SOMETHING NEW TO WORRY ABOUT--QUASI-RESONANT AMPLIFICATION

Picture a river flowing down from the mountains to the plains. In the high country, where the river's descent is steep and hedged in by canyon walls, it's likely to follow a relatively straight path, basically tracing the shortest route down. Once it gets to the plains, however, there's no big difference between one path and another, and the river will begin to meander.

 Meandering river

Credit: Alana Whitman

Something similar is true for the jet streams, vast rivers of air that circle the globe from west to east, sometimes reaching speeds of 250 miles per hour. Like rivers, jet streams typically meander north and south. The size of those meanders and the speed with which they gradually drift eastward have major impacts on the weather. The UK, for example, was deluged by record floods in 2007 and again in 2012 when the jet stream looped far to the south and then stalled, unleashing extended periods of heavy rains.

Meandering polar jet stream

Credit: NASA/Goddard Space Flight Center 

That, in turn, gets us to climate change and quasi-resonant amplification (QRA). 

One of the most dramatic impacts of global warming and climate change is that the far north and south are warming much faster than the mid-latitudes and the tropics, a phenomenon known as polar amplification. What this means is that the temperature difference between the poles and the tropics-- which is what creates and drives the jet streams--is reduced. And like a river crossing a plain, this reduced gradient lets the jet stream meander farther north and south, and also tends to make the individual loops, known as Rossby waves, drift more slowly from west to east.

At the extreme, the meanders in the jet stream can form a stable sequence of exaggerated loops around the planet that can stay in place for weeks or months. This is known as quasi-resonant amplification  (QRA) and its results can be devastating. Warm, sunny days can extend into deadly heat waves, droughts and wildfires; while cool, rainy weather can linger, drenching an unlucky region with unprecedented rains and floods.

Michael Mann, a distinguished professor of atmospheric science and Pennsylvania State University, says that as of 2018 this phenomenon has now passed from the theoretical to the all-too-real and threatening. "It played out in real time on our television screens and newspaper headlines in the form of an unprecedented hemisphere-wide pattern of extreme floods, droughts, heatwaves and wildfires," he says.

Unfortunately, Mann adds, climate models indicate that such QRA-caused weather extremes will grow more frequent and more severe unless we get a handle on global warming. Recent research reinforces the link between reduced Arctic sea ice and the meandering jet stream, along with equally dire predictions. We can hope that humanity (and the politicians and corporations who hold the reins) will get their act together. In the meantime, however, we can all expect more QRAs and the devastating weather extremes they bring coming to a region near us.

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You can read an earlier post on this subject here.

For more detail on arctic warming and its impacts on our weather click here.

And for a new study that shows that these destructive "blocking events" will cover greater areas as the world heats up, navigate to this URL.

(As-yet unpublished research shows that these stalled atmospheric waves have the potential to cut crop production across much of the northern hemisphere.)

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WHEN CATASTROPHE COMES HOME

I live in Santa Rosa, California. As you know, Santa Rosa, along with many other parts of California, is still reeling from the impact of raging wildfires.

A barn goes up in flames in Glen Ellen, California

Credit: Justin Sullivan/Getty Images

My wife and I are lucky--our house happens to be located a mile or two from where the firestorm stopped. We've spent several sleepless nights, bags packed and in our car, monitoring whether or not we would need to flee. But other than that, we have not been directly impacted by the fires.

Many people were not so lucky. This morning's paper lists 50,000 residents of our county--that's one out of every ten--under evacuation orders, 35 confirmed deaths, 235 people still missing, 5700 homes and businesses destroyed, and more than $1.2 billion in economic damage in Santa Rosa alone. Many of our friends and people we know have lost their homes, businesses or jobs.

We're all-too-used to reading about or seeing images of catastrophes somewhere else--floods in Bangladesh, drought in Australia, hurricanes battering Puerto Rico, the earthquake and tsunami in Japan. Perhaps we've been moved to a moment's empathy or pity, perhaps we make a donation to some aid agency, or perhaps we just shake our heads and move on.

It's different when it's here rather than there, in our home town rather than someone else's, harming our family or friends rather than strangers.

Our natural disaster, our catastrophe has brought several realizations home to me:

--It can happen here. None of us is immune. Here in Santa Rosa, it wasn't just the Journey's End mobile home park that was destroyed, it was also the middle-class Coffey Park neighborhood and the idyllic Fountaingrove neighborhood, home to many doctors, lawyers and other well-off citizens. Like the residents of Journey's End and Coffey Park, the residents of Fountaingrove had to desert their homes with little or no warning in the middle of the night as the unexpected firestorm blasted through, driven by 70 miles-per-hour winds. Some, many of them elderly or disabled, simply could not get out in time.

--It's real, and it hurts.  It's one thing to see struggling people on TV. It's very different when it's you spending hours hosing down your house and yard while hot embers fall from the sky, when it's you trying to decide what necessities to throw into the car, looking around your house wondering if you'll see it again, or you helping a desperate friend rescue a few precious things before the fire strikes again. It's different when the store you shopped in yesterday is gone today and the neighborhood you've visited a hundred times is a blackened wasteland.

--Ordinary, daily life is precious. It's trite to repeat that "you don't really know what you've got 'till it's gone," but it's also a profound truth. We may all strive to do or experience something extraordinary, have a peak experience, change the world, but in the end what's truly valuable is the everyday life of everyday people. When that's disrupted or lost, you suddenly realizes how precious it was.

We've experienced just one corner of one natural disaster. The dozens who have died, the thousands who've been displaced, represent just a tiny fraction of the estimated 65 million displaced persons and refugees in the world today. But even that enormous number pales in comparison to the number of people--people just like you and me--who are at risk from two existential threats--climate disruption and nuclear war.

I'm not going to argue the reality of either threat. I'll only point out that common sense should tell us that the number and intensity of the extreme climatic events that we're experiencing is far from normal, and that further destabilization of the climate could threaten any or all of us. And a moment's thought should be more than enough to remind us that even a "limited nuclear exchange" could result in misery or death for hundreds of millions of people.

The limited, local disaster I'm living through has brought home to me the preciousness--and fragility--of each of our lives. Multiplying the losses experienced here by millions is no longer unthinkable, but it is unacceptable.

I've been extremely impressed by the local leaders who have come to the fore in this disaster--the local and state fire officials, the sheriff and police officers, mayors and other elected officials. They have all been clear, direct, factual, and focused on responding to and resolving the crisis, step by step. Their efforts to protect lives, contain the fires, begin to bring them under control and now, line up the resources needed to rebuild, seem to be well coordinated and, as more resources have been marshaled, increasingly effective. I've been similarly impressed by how ordinary people have responded--rescuing and helping others, giving time, goods and money to help people who've had to evacuate or who have lost their homes, and showing great dignity and resilience in the face of disaster.

Unfortunately, the contrast with how our national leaders are dealing with the existential threats of climate disruption and nuclear war could not be greater. In both cases, actions by President Trump, his advisers and appointees, and Congress are making things worse rather than  better. Pulling the United States out of the Paris Climate Agreement is just the most blatant of the many steps Trump has taken to reverse global progress on the climate. And undermining the nuclear accord with Iran, and the belly-thumping battle between Trump and Korea's leader, Kim Jong-un are dramatically increasing the risk of a nuclear war.

The point of this commentary is to remind everyone that when it comes to the global risks from climate disruption or nuclear war, there is actually here, and they are actually us. People here in Santa Rosa took action as the flames approached, and most were able to save their lives and those of their loved ones. Government officials and agencies took coordinated action to limit the scope of the disaster. People at all levels did what what needed. We need our nation's leaders to act equally well.

We all need to take action now with respect to the threats of runaway climate change and nuclear war. Now, with every tool at our disposal, because when those fires come roaring out of the skies, it will simply be too late.

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