weather

Polar Vortex, Climate Change, Red Herring?

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Wow, it was unusually cold last week. In a small fraction of the globe. For a couple of days. And what does that cold snap, that big wiggle in the Polar Vortex that carries high-atmospheric winds around the North Pole, imply about “climate change”, also known as “global warming”, also known as “global weirding”?

The answer is very simple. Nothing.

If you heard anyone suggest otherwise — whether they said that the extreme cold implies that there is no global warming going on, or they said that the extreme cold implies that global warming is happening — you should seriously question anything that person says when it comes to climate change. Because that person does not respect (or perhaps even understand) the difference between anecdote and evidence; between weather and climate; between a large fluctuation and a small but long-term trend. Or between media hoopla and science.

In the interest of an imperfect analogy: Let me ask you this. Are you generally happier, or less happy, than you were five years ago? Answer this as best you can.

Now let me ask you another question. Did you, within the last month, have a really, really bad day, or a really, really good one?

Does the answer to the second question have much to do with the answer to the first one?

Barring an exceptional recent disaster in your personal or professional life, the fact that, say, last Thursday your car broke down, you locked yourself out of your house, your dog vomited on the carpet and you got caught in the rain without your umbrella does not have anything to do with whether you are a happier person than you were five years ago. Being a happier person has more to do with whether you have a better job, a happier family, a better sense of self-esteem, and things like that. And even if you love your job, you know there are going to be really bad days in the office sometimes. That’s just the way it goes. We all know that.

It’s the same with daily and monthly and yearly fluctuations in the stock market compared to the slow but fairly steady century-long growth of the U.S. economy (both curves corrected for inflation.)

So why, when there’s a big fluctuation in the daily, monthly or even seasonal weather, do people jump up and down about what the implications are for the long-term trends in climate?

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Happy (Chilly) New Year

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Welcome 2014! And quite a start to the year, with a cold snap that rivals anything we’ve seen in two decades. I don’t remember cold like this since the horrid winter of 1994, when the Northeastern U.S. saw snowstorms and extreme cold that alternated back and forth for weeks. Of course, when I was a child in the 1970s, such chills happened a lot more often; I remember a number of New England mornings where I awoke to a thermometer reading of -20ºFahrenheit (-29ºCelsius) [244 Kelvin].

The scariest negative temperature numbers that one hears about from the media are associated with the “wind chill”, which is a number that is supposed to measure how cold the air “feels” to your skin.  But “wind chill” is a rather subjective and controversial measure — there’s no unique way to define it, since you’ll feel differently depending on how much exposed skin you have, on your body weight, on your age and conditioning, etc.  By contrast, the temperature measured by a thermometer is defined independent of how humans feel, and experts agree on what it is and means. Oh sure, people use different scales to measure it: Fahrenheit (F), Centigrade or Celsius (C), and Kelvin (K).  But the differences are no more than the distinction between meters and feet, or between kilograms and pounds; it’s straightforward, if a bit annoying, to convert from one to the other.

So everyone agrees the temperature is and feels extremely cold, But is it, from the point of nature, really that much colder than usual? To say it another way: it was 84ºF (29ºC) in southern Florida yesterday.  How much warmer is that than the -40ºF (-40ºC) that was registered in the cold Minnesota morning?

Well, you might first think: wow, it’s a difference of 124ºF (69ºC), which sounds like a huge difference.  But is it really so huge?

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Change of Climate on the Right

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There is no room for politics when we are playing for keeps. So say four Republicans, who served four Republican presidents as heads of the Evironmental Protection Agency.  The climate is changing in Washington D.C., though still more slowly than in the Arctic. My own view? Our uncontrolled experiments on our one and only planet … Read more

A Few Items of Interest

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I was sent or came across a few interesting links that relate to things covered on this blog and/or of general scientific interest. It was announced yesterday that the European Physical Society 2013 High Energy Physics Prize was awarded to the collaboration of experimental physicists that operate the ATLAS and CMS experiments that discovered a … Read more

European Weather Model Does It Again?

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We’re gearing up for another big-time storm predicted for the northeastern United States — we’ve had more than we need over recent months — so before we perhaps lose power (or you do)… …I want to remind you that Sean Carroll and I were interviewed last night by science writer Alan Boyle.  My impression is … Read more

Another Storm Predicted

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The greater New York region, having been broken into disconnected and damaged pieces by Hurricane/Nor’Easter Sandy, is still reassembling itself.  Every day sees improvements to electrical grids and mass transit and delivery of goods, though there have been many hard lessons about insufficient preparations.  Here’s an impressive challenge: over a million people and thousands of businesses lack electrical power; therefore many of them are running generators, to stay warm, keep food cold, and so forth; but the generators require fuel, typically diesel or gasoline; and so there is a greater need for fuel than usual; but a significant fraction of the petrol stations can’t pump fuel for their customers… because they lack electrical power and don’t have their own generators. These and other nasty surprises of post-storm recovery should be widely noted by policy makers and the public everywhere, especially in places that, like New York when I was a child, rarely experience disasters.

Unfortunately, another storm (a simple nor’easter) is now forecast for mid-week. While much weaker than the last, it is potentially still a dangerous situation for a region whose defenses are still being repaired.  As was the case with Sandy, the new storm was already signaled a week in advance by the ECMWF (European Center for Medium-range Weather Forecasting), the current European weather-forecasting computer program or “model”.  Confidence in the prediction has been growing, but still, predictions so far in advance do change.  Also one must keep in mind that a shift in the storm’s track of one or two hundred miles or so could very much change its impact, so the consequences of this storm, even if it occurs, are still very uncertain.  But again we are reminded, as we were last week, that weather forecasting has dramatically improved compared to thirty years ago; the possibility of a significant storm can now often be noted a week in advance.

What is this European ECMWF model? what is its competitor, the US-based GFS (Global Forecast System) model? And what about the other models that also get used?   All of these are computer programs for forecasting the weather; all of them use the same basic weather data as their starting point, and all have the same basic physics of weather built into their computer programs.  So what makes them different, and more or less reliable than one another?  I asked one of my commenters, Dan D., about this after my last post.  Here’s what he said, along with my best (and hopefully accurate) attempts at translation for less experienced readers:

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Sandy: Amazing. Science: Amazing.

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My neighborhood of New York City may remain without power for a few more days, but fortunately visible signs of damage are limited — none of the widespread destruction found along the immediate coast of the city and of nearby communities, where the sea rose and swallowed up land that had not seen salt water in many decades, even centuries.  Many trees are down, and countless houses and businesses are wiped out by the sea’s wrath, even entire beach communities. The numbers of lost homes are surely in the thousands, if not more, with 100 houses alone destroyed in a runaway fire in the neighborhood of Breezy Point, cut off from firefighters by the storm’s high water.

Unfortunately, many people along the coast, lulled into complacency by the fact that last year’s Tropical Storm (formerly Hurricane) Irene was a bit less furious along the coast than was forecast, decided not to evacuate. Unfortunately indeed, because the forecast for Hurricane Sandy was worse than for Irene, and this time, there was no lucky break to make the reality of the storm significantly less severe than the worst-case prediction.  I myself know of households who decided to evacuate at the last minute and almost didn’t make it out alive, and others who rode out the storm and found themselves in considerable danger. That so many people remained in harm’s way required “first responders”, as they are termed here, mainly members of the police and fire departments, to make many rescues, quite a few of which wouldn’t have been necessary had people heeded the warnings. For risking their lives to save so many others, the first responders are widely and justifiably hailed as heroes.

Also deserving of high praise, in my view, are some of the leading politicians and other civic leaders in our region’s states and cities.  There are quite of few of them whom I don’t agree with politically and whom I personally don’t like very much, but on the whole they all seem very smart.   And in this case they understood the risks, took them seriously, and made prudent decisions to order evacuations of areas in danger and to protect public property.  They deserve a lot of credit for their non-nonsense approach.

But I feel that there’s an important story that the press is almost ignoring.  There’s another group of people, little-mentioned in the media, who probably saved more lives and property than anyone else.  I refer to the experts at the National Hurricane Center (NHC), and more generally the various branches of the National Weather Service (NWS) and its parent, the National Oceanic and Atmospheric Administration (NOAA).

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Guest Post: Anand Gnanadesikan, Oceanographer

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I know Anand Gnanadesikan, professor at Johns Hopkins University’s department of Earth and Planetary Sciences, from when we were both studying physics as undergraduates in college.  He wrote something today that speaks with more authority than I could in my post earlier this morning, and it is a pleasure to make it available to you. … Read more

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