Antarctic sea ice with Marilyn Raphael

In episode 52 of Forecast, Mike and Marilyn Raphael from the University of California at Los Angeles talk about Antarctic sea ice. Arctic sea ice is, on a relative scale, well understood: observations and models show a massive decline. Antarctic sea ice is weirder. Overall, the extent of Antarctic sea ice is increasing, slightly. But this masks nearby areas with both large increases and decreases. Mike and Marilyn discuss the many mechanisms that might be underlying the interesting and somewhat bedeviling trends, as well as the multitude of ways in which Antarctic sea ice interacts with the broader climate system. We wrap up with a personal discussion of what it’s like being an introvert in science, and some ways to navigate the often-draining interpersonal demands.

Marilyn Raphael

The hot world of cold ice with Jérôme Chappellaz

In episode 51 of Forecast, Jérôme Chappellaz regales Mike with all manner ice core tales. The early days of discovering that methane varies hugely between glacial and interglacial states; profligate consumption of ice in the early days; the intensely competitive yet fundamentally friendly nature of the field; the ever-present need to take scientific risks; documentary film making. Spontaneity, chance and inspiration dominate the conversation. Jérôme’s insomnia while in Antarctica leads to the crazy dream of Subglacior, a radical development in ice core technology, and a meeting with royalty leads to funding for the Ice Memory project. Perhaps unique among the geosciences, the ice core community and Jérôme in particular are constantly faced with disappearing/melting records, and the pressing need to create an ice archive for the next generation and whatever hammers will be in their toolbox. Leading to … sequencing the history of the Black Plague from ice cores, maybe?

Credit: CNRS Phototheque

Nerilie Abram

Alternative facts are much in the news. The idea is, of course, ridiculous. Some things are clearly facts. Pizza is delicious; cake makes me happy; serving a white Burgundy at 40 F is an abomination; you should never wear a backpack with a suit.

Much of climate science, however, is not what you would call a hard fact. Yes, we can begin with some facts, following immediately with a suite of questions on quantification and mechanism. Yes, the Greenland Ice Sheet is losing mass. But what is driving the variations in time and space, are there physical limitations to retreat rates, what are the constraints on ice sheets behavior from paleoclimate, what is the role of firn/cryoconite/black carbon?

Research moves to the open questions, which, to some, provides an opening to say that scientists don’t have the facts. For the immediate questions at hand, it is of course true that we don’t have the answers — that’s why there’s research! Let’s not lose track of the vast amount of knowledge, and the big picture facts, that we do have.

Rant over, at least for now!

Nerilie Abram. Credit: Stuart Hay.

Sometimes I don’t fully grasp the scope of what Forecast guests are doing until I have time to reflect, during editing or while writing the show notes. That was certainly the case with today’s guest, Nerilie Abram. Nerilie has astonishingly broad interests. She works with corals, ice cores, speleothems, and modelers on topics all over the world (literally!) from the past to the future.

Much of our discussion centered around the process by which Nerilie cracks open new topics: framing questions, conducting research, challenging her own ideas, and grinding through the review process. Over time, this is the work that ends up in the fact category. It takes, in addition to mad technique, stubbornness:

Science requires, for all sorts of reasons, people who are going to be able to stick it out in this game, to have that kind of determination … not just the skills

Facts are indeed hard to come by, and proxies can be particularly bedeviling, particularly if one takes the time to actually think about them:

When you’re dealing with indirect proxies, things can change that you’re not expecting

The geochemistry behind proxies is hard enough. Interpreting the data with physically meaningful hypotheses, and testing everything with compelling statistics — is even harder. Nerilie is doing all of this, on topics ranging from tropical ocean-atmosphere-coral interactions, Holocene climate, sea ice proxies, and hemispheric reconstructions.

All of which makes me think of Nerilie as the Danny Meyer of science. What, you’re running a restaurant in a museum now? Or in Nerilie’s case, what, you had a quick talk with Nick Shackleton and now you’re off to the British Antarctic Survey? Smashing!

And the field work. Oh yes, the field work. Plenty of people get into geosciences for the amazing field sites. Nerilie never said that she’s in it for the travel, but it couldn’t have hurt.


Music: Alice in Horror Land by Voodoo Puppets CC BY 3.0; Russki Psycho by The Vivisectors CC BY-NC-ND 4.0; Sleepwalkin’ by The Carmines CC BY-NC-SA 4.0.

Josh Willis

Normally my show notes are carefully reasoned, sober discussions of the remarkable pathways forged by inspirational scientists, and their subsequent breakthroughs. Not this time. This time, I will begin with a headline about today’s Forecast victim guest, Josh Willis, that might be suitable for The Onion:


Idiot leftist scientist thrown out of school, concludes that warm water melts ice


Josh Willis

This is all true, from a certain point of view. Josh was called an idiot leftist scientist by Rush Limbaugh (a moniker enthusiastically adopted by Josh and, err, Josh’s wife), had to leave his PhD program in Physics, and is now leading the massive Oceans Melting Greenland program. But a more realistic telling is doubtless in order.

Josh grew up in Texas and completed a bachelor’s degree in Physics at the University of Houston. There, in the honors program, he met his future wife, a California native. The two soon relocated to SoCal, where Josh entered the PhD program in physics at the University of California San Diego and his wife attended medical school in Los Angeles.

Physics, however, was not to be Josh’s calling and he ultimately did not pass the departmental examinations. Although he came out with a master’s degree in physics, the experience was certainly a setback, and one that took Josh a year or two to get over.

Failure, as is so often the case, had an upside. Rather than inducing a downward spiral, the physics experience ultimately proved a huge relief for Josh, and one that led him to a vastly more fulfilling career studying oceanography at Scripps, where he worked with the great Dean Roemmich. There, Josh did some of the early work on coupling satellite altimetry with ocean observations to estimate ocean heat content.

The start of Josh’s PhD coincided almost exactly with one of the most important advances in oceanography, maybe ever: the Argo program. As Josh says

It was super exciting … it was also kind of scary … In retrospect it seems obvious, but at the time, it was almost crazy

The launch of the incredible Argo data stream created nearly new fields of inquiry, particularly into ocean heat content. But as is the case with any new data explosion, particularly when trying to bolt it onto older datasets, problems can emerge. Josh and his colleagues published a paper entitled “Recent cooling of the upper ocean“, but soon found out that the cooling was due to problems in both the earlier XBT data and software problems in a group of North Atlantic Argo floats. A correction soon followed. I completely view this as a positive, rather than negative, example of how climate science actually functions: scientists follow the data, and revise their conclusions based on new information.

Unfortunately, Josh figured out the error upon walking out the door for a Valentine’s day dinner with his wife. Dinner was a disaster, and

As retribution, my wife had business cards made that have my job title as idiot leftist scientist

Josh’s fake business card, kindly made by Josh’s wife after he botched a Valentine’s day dinner.

Now Josh is pursuing one of the main topics in sea level research: the interactions between Greenland’s marine-terminating glaciers and the surrounding ocean. Prior work had revealed some of these interactions in particular fjords, but Josh and his colleagues are now conducting systematic radar surveys of all of Greenland’s outlet glaciers, combined with sensors parachuted into the fjords. The project — Oceans Melting Greenland — is in the data collection phase, and is part of a recent special issue in Oceanography. Once complete, we should have a much better idea of how and where ice-ocean interactions are strongest, and what the implications will be for sea level rise.

Josh has a wicked sense of humor, even in the face of potential impending disaster for federally-funded climate science. Just check out Dick Dangerfield on the video section of the OMG Facebook page. I like episode 1 in particular.


Music: As Colorful As Ever, by Broke For Free. CC BY-NC 3.0.

Amelia Shevenell, big ideas and big risks

Amelia Shevenell from the University of South Florida specializes in big ideas about paleoceanography and the Antarctic Ice Sheet. She’s also keen to push the methodological envelope, which can be risky if things go pear shaped. For Amelia, though, the work resulted in papers in Science (Mg/Ca) and Nature (TEX86). Continue reading →

Rob DeConto and Antarctica in the climate system

I think I first learned of Rob DeConto when I saw his paper entitled Thresholds for Cenozoic bipolar glaciation, published soon after my arrival at Nature.  Specific and testable thresholds for the initiation of large scale glaciation in Antarctica and the Northern Hemisphere? Interesting! Continue reading →

Jerry Mitrovica and geological influences on sea level rise

Jerry Mitrovica from Harvard University sits at the surprisingly wobbly interface between the solid Earth, oceans and ice. Trained in serious geophysics, Jerry quickly found a niche in explaining how movements of the Earth’s mantle – in three dimensions – control the apparent variation of past sea levels. In many cases, this means pointing out that many or all of our records of past sea level are fundamentally altered by processes like dynamic topography and isostatic rebound. Continue reading →

Valérie Masson-Delmotte and the jigsaw puzzle of climate science

For Valérie Masson-Delmotte, climate science is like a jigsaw puzzle. Unlike a house of cards, where the removal of one element causes the whole thing to crash down, the central picture of a puzzle is still apparent when pieces — maybe even many pieces — are missing. Continue reading →

Lauren Andrews on glacial hydrology and field work in Greenland

Lauren Andrews has done some of the most interesting work I’ve seen on subglacial hydrology — as a grad student, and with a degree of independence that would be unusual in most any PhD.

Credit: Joseph MacGregor
Credit: Joseph MacGregor

Lauren grew up in a scientific/agricultural household: her father was a groundwater hydrologist but the family also ran a small farm, with a range of animals. Lauren was active in 4-H, an organization that promotes (among other things) individual responsibility and organization, skills that came into play during Lauren’s time on the Greenland Ice Sheet.

Continue reading →

Robin Bell and the physics of glaciology

Running a small business

Robin Bell and her colleagues found a volcano under the Antarctic Ice Sheet and water freezing onto the bottom of kms-thick ice. She championed the idea that glaciology needed instrumentation capable of observing the full ice sheet — from surface to base — all at the same time. To this end, she bolted ship-based gear on a small plane and … tried it out. And it worked! And continues to work, all in support of the massive question of trying to figure out how the ice sheets will behave in warming world, and what sea levels will be in the coming decades to centuries.

Continue reading →