Miracle or mirage? Atmospheric rivers end California drought year with heavy snow and rain

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After the driest start to any year on record, California will end 2022 with snow-capped mountains, soaked roadways and—in some places—flood warnings.

The soggy end to an otherwise bone-dry year came as something of a surprise. Only weeks earlier, officials sounded the alarm about a rare third appearance of La Niña—a climate pattern in the tropical Pacific that is often associated with dry conditions in the state. On Thursday, skiers in Mammoth enjoyed some of the deepest snow in the nation, while in Los Angeles, a steady drizzle signaled stronger storms to come.

Officials said the parade of atmospheric rivers dousing the state will probably continue in the days ahead, providing a glimmer of optimism after a year marked by , drying wells and perilous lows on the Colorado River. But though California’s wet season has defied expectations so far, the pattern must persist to truly undo several years of significant rain deficits.

“The moisture that we’re getting now is a big help, but we need more—a lot more—to really put a major dent in the drought,” said Richard Heim, a meteorologist with the National Centers for Environmental Information and one of the authors of the U.S. Drought Monitor.

Still, the damp December has come as a welcome change. While the drought monitor shows nearly 81% of the state under severe, extreme or exceptional drought, that’s a notable improvement from three months ago, when about 94% of the state was classified in the three worst categories. Heim said next Thursday’s update should show even more gains.

“When we’re dealing with drought in the West, in some regards we have to take it slow in showing improvement because reservoirs take forever to refill and you really need a good mountain snowpack,” he said. “And we don’t know if we have a good mountain snowpack for the until somewhere around April 1.”

State climatologist Mike Anderson of the Department of Water Resources said the storms could signal the decay of La Niña, which arrived as anticipated but started to weaken around the on Dec. 21, when Earth stopped tilting away from the sun in the Northern Hemisphere. Around the same time, regional high-pressure systems weakened, which allowed some of the storms to push through, he said.

“We’re kind of seeing things that are more in tune with what we would expect climatologically, and lot of it has to do with that high pressure yielding in its strength,” Anderson said. “In previous winters, it hung in there strong and prevented storms from making their way into California.”

The late December storms have also delivered some improvements when it comes to the state’s snowpack and reservoirs. California’s snow water equivalent, or the amount of water contained in the Sierra Nevada snowpack, was at 156% of normal for the date on Thursday.

The state’s two largest reservoirs also saw gains, with storage in Lake Shasta at 1.47 million acre-feet, up from 1.4 million at the start of December, and Lake Oroville at 1.12 million acre-feet, up from 965,000 at the start of December, Anderson said.

But he cautioned that more moisture is needed. Though high for the date, the snow water equivalent is still only 51% of its April 1 average, meaning that if no more rain and snow were to fall, the wet season would end with about half of what’s needed. Similarly, though Shasta and Oroville have improved, both remain well below normal for the time of year.

“It just has to sustain itself, because we still have two more of the wettest months of the year to go, and we really need them to be wet as well, where this year they were record dry,” Anderson said.

But though the storms have brought welcome moisture, they have also created instances of havoc across the state. Winter hazards, including snow, ice and fog, have already prompted some road closures in portions of Central and Northern California, and travel could be “near impossible” in some places through the weekend, the National Weather Service said.

Hannah Chandler-Cooley, a meteorologist with the in Sacramento, said the atmospheric rivers are coming from the tropics, not the Arctic, so they are warm systems that could bring rain instead of snow to elevations as high as 7,000 feet. Flood watches and warnings have been issued in several areas, including Lake Tahoe, Hanford and Sacramento, where several inches of rain are expected to fall.

Officials in the region are particularly concerned about flooding in communities along the Cosumnes, Mokelumne and Sacramento rivers, as well as potential urban flooding in areas with poor drainage and low-lying areas and roadways, she said.

“There will be and homes and roads and farms that could be impacted, but it will be a bit more localized to just those few river points, and not all of the river systems in Northern California,” she said.

Despite the potential hazards, the storms are undoubtedly beneficial for the parched state. The latest outlook from the National Oceanic and Atmospheric Administration’s Climate Prediction Center now shows an equal chance of above- or below-average precipitation in Northern California in January, but it’s not a guarantee.

Heim recalled that 2021 saw a similarly wet December, which was then followed by California’s driest-ever January through March on record in 2022. He feared a similar pattern could play out next year.

“A few months of really wet weather, well, it’s not going to make much of a dent in these deficits that have accumulated over the years and are reflected in the low reservoirs,” Heim said. He added that Lake Mead, the largest reservoir on the Colorado River, has more than 20 years of precipitation deficits to make up for.

But such dire conditions seemed a world away from the scene at Mammoth Mountain on Thursday, where officials were bracing for up to 5 feet of snow on top of the 2 to 3 feet received earlier this

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They survived the hunters: now king penguins face climate change

Hexbyte Glen Cove

King penguins were almost hunted to extinction in the 19th and 20th centuries.

Once hunted to the brink of extinction, the thousands of king penguins that densely congregate on the remote Possession Island each year now face a new threat: climate change.

The birds spend most of their life at sea, but come breeding time in December half the world’s population flock to the islands in the southern Indian Ocean’s Crozet archipelago, roughly halfway between Antarctica and the southeastern tip of Africa.

Robin Cristofari, a specialist in penguins at Finland’s University of Turku, looks out on a colony massed at a bay on Possession Island.

“This species was not very far from extinction” after being massacred by seal hunters from the end of the 19th century to the first half of the 20th, he said.

When the hunters ran out of seals to kill, they used the penguins as fuel, burning them to melt seal blubber in cauldrons, said Cristofari.

For a short time they even made penguin oil, “but it was not good quality”, he added.

The king penguin population rebounded in the latter half of the 20th century, but their numbers plateaued around 20 years ago.

“After that first hurdle, the species now faces a second, more insidious one: climate change,” Cristofari said.

He was the lead author of a 2018 study that found that was on track to wipe out 70 percent of the world’s by the end of the century.

King penguins pair up to share joint responsiblities for their offspring.

Polar front

King penguins stand just under a metre (three feet) tall and sport black-and-white tuxedos accessorised with on their necks and beaks.

They only return to land to breed, and are very picky about where they do so.

It must be a dry place, without winter sea ice around the island, and have a smooth beach of sand or pebbles as well as plentiful, accessible sources of food.

This means breeding spots need to be close to the Antarctic Polar Front, where from the south converge with warmer northern flows to create an area abundant with fish, squid and other marine food.

In January, the polar front is usually 350 kilometres (about 220 miles) south of the Crozet archipelago.

But during hot years it can be up to 750 kilometres away—too far for penguins to get food and quickly return to their hungry hatchlings and relieved partner.

Out of more than a million breeding pairs worldwide, around half breed on the Crozet Islands.

“Reproductive success is directly related to the distance from the polar front,” Cristofari said.

But with the polar front drifting southwards as human-driven warms the world, the Crozet Islands could soon become uninhabitable for king penguins.

And that would leave the with only a handful of islands to the south, many of which cannot sustain large breeding colonies.

“We are not worried about the species, the population will not disappear in the next 50 years,” Cristofari said. But their way of life could be seriously disrupted, he said.

‘Playful and curious’

King penguins live for about 25 years and have their first chicks aged about six or seven.

Out of more than a million breeding pairs worldwide, around half breed on the Crozet Islands.

They typically arrive in early November, selecting and mating with the partner with whom they will stay faithful for a year.

The parents share equal responsibilities during the 50-day incubation period and the first month after the chick hatches.

Cristofari said the “playful and curious” birds barge into the gigantic nesting colonies on the islands, carefully waddling with their egg nestled between their feet.

Finding a place among the crowd, the partners take turns using their bellies to warm their precious future offspring, Cristofari said.

The parent not caring for the egg or chick heads out to sea in search of food. Their partner back on land can go a month without eating.

The chicks are well fed until May then fast during the Southern Hemisphere’s winter. The parents come back to feed their offspring occasionally until spring.

“The cycle is timed to make it as easy as possible for the chick to start feeding on its own, ideally during the peak of summer,” Cristofari said.

Then, a full year after hatching, the hungry penguins enter the water to catch their own food for the first time.

© 2022 AFP

They survived the hunters: now king penguins face climate change (2022, December 29)
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