High in the sky and splashing in the oceans, two of the world’s smallest but most influential things have stubbornly guarded their secrets: aerosols and phytoplankton. Today, NASA launched it. Plankton, aerosol, cloud, ocean ecosystem mission, or PACE, to unravel their mysteries. The mission’s results could be key to understanding how fast the world is changing as it warms.

Aerosols are small particles of dust, Forest fire smokeand fossil fuel pollution floating in the atmosphere, which absorbs and reflects the sun’s energy and helps build clouds. Still struggling for accountability.. And phytoplankton are microscopic, plant-like marine organisms that form the base of the food web. They also sequester carbon, Preventing Earth’s climate from warming further. “Phytoplankton are essentially moving carbon around, and we need to understand how that changes over time,” says Jeremy Verdell of NASA’s Goddard Space Flight Center.

PACE is a satellite observatory that will provide scientists with unprecedented views of these vital inhabitants of the skies and oceans, to help them predict how our world will evolve. “There is a cost to a warming atmosphere and warming oceans, and that cost from a biological perspective is that the base of the food chain will obviously change,” says PACE project scientist Verdell.

Microscopic image of green phytoplankton on a black background

Plankton comes in all shapes, sizes and shades of green, filling all sorts of different roles in ecosystems.

Photo: Almi

Although phytoplankton are small, they bloom in such numbers that they spread green streaks in the oceans. It’s easy enough to monitor via satellite, sure, but all that’s been seen so far has been more or less a uniform line of green. But PACE is equipped with a highly sensitive instrument that can see in high resolution across the electromagnetic spectrum from ultraviolet to near-infrared. (The visible spectrum, which we can see, is somewhere between the two.) This has the effect that PACE can see all kinds of different greens.

Think about what you see when you gaze into the forest. “Different trees all have green leaves, but they’re all precisely different greens, which means they’re different plants,” Werdel says. “What we’re really looking for are very subtle changes in color.”

This will allow scientists to determine not only where phytoplankton blooms are occurring and why, but also what type of community they create. There are thousands of species of phytoplankton – some that serve as food for tiny animals known as zooplankton, others that are highly toxic, some that sequester carbon better than others. What modern satellites can see from space is like drawing with a box of eight crayons, but species will look different to PACE’s eye. “What we’re getting with PACE is a box of 128,” says Virdel.

Video: Andy Sayer/NASA

A better understanding of these phytoplanktonic communities is important because of how rapidly the oceans are changing. They have absorbed something like 90 percent of the extra heat humanity has added to the atmosphere, and over the past year or so, particularly, sea surface temperatures. Record highs have been reached. And Stay there. Higher temperatures themselves may adversely affect the growth of some phytoplankton species, but may actually benefit those that thrive as the mercury rises.

More subtly, the warm water acts as a kind of cap on the surface of the ocean, under which the cold water circulates. “It’s kind of like drinking alcohol. Half and half In your favorite Irish pub: Guinness floats on top of the harp,” says Weirdale. “It creates a barrier to this large piece of property in the upper ocean, where the nutrients in the cold water beneath this layer of warm water are trapped. Can’t get in.”

Phytoplankton need these nutrients to grow, so if a warm water cap persists in a given location, it will further shake up the community of photosynthesizing species. If there are fewer species that zooplankton need to eat, their numbers may also decrease. And then large predators like fish that eat zooplankton will affect the food chain. This may ultimately affect the types of food that humans rely on for protein.