Category Archives: Marshall Islands

Research Poster

If you want a not-too-technical introduction to the current state of my research, check this out.

I made this poster for an event at Boston College tomorrow. The goal: introduce freshmen in an introductory climate class to an area of active climate research (and recruit interested students for our lab).  I swapped the jargon/technical details for field photos. After all, scuba pictures capture students’ attention in a way no graph can!

PDF research overview

Raindrops keep falling on my head

Tropical cloud-watching never gets old.  Near the equator, the warm ocean generates a ton of fuel for cloud growth.  Over the course of a few hours, you can watch a small cloud grow into a tower tens of thousands of feet tall.  If you look at satellite images of the Pacific, you’ll often see a band of these clouds just north of the Equator.  That band is called the Intertropical Convergence Zone (ITCZ), which I’ve discussed before, and is the pillar of global atmospheric circulation.

Rainbow in the Marshall Islands
A developing storm brings a rainbow to the Marshall Islands. (photo by Diane Thompson)

The seasonal movement of the ITCZ over the Marshalls provides the country’s drinking water.  Needless to say, it’s pretty important; when it’s too far from the Marshalls, wells and catchments run dry.  However, it’s hard to simulate the ITCZ accurately in climate models, which makes its future behavior difficult to predict.  As a first step, though, we can look at how its location and strength has changed in the past.

Unfortunately, I haven’t found many good visualizations of the ITCZ through time, so I made my own.  This video shows monthly precipitation from 1979 through 2016, from NOAA’s Global Precipitation Climatology Project (GPCP).

Brief rant: Mapping the Pacific is hell.  Most files and programs pretend that the world ends at the International Date Line, which runs smack-dab down the middle of the Pacific.  So, when I tried to map the Pacific Islands, everything beyond the date line simply didn’t exist, and it took nearly a week to fix it.  The result, though, is worth it, because I can finally generate plots that show the outlines of the oft-ignored Pacific Islands and reefs!

What climate patterns can we identify here?

Continue reading Raindrops keep falling on my head

Visualizing Sea Level Rise in the Marshall Islands

A best-case scenario for sea level rise over the next ~100 years.
An optimistic scenario for sea level rise over the next ~100 years (pen & ink, colored in GIMP because Photoshop ain’t cheap).

In the past few weeks, I’ve been reading this book on climate change and tradition in the Marshall Islands, and it’s yielded some interesting quotes on how the Marshallese perceive sea level rise.

For example, when asked what would happen if the Marshall Islands are submerged, one resident had a simple solution:


It’s a funny answer, but it masks the nervous uncertainty that many Marshallese people share about their future.  In the coming decades, the rate of sea level rise will depend on how aggressively we mitigate our carbon emissions, so estimates of future sea level rise can vary.  Some Marshallese imagine a future in which the ocean engulfs the tops of their palm trees.  That’s a bit extreme: most estimates put sea level rise between 0.6 and 1 meter by 2100.

At the other extreme, there’s a widespread misconception (debunked here and in my animation here) that sea level rise isn’t accelerating, or, wronger still, that it isn’t rising at all.

These misconceptions led me to dig through the tide gauge records on Kwajalein Atoll, available here:

Monthly mean sea level for Kwajalein Atoll in the Marshall Islands.  Between 1946 and 2015, sea level rose by 2.2 mm/yr (±0.82 mm/yr), but that rate is accelerating.

Some observations: 1) Sea level is rising.  2) There are sudden but temporary dips in sea level, in 1983 and 1997 for example.  These drops in sea level match El Niño events.  For the same reason, sea level dropped in 2015, but has since risen back up to pre-El Niño levels.

Sea level rise will continue to accelerate in the next century, reaching ~0.4 meters by 2100 (compared to 1986-2005) in the very best case, but more likely between 0.6 and 1 m.

Is that enough to put the Marshall Islands under water?

Continue reading Visualizing Sea Level Rise in the Marshall Islands

Sea Life

On Tuesday, June 28, we surveyed sites along the southern coast of Arno.  Apparently it’s a good place to spot marine life.  Even though dolphins have been chasing our boat every day, Tuesday was truly exceptional.  A pilot whale started following us, and I was able to snag some video (thanks to Diane for posting it!):

Continue reading Sea Life

Beneath the waves of Arno

Diane and I went to the Marshall Islands with the goal of locating corals that would make good candidates for climate records.  At Arno, this involved three dives per day for five days.  That’s a lot of time underwater, especially since each dive was roughly an hour long.  Though Diane was unfortunately unable to dive with us until the last day, I was lucky enough to dive with Kalena de Brum, who works for the Marshall Islands Marine Resources Authority, instead.  She has a sharp eye for hidden wonders underwater!

Simon and Sara identify, measure, and photograph corals along a transect at each site.  Kalena and I swim in the general area of each transect, scouting for corals.  We’re looking for corals of the genus Porites, which you might know as lobe coral.  The ideal Porites for sampling is a solid, tall mound, without any bore holes from clams or worms.

Good Porites, as it turns out, are really hard to find.  When we spot one, I note its size, depth, and condition, and my dive buddy takes pictures.

Assessing the size and health of a Porites coral. (Photo by Kalena de Brum)

Continue reading Beneath the waves of Arno

Exploring the mysterious island: field work in the Marshall Islands

I was (and am) an unabashed science fiction fan.  As a kid, one of my favorite books was Jules Verne’s The Mysterious Island, which tells the tale of a motley group of Civil War survivors stranded on an unexplored Pacific Island.  It’s not your typical Cast Away story of a bitter struggle against the elements.  Instead, the novel is partly a how-to book: by combining the skills of an engineer, a freedman, two sailors, and a journalist, the group concocts nitroglycerin, erects a telegraph, and even builds a ship!

I promise, the rest of the book isn’t as ominous as this cover suggests. (from Wikimedia Commons)

In other words, I’ve always been interested in how people can turn an inhospitable island into a home.  So, like the castaways in The Mysterious Island, I’ve found my way to the scattered islands of the Pacific.

Continue reading Exploring the mysterious island: field work in the Marshall Islands