Sea-surface temperatures in parts of the North Atlantic have soared to record heights in the past few weeks, causing concerns among scientists and meteorologists. What’s causing the unusual warm-up isn’t clear, but several factors might be at play. In this article, we’ll explore the possible causes of the North Atlantic’s record-breaking heat and its potential impact on hurricane season.
Unusual Warm-up in the North Atlantic
In the past few weeks, satellite data has revealed that sea-surface temperatures in some parts of the North Atlantic Ocean have soared to record heights. The anomalous warming is occurring in a large swath stretching almost one-third of the way across the Atlantic westward from the northwestern coast of Africa. Some surface waters in the area are almost 4 degrees Celsius above normal for this time of the year.
Global Warming Trends
This year marks the return of El Niño, a climate phenomenon whose hallmark is warmer-than-normal sea-surface temperatures along the equator west of South America. Each El Niño has its own personality. But in general, El Niño boosts average surface temperatures both on land and at sea worldwide. Human-caused climate change has done the same.
The Dearth of Sahara Dust
Occasionally, vast swathes of desert dust from the Sahara waft across the ocean, carried by winds stirred up by a semi-permanent high-pressure system dubbed the “Azores high” due to its proximity to those islands. But lately, the Azores high has weakened and shifted southwest away from Africa. So those winds that typically pick up and transport Saharan dust westward over the North Atlantic are calmer and largely dust-free. As a result, solar radiation that normally would be scattered back into space by the dust reaches the ocean surface, warming the dark waters.
Decreased Air Pollution
In 2020, new emissions rules kicked in for long-haul container ships that spew sulfate-rich exhaust plumes. There’s been some speculation that less pollution could lead to more heating. With fewer plumes scattering sunlight back into space, more radiation reaches the sea surface. But some studies suggest that the cooling effect of ship plumes may have been minor, to begin with.
Impact on Hurricane Season
This year’s warmer-than-normal waters might help strengthen storms that form in the eastern Atlantic and eventually spawn hurricanes, scientists say. However, the El Niño that’s now developing in the equatorial Pacific may hamper their formation by strengthening winds in the upper atmosphere that can shear the tops off nascent hurricanes. How active this year’s hurricane season will be depends on which of these forces will prevail.
In conclusion, the North Atlantic is breaking heat records, and scientists are still trying to determine the underlying causes. Some possible factors include a dearth of Sahara dust, decreased air pollution, and global warming trends. While the warmer-than-normal waters might help strengthen storms that form in the eastern Atlantic and eventually spawn hurricanes, scientists are uncertain about how current conditions may affect the coming forecast. It’s important to stay informed about these developments and take necessary precautions to safeguard ourselves and our communities.