Nav: Home

Tropical cyclone 'maximum intensity' is shifting toward poles

May 14, 2014

Over the past 30 years, the location where tropical cyclones reach maximum intensity has been shifting toward the poles in both the northern and southern hemispheres at a rate of about 35 miles, or one-half a degree of latitude, per decade according to a new study, The Poleward Migration of the Location of Tropical Cyclone Maximum Intensity, published tomorrow in Nature.

As tropical cyclones move into higher latitudes, some regions closer to the equator may experience reduced risk, while coastal populations and infrastructure poleward of the tropics may experience increased risk. With their devastating winds and flooding, tropical cyclones can especially endanger coastal cities not adequately prepared for them. Additionally, regions in the tropics that depend on cyclones' rainfall to help replenish water resources may be at risk for lower water availability as the storms migrate away from them.

The amount of poleward migration varies by region. The greatest migration is found in the northern and southern Pacific and South Indian Oceans, but there is no evidence that the peak intensity of Atlantic hurricanes has migrated poleward in the past 30 years.

By using the locations where tropical cyclones reach their maximum intensity, the scientists have high confidence in their results.

"Historical intensity estimates can be very inconsistent over time, but the location where a tropical cyclone reaches its maximum intensity is a more reliable value and less likely to be influenced by data discrepancies or uncertainties," said Jim Kossin, the paper's lead author, who is a scientist with NOAA's National Climatic Data Center currently stationed at the NOAA Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin-Madison.

Consistent with this poleward shift, many other studies are showing an expansion of the tropics over the same period since 1980.

"The rate at which tropical cyclones are moving toward the poles is consistent with the observed rates of tropical expansion," explains Kossin. "The expansion of the tropics appears to be influencing the environmental factors that control tropical cyclone formation and intensification, which is apparently driving their migration toward the poles."

The expansion of the tropics has been observed independently from the poleward migration of tropical cyclones, but both phenomena show similar variability and trends, strengthening the idea that the two phenomena are linked. Scientists have attributed the expansion of the tropics in part to human-caused increases of greenhouse gases, stratospheric ozone depletion, and increases in atmospheric pollution.

However, determining whether the poleward shift of tropical cyclone maximum intensity can be linked to human activity will require more and longer-term investigations.

"Now that we see this clear trend, it is crucial that we understand what has caused it - so we can understand what is likely to occur in the years and decades to come," says Gabriel Vecchi, scientist at NOAA's Geophysical Fluid Dynamics Laboratory and coauthor of the study.
-end-
NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter, Instagram and our other social media channels.

NOAA Headquarters

Related Cyclones Articles:

First results from Juno show cyclones and massive magnetism
On Aug. 27, 2016, the Juno spacecraft made its first close pass around our solar system's largest planet, Jupiter, obtaining insights into its atmosphere and interior that challenge previous assumptions.
Researchers catch extreme waves with higher-resolution modeling
A new Berkeley Lab study shows that high-resolution models captured hurricanes and big waves that low-resolution ones missed.
NASA sees heavy rain in Tropical Depression Ma-on
Tropical Depression Ma-on formed on Nov. 10, 2016, northeast of Guam.
Evaluating forecasting models for predicting rainfall from tropical cyclones
To help improve hurricane preparedness and mitigation efforts, new University of Iowa-led research examines how accurate current forecasting systems are in predicting rainfall from North Atlantic tropical cyclones that make landfall in the United States.
NASA infrared imagery shows new tropical depression coming together
Tropical Depression 06W appeared to be consolidating and coming together in infrared imagery from NASA's Aqua satellite.
Tropical cyclones on track to grow more intense as temperatures rise
Powerful tropical cyclones like the super typhoon that lashed Taiwan with 150-mile-per-hour winds last week and then flooded parts of China are expected to become even stronger as the planet warms.
Suomi NPP satellite sees depression becoming Tropical Storm Darby
The Suomi NPP satellite captured a visible image of Tropical Storm Darby as it was developing in the Eastern Pacific Ocean.
Hurricanes key to carbon uptake by forests
New research reveals that the increase in forest photosynthesis and growth made possible by tropical cyclones in the southeastern United States captures hundreds of times more carbon than is released by all vehicles in the US in a given year.
Philippines affected by more extreme tropical cyclones
University of Sheffield study finds hazardous tropical cyclones in the Philippines are increasing in intensity causing widespread damage and loss of life, which may be due to rising sea-surface temperatures.
Philippine coastal zone research reveals tropical cyclone disruption of nutrient cycling
The influence of Typhoon Haiyan damage on leaf nutrient traits in coastal habitats is explored.

Related Cyclones Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".