# Presentation: 935177

## “This broad consistency between observations, models, and theory is a powerful indicator that we are likely already experiencing more intense tropical cyclones as a result of global warming." --- Anthes, Correll, Holland, Hurrell, MacCracken, Trenberth 

- “This broad consistency between observations, models, and theory is a powerful indicator that we are likely already experiencing more intense tropical cyclones as a result of global warming." --- Anthes, Correll, Holland, Hurrell, MacCracken, Trenberth
-  --- Bulletin of the American Meteorological Society, 2006

- "There is an inconsistency between the small changes in wind-speed projected by theory and modeling versus large changes reported by some observational studies." --- Statement on Tropical Cyclones and Climate Change --- International Workshop on Tropical Cyclones, 2006

**Notes:**
The Great Galveston Hurricane will be remembered for being the deadliest hurricane of the 1900s.  Isaac Cline was the meteorologist in charge of the Galveston weather office.  He had an article published a few years earlier stating that Galveston was immune to hurricanes.  In those days, the Weather Bureau didn’t like to use words like hurricane because it created fear in the public and was bad for the economy.  That sounds familiar, doesn’t it.  Well, a very severe hurricane struck Galveston without sufficient warning and it is estimated that 8,000 people died.  Some of the bodies were weighted down, put on a barge and dumped in the Gulf of Mexico.  Unfortunately, the ones that were not weighted down properly ended up back on the beach with the next high tide.

## Hurricanes and Global Warming:

**Hurricanes and Global Warming:**
**Observations versus Expectations**

- National Hurricane Center, Miami

- Chris Landsea

**11 December, 2008**
**Environmental Modeling Center**

## Slide 3

## Emanuel (2005) Webster et al. (2005)Mann/Emanuel (2006)

## Emanuel (2005) Webster et al. (2005)Mann/Emanuel (2006)

## Before Katrina...

- David & Kimberly King Waveland, MS

## ...After Katrina

- ...After Katrina

- David & Kimberly King Waveland, MS

## Global Warming – 

- Source:  NASA/GISS    http://data.giss.nasa.gov/gistemp/graphs/

- Global Warming –
- Past Temperature Changes

## Outflow (“Exhaust”)

**Outflow (“Exhaust”)**

**Ocean (“Fuel”)**

**Energy Release**
**(“Cylinders”)**

- Nature's great heat engine...
- The Hurricane

## Global Warming and Hurricane Winds:

- Theory and Modeling Work Suggest ~1% Increase Today

## Global Warming and Hurricane Winds:

- Theory and Modeling Work Suggest ~1% Increase Today

- ~0.5-1 m/s of Katrina’s 75 m/s Winds

## Frequency of Tropical Cyclones in Today’s Climate

- Today’s Climate

- Bengtsson et al. (2007)

## Frequency of Tropical Cyclones in Today’s Climate

-                Versus Global Warming Climate

- Today’s Climate          Late 21st Century

- Bengtsson et al. (2007)

## NOAA Dork Logo

**Notes:**
This is the NOAA dork logo...

## Slide 15

## Increases in personal wealth (people have more “stuff”, and larger homes to stow their stuff, etc.) has led to greatly increased damage from hurricanes.

## Slide 17

**Notes:**
This is the NOAA dork logo...

## Slide 18

## NORMALIZED DAMAGE...

- Estimated direct damage if past storms made
- landfall with present-day societal conditions
- ND = f(inflation, coastal population, wealth)
- Pielke and Landsea (1998)
- ND = f(inflation, coastal housing, wealth)
- Pielke et al. (2008)

## 1926 Great Miami Hurricane$140-157 Billion Today                           

- Wendler Collection

- Miami Beach 1926

- Joel Gratz © 2006

- Miami Beach 2006

## Slide 21

## Linking frequency of Atlantic tropical cyclones to SSTs

- Mann and Emanuel (2006)

##    “Although wind estimates prior to the 1940s are problematic, detection of the existence of tropical cyclones is less so,

- because without aircraft and satellites to
- warn them off, ships often encountered
- storms at sea, at least peripherally. A reasonably reliable record of annual North Atlantic tropical cyclone counts is thus available back into the late nineteenth century.”
- --- Mann and Emanuel (2006)

##  1933 Hurricane Season

- Open Atlantic
- Ocean Differences

-  1933 Hurricane Season

-  2005 Hurricane Season

## A Typical Day in 2008 – Marine Data Available around 12 UTC

## A Typical Day in 2008 – Marine Data Available around 12 UTC

## A Typical Day in 2008 – Marine Data Available around 12 UTC

## A Typical Day in 2008 – Marine Data Available around 12 UTC

## A Typical Day in 1908 – Marine Data Available around 12 UTC

## A Typical Day in 1908 – Marine Data Available around 12 UTC

## Atlantic Hurricane Database Re-Analysis Project

**Atlantic Hurricane Database Re-Analysis Project**

**"Florida's Hurricane History"**

- http://www.aoml.noaa.gov/hrd/data_sub/re_anal.html

- 1851 through 1920 changes accepted and officially adopted by NHC.  1921 through 1928 have been submitted to NHC.  Remainder of 20th Century currently being reanalyzed.

**RE-ANALYSES NEED TO BE CONDUCTED GLOBALLY!!!**

## Tropical Storm and Hurricane Numbers –

**Tropical Storm and Hurricane Numbers –**
**A Very Large Trend over a Century**

## 2007 Hurricane Season - 

**2007 Hurricane Season - **
- 16 Tropical Storms & Hurricanes...
- ...9 of which were very short-lived (< 36 hr)

## New Tools and Technologies ~ Additional TCs recently?

- AMSU Tropospheric
- Temperatures

- Hart’s Cyclone Phase
- Space Analyses

- Quikscat Surface Vectors

## Changes in “Naming” Criteria

- 	“If it was quite marginal as to whether or not a storm would be upgraded to tropical storm status or equivalent, that decision would likely be influenced by proximity to possible impacts on land within the next 48 hours or so.  That is, I suspect that the margin of acceptable error for most of us would be a little larger over the open sea as compared to potential landfall for such storms that are not all that strong anyway.”
- Bob Sheets, National Hurricane Center Director, 1987-1995

**Changes in “Naming” Criteria**

## Six weak, short-lived storms in last two seasons – 

**Unlikely to have been “named” previously**

## 1900-1943:  Only Ships and Coastal Stations

## 1944-1965:  Aircraft Reconnaissance Available

## 1966-2001:  Geostationary Satellite Imagery Available

## 2002 onward:  AMSU,        QuikScat,       Cyclone Phase Space, Advanced Dvorak

## Big Upward Trend – Consistent with Technological Improvements

## Tropical Storm and Hurricane Numbers –

**Tropical Storm and Hurricane Numbers –**
**Still a Trend After Removal of **
**Very Short-Lived Cyclones**

## Atlantic ship traffic changes

**Vecchi and Knutson (2008)**

## Estimated Number of “Missed” Tropical Storms and Hurricanes of Medium to Long Duration

**Estimated Number of “Missed” Tropical Storms and Hurricanes of Medium to Long Duration**

- 3 per year
- in 1880s

- 2 per year
- in 1900s

- <1 per year
- in 1950s

## Tropical Storm and Hurricane Numbers –

**Tropical Storm and Hurricane Numbers –**
**No Trend After Adding in “Missed” and **
**Removing Very Short-Lived Cyclones**

## Slide 46

## Residual Atlantic Multidecadal Oscillation

- Enfield and Cid (2008)

- North Atlantic SSTs and Quadratic Trend

## Slide 48

## Slide 49

## Hurricanes and Global Warming:

**Hurricanes and Global Warming:**
**Observations versus Expectations**

- National Hurricane Center, Miami

- Chris Landsea

**11 December, 2008**
**Environmental Modeling Center**

## Estimated Number of “Missed” Tropical Storms and Hurricanes of Medium to Long Duration

## Slide 52

## Changes in “Naming” Criteria

- 	““[The National Hurricane Center] seems to be naming a lot more than they used to.  This year, I would put four storms in the very questionable category, and maybe even six.  In the past, we would have waited to see if another observation supported naming the system.  We would have been a little more conservative."
- Neil Frank, National Hurricane Center Director, 1974-1987

**Changes in “Naming” Criteria**

## Slide 54

## The Webster et al. study began with 1970 data...

## Frequency of Tropical Cyclones in Today’s Climate

- Today’s Climate

- Landsea and Bengtsson (2008)

## Frequency of Tropical Cyclones in Today’s Climate

- Landsea and Bengtsson (2008)

- ...Based upon Differing Thresholds of Duration