Heart

McKenzie Prillaman was the Spring 2023 science writing intern at Science News. She holds a bachelor’s degree in neuroscience with a minor in bioethics from the University of Virginia and a master’s degree in science communication from the University of California, Santa Cruz. More

Something strange is happening to the Antarctic’s sea ice. The areal expanse of floating ice fringing the continent is not only at a record low for this time of year — surpassing a record just set in 2022 — but ice extent has been hitting record lows throughout the year.

“What’s happened here is unlike the Arctic sea ice expanse,” says Mark Serreze, a climate scientist and the director of the U.S. National Snow and Ice Data Center, or NSIDC, in Boulder, Colo. We’ve come to expect a dramatic decline in sea ice at Earth’s other pole, he says (SN: 9/25/19). “Not much has happened to Antarctica’s sea ice until the last few years. But it’s just plummeted.”

NSIDC uses satellite-gleaned data, collected daily, to keep an eye on the spread of sea ice at both poles. Throughout most of 2023, the ring of sea ice around Antarctica has repeatedly set new record lows, staying well below the average extent from 1981 to 2010. On February 21 — the height of the Southern Hemisphere’s summer — the sea ice expanse hit an all-time low since record-keeping began in 1978, of 1.79 million square kilometers. That’s 130,000 square kilometers — about the size of the state of New York — smaller than the previous recorded minimum, reached on February 25, 2022.

Subpar sea ice

The amount of ocean around Antarctica covered in sea ice in 2023 (red) has stayed well below the average from 1981 to 2010 (black). Sea ice expanse hit a record low in late February — surpassing a record set just in 2022 (blue). The sea ice expanse for every year from 1981 to 2021 is shown in gray.

Even as the Southern Hemisphere shifted into winter, Antarctic sea ice remained at record low levels. On June 27, the ice was dotted across about 11.7 million square kilometers of ocean. That’s about 2.6 million square kilometers below the 1981–2010 average, and about 1.2 million square kilometers below the previous lowest extent on record for June 27, set in 2022.

Unlike Arctic ice, whose dwindling is known to be closely tied to global warming, it’s been harder to parse the reasons for changes in Antarctic sea ice extent. That difficulty has made it unclear whether changes are the result of natural variability or whether “something big has changed,” Serreze says.

As of June 28, the sea ice surrounding Antarctica, as measured by satellite, covered a smaller area of ocean than the average extent from 1981 to 2010 for this time of year. Yellow lines and dots represent missing satellite data.U.S. National Snow and Ice Data Center

The last few years have given scientists pause (SN: 6/27/17). “We’re kind of dropping off an edge,” Serreze says. It’s not yet clear whether this year’s extent is part of a larger trend, he notes. But “the longer that persists, the more likely it is that something big is happening.”

The Arctic and the Antarctic regions are polar opposites, so to speak, in their geographic setting. Ice in the Arctic Ocean is confined to a relatively small body of water ringed by land. The Antarctic, by contrast, is a landmass surrounded by ocean, which means the sea ice around the continent is much more mobile than up north, with a larger seasonal range as it expands in the Southern Hemisphere’s winter and shrinks in summer. Climate simulations have, accordingly, consistently predicted that the Arctic would show bigger sea ice losses as the planet warms, at least at first, while Antarctica would be slower to respond.

As to why the Antarctic ice has tracked so low this year there are a few possible culprits. Regional climate patterns — particularly an air pressure pattern known as the Southern Annular Mode that shifts the direction of winds blowing around the continent — can pack or diffuse the sea ice cover around Antarctica. And other regional patterns, such as the El Niño Southern Oscillation, can affect both ocean and air circulation in the southern high latitudes.

.subscribe-cta {
color: black;
margin-top: 0px;
background-image: url(“”);
background-size: cover;
padding: 20px;
border: 1px solid #ffcccb;
border-top: 5px solid #e04821;
clear: both;
}

Subscribe to Science News

Get great science journalism, from the most trusted source, delivered to your doorstep.

Right now, scientists are concerned most with what lies beneath the ice (SN: 12/13/21). “There’s growing evidence that there has been some kind of change in ocean circulation that is bringing more heat” to the region, which affects the ice cover, Serreze says. “There are a bunch of people looking into this; we’re really blitzing to get the data. We need to understand what the heck is going on in the ocean.” More

In the past few weeks, 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. Satellite data reveal that some surface waters in the area are almost 4 degrees Celsius (about 7 degrees Fahrenheit) above normal for this time of the year, says Brian McNoldy, a meteorologist at the University of Miami in Coral Gables, Fla.

.email-conversion {
border: 1px solid #ffcccb;
color: white;
margin-top: 50px;
background-image: url(“/wp-content/themes/sciencenews/client/src/images/cta-module@2x.jpg”);
padding: 20px;
clear: both;
}

.zephr-registration-form{max-width:440px;margin:20px auto;padding:20px;background-color:#fff;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form *{box-sizing:border-box}.zephr-registration-form-text > *{color:var(–zephr-color-text-main)}.zephr-registration-form-relative-container{position:relative}.zephr-registration-form-flex-container{display:flex}.zephr-registration-form-input.svelte-blfh8x{display:block;width:100%;height:calc(var(–zephr-input-height) * 1px);padding-left:8px;font-size:16px;border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);border-radius:calc(var(–zephr-input-borderRadius) * 1px);transition:border-color 0.25s ease, box-shadow 0.25s ease;outline:0;color:var(–zephr-color-text-main);background-color:#fff;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input.svelte-blfh8x::placeholder{color:var(–zephr-color-background-tinted)}.zephr-registration-form-input-checkbox.svelte-blfh8x{width:auto;height:auto;margin:8px 5px 0 0;float:left}.zephr-registration-form-input-radio.svelte-blfh8x{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x{width:50px;padding:0;border-radius:50%}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x::-webkit-color-swatch{border:none;border-radius:50%;padding:0}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x::-webkit-color-swatch-wrapper{border:none;border-radius:50%;padding:0}.zephr-registration-form-input.disabled.svelte-blfh8x,.zephr-registration-form-input.disabled.svelte-blfh8x:hover{border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);background-color:var(–zephr-color-background-tinted)}.zephr-registration-form-input.error.svelte-blfh8x{border:1px solid var(–zephr-color-warning-main)}.zephr-registration-form-input-label.svelte-1ok5fdj.svelte-1ok5fdj{margin-top:10px;display:block;line-height:30px;font-size:12px;color:var(–zephr-color-text-tinted);font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input-label.svelte-1ok5fdj span.svelte-1ok5fdj{display:block}.zephr-registration-form-button.svelte-17g75t9{height:calc(var(–zephr-button-height) * 1px);line-height:0;padding:0 20px;text-decoration:none;text-transform:capitalize;text-align:center;border-radius:calc(var(–zephr-button-borderRadius) * 1px);font-size:calc(var(–zephr-button-fontSize) * 1px);font-weight:normal;cursor:pointer;border-style:solid;border-width:calc(var(–zephr-button-borderWidth) * 1px);border-color:var(–zephr-color-action-tinted);transition:backdrop-filter 0.2s, background-color 0.2s;margin-top:20px;display:block;width:100%;background-color:var(–zephr-color-action-main);color:#fff;position:relative;overflow:hidden;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-button.svelte-17g75t9:hover{background-color:var(–zephr-color-action-tinted);border-color:var(–zephr-color-action-tinted)}.zephr-registration-form-button.svelte-17g75t9:disabled{background-color:var(–zephr-color-background-tinted);border-color:var(–zephr-color-background-tinted)}.zephr-registration-form-button.svelte-17g75t9:disabled:hover{background-color:var(–zephr-color-background-tinted);border-color:var(–zephr-color-background-tinted)}.zephr-registration-form-text.svelte-i1fi5{font-size:19px;text-align:center;margin:20px auto;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-divider-container.svelte-mk4m8o{display:flex;align-items:center;justify-content:center;margin:40px 0}.zephr-registration-form-divider-line.svelte-mk4m8o{height:1px;width:50%;margin:0 5px;background-color:var(–zephr-color-text-tinted);;}.zephr-registration-form-divider-text.svelte-mk4m8o{margin:0 12px;color:var(–zephr-color-text-main);font-size:14px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);white-space:nowrap}.zephr-registration-form-input-inner-text.svelte-lvlpcn{cursor:pointer;position:absolute;top:50%;transform:translateY(-50%);right:10px;color:var(–zephr-color-text-main);font-size:12px;font-weight:bold;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-response-message.svelte-179421u{text-align:center;padding:10px 30px;border-radius:5px;font-size:15px;margin-top:10px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-response-message-title.svelte-179421u{font-weight:bold;margin-bottom:10px}.zephr-registration-form-response-message-success.svelte-179421u{background-color:#baecbb;border:1px solid #00bc05}.zephr-registration-form-response-message-error.svelte-179421u{background-color:#fcdbec;border:1px solid #d90c00}.zephr-registration-form-social-sign-in.svelte-gp4ky7{align-items:center}.zephr-registration-form-social-sign-in-button.svelte-gp4ky7{height:55px;padding:0 15px;color:#000;background-color:#fff;box-shadow:0px 0px 5px rgba(0, 0, 0, 0.3);border-radius:10px;font-size:17px;display:flex;align-items:center;cursor:pointer;margin-top:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-social-sign-in-button.svelte-gp4ky7:hover{background-color:#fafafa}.zephr-registration-form-social-sign-in-icon.svelte-gp4ky7{display:flex;justify-content:center;margin-right:30px;width:25px}.zephr-form-link-message.svelte-rt4jae{margin:10px 0 10px 20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-recaptcha-tcs.svelte-1wyy3bx{margin:20px 0 0 0;font-size:15px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-recaptcha-inline.svelte-1wyy3bx{margin:20px 0 0 0}.zephr-registration-form-progress-bar.svelte-8qyhcl{width:100%;border:0;border-radius:20px;margin-top:10px}.zephr-registration-form-progress-bar.svelte-8qyhcl::-webkit-progress-bar{background-color:var(–zephr-color-background-tinted);border:0;border-radius:20px}.zephr-registration-form-progress-bar.svelte-8qyhcl::-webkit-progress-value{background-color:var(–zephr-color-text-tinted);border:0;border-radius:20px}.zephr-registration-progress-bar-step.svelte-8qyhcl{margin:auto;color:var(–zephr-color-text-tinted);font-size:12px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-progress-bar-step.svelte-8qyhcl:first-child{margin-left:0}.zephr-registration-progress-bar-step.svelte-8qyhcl:last-child{margin-right:0}.zephr-registration-form-input-error-text.svelte-19a73pq{color:var(–zephr-color-warning-main);font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input-select.svelte-19a73pq{display:block;appearance:auto;width:100%;height:calc(var(–zephr-input-height) * 1px);font-size:16px;border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-color-text-main);border-radius:calc(var(–zephr-input-borderRadius) * 1px);transition:border-color 0.25s ease, box-shadow 0.25s ease;outline:0;color:var(–zephr-color-text-main);background-color:#fff;padding:10px}.zephr-registration-form-input-select.disabled.svelte-19a73pq{border:1px solid var(–zephr-color-background-tinted)}.zephr-registration-form-input-select.unselected.svelte-19a73pq{color:var(–zephr-color-background-tinted)}.zephr-registration-form-input-select.error.svelte-19a73pq{border-color:var(–zephr-color-warning-main)}.zephr-registration-form-input-textarea.svelte-19a73pq{background-color:#fff;border:1px solid #ddd;color:#222;font-size:14px;font-weight:300;padding:16px;width:100%}.zephr-registration-form-input-slider-output.svelte-19a73pq{margin:13px 0 0 10px}.zephr-registration-form-input-inner-text.svelte-lvlpcn{cursor:pointer;position:absolute;top:50%;transform:translateY(-50%);right:10px;color:var(–zephr-color-text-main);font-size:12px;font-weight:bold;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.spin.svelte-1cj2gr0{animation:svelte-1cj2gr0-spin 2s 0s infinite linear}.pulse.svelte-1cj2gr0{animation:svelte-1cj2gr0-spin 1s infinite steps(8)}@keyframes svelte-1cj2gr0-spin{0%{transform:rotate(0deg)}100%{transform:rotate(360deg)}}.zephr-registration-form-checkbox.svelte-1gzpw2y{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-checkbox-label.svelte-1gzpw2y{display:flex;align-items:center;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-checkmark.svelte-1gzpw2y{position:relative;box-sizing:border-box;height:23px;width:23px;background-color:#fff;border:1px solid var(–zephr-color-text-main);border-radius:6px;margin-right:12px;cursor:pointer}.zephr-registration-form-checkmark.checked.svelte-1gzpw2y{border-color:#009fe3}.zephr-registration-form-checkmark.checked.svelte-1gzpw2y:after{content:””;position:absolute;width:6px;height:13px;border:solid #009fe3;border-width:0 2px 2px 0;transform:rotate(45deg);top:3px;left:8px;box-sizing:border-box}.zephr-registration-form-checkmark.disabled.svelte-1gzpw2y{border:1px solid var(–zephr-color-background-tinted)}.zephr-registration-form-checkmark.disabled.checked.svelte-1gzpw2y:after{border:solid var(–zephr-color-background-tinted);border-width:0 2px 2px 0}.zephr-registration-form-checkmark.error.svelte-1gzpw2y{border:1px solid var(–zephr-color-warning-main)}.zephr-registration-form-input-radio.svelte-1qn5n0t{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-radio-label.svelte-1qn5n0t{display:flex;align-items:center;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-radio-dot.svelte-1qn5n0t{position:relative;box-sizing:border-box;height:23px;width:23px;background-color:#fff;border:1px solid #ebebeb;border-radius:50%;margin-right:12px}.checked.svelte-1qn5n0t{border-color:#009fe3}.checked.svelte-1qn5n0t:after{content:””;position:absolute;width:17px;height:17px;background:#009fe3;background:linear-gradient(#009fe3, #006cb5);border-radius:50%;top:2px;left:2px}.disabled.checked.svelte-1qn5n0t:after{background:var(–zephr-color-background-tinted)}.error.svelte-1qn5n0t{border:1px solid var(–zephr-color-warning-main)}.zephr-form-link.svelte-64wplc{margin:10px 0;color:#6ba5e9;text-decoration:underline;cursor:pointer;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-form-link-disabled.svelte-64wplc{color:var(–zephr-color-text-main);cursor:none;text-decoration:none}.zephr-registration-form-google-icon.svelte-1jnblvg{width:20px}.zephr-registration-form-password-progress.svelte-d1zv9r{display:flex;margin-top:10px}.zephr-registration-form-password-bar.svelte-d1zv9r{width:100%;height:4px;border-radius:2px}.zephr-registration-form-password-bar.svelte-d1zv9r:not(:first-child){margin-left:8px}.zephr-registration-form-password-requirements.svelte-d1zv9r{margin:20px 0;justify-content:center}.zephr-registration-form-password-requirement.svelte-d1zv9r{display:flex;align-items:center;color:var(–zephr-color-text-tinted);font-size:12px;height:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-password-requirement-icon.svelte-d1zv9r{margin-right:10px;font-size:15px}.zephr-registration-form-password-progress.svelte-d1zv9r{display:flex;margin-top:10px}.zephr-registration-form-password-bar.svelte-d1zv9r{width:100%;height:4px;border-radius:2px}.zephr-registration-form-password-bar.svelte-d1zv9r:not(:first-child){margin-left:8px}.zephr-registration-form-password-requirements.svelte-d1zv9r{margin:20px 0;justify-content:center}.zephr-registration-form-password-requirement.svelte-d1zv9r{display:flex;align-items:center;color:var(–zephr-color-text-tinted);font-size:12px;height:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-password-requirement-icon.svelte-d1zv9r{margin-right:10px;font-size:15px}
.zephr-registration-form {
max-width: 100%;
background-image: url(https://www.sciencenews.org/wp-content/uploads/2023/05/newsletter-signup-background_REV.jpg);
background-position: top 75% left 67%;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
margin: 0px auto;
margin-bottom: 4rem;
padding: 20px;
}

.zephr-registration-form-text.svelte-i1fi5 p {
padding-left: 10px;
padding-right: 10px;
padding-bottom: 10px;
}

.zephr-registration-form-text.svelte-i1fi5 h2 {
padding-top: 10px;
}

.zephr-registration-form-text h6 {
font-size: 0.8rem;
}

.zephr-registration-form h4 {
font-size: 3rem;
}

.zephr-registration-form h4 {
font-size: 1.5rem;
}

.zephr-registration-form-button.svelte-17g75t9:hover {
background-color: #fc6a65;
border-color: #fc6a65;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-button.svelte-17g75t9:disabled {
background-color: #e04821;
border-color: #e04821;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-button.svelte-17g75t9 {
background-color: #e04821;
border-color: #e04821;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-text > * {
color: #FFFFFF;
font-weight: bold
font: 25px;
background-color: rgba(10,10,10,0.7)
}
.zephr-registration-form-progress-bar.svelte-8qyhcl {
width: 100%;
border: 0;
border-radius: 20px;
margin-top: 10px;
display: none;
}
.zephr-registration-form-response-message-title.svelte-179421u {
font-weight: bold;
margin-bottom: 10px;
display: none;
}
.zephr-registration-form-response-message-success.svelte-179421u {
background-color: #8db869;
border: 1px solid #8db869;
color: white;
margin-top: -0.2rem;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(1){
font-size: 18px;
text-align: center;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(5){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(7){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(9){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-input-label.svelte-1ok5fdj span.svelte-1ok5fdj {
display: none;
color: white;
}
.zephr-registration-form-input.disabled.svelte-blfh8x, .zephr-registration-form-input.disabled.svelte-blfh8x:hover {
border: calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);
background-color: white;
}
.zephr-registration-form-checkbox-label.svelte-1gzpw2y {
display: flex;
align-items: center;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
font-size: 20px;
margin-bottom: -20px;
}
.zephr-registration-progress-bar-step.svelte-8qyhcl:first-child {
display: none;
}
.zephr-registration-progress-bar-step.svelte-8qyhcl:last-child {
display: none;
}

“There’s been record-breaking warmth since March, but even more so now,” he says.

On June 10, for instance, the average sea-surface temperature for the portion of the Atlantic that stretches from the equator to 60 degrees north — up to southern Norway, southern Greenland and the central portions of Canada’s Hudson Bay — was 22.7° C (nearly 73° F). That’s about 1 degree C higher than the average recorded from 1991 through 2020, McNoldy notes. The previous record for the same date, 22.1° C, occurred in 2010.

Hot Atlantic

Sea-surface temperatures in the North Atlantic in 2023 (red) have been breaking daily records since March. In this plot, the 1982–2022 daily mean temperatures have been subtracted from this year’s temperatures as well of those from 1982 to 2022 (gray).

This year’s warmer-than-normal waters might help strengthen storms that form in the eastern Atlantic and eventually spawn hurricanes, scientists say.

What’s causing the unusual warm-up isn’t clear. But here’s a rundown of several factors that might be at play.

A dearth of Sahara dust

Occasionally, vast swathes of desert dust from the Sahara waft across the ocean. They are carried by winds stirred up by a semipermanent 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, says Michael Mann, a climate scientist at the University of Pennsylvania.

As a result, solar radiation that normally would be scattered back into space by the dust reaches the ocean surface, warming the dark waters (SN: 9/25/01).

If and when the trade winds strengthen, increased dust from Africa could help cool the area somewhat.

In a typical year, vast plumes of dust from the Sahara Desert (left in this satellite image of northwest Africa from 2020) block sunlight, shading and cooling the underlying ocean. This spring, a lack of dusty air has contributed to warming of the North Atlantic.NOAA

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: Not only do the exhaust plumes have a short life span, the pollutants can cause natural clouds to evaporate more quickly and thus lead to warming, not cooling (SN: 2/1/21).

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. By winter, there’s a more than 4 in 5 chance that the El Niño will be either strong or moderate, according to scientists with the National Oceanic and Atmospheric Administration’s Climate Prediction Center.

Each El Niño has its own personality (SN: 5/2/16). But in general, El Niño boosts average surface temperatures both on land and at sea worldwide, Mann says. Human-caused climate change has done the same, he notes.

But there’s still a lot of uncertainty about how current conditions may affect the coming forecast.

The unusually warm waters of the North Atlantic may tend to strengthen storm systems that later develop into tropical depressions and then hurricanes. But 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, scientists say (SN: 5/26/23).  More

Even as the thick clouds of smoke from wildfires raging in eastern Canada, which blanketed the U.S. East Coast in a dangerous orange haze, begin to dissipate, researchers are warning it’s a sign of the times.

Canada’s fire outlook will remain higher than normal for June. And on a larger scale, climate change is projected to make fire conditions more common across Canada, Russia and Alaska’s boreal forests.

The current fires were sparked by lightning in the Canadian province of Quebec; like much of Canada, parts of Quebec were abnormally dry this spring.

.email-conversion {
border: 1px solid #ffcccb;
color: white;
margin-top: 50px;
background-image: url(“/wp-content/themes/sciencenews/client/src/images/cta-module@2x.jpg”);
padding: 20px;
clear: both;
}

.zephr-registration-form{max-width:440px;margin:20px auto;padding:20px;background-color:#fff;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form *{box-sizing:border-box}.zephr-registration-form-text > *{color:var(–zephr-color-text-main)}.zephr-registration-form-relative-container{position:relative}.zephr-registration-form-flex-container{display:flex}.zephr-registration-form-input.svelte-blfh8x{display:block;width:100%;height:calc(var(–zephr-input-height) * 1px);padding-left:8px;font-size:16px;border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);border-radius:calc(var(–zephr-input-borderRadius) * 1px);transition:border-color 0.25s ease, box-shadow 0.25s ease;outline:0;color:var(–zephr-color-text-main);background-color:#fff;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input.svelte-blfh8x::placeholder{color:var(–zephr-color-background-tinted)}.zephr-registration-form-input-checkbox.svelte-blfh8x{width:auto;height:auto;margin:8px 5px 0 0;float:left}.zephr-registration-form-input-radio.svelte-blfh8x{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x{width:50px;padding:0;border-radius:50%}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x::-webkit-color-swatch{border:none;border-radius:50%;padding:0}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x::-webkit-color-swatch-wrapper{border:none;border-radius:50%;padding:0}.zephr-registration-form-input.disabled.svelte-blfh8x,.zephr-registration-form-input.disabled.svelte-blfh8x:hover{border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);background-color:var(–zephr-color-background-tinted)}.zephr-registration-form-input.error.svelte-blfh8x{border:1px solid var(–zephr-color-warning-main)}.zephr-registration-form-input-label.svelte-1ok5fdj.svelte-1ok5fdj{margin-top:10px;display:block;line-height:30px;font-size:12px;color:var(–zephr-color-text-tinted);font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input-label.svelte-1ok5fdj span.svelte-1ok5fdj{display:block}.zephr-registration-form-button.svelte-17g75t9{height:calc(var(–zephr-button-height) * 1px);line-height:0;padding:0 20px;text-decoration:none;text-transform:capitalize;text-align:center;border-radius:calc(var(–zephr-button-borderRadius) * 1px);font-size:calc(var(–zephr-button-fontSize) * 1px);font-weight:normal;cursor:pointer;border-style:solid;border-width:calc(var(–zephr-button-borderWidth) * 1px);border-color:var(–zephr-color-action-tinted);transition:backdrop-filter 0.2s, background-color 0.2s;margin-top:20px;display:block;width:100%;background-color:var(–zephr-color-action-main);color:#fff;position:relative;overflow:hidden;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-button.svelte-17g75t9:hover{background-color:var(–zephr-color-action-tinted);border-color:var(–zephr-color-action-tinted)}.zephr-registration-form-button.svelte-17g75t9:disabled{background-color:var(–zephr-color-background-tinted);border-color:var(–zephr-color-background-tinted)}.zephr-registration-form-button.svelte-17g75t9:disabled:hover{background-color:var(–zephr-color-background-tinted);border-color:var(–zephr-color-background-tinted)}.zephr-registration-form-text.svelte-i1fi5{font-size:19px;text-align:center;margin:20px auto;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-divider-container.svelte-mk4m8o{display:flex;align-items:center;justify-content:center;margin:40px 0}.zephr-registration-form-divider-line.svelte-mk4m8o{height:1px;width:50%;margin:0 5px;background-color:var(–zephr-color-text-tinted);;}.zephr-registration-form-divider-text.svelte-mk4m8o{margin:0 12px;color:var(–zephr-color-text-main);font-size:14px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);white-space:nowrap}.zephr-registration-form-input-inner-text.svelte-lvlpcn{cursor:pointer;position:absolute;top:50%;transform:translateY(-50%);right:10px;color:var(–zephr-color-text-main);font-size:12px;font-weight:bold;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-response-message.svelte-179421u{text-align:center;padding:10px 30px;border-radius:5px;font-size:15px;margin-top:10px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-response-message-title.svelte-179421u{font-weight:bold;margin-bottom:10px}.zephr-registration-form-response-message-success.svelte-179421u{background-color:#baecbb;border:1px solid #00bc05}.zephr-registration-form-response-message-error.svelte-179421u{background-color:#fcdbec;border:1px solid #d90c00}.zephr-registration-form-social-sign-in.svelte-gp4ky7{align-items:center}.zephr-registration-form-social-sign-in-button.svelte-gp4ky7{height:55px;padding:0 15px;color:#000;background-color:#fff;box-shadow:0px 0px 5px rgba(0, 0, 0, 0.3);border-radius:10px;font-size:17px;display:flex;align-items:center;cursor:pointer;margin-top:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-social-sign-in-button.svelte-gp4ky7:hover{background-color:#fafafa}.zephr-registration-form-social-sign-in-icon.svelte-gp4ky7{display:flex;justify-content:center;margin-right:30px;width:25px}.zephr-form-link-message.svelte-rt4jae{margin:10px 0 10px 20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-recaptcha-tcs.svelte-1wyy3bx{margin:20px 0 0 0;font-size:15px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-recaptcha-inline.svelte-1wyy3bx{margin:20px 0 0 0}.zephr-registration-form-progress-bar.svelte-8qyhcl{width:100%;border:0;border-radius:20px;margin-top:10px}.zephr-registration-form-progress-bar.svelte-8qyhcl::-webkit-progress-bar{background-color:var(–zephr-color-background-tinted);border:0;border-radius:20px}.zephr-registration-form-progress-bar.svelte-8qyhcl::-webkit-progress-value{background-color:var(–zephr-color-text-tinted);border:0;border-radius:20px}.zephr-registration-progress-bar-step.svelte-8qyhcl{margin:auto;color:var(–zephr-color-text-tinted);font-size:12px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-progress-bar-step.svelte-8qyhcl:first-child{margin-left:0}.zephr-registration-progress-bar-step.svelte-8qyhcl:last-child{margin-right:0}.zephr-registration-form-input-error-text.svelte-19a73pq{color:var(–zephr-color-warning-main);font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input-select.svelte-19a73pq{display:block;appearance:auto;width:100%;height:calc(var(–zephr-input-height) * 1px);font-size:16px;border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-color-text-main);border-radius:calc(var(–zephr-input-borderRadius) * 1px);transition:border-color 0.25s ease, box-shadow 0.25s ease;outline:0;color:var(–zephr-color-text-main);background-color:#fff;padding:10px}.zephr-registration-form-input-select.disabled.svelte-19a73pq{border:1px solid var(–zephr-color-background-tinted)}.zephr-registration-form-input-select.unselected.svelte-19a73pq{color:var(–zephr-color-background-tinted)}.zephr-registration-form-input-select.error.svelte-19a73pq{border-color:var(–zephr-color-warning-main)}.zephr-registration-form-input-textarea.svelte-19a73pq{background-color:#fff;border:1px solid #ddd;color:#222;font-size:14px;font-weight:300;padding:16px;width:100%}.zephr-registration-form-input-slider-output.svelte-19a73pq{margin:13px 0 0 10px}.zephr-registration-form-input-inner-text.svelte-lvlpcn{cursor:pointer;position:absolute;top:50%;transform:translateY(-50%);right:10px;color:var(–zephr-color-text-main);font-size:12px;font-weight:bold;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.spin.svelte-1cj2gr0{animation:svelte-1cj2gr0-spin 2s 0s infinite linear}.pulse.svelte-1cj2gr0{animation:svelte-1cj2gr0-spin 1s infinite steps(8)}@keyframes svelte-1cj2gr0-spin{0%{transform:rotate(0deg)}100%{transform:rotate(360deg)}}.zephr-registration-form-checkbox.svelte-1gzpw2y{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-checkbox-label.svelte-1gzpw2y{display:flex;align-items:center;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-checkmark.svelte-1gzpw2y{position:relative;box-sizing:border-box;height:23px;width:23px;background-color:#fff;border:1px solid var(–zephr-color-text-main);border-radius:6px;margin-right:12px;cursor:pointer}.zephr-registration-form-checkmark.checked.svelte-1gzpw2y{border-color:#009fe3}.zephr-registration-form-checkmark.checked.svelte-1gzpw2y:after{content:””;position:absolute;width:6px;height:13px;border:solid #009fe3;border-width:0 2px 2px 0;transform:rotate(45deg);top:3px;left:8px;box-sizing:border-box}.zephr-registration-form-checkmark.disabled.svelte-1gzpw2y{border:1px solid var(–zephr-color-background-tinted)}.zephr-registration-form-checkmark.disabled.checked.svelte-1gzpw2y:after{border:solid var(–zephr-color-background-tinted);border-width:0 2px 2px 0}.zephr-registration-form-checkmark.error.svelte-1gzpw2y{border:1px solid var(–zephr-color-warning-main)}.zephr-registration-form-input-radio.svelte-1qn5n0t{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-radio-label.svelte-1qn5n0t{display:flex;align-items:center;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-radio-dot.svelte-1qn5n0t{position:relative;box-sizing:border-box;height:23px;width:23px;background-color:#fff;border:1px solid #ebebeb;border-radius:50%;margin-right:12px}.checked.svelte-1qn5n0t{border-color:#009fe3}.checked.svelte-1qn5n0t:after{content:””;position:absolute;width:17px;height:17px;background:#009fe3;background:linear-gradient(#009fe3, #006cb5);border-radius:50%;top:2px;left:2px}.disabled.checked.svelte-1qn5n0t:after{background:var(–zephr-color-background-tinted)}.error.svelte-1qn5n0t{border:1px solid var(–zephr-color-warning-main)}.zephr-form-link.svelte-64wplc{margin:10px 0;color:#6ba5e9;text-decoration:underline;cursor:pointer;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-form-link-disabled.svelte-64wplc{color:var(–zephr-color-text-main);cursor:none;text-decoration:none}.zephr-registration-form-google-icon.svelte-1jnblvg{width:20px}.zephr-registration-form-password-progress.svelte-d1zv9r{display:flex;margin-top:10px}.zephr-registration-form-password-bar.svelte-d1zv9r{width:100%;height:4px;border-radius:2px}.zephr-registration-form-password-bar.svelte-d1zv9r:not(:first-child){margin-left:8px}.zephr-registration-form-password-requirements.svelte-d1zv9r{margin:20px 0;justify-content:center}.zephr-registration-form-password-requirement.svelte-d1zv9r{display:flex;align-items:center;color:var(–zephr-color-text-tinted);font-size:12px;height:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-password-requirement-icon.svelte-d1zv9r{margin-right:10px;font-size:15px}.zephr-registration-form-password-progress.svelte-d1zv9r{display:flex;margin-top:10px}.zephr-registration-form-password-bar.svelte-d1zv9r{width:100%;height:4px;border-radius:2px}.zephr-registration-form-password-bar.svelte-d1zv9r:not(:first-child){margin-left:8px}.zephr-registration-form-password-requirements.svelte-d1zv9r{margin:20px 0;justify-content:center}.zephr-registration-form-password-requirement.svelte-d1zv9r{display:flex;align-items:center;color:var(–zephr-color-text-tinted);font-size:12px;height:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-password-requirement-icon.svelte-d1zv9r{margin-right:10px;font-size:15px}
.zephr-registration-form {
max-width: 100%;
background-image: url(/wp-content/themes/sciencenews/client/src/images/cta-module@2x.jpg);
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
margin: 0px auto;
margin-bottom: 4rem;
padding: 20px;
}

.zephr-registration-form-text h6 {
font-size: 0.8rem;
}

.zephr-registration-form h4 {
font-size: 3rem;
}

.zephr-registration-form h4 {
font-size: 1.5rem;
}

.zephr-registration-form-button.svelte-17g75t9:hover {
background-color: #fc6a65;
border-color: #fc6a65;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-button.svelte-17g75t9:disabled {
background-color: #e04821;
border-color: #e04821;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-button.svelte-17g75t9 {
background-color: #e04821;
border-color: #e04821;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-text > * {
color: #FFFFFF;
font-weight: bold
font: 25px;
}
.zephr-registration-form-progress-bar.svelte-8qyhcl {
width: 100%;
border: 0;
border-radius: 20px;
margin-top: 10px;
display: none;
}
.zephr-registration-form-response-message-title.svelte-179421u {
font-weight: bold;
margin-bottom: 10px;
display: none;
}
.zephr-registration-form-response-message-success.svelte-179421u {
background-color: #8db869;
border: 1px solid #8db869;
color: white;
margin-top: -0.2rem;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(1){
font-size: 18px;
text-align: center;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(5){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(7){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(9){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-input-label.svelte-1ok5fdj span.svelte-1ok5fdj {
display: none;
color: white;
}
.zephr-registration-form-input.disabled.svelte-blfh8x, .zephr-registration-form-input.disabled.svelte-blfh8x:hover {
border: calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);
background-color: white;
}
.zephr-registration-form-checkbox-label.svelte-1gzpw2y {
display: flex;
align-items: center;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
font-size: 20px;
margin-bottom: -20px;
}

Their smoky haze has dominated headlines, prompting warnings of dangerous air pollution levels. People were urged to stay indoors as much as possible, or wear masks, to avoid inhaling the fine particulate matter. The smoke, a toxic brew of irritant gases and tiny particles, can cause asthma, respiratory and cardiovascular problems, and can exacerbate existing conditions such as diabetes and chronic lung conditions (SN: 6/17/22; SN: 9/18/20).

Wildfire-driven air pollution is all too familiar to residents of the Pacific Northwest and the U.S. West, where most of the continent’s large wildfires occur, but it’s less common in the eastern part of North America. So June’s headline-grabbing haze might be a wake-up call to East Coast policy makers about the hazards of climate change, some researchers hope.

Smoke from wildfires in Eastern Canada shrouded New York City (shown) and other cities along the U.S. East Coast in a thick haze of fine particles on June 7, leading to a Code Purple day indicating the air was very unhealthy.ANGELA WEISS/AFP via Getty Images

There’s plenty of historical precedent for that, says Nicholas Bond, state climatologist for the state of Washington, who is based in Seattle. “There were some periods when dust [from the Dust Bowl years of the 1930s] made it all the way to Washington, D.C., bringing attention to the disaster that was occurring in the Plains states,” he says.

Whether eastern Canada’s forests in particular will become more fire-prone due to climate change isn’t clear from recent simulations of future climate and fire behavior. The current fires are not necessarily a harbinger of things to come so much as a reminder of what’s already here: They’re burning in regions that are already considered at risk of fire.

Climate change is projected to boost fires across other vast swaths of boreal forest in the Northern Hemisphere. It’s already having an impact. “Wildfires in the boreal forests of Alaska burned more acres in the past 20 years” than in the previous 20 years, Bond says. How much of the forest is on fire can vary significantly from year to year; 2020 was below-average, with about 73,000 hectares burned. But the overall trend of burned area in boreal forests is expected to curve steeply upward by the middle of the century: The acreage of burned area in Alaska is projected to increase by 24 to 169 percent from 2020 to 2050.

Fire seasons in boreal forests are also expected to last longer and produce larger fires each year. Climate change may also increase the frequency of lightning strikes that spark fires such as those currently burning in Quebec — although that, too, is still uncertain.

Canada is currently fighting severe fires across the country, from coast to coast, stretching its resources thin — and the threat is expected to remain high in the coming weeks, the Canadian government reported on June 5.

That’s also true for the United States. “The Pacific Northwest is liable to be dealing with considerable smoke later this summer,” Bond says, based on a fire potential outlook report released June 1 by the U.S. National Interagency Fire Center. “For personal, selfish reasons I hope the winds do not bring the smoke our way.” More