Paleo trash and unfrozen cavemen

Temperatures in NYC have finally risen persistently above freezing, and the ice and snow are starting to melt. In NYC one of the consequences of this is that all the garbage that was buried by the snow comes to the surface. The streets haven’t really been cleaned in weeks to months, and they are a mess.

It reminds me a bit of other things revealed by melting ice. Like Captain America in the movie… or, ok, if we want to be more real life-based, like Oetzi, the “iceman”, found in 1991 in the Alps between Austria and Italy. He was frozen 5000 years ago, and then unfrozen as the glacier he was in melted due to whatever combination of natural climate variability and anthropogenic warming.

So now today, we have scenes like this:

paleo trash march 2015

A little less scientifically important than Oetzi, but still, recent history (of a New York City sidewalk) preserved in ice and then revealed.

Of course, the most important artistic comment on this particular phenomenon is this.

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Two talks

I am giving two talks tomorrow. Both are big deals, by my humble standards. Either one alone would be enough to make me a little nervous. But excited.

In the morning, I’m speaking in TEDx Broadway 2015. I’m going to talk about climate change. Why talk about climate change in a conference about the future of Broadway, in which most of the other speakers are connected to the theater industry in some way? Well, Broadway is on planet earth too… beyond that, if you’re not going to the event, you’ll have to wait til the video shows up on the internet.

In the evening, I’m speaking at Columbia, in the Low Rotunda under the big dome, in an event that is part of the President’s World Leaders Forum series, to launch our new Initiative on Extreme Weather and Climate. We have an outstanding panel of four speakers who will be talking about what we have learned in the two and a half (almost) years since Sandy – about how to make the City more resilient to extreme weather; about how science, government and industry can work together; about what lessons the rest of the world can learn from NYC’s experience and vice versa, and so on. I’m the moderator of the panel.

Before the panel discussion starts, I’ll speak for a few minutes about what the Initiative is and what its goals are. If you can’t make it (it’s open to the CU community, but registration is required and I believe there is a wait list by now), you can go to the web page which we will have up by the time of the event, at extremeweather.columbia.edu, to learn about the Initiative. You can also follow @CUextremewx on twitter.

For now, I’m polishing my talks. And I got a haircut.

Blizzard of 2015 post-mortem media blitz

We had a huge snowstorm in the northeast US over the last couple of days. Here in New York City, it was not so huge as was forecast, leading to a lot of discussion in the media (social, traditional, and other) about what went wrong and right.

I have an op-ed in CNN summarizing my take on it. I don’t have a lot to add to that, except to say that if I could write it again there is one sentence I would change: “Being over-prepared, in contrast, merely leads to lots of griping on the Internet.” That’s a little too cavalier; there are real economic costs from all the transit shutdowns. I stand by everything else in the piece, including the overall message that those costs (which are not too huge according to the NY Times today) are a price worth paying for the benefits gained overall from forecasting and proactive emergency management.

I am quoted in stories in the Times, Mashable, and Climate Central saying similar things. Of the many many other interesting pieces on this event, Eric Holthaus’ piece in Slate gives a good inside view into how the Weather Channel arrived at a prediction of low snow numbers for NYC when the Weather Service was still going high, and Dennis Merserau’s piece in Gawker gives some good perspective.

While I think most thoughtful people understand that the proactive stance of the local & state governments was the right one overall, one specific question that seems legitimate is whether the subways really needed to close. They had never closed for snow before, and even in the moment it wasn’t obvious that it was necessary, even assuming the snow totals were going to be as high as forecast. This piece makes it seem as though it was Cuomo’s own – bad – decision, totally imposed by him on the MTA with no input from them, but the front page story in the NY Times today reports that the MTA head recommended it. This is one where I would like to understand the details bit better.

Slush is life

Last night into this morning we had a little winter storm pass through. The precipitation forecast was tricky. Here in New York City we were, as we often are in winter, very close to the rain-snow line. In the end, we got maybe a couple inches of snow, plus some rain. Walking around today was messy business, with big sloppy puddles and lots of slush. Here’s a photo from my window down onto the street:

slush_jan_24_2015

Many people don’t like this kind of weather. Many people would rather it were a little colder, so that we’d have nothing but clean white snow. (Of course in NYC it is only ever clean and white for a very short while, but never mind.) I get that. But actually, I like the slush.

Before saying anything else I have to admit that I don’t particularly like cold weather, period. I have mediocre circulation in my hands and feet. I get cold. I can enjoy some winter sports, but put me on the nicest ski slope around and then offer me the chance to be instantly transported somewhere warm and I’ll never say no. I grew up here and have lived here most of my life, but apparently I’m still not adjusted to the climate. I still find every winter a little harsh. And I know, a New York City winter is nothing compared to a lot of places.

Maybe that’s why I ended up working on tropical meteorology – thinking warm thoughts is part of my job. (And yes, occasionally I get to go to a conference or a field campaign in a tropical place when it’s winter here.)

So my appreciation for slush is partly about realizing that it could be even colder than it is. But it’s a little more than that. Slush tells us, in the most visceral way possible as it soaks through our shoes, how special a planet we live on. We can have slush only when the temperature is right near the freezing point of water, at which water can coexist in all three of its phases: solid, liquid, vapor.

A planet which has liquid water can support life. As scientists try to figure out if there’s life on Mars, looking for evidence of liquid water there seems to be most of the ballgame. And it’s only in a pretty narrow temperature range – compared to the range of possible planetary climates – that liquid water can exist; too cold and it all freezes (Mars, at least now), too warm and it all evaporates (Venus).

While we may need liquid water to support life, we don’t need ice. But the ice helps us appreciate the liquid. It shows us just how close we are to the edge. When it’s slushy, we can feel the transition between a frozen climate that is fundamentally inhospitable to life (sorry, Canadians, Midwesterners, Russians etc.) and one that isn’t. When I’ve been on a winter car trip to somewhere really cold and snowy, and I’m returning back to somewhere warmer, I always feel something magical at that slushy boundary in between.

On some days, we live right on that boundary. This was one of those days, in a particularly complete and interesting way. Let’s look at some data.

The picture below shows the local sounding — set of upper air measurements taken by weather balloon, plotted vs. height — from our National Weather Service station in Upton, New York (Long Island) from 7 AM local time this morning.

skew_KOKX_012415

This is a “skew-T log-p diagram”. If you don’t know how to read one of these, I’m going to teach you what you need to know for today. It shows all the variables (temperature, humidity, wind) the balloon measured as functions of height, which is on the vertical axis just as you think it would be (see the white numbers just to the right of the vertical axis on the left, which give the height in meters; the blue letters to the left give the pressure, in hectoPascals). The higher you are on the plot, the higher the balloon was.

The two white lines are the temperature and dew point temperature. If they are on top of each other — as they are below about 5000 m (~3 miles up) — that means the atmosphere is saturated, relative humidity = 100%. Not a big surprise, as precipitation was falling when this balloon was flying.

More interesting is the temperature itself. The reason this is called a “skew-T” plot is that the axes are not at right angles — temperature is not on the horizontal axis, but rather on a tilted axis. The blue lines angling up to the right are lines of constant temperature, or isotherms. You can tell the temperature (in Celsius) of each one by the blue number where it hits the bottom. So a vertical line, for example, would mean the balloon is getting colder as it goes up, as it would be crossing blue lines with lower temperatures. In most soundings, from nearly everywhere on earth, the atmosphere does get colder with altitude, with only a few exceptions. (The word “inversion” is used to describe a layer where temperature increases with height; the word itself tells you right away that it’s an exception to a rule.)

Our balloon’s temperature trace, though, tracks right along one of the blue lines in a layer between about 1000 and 2500 m (or between 900 and 750 hPa, if you like). That means that in that layer, temperature was not decreasing with altitude, but staying the same – it was an isothermal layer. And not at any old temperature – the blue line is the one with a zero below it where it hits the bottom of the plot. That means that a roughly mile-thick slab of atmosphere was almost exactly at freezing.

Why would that happen? Most likely the layer started out somewhere in the vicinity of zero C, but with more variation — part of the layer was colder, part warmer. Then precipitation (ice, liquid, or more likely some combination) started falling through it, and freezing and melting. Freezing liquid warms the air by the latent heat of fusion, while melting ice cools it for the same reason. So layers colder than zero would be warmed by freezing rain, while warmer layers would be cooled by melting snow or sleet. This would bring the temperature everywhere towards zero.

Just above the surface, the sounding shows an inversion layer, where temperature increases with height, so any frozen precip had a little more chance to melt before hitting the surface – which was, itself, exactly at zero C, about to become the perfect environment for slush as sunrise warmed it a bit above that temperature.

In other words, not just the ground, but the atmosphere itself was slushy. Organically, perfectly so.

And tonight, the temperature will drop, and we’ll have black ice. I don’t think I’ll be able to write such a happy meditation on that.

Climate Services: Two conferences on two continents

I spent this past week in Darmstadt, Germany, for the Climate Symposium. This was a conference organized by EUMETSAT (one of the European space agencies) and the World Climate Research Program.

The conference had a couple of goals. Perhaps most prominent was to “ascertain critical objectives to be achieved with satellite-based climate information, and identify gaps in the current space-based component of the climate observing system” – in other words, help EUMETSAT decide what new satellite instruments to build and launch in the coming years. The idea here was to present the current state and future needs of climate science in order to determine how new satellite observations could help. The climate science was presented through the lens of WCRP’s new Grand Challenges. (I am involved directly in one of these, on Clouds, Circulation and Climate Sensitivity, and interacting with the leaders of another, on Understanding and Predicting Weather and Climate Extremes.)

Climate science justifies its funding largely on the basis of its benefit (real or potential) to society, and that justification was particularly explicit at this conference. A lot of the program was devoted to “Climate Services”. This term refers to entities and people whose jobs lie in between the physical science of climate and “users” of climate information, also known as “stakeholders”. Climate Services involves translating the information that climate science can provide into terms that will be most useful for specific human purposes. (In the US, NOAA tried a few years ago – at the instruction of President Obama – to create a National Climate Service, with a status analogous to the National Weather Service. Congress, much of which hates even the word “climate”, killed it.) In practice, Climate Services is about taking the time to learn what specific users’ needs are, teaching those users what climate information current science can and can’t provide, and packaging the information to make it easier for them to digest.

Most of what I know about Climate Services comes from the International Research Institute for Climate and Society (IRI) at Columbia, which has been providing climate services since well before I (or most other people) ever heard the term. I was initially hired at Columbia through the IRI, which came into being a couple of years before I arrived here in January 2000. The IRI, in turn, exists because of the work of Mark Cane.

In the 1980s, Mark and his then student Steve Zebiak (later to become a founding member, and then director of IRI) developed the first numerical model that was capable of predicting the El Niño/Southern Oscillation (ENSO) phenomenon. They demonstrated this by making a successful prediction of the 1986/87 event.

While ENSO occurs in the equatorial Pacific, it has influences on climate and weather across much of the earth. An El Niño, for example, typically causes drought in Australia, Indonesia, southern Africa, and northeast Brazil, wet weather in southern California and unusually clear weather in the Pacific Northwest, and fewer hurricanes in the Atlantic, among other changes. Cane and Zebiak realized that the forecast capability they had developed had the potential to make a positive difference to the lives of a substantial fraction of the planet’s population. By knowing something about how the upcoming season or two would be likely to differ from the usual, people and governments could plan ahead across many sectors of activity: agriculture, water, health.

The IRI was created to realize that potential, and has been working with countries around the world for over 15 years to that end. While the notion of Climate Services now is as much about long-term anthropogenic climate change as it is about interannual variability (a la ENSO), ENSO and the IRI were at the start of it as much as anything, and are still a critically important component.

Tomorrow – Monday October 20 – we will start The Tropics Rule, a Symposium Honoring Mark Cane’s Contribution to Climate Science. This will be a two-day event on the occasion of Mark’s 70th birthday, featuring a long list of distinguished scientists presenting new research and historical reflections on Mark’s long career of truly amazing scientific achievements. It will take place in Monell Auditorium, the physical home of the IRI, on the Lamont Campus.

So in summary, I got on a plane to fly to Germany for a conference where I heard about the present and future of Climate Services. Then I got back on a plane to fly home to attend another conference at my own institution, in honor of the scientist who, it is not a great exaggeration to say, invented the idea.

The size of it

What a day yesterday.

adam march photo

The organizers are saying 400,000 people. That is an astonishing number, but it did seem an endless throng. It didn’t move at all for the first couple of hours; we were wondering what was going on. Afterwards, I read somewhere that people filled the entire 4-mile length of the route, so some had to finish before others could start.

A friend who didn’t march said right after that she had thought she wouldn’t fit in because it was all “climate scientists and ex-hippies”. I said that wasn’t what I had seen. Ok, there were a few of both for sure, but you don’t get to 400K with just those factions. Most of the crowd looked pretty civilian to me.

I read a quote from someone today (can’t remember who now, nor find it) to the effect that this was the biggest political demonstration about anything in the USA in a very long time. True, no doubt; what came closest? Can’t have been anything more recent than the last Iraq war, if that. Certainly, I can remember no show of feet like this in my adult lifetime on any “environmental issue”, let alone climate.

The mass of the thing was profoundly heartening, because ignorance and denial still loom so large on this issue in this country, and nothing else seems able make a dent in the hard core of it. We know that facts from the mouths of scientists (or anyone) are not going to cut any ice with those who get their information from Fox News or the Wall Street Journal op-ed page – which unfortunately includes about half of Congress – because if they could, they would have by now. The only thing that will matter is sheer force of numbers. We showed that we had that.

On a much smaller scale, I carried an intentionally nerdy and obscure sign (thanks for the idea Michela) to create teachable moments. Indeed maybe half a dozen people asked me what it meant, allowing me to explain the mechanics of carbon emissions scenarios and IPCC assessments to interested citizens. Here’s a photo of me explaining it to one of New York’s finest:

nypd

We ended the day exhausted but happy. It was a privilege and a great thrill to have been able to march. We made the kids come, figuring that someday they’d appreciate  having been there. In the event, they seemed to appreciate it right then. There’s hope yet.