By Alex Kinsella, Postdoctoral Investigator at Woods Hole Oceanographic Institution // Aboard the Bold Horizon //
My favorite part of being at sea is the opportunity to see unique parts of the natural world that aren’t accessible from land. My colleagues have done a fantastic job in their blog posts explaining the science that we’ve been conducting during S-MODE, so I want to take this opportunity to describe some of the sights that those of us on the Bold Horizon have been able to enjoy during our field work: birds, mammals, weather, and stars.
The nature highlight of the cruise for me has been the opportunity to see pelagic birds, which are those that spend most of their lives at sea and are rarely, if ever, seen from land. The most majestic seabird in our region is undoubtably the albatross, which uses an elegant method called dynamic soaring to fly with almost no effort. Throughout the cruise, we have seen many black-footed albatrosses, with as many as six at one time flying back and forth over the wake of our ship. By soaring in loops between a low-altitude track sheltered behind the waves and a higher-altitude track in the open air, they are able to harvest energy from small-scale wind shear to fly for miles without flapping their wings. These birds have been our most constant companions during the day, but we have also been joined overhead at night by many flocks of Leach’s storm petrels, blackbird-sized seabirds which have been in the midst of their autumn migration. Shearwaters, jaegers, murrelets, and fulmars have rounded out the pelagic cast for a wonderful birdwatching experience.
The other prominent animal life during the cruise has been the marine mammals, which have sometimes showed up in impressive numbers. The California coast is a region of plentiful food availability due to large-scale upwelling of nutrient-rich deep water driven by northwesterly winds. Pods of Pacific white-sided dolphins have been swimming up to our ship to play in the bow wake, breaching and diving from side to side. We have spotted several fin whales too, which amaze us all and beckon a rush of scientists with cameras in hand. Ocean fronts are often nutrient hotspots, so it’s possible that the whales are searching for the same features that we are.
We have also been enjoying (and enduring) the vagaries of the weather, one of the most ancient forms of entertainment. The cruise has featured two contrasting weather patterns: in the first half of the cruise, we had an endless gray stratus deck and occasional dense fog. We didn’t see the sun, moon, or stars for over a week! Around the halfway point of the cruise, a cold front passed through and cleared away the low clouds, replacing them with mostly clear skies that have featured interesting patches of mid- and high-level clouds, but also interminable wind and waves.
For our purposes, the most important part of weather at sea is the ocean surface waves, the characterization of which we call the “sea state”. A calm sea state is much better for our operations, but a lively sea state can make for great nature-watching. My colleague Gwen Marechal, a postdoc at Colorado School of Mines, is our resident wave expert, and the way he looks at waves reminds me of the way that most of us look at wild animals. We’ll be gazing out at the ocean and Gwen will point off to the distance. “Bird?” I ask. “No, a really good wave!” he says with reverence and a smile. One can think of there being at least two “species” of waves: wind waves and swell, but in a given sea state, each passing wave is unique, with its own height and character. Watching for good waves can be as satisfying as watching for good birds.
When we’ve had clear skies at night, stargazing has been a favorite evening activity, as it always is at sea. Jupiter has been rising in the early evening, giving us a bright companion in the southeast sky as we transition from day watch to night watch on the ship. Around 8 p.m. each night, the sun is far enough below the horizon that the Milky Way becomes clearly visible, along with familiar constellations like Ursa Major, Cassiopeia, and Sagittarius. Finding those landmarks in the sky can be harder at sea than in a city, because there are almost too many stars, so the familiar ones are harder to find! We have continued the maritime tradition of philosophizing under the stars at night, wondering about the ocean below, the sky above, and much more.
Being at sea truly feels like being in another world, but, at least by surface area, this is what most of the world looks like. It has been a gift to be on the ocean watching this part of our planet in its daily motions. The science we’ve conducted on this cruise will help us understand one more piece of nature’s workings, but no amount of knowledge can quite capture the experience of being in the midst of it all.