The 2020 Atlantic Hurricane Season Was A Record-Breaker, and It's Raising More Concerns About Climate Change

The 2020 Atlantic Hurricane Season Was A Record-Breaker, and It's Raising More Concerns About Climate Change
Hurricanes Sally and Paulette, Tropical Depression Rene, and Tropical Storms Teddy and Vicky were all active on Sept. 14, 2020.
NOAA

It was clear before the 2020 Atlantic hurricane season started that it was going to be busy. Six months later, we’re looking back at a trail of broken records, and the storms may still not be over even though the season officially ended on Nov. 30.

This season had the most named storms, with 30, taking the record from the calamitous 2005 season that brought Hurricane Katrina to New Orleans. It was only the second time the list of storm names was exhausted since naming began in the 1950s.

Ten storms underwent rapid intensification, a number not seen since 1995. Twelve made landfall in the U.S., also setting a new record. Six of those landfalling storms were hurricane strength, tying yet another record.

Tropical storm tracks show how busy the 2020 Atlantic hurricane season was.
Tropical storm tracks show how busy the 2020 Atlantic hurricane season was.
Brian McNoldy, CC BY-ND

As atmospheric scientists, we target our research at better understanding both what drives the formation of tropical cyclones and how climate change is affecting them on longer time scales. Here’s what research tells us about the 2020 season and what may be ahead.

Why did 2020 have so many storms?

An unfortunate combination of two key factors made this season ripe for tropical storms.

First, a La Niña pattern of cool surface waters developed in the equatorial Pacific, and it was stronger than anticipated.

Ironically, cooling in the equatorial Pacific makes it easier for tropical storms to form and gain strength in the Atlantic. That’s because La Niña weakens the vertical wind shear over the tropical Atlantic. Vertical wind shear – a change in wind speeds with altitude – is highly disruptive to storm development.

As the La Niña pattern became established this season, it made the tropical Atlantic much more hospitable for storms to form and intensify.

Atlantic sea surface temperatures in September 2020 were warmer than the 1981-2010 average.
Atlantic sea surface temperatures in September 2020 were warmer than the 1981-2010 average.
NOAA

The second critical factor was the extremely warm temperatures in the Atlantic, including the Gulf of Mexico and the Caribbean.

Hurricanes are powered by the transfer of heat from the ocean to the atmosphere. The sea surface temperature therefore dictates the maximum potential intensity a storm can attain under perfect conditions – it’s like a thermodynamic “speed limit” on hurricane intensity.

The sea surface temperature approached record levels in the Atlantic hurricane basin this season, including in September, the most active Atlantic storm month on record.

What does climate change have to do with it?

An important part of this season’s story is the Atlantic warming trend we’re witnessing, which is unprecedented going back at least several millennia.

The oceans store much of the excess heat trapped by greenhouse gases. With greenhouse gas concentrations still increasing due to human activities, such as the burning of fossil fuels, average sea surface temperatures are likely to continue rising over the coming decades.


NOAA’s satellite imagery shows 2020’s named Atlantic storms through Nov. 18, 2020.

Whether climate change caused the extremely high number of storms this season is unclear. There is no detectable trend in global hurricane frequency, and computer modeling studies have had conflicting results.

However, the warming climate is increasing the threat posed by hurricanes in other ways.

A growing proportion of high-intensity storms, Category 3, 4 and 5, is being observed around the world, including in the Atlantic. Since ocean temperature controls the potential intensity of tropical cyclones, climate change is likely behind this trend, which is expected to continue.

The U.S. is also seeing more storms with extreme rainfall. Think about Hurricane Harvey’s 50 inches of rain in the Houston area in 2017 and Florence’s 30-plus inches in North Carolina in 2018. The warming climate plays a key role here, too. With warmer temperatures, more water is able to evaporate into the atmosphere, resulting in greater moisture in the air.

Implications of the 2020 season

Ten storms this season underwent rapid intensification – a 35 mph increase in maximum winds within 24 hours. Rapidly intensifying storms are especially dangerous because 1) they are challenging to accurately predict, and 2) they provide minimal time for evacuations when they intensify just before making landfall.

Satellite instruments capture Hurricane Iota making landfall in Nicaragua on Nov. 16. The image shows the temperature of cloud tops, which tells scientists how tall the clouds are.
Satellite instruments capture Hurricane Iota making landfall in Nicaragua on Nov. 16. The image shows the temperature of cloud tops, which tells scientists how tall the clouds are.
NOAA; James H. Ruppert Jr.

Hurricanes Laura and Sally both rapidly intensified just before making landfall on the Gulf Coast this season. Eta rapidly intensified to a Category 4 just before hitting Nicaragua, and just two weeks later, Iota essentially repeated the act in the same location.

Forecasts for the tracks or paths of tropical cyclones have dramatically improved in recent decades, as much as five days in advance. However, forecasts of storm formation and intensification have improved very little by comparison.

The forecasts for hurricane rapid intensification are especially poor.

While the official forecasts issued by the National Hurricane Center are issued by human forecasters, they depend on the guidance of prediction models, which aren’t very accurate when it comes to rapid intensification.

The complexity of weather models makes this a daunting challenge. However, it becomes more tractable as researchers learn more about how hurricanes form and intensify and identify the root causes for errors in computer model predictions.

Our latest research explores how clouds create their own greenhouse effect, trapping heat that causes hurricanes to form and intensify more quickly. Improving how numerical models account for this cloud feedback may ultimately hold promise for more accurate forecasts. Innovative ways of collecting new measurements in developing storms, down to their smallest scales, will also be necessary for guiding these improvements.

Given the upward trend in high-intensity storms, the risks from these storms will only grow. The ability to accurately predict how and when they will form, intensify and threaten coastal populations is crucial.

This article has been updated with the season ending and NOAA video of 2020’s Atlantic storms.

About the AuthorsThe Conversation

James H. Ruppert Jr., Assistant Research Professor, Penn State and Allison Wing, Assistant Professor of Meteorology, Florida State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

Life After Carbon: The Next Global Transformation of Cities

by Peter Plastrik , John Cleveland
1610918495The future of our cities is not what it used to be. The modern-city model that took hold globally in the twentieth century has outlived its usefulness. It cannot solve the problems it helped to create—especially global warming. Fortunately, a new model for urban development is emerging in cities to aggressively tackle the realities of climate change. It transforms the way cities design and use physical space, generate economic wealth, consume and dispose of resources, exploit and sustain the natural ecosystems, and prepare for the future. Available On Amazon

The Sixth Extinction: An Unnatural History

by Elizabeth Kolbert
1250062187Over the last half-billion years, there have been Five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In prose that is at once frank, entertaining, and deeply informed, New Yorker writer Elizabeth Kolbert tells us why and how human beings have altered life on the planet in a way no species has before. Interweaving research in half a dozen disciplines, descriptions of the fascinating species that have already been lost, and the history of extinction as a concept, Kolbert provides a moving and comprehensive account of the disappearances occurring before our very eyes. She shows that the sixth extinction is likely to be mankind's most lasting legacy, compelling us to rethink the fundamental question of what it means to be human. Available On Amazon

Climate Wars: The Fight for Survival as the World Overheats

by Gwynne Dyer
1851687181Waves of climate refugees. Dozens of failed states. All-out war. From one of the world’s great geopolitical analysts comes a terrifying glimpse of the strategic realities of the near future, when climate change drives the world’s powers towards the cut-throat politics of survival. Prescient and unflinching, Climate Wars will be one of the most important books of the coming years. Read it and find out what we’re heading for. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

LATEST VIDEOS

The Great Climate Migration Has Begun
The Great Climate Migration Has Begun
by Super User
The climate crisis is forcing thousands around the world to flee as their homes become increasingly uninhabitable.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
by Toby Tyrrell
It took evolution 3 or 4 billion years to produce Homo sapiens. If the climate had completely failed just once in that…
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
by Brice Rea
The end of the last ice age, around 12,000 years ago, was characterised by a final cold phase called the Younger Dryas.…
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
by Frank Wesselingh and Matteo Lattuada
Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a…
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
by Richard Ernst
We can learn a lot about climate change from Venus, our sister planet. Venus currently has a surface temperature of…
Five Climate Disbeliefs: A Crash Course In Climate Misinformation
The Five Climate Disbeliefs: A Crash Course In Climate Misinformation
by John Cook
This video is a crash course in climate misinformation, summarizing the key arguments used to cast doubt on the reality…
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
by Julie Brigham-Grette and Steve Petsch
Every year, sea ice cover in the Arctic Ocean shrinks to a low point in mid-September. This year it measures just 1.44…

LATEST ARTICLES

trees to plant for climate2
Plant These Trees To Improve City Life
by Mike Williams-Rice
A new study establishes live oaks and American sycamores as champions among 17 “super trees” that will help make cities…
north sea sea bed
Why We Must Understand Seabed Geology To Harness The Winds
by Natasha Barlow, Associate Professor of Quaternary Environmental Change, University of Leeds
For any country blessed with easy access to the shallow and windy North Sea, offshore wind will be key to meeting net…
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
by Bart Johnson, Professor of Landscape Architecture, University of Oregon
A wildfire burning in hot, dry mountain forest swept through the Gold Rush town of Greenville, California, on Aug. 4,…
China Can Meet Energy and Climate Goals Capping Coal Power
China Can Meet Energy and Climate Goals Capping Coal Power
by Alvin Lin
At the Leader’s Climate Summit in April, Xi Jinping pledged that China will “strictly control coal-fired power…
Blue water surrounded by dead white grass
Map tracks 30 years of extreme snowmelt across US
by Mikayla Mace-Arizona
A new map of extreme snowmelt events over the last 30 years clarifies the processes that drive rapid melting.
A plane drops red fire retardant on to a forest fire as firefighters parked along a road look up into the orange sky
Model predicts 10-year burst of wildfire, then gradual decline
by Hannah Hickey-U. Washington
A look at the long-term future of wildfires predicts an initial roughly decade-long burst of wildfire activity,…
White sea ice in blue water with the sun setting reflected in the water
Earth’s frozen areas are shrinking 33K square miles a year
by Texas A&M University
The Earth’s cryosphere is shrinking by 33,000 square miles (87,000 square kilometers) per year.
A row of male and female speakers at microphones
234 scientists read 14,000+ research papers to write the upcoming IPCC climate report
by Stephanie Spera, Assistant Professor of Geography and the Environment, University of Richmond
This week, hundreds of scientists from around the world are finalizing a report that assesses the state of the global…

 Get The Latest By Email

Weekly Magazine Daily Inspiration

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.