It's been a little while since I've updated. Here's where I currently stand.
I've finalized the field work proposal, and have a pretty good idea of what I want to do. My current thoughts are based around the idea of creating a new hurricane intensification index involving storm size - who better to ask about a new index than the experts themselves? My plan is to e-mail a couple dozen experts in the field of hurricane intensity, and ask them for their opinions on how they would make changes to hurricane intensity indexes such as ACE or the Saffir-Simpson scale, especially with regards to storm size. While taking their recommendations into account, I will begin my own research into the topic, beginning broadly at first and then quickly getting more specific as I get more responses. There's the possibility of visiting a few libraries and universities, but most information now is available, free of charge, on the internet. Finally, a few nights ago I reflected on why the goal of this research project is important. One of the reasons, besides accuracy, is that perhaps an introduction of storm size into hurricane intensity indexes, such as ACE, will give us a better understanding of the trends in hurricane power over time. Perhaps changing the index will reveal that hurricanes have had a noticeable, significant spike in overall intensity over the past 30 years, or maybe it will further conclude that there has been little change in overall hurricane intensity over the past few decades. The possibilities are exciting.
Sunday, February 21, 2010
Tuesday, February 16, 2010
First Ideas/Initial Proposal
Revising Hurricane Intensity Indexes
The intensity of tropical systems has long been determined simply by the maximum wind speed within a storm; both accumulated cyclone energy (ACE) and the Saffir-Simpson Scale only utilize maximum wind speed as a factor in their calculation. These scales both fail to take into account the wind radii of a tropical system, which can affect the area of damage, the storm surge caused by the system, and the overall power of the cyclone. The project aims to redefine and update the ACE index, and perhaps the Saffir-Simpson Scale (a secondary goal) to make wind speed radii a factor in determining cyclone energy.
The potential impact of this project is the creation of an index that would be more accurately classify hurricanes and hurricane seasons by not just maximum wind speed, but a more general measurement of storm intensity based on the size of the storm and size of the wind radii. It would be helpful in determining the overall intensity and impact of a storm to a much greater extent than our current systems of measurement allow. In the past 10 years, there has been a great push in the development of a system that would account for the overall strength of a system. In a paper by Power and Reinhold (2007), the pair of researchers describe all of the attempts to update hurricane intensity indexes, saying “Alternative measures to assess hurricane destructive potential include accumulated cyclone energy (ACE; Bell et al. 2000), hurricane outer- and inner-core strengths (Weatherford and Gray 1988; Croxford and Barnes 2002), roof cladding fatigue damage index (Mahendran 1998), turbulence kinetic energy dissipation (Businger and Businger 2001), power (Emanuel 2005), and hurricane intensity and hazard indices (Kantha 2006).” There seems to be a growing consensus in the scientific community that something is wrong with the current system – both that it is not an accurate portrayal of overall hurricane intensity, and that a system that goes by merely one characteristic can produce misleading results. The paper later goes on to say that “Most of these measures have limitations related to the lack of information on the spatial extent of damaging winds. For example ACE and power are computed from the square or cube of [maximum velocity] without considering storm structure.” An update to ACE would include the storm structure as well as the maximum velocity in consideration to measure overall storm intensity.
To collect the data, I would use the same data set I used for the second part of my paper, utilizing the wind radii for storms combined with the maximum wind speed. Similarly, there is a project by the Hurricane Research Department called “surface wind analysis”, which produces some beautiful maps and represents the radii of the wind speeds incredibly well. More information on the project can be found at - http://www.aoml.noaa.gov/hrd/data_sub/wind.html. Another possibility would be hand-drawn (or computer drawn) images of storms, as well as a reconstruction of past storms and hurricane seasons using my newly developed system.
Sources:
Powell, M. D., & Reinhold, T. (2007). Tropical Cyclone Destructive Potential by Integrated Potential Energy . American Meteorological Society , 513-526.
Papers mentioned by Powell and Reinhold, as well as a version of an updated ACE index, referenced next.
Jia-Yuh Yu, C. C.-G. (2009). A Revised Accumulated Cyclone Energy Index. Geophysical Research Letters .
The intensity of tropical systems has long been determined simply by the maximum wind speed within a storm; both accumulated cyclone energy (ACE) and the Saffir-Simpson Scale only utilize maximum wind speed as a factor in their calculation. These scales both fail to take into account the wind radii of a tropical system, which can affect the area of damage, the storm surge caused by the system, and the overall power of the cyclone. The project aims to redefine and update the ACE index, and perhaps the Saffir-Simpson Scale (a secondary goal) to make wind speed radii a factor in determining cyclone energy.
The potential impact of this project is the creation of an index that would be more accurately classify hurricanes and hurricane seasons by not just maximum wind speed, but a more general measurement of storm intensity based on the size of the storm and size of the wind radii. It would be helpful in determining the overall intensity and impact of a storm to a much greater extent than our current systems of measurement allow. In the past 10 years, there has been a great push in the development of a system that would account for the overall strength of a system. In a paper by Power and Reinhold (2007), the pair of researchers describe all of the attempts to update hurricane intensity indexes, saying “Alternative measures to assess hurricane destructive potential include accumulated cyclone energy (ACE; Bell et al. 2000), hurricane outer- and inner-core strengths (Weatherford and Gray 1988; Croxford and Barnes 2002), roof cladding fatigue damage index (Mahendran 1998), turbulence kinetic energy dissipation (Businger and Businger 2001), power (Emanuel 2005), and hurricane intensity and hazard indices (Kantha 2006).” There seems to be a growing consensus in the scientific community that something is wrong with the current system – both that it is not an accurate portrayal of overall hurricane intensity, and that a system that goes by merely one characteristic can produce misleading results. The paper later goes on to say that “Most of these measures have limitations related to the lack of information on the spatial extent of damaging winds. For example ACE and power are computed from the square or cube of [maximum velocity] without considering storm structure.” An update to ACE would include the storm structure as well as the maximum velocity in consideration to measure overall storm intensity.
To collect the data, I would use the same data set I used for the second part of my paper, utilizing the wind radii for storms combined with the maximum wind speed. Similarly, there is a project by the Hurricane Research Department called “surface wind analysis”, which produces some beautiful maps and represents the radii of the wind speeds incredibly well. More information on the project can be found at - http://www.aoml.noaa.gov/hrd/data_sub/wind.html. Another possibility would be hand-drawn (or computer drawn) images of storms, as well as a reconstruction of past storms and hurricane seasons using my newly developed system.
Sources:
Powell, M. D., & Reinhold, T. (2007). Tropical Cyclone Destructive Potential by Integrated Potential Energy . American Meteorological Society , 513-526.
Papers mentioned by Powell and Reinhold, as well as a version of an updated ACE index, referenced next.
Jia-Yuh Yu, C. C.-G. (2009). A Revised Accumulated Cyclone Energy Index. Geophysical Research Letters .
Research Paper
My research paper is now posted - see the sidebar of the blog for a link to it.
Below is a quick abstract/summary of said paper.
Examining Rapidly Intensifying Hurricanes in the North Atlantic Basin
Abstract:
Hurricane forecasting, along with weather forecasting in general, has only begun to develop successful methods for the prediction of future weather events in the past 30 years through the introduction of GOES satellites and numerical weather models. However, when compared with the great advancements made in hurricane track forecasting, hurricane intensity forecasting has greatly lagged in improvement in the past twenty years, mostly due to the complexity of the interaction of the above features that control hurricane intensity. The factors that affect the ability for tropical systems to rapidly intensify can be pared down into three main categories: atmospheric conditions, oceanic thermodynamics, and inner core characteristics of the tropical system. Within each of these main categories, there are individual characteristics such as wind shear, sea surface temperatures, and eyewall structure, most of which have been extensively analyzed (however, they are not always well understood in real-world applications). One of the less examined factors, storm size, is analyzed in this paper and found to have a notable effect on the potential for tropical systems to rapidly intensify. The goal in analyzing storm size is to try and improve upon a Rapid Intensification Index (RII) developed by leading hurricane researchers, by discussing the plausibility of adding storm size as a possible factor in the potential for rapid intensification.
Below is a quick abstract/summary of said paper.
Examining Rapidly Intensifying Hurricanes in the North Atlantic Basin
Abstract:
Hurricane forecasting, along with weather forecasting in general, has only begun to develop successful methods for the prediction of future weather events in the past 30 years through the introduction of GOES satellites and numerical weather models. However, when compared with the great advancements made in hurricane track forecasting, hurricane intensity forecasting has greatly lagged in improvement in the past twenty years, mostly due to the complexity of the interaction of the above features that control hurricane intensity. The factors that affect the ability for tropical systems to rapidly intensify can be pared down into three main categories: atmospheric conditions, oceanic thermodynamics, and inner core characteristics of the tropical system. Within each of these main categories, there are individual characteristics such as wind shear, sea surface temperatures, and eyewall structure, most of which have been extensively analyzed (however, they are not always well understood in real-world applications). One of the less examined factors, storm size, is analyzed in this paper and found to have a notable effect on the potential for tropical systems to rapidly intensify. The goal in analyzing storm size is to try and improve upon a Rapid Intensification Index (RII) developed by leading hurricane researchers, by discussing the plausibility of adding storm size as a possible factor in the potential for rapid intensification.
Introduction
Hello, all who have come to this blog!
A little background/introduction as to the point of this blog - as a senior in high school, I am taking a course my school offers that allows me to basically study whatever I'm interested in (yes, I actually have to do work for the class - such as writing a 20+ page research paper). My interests are in meteorology, and so this project was born. This blog is to keep up on my research during the second half of the school year - with regards to hurricane intensity and the revision of the ACE index to include storm size as a measure of hurricane intensity. Over the coming days I'll post a copy of my research paper and the beginnings of my thoughts for the next stage of my research.
A little background/introduction as to the point of this blog - as a senior in high school, I am taking a course my school offers that allows me to basically study whatever I'm interested in (yes, I actually have to do work for the class - such as writing a 20+ page research paper). My interests are in meteorology, and so this project was born. This blog is to keep up on my research during the second half of the school year - with regards to hurricane intensity and the revision of the ACE index to include storm size as a measure of hurricane intensity. Over the coming days I'll post a copy of my research paper and the beginnings of my thoughts for the next stage of my research.
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