Oceans

As we focused our microscope on the soil sample for the first time, bits of organic material came into view: a tiny poppy seed, the compound eye of an insect, broken willow twigs and spikemoss spores. Dark-colored spheres produced by soil fungi dominated our view. These were unmistakably the remains of an arctic tundra ecosystem – and proof that Greenland’s entire ice sheet disappeared more recently than people realize. These tiny hints of past life came from a most unlikely place – a handful of soil that had been buried under 2 miles of ice below the summit of the Greenland ice sheet. Projections of future melting of the ice sheet are unambiguous: When the ice is gone at the summit, at least 90% of Greenland’s ice will have melted. Results of an ice sheet model show how much of Greenland’s ice sheet survives when the ice is gone from the Camp Century (white dot), GISP2 (red dot) and DYE-3 (black dot) ice...

There are more than 500 species of sharks in the world’s oceans, from the 7-inch dwarf lantern shark to whale sharks that can grow to over 35 feet long. They’re found from polar waters to the equator, at the water’s surface and miles deep, in the open ocean, along coasts and even in some coastal rivers. With such diversity, it’s no surprise that sharks serve many ecological functions. For example, the largest individuals of some big predatory species, such as tiger and white sharks, can have an oversized role in maintaining balances among species. They do this by feeding on prey and sometimes by just being present and scary enough that prey species change their habits and locations. In a newly published study, colleagues and I surveyed decades of research on sharks’ ecological roles and considered their future in oceans dominated by people. We found that because sharks play such diverse and sometimes important functions in maintaining healthy ocean...

The North Atlantic Ocean has been running a fever for months, with surface temperatures at or near record highs. But cooling along the equator in both the Atlantic and eastern Pacific may finally be starting to bring some relief, particularly for vulnerable coral reef ecosystems. This cooling comes from two climate phenomena with similar names: La Niña, which forms in the tropical Pacific, and the less well-known Atlantic Niña. Both can affect the Atlantic hurricane season. While La Niña tends to bring conditions ideal for Atlantic hurricanes, the less powerful Atlantic Niña has the potential to reduce some of the hurricane risk. Cooling in the tropical Atlantic along the equator is a sign an Atlantic Niña may be forming. NOAA Climate.gov We’re ocean and atmospheric scientists who study this type of climate phenomenon. It’s rare to see both Niñas at the same...

My favorite place in the world isn’t a fixed location. It’s the JOIDES Resolution, an internationally funded research ship that has spent its service life constantly on the move, from deep in the Antarctic to high in the Arctic. Since 1985, scientific expeditions on this one-of-a-kind oceangoing laboratory have drilled 230 miles (370 kilometers) of sediment and rock cores – long cylindrical samples that provide a unique view of the ocean floor. The cores come from a thousand different locations, enabling scientists from many universities around the world to explore changes within the Earth. They also provide a window into our planet’s history. The ocean floor preserves a geological library that documents millions of years of climate change and evolution. The JOIDES Resolution leaves Honolulu in 2009. IODP/Wikipedia, CC BY Sadly, the JOIDES Resolution, also known as the JR...

Ocean-related tourism and recreation supports more than 320,000 jobs and US$13.5 billion in goods and services in Florida. But a swim in the ocean became much less attractive in the summer of 2023, when the water temperatures off Miami reached as high as 101 degrees Fahrenheit (37.8 Celsius). The future of some jobs and businesses across the ocean economy have also become less secure as the ocean warms and damage from storms, sea-level rise and marine heat waves increases. Ocean temperatures have been heating up over the past century, and hitting record highs for much of the past year, driven primarily by the rise in greenhouse gas emissions from burning fossil fuels. Scientists estimate that more than 90% of the excess heat produced by human activities has been taken up by the ocean. That warming, hidden for years in data of interest only to oceanographers, is now having profound consequences for coastal economies around the world. Understanding the role of the ocean in th...