This is a public service column to reassure readers that the basic laws of physics are still working even if most other laws don’t seem to be. It starts and ends in Greenland. Any warm feelings engendered for snow should be regarded as seasonal and timely rather than contrived.
Three months ago a late summer blizzard dumped ten billion tonnes of snow on a relatively small area of coastal south-eastern Greenland. This was notable for at least three reasons, first among them that even this far north, snow is rare at sea level early in September. It’s supposed to be the end of the melting season.
Secondly, the snow was delivered by a hurricane. Hurricanes are essentially low latitude creatures, created by sun-warmed surface waters in the tropics and sub-tropics and generally exhausted by the time they’ve beaten up the Caribbean and the US mid-Atlantic seaboard. This one – Larry – was different, still strong enough to hold aloft ten cubic kilometers of water as it churned north-east past New England, Nova Scotia, Newfoundland and Labrador; still full of puff as it headed out over the ocean towards Narsarsuaq on Greenland’s southwestern tip, legendary wartime staging post on the Atlantic air bridge to Scotland; still on a mission as it followed the ocean currents round the bottom of the island and up its lonely eastern shore towards a scattering of red wood homes and storehouses called Tasiilaq.
There or thereabouts, Hurricane Larry moved inland and let the mountains take its moisture. Through the simple miracle of orographic uplift (a rising air mass cools), it turned to snow.
The third reason this snow was noteworthy was the contrast it provided with rain. The previous month it had been raining on Greenland at 10,000 feet. That is, it had been raining on the highest point of the ice sheet (for the first time in recorded history) a few short weeks before it was snowing on the coast.
For most people the rain was the story, and for good reason. Rain at the top of Greenland is a disaster. It melts the ice where the ice should be coldest. It turns the ice darker so it absorbs more light and melts some more. It opens up rivers and melt-ponds on what used to be a pristine, reflective shield foro two vertical miles of glacier. It’s a symptom and a harbinger of warming – especially in the Arctic Ocean, where most of the moisture for the rain came from. A widely-reported study last month by the University of Manitoba forecast more rain than snow in the Arctic as soon as 2060.
If you’re fond of snow and hear stuff like that you start clutching at straws. You lunge for anything that brings you comfort. I lunged for Larry, partly as scientific evidence; partly as a waypoint in a personal quest.
Hurricane Larry was evidence of the Clausius-Clapeyron equation in action. The equation is named for Rudolf Clausius, a German physicist, and Benoit Clapeyron, a French railway engineer, who between them established in the early 19th Century that as air warms over oceans it gets wetter. Specifically, they worked out that for every degree sea surface temperatures rise, the water content in the air above goes up by 7 per cent. That means there are at least 500 cubic kilometers more water in the atmosphere now than in the 1970s, quite apart from the effects of one-off events like Larry.
As for the quest, it’s based on the paradox that as long as temperatures still dip below freezing somewhere in the world, a warming climate should mean heavier snowstorms – increasingly rare but unbelievably intense when they occur – before they surrender to rain for eternity. The goal of the quest is to identify and if possible observe the biggest blizzard ever.
I used to think the heaviest snowfall since the ice age occurred unwitnessed by humans more than 5000 metres up the Pico Cristobal Colón in northern Colombia. Here, on the slopes of a giant and relatively isolated volcano, altitude provides refrigeration and the extreme proximity of the Caribbean means the Clausius-Clapeyron effect is working overtime.
Then a scientist who knew better suggested the Tyndall Glacier in southern Patagonia. This is one of the few places in the world where it almost never stops snowing, and a Japanese expedition dug up evidence of record-breaking snowfall there in an ice core in 1999. But all that was before climate change started sending hurricanes to Greenland. Could the Greenland snowstorm of September 2021 have been the strongest ever?
Remote sensing with the help of satellites and mass spectronomy tells us it definitely packed a punch. “The remnants of Larry did indeed increase the mass of the Greenland ice sheet,” says Nasa’s Dr Lauren Andrews, “but not nearly enough to offset the total summer melt.”
In the year to August, scientists recorded a net loss of ice sheet mass of 170 billion tonnes – which is a lot, but a lot less than the current average of 280 billion tonnes a year. All in all it was a big year for snow. So even though the macro trends are in the wrong direction, for sheer spectacular blizzardry the fjordlands of southeastern Greenland may be the new place to go.
Maybe. I phoned the only number I could find in Tasiilaq – for the hospital. My knowledge of inuit dialects is shamefully lacking. Ditto my Danish, and none of the first three people to whom the phone was passed spoke English. Eventually a doctor offered to try to find out more about the storm, but gave no sign of remembering it. That could mean one of two things: either massive blizzards are so routine in Tasiilaq that no one bothers distinguishing between them, or the reports of a stonker in September – all filed from thousands of miles away – were wrong.
So the quest goes on. In the meantime here’s a forecast for 2022: it will rain again on Greenland, but it’ll snow too.