Weather

Actions

What does prolonged ocean heat mean for our weather?

Some of the ocean temperatures scientists are seeing now are without precedent — which makes forecasting their effects difficult.
The Atlantic Ocean
Posted at 9:18 PM, Jul 28, 2023

Global average sea temperatures are at unprecedented highs.

Ocean heat is contributing to significant ice melt and causing coral die-offs.

In places, our instruments are registering what may be the highest ocean temperatures ever recorded on Earth.

Scientists say the oceanic heat waves that have pushed sea surface temperatures to new records this summer are expected to persist, which may continue to contribute to extreme weather later in the year.

Svenja Ryan, a physical oceanographer at the Woods Hole Oceanographic Institution in Massachusetts, told NBC News: "We’re not even at the height of the summer. Typically, the ocean continues to warm until September, so I think certainly we can expect this heat wave to last into the fall."

But experts can't say exactly what exactly to expect in terms of effects — in some cases, the conditions now are unlike anything they've ever seen before.

So researchers are studying whether the warm ocean temperatures are influencing this year's weather. Rainfall patterns may have been affected in places as far apart as Norway, which saw unusually dry conditions this year, and South Asia, where the monsoon that waters rice and other crops has been weaker than usual.

Typically, warmer waters also fuel stronger hurricanes, which draw their energy from the ocean as they move across it. 

However, any intensification of this year's storms may be moderated by the characteristic wind shear from the El Niño weather pattern in the Pacific; the competing winds make it difficult for storms to keep their form and strength.

Rising ocean temps contributing to Florida's dying coral reefs
Coral shows signs of bleaching in Florida

Rising ocean temps contributing to Florida's dying coral reefs

Potential record temperatures in waters off Florida may have lead to coral death on state reefs — and could affect larger climate systems, too.

LEARN MORE

Looking past just this year's effects, warmer oceans are expected to increase pressure on ocean ecosystems, intensify hurricanes, and accelerate ice loss — which could then cause other imbalances in the climate that we're used to.

Research published this week found that accelerated melting from ice in Greenland is changing the speed of the Atlantic Meridional Overturning Current, which is expected to eventually destabilize, now possibly as early as midcentury.

A weakening or collapse of the ocean-wide current could disrupt weather patterns on multiple continents, threaten the reliability of agricultural zones and displace millions of people due to sea level rise.

A major Atlantic Ocean current could collapse as early as 2025
The Atlantic Meridional Overturning Current

A major Atlantic Ocean current could collapse as early as 2025

Researchers warn that a collapse of the AMOC could be far-reaching, impacting tens of millions of people.

LEARN MORE