisture source is removed and the storm begins to dissipate. As of the last advisory, TC Phailin has winds of 190 kilometers per hour and has moved inland, headed on a northwest track. That is a Category 3 storm. The forecast is for a continued decline in strength to a tropical storm within 24 hours and a tropical depression within 36 hours. However, there will be very heavy rains and flooding along its path.
- Snow: Yes, it will loose strength steadily as more and more of this swirling system moves from being over ocean to being over land. This occurs for two reasons:
- 1) As it moves over land, it is cut off from the source of energy driving the storm [which is] the evaporation of water from the warm sea surface;
- 2) Increased friction — the ocean surface is much, much smoother than the land surface.
- Snow: Yes, it will loose strength steadily as more and more of this swirling system moves from being over ocean to being over land. This occurs for two reasons:
- Saravanan: Tropical cyclones are sustained by a form of energy called latent heat, which is released by moisture evaporated from the ocean that condenses to form rain. As tropical cyclones make landfall, this energy source is cut-off and they rapidly lose strength as they move over land.
- Zhang: Yes, the Cyclone is almost certain to lose strength as it surges over land. Cyclones gather their strength through scraping moisture and heat from warm ocean water that it is not the case over land. In the mean time, much stronger friction over land quickly reduces their strength.
- Titley: Yes. All tropical cyclones lose strength once they make landfall. However, they can remain dangerous storms due to very heavy rains and subsequent landslides, and river flooding.
- Knight: Phailin's winds will rapidly weaken as it pushes inland.
- Morrissey: Once Cyclone Phailin comes on shore it will immediately begin to lose strength. However, and this is important, it still will contain lots of rainfall making flooding an almost certainty.
Image: R Saravanan.
((WN)) A previous cyclone in 1999 in the Bay of Bengal area of India left 10,000 people dead. Is the Indian government well prepared to deal with this cyclone?
- Richman: I have not followed that aspect of the societal response for the present storm. However, historically, there have been several events that should cause a societal response. Hopefully, we all learn from past mistakes. The history of strong cyclones and death in the region is notable, with at least 5 large cyclone events in the past 35 years with 10,000 and as many as 300,000 people killed, millions left homeless and estimated damages as high as US$10 billion.
- Snow: I don't have enough information to answer this question, one way or the other.
- Saravanan: From all the press reports that I have read, the Indian government appears to have taken the threat of Cyclone Phailin very seriously indeed. The government has been much more pro-active in preparing for this cyclone than in the past. The forecasts of cyclone track and intensity have been fairly accurate. Mandatory mass evacuations have been carried out, which is essential to minimize loss of life in these situations. Unfortunately, extensive property damage is bound to occur even with the best preparation.
- Zhang: My knowledge of the responsiveness of the Indian government to this storm is purely from the cyber space. I heard that they orchestrated the largest people evacuation to a natural disaster in Indian history. This shall be applauded given the size and strength of Phailin. I visited the damaged area of the 1999 storm near Bhubaneshwar in the summer of 2012 for an invited symposium and summer school on tropical cyclones [...] sponsored by the Indian government. Given the living standard and residence of people living near the coastal areas in this region, the evacuation is certainly necessary and essential to save lives.
- Titley: I cannot comment directly on how the Indian government was prepared for this cyclone. However, the news reports (BBC etc.) were very encouraging in that the authorities were reportedly making strenuous efforts to evacuate the population from near the coast and areas that are prone to flooding. Water is the main killer in these storms.
- Knight: From all reports that I have seen, the government was well prepared for this cyclone.
- Morrissey: For this question I don’t know the ‘preparedness’ of the Indian gov’t to deal with this.
Image: Michael Richman.
((WN)) Despite it being the Monsoon season in India, are cyclones of this power and magnitude unusual in India?
- Richman: Since the Bay of Bengal is very warm, and the environmental conditions associated with the storm along most of its recent track were conducive to strengthening, it was an expected and well-forecast outcome. In general, the Indian Ocean has been undergoing a gradual warming over the past two decades [...] and, the warmer the water, the higher the heat content and the higher the potential is for a very strong tropical cyclone. Phailin intensified rapidly when moving into a low wind-shear environment. It became a Category 5 cyclone, which is rare. However, if the Indian Ocean continues to warm, it may become less rare to see high-end cyclones. The only caveat I have is that takes only one of several factors detrimental to storms to prevent a tropical cyclone from intensifying this way. Wind shear or ingesting dry air are two, for example. We saw this in 2013 with the Atlantic hurricane season. There were waves of Saharan dust and dry air that damped the season, despite warm sea surface temperatures. Everything has to line up just right to get a category 5 cyclone. That is what makes prediction of tropical cyclone frequency and strength so difficult under global warming projections. However, the data [...] suggest that the Indian Ocean is warming.
- Snow: I am basing my answer on reports I have seen in the popular news media. Taking what was reported at face value, this is a super-typhoon/cyclone. Cyclones of this level of intensity (as measured by top wind speed and central pressure value) are very, very rare. Everywhere, including near India.
- Saravanan: In terms of average numbers, major cyclones are less frequent in the Indian Ocean than some other regions of the world, such as the Caribbean or the Gulf of Mexico. However, Cyclone Phailin cannot be considered unusual because storms of similar power have occurred in the past. In fact, many of the deadliest cyclones in the world have occurred in the Indian Ocean region. The high death tolls have more to do with high population density and poor infrastructure than with the actual strength of the storms.
- Zhang: It is the strongest in 14 years so in this sense it is certainly rare in India. Also, there are indications that in recent years cyclone activities in the Bay of Bengal have been in a decline.
- Titley: Cyclones of this power and magnitude, while infrequent, are by no means unprecedented in the Bay of Bengal. They are most common in the transition seasons between the Winter and Summer Monsoon seasons, like now.
- Knight: This is a very strong cyclone, but not unprecedented.
- Morrissey: Actually cyclones are more prevalent during the onset and retreat of the monsoon. So, in the Bay of Bengal a tropical cyclone at this time is not unusual.
((WN)) Some forecasters have likened Cyclone Phailin's size and intensity to Hurricane Katrina which devastated the US Gulf Coast in 2005, would you agree?
- Richman: Yes. See above. Katrina was also in a low shear environment over high heat content waters passing over a loop current in the Gulf of Mexico and responded by intensifying to a category 5 hurricane. Also, a second similarity is that Katrina encountered some shear and slightly cooler water before making landfall and crossed the Louisiana coast as a category 3 hurricane, similar to Phailin.
Image: John Snow.
- Snow: From what I have seen and heard on the popular media, in terms of winds Phalin will be a much more intense storm than Katrina at landfall. Katrina was actually weakening rapidly as it came ashore. Phalin looks to be at a much higher intensity as it approach[es] land. The last few hours will tell.
- Where a comparison with Katrina may be [of] value is with respect to the magnitude of the storm surge. Katrina's winds drove an enormous surge of water (10+ meters above high tide) ashore to the east of New Orleans. My understanding from media reports is that Phalin may produce a surge of similar magnitude over a long stretch of coast.
- Saravanan: The size and the intensity of Cyclone Phailin are roughly comparable to Hurricane Katrina, although Phailin may be somewhat weaker overall. The actual intensity of Phailin at landfall is still uncertain, because it is difficult to measure cyclone intensity accurately using only satellite information. One of the problems with the response to Katrina in the United States was that some residents in the vulnerable regions failed to heed the warnings and evacuations were not well coordinated. The sheer scale of the damage caused by Katrina was also not anticipated very well. Hopefully, the response to Phailin would have benefited from the lessons learned from Katrina.
- Zhang: It certainly has some similarity in that regard though Katrina was still stronger with a longer history over the ocean.
- Titley: Each Hurricane, or Cyclone, is unique and the impacts depend not only on the cyclone itself but also upon the specific area of the coast where it makes landfall. But in the sense that Phailin was a large and potentially dangerous storm, then yes there are similarities with Katrina. Perhaps a better analogy is the hurricane that struck Charleston, South Carolina in 1989: Hurricane Hugo also had winds around 200 km/h and was a large storm when it made landfall.
- Knight: Phailin and Katrina have some similarities, especially in their size.
- Morrissey: Since Cyclone Phailin has already hit one can easily say ‘oh it wasn’t as bad as Katrina’. However, the amount of damage has a lot to do with the coastline shape, height, whether rivers are nearby,etc. For example, Bangladesh has the Ganges which floods due to heavy rain at the same time as the cyclone-induced storm surge, so it is very prone to heavy damage.
Image: Paul Knight.
((WN)) The evacuation is one of the biggest exercises in India's history. Do you think that this as well as the clear-up to follow will cost a lost of money?
- Richman: Any action costs money. In 1995, in the US, we had Katrina, with an inadequate evacuation and then the levees were breached. That had a huge cost in terms of thousands of lives lost and billions of dollars in damage. Later in that same season, hurricane Rita was forecast to cross the Texas coast and hit Houston. A massive evacuation took place and then the storm missed Houston. However, there were deaths and loss of money because of the evacuation. What needs to evaluate is the relative cost of the a good forecast versus those of a missed forecast versus the costs of a false alarm forecast. There is no free lunch when you move millions of people.
- Snow: While I don't know any particulars re India, the clean-up and fix-up after any great disaster anywhere is always expensive, e.g., Haiti after the most recent earthquake.
- Saravanan: Yes, the evacuations and the follow-up relocations will cost a lot of money, but it will certainly be worth it in terms of the number of lives saved. This was one of the lessons learned from Katrina in the U.S. I moved to my present job in Texas in July 2005, just before Katrina struck the near-by Louisiana coast in August 2005. As I mentioned earlier, the evacuations for Katrina were carried out poorly. After Katrina, when another powerful hurricane called Rita approached the same region in September 2005, evacuation warnings were taken very seriously. Many people returned after the evacuations with little damage to their homes, but felt that it was better to be safe than sorry, despite the cost and inconvenience of the evacuation.
- Zhang: Yes, it has and it will but the evacuation is certainly necessary and the clear-up is unavoidable.
- Titley: No doubt the evacuation and subsequent clean up will cost a lot of money. Hopefully as communities rebuild they can take into account the lessons learned from such powerful cyclones and make their communities and infrastructure increasingly resilient to these types of storms. Because you either "pay me now or pay me later" when fixing and repairing the damage.
- Knight: All strong cyclones require an immense effort to help people get out of harm's way and then to clean up its path of destruction, and Phailin will be no exception.
- Morrissey: I’m sure that the evacuation was costly, but it probably saved many lives. The cyclone was a category 4, very strong.
Image: Fuqing Zhang.
((WN)) Would you expect the death toll to continue to rise?
- Richman: No doubt this will be the case. If you use either Hurricane Katrina or Sandy as a template, some people do not evacuate in time and then the two leading causes of death are storm surge or floods. As the storm moved inland, flooding can continue for several days and all the water will flood river until it enters the Bay of Bengal.
- Snow: Again, I don't know particulars, but if people failed to evacuate or were unable to get far enough inland and/or to higher ground, then yes, one would expect additional casualties.
- Saravanan: I am not an expert on the human impacts of landfalling tropical cyclones, but I am hoping that the evacuations were largely successful and the inevitable increase in death toll noted as rescue workers return to the affected regions will not be too high.
- Zhang: Yes, certainly but hope the preparation by the people and the government will considerably reduce the death toll by orders of magnitude compared to 1999.
- Titley: I hope not. So far the numbers of fatalities reported in the press have been very low. I hope these numbers do not rise further, but the authorities are busy returning to the hardest-hit areas so we will see. The very preliminary numbers of low fatalities gives hope though that many citizens heeded their authorities' pleas for action and evacuation. I hope that turns out to be the real story and lesson from Phailin — strong cyclones do not have to be killer cyclones.
- Knight: Unfortunately, inland flooding will likely add to the death toll.
- Morrissey: Yes. Unfortunately, the death toll for Katrina continued to rise as searchers went house to house. But the early news for Cyclone Phailin is encouraging.
Sources
