Oblivious

oblivious

Crowd Vortices

The Feast of San Fermín in Pamplona, Spain draws crowds of thousands. Scientists recently published an analysis of the crowd motion in these dense gatherings. The team filmed the crowds at the festival from balconies overlooking the plaza in 2019, 2022, 2023, and 2024. Analyzing the footage, they discovered that at crowd densities above 4 people per square meter, the crowd begins to move in almost imperceptible eddies. (Image credit: still - San Fermín, animation - Bartolo Lab; research credit: F. Gu et al.; via Nature) Read the full article

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csmsdust

2 years ago

What are Phytoplankton and Why Are They Important?

Breathe deep… and thank phytoplankton.

Why? Like plants on land, these microscopic creatures capture energy from the sun and carbon from the atmosphere to produce oxygen.

This moving image represents phytoplankton in motion. The background is blue. In the first motion two circular phytoplankton with six tentacles across the screen. After that, three circles of phytoplankton colored in red, blue and orange move from right to life. The final image shows a variety of phytoplankton appearing. NASA/Michael Starobin

Phytoplankton are microscopic organisms that live in watery environments, both salty and fresh. Though tiny, these creatures are the foundation of the aquatic food chain. They not only sustain healthy aquatic ecosystems, they also provide important clues on climate change.

Let’s explore what these creatures are and why they are important for NASA research.

Phytoplankton are diverse

Phytoplankton are an extremely diversified group of organisms, varying from photosynthesizing bacteria, e.g. cyanobacteria, to diatoms, to chalk-coated coccolithophores. Studying this incredibly diverse group is key to understanding the health - and future - of our ocean and life on earth.

This set of illustrations shows five different types of phytoplankton: cyanobacteria, diatom, dinoflagellate, green algae, and coccolithophore. Cyanobacteria look like a column of circles stuck together. Diatoms look like a triangle with rounded sides; there is a spherical shape at each corner of the triangle. Dinoflagellates look like an urn with fish-like fins on the top and right side, and a long whiplike appendage. Green algae are round with sharp spikes emanating like the teeth of a gear. Coccolithophores are spherical, and covered with flat round features, each circled with fluted edges like a pie crust. Credit: NASA/Sally Bensusen

Their growth depends on the availability of carbon dioxide, sunlight and nutrients. Like land plants, these creatures require nutrients such as nitrate, phosphate, silicate, and calcium at various levels. When conditions are right, populations can grow explosively, a phenomenon known as a bloom.

This image shows phytoplankton growing in a bloom. The bloom is colored in shades of green in the South Pacific Ocean off the Coast of New Zealand. In the left of the image clouds and blue water appear. In the left bottom corner a land mass colored in green and brown appears. To the middle the Cook Strait appears between the North and South Island of New Zealand in green. Credit: NASA

Phytoplankton blooms in the South Pacific Ocean with sediment re-suspended from the ocean floor by waves and tides along much of the New Zealand coastline.

Phytoplankton are Foundational

Phytoplankton are the foundation of the aquatic food web, feeding everything from microscopic, animal-like zooplankton to multi-ton whales. Certain species of phytoplankton produce powerful biotoxins that can kill marine life and people who eat contaminated seafood.

This image is divided into five different images. On the left, tiny phytoplankton, clear in color, are present. On the second a larger plankton, orange in color appears. In the middle, a blue sea image shows a school of fish. Next to that a large green turtle looks for food on the ocean floor. On the right, a large black whale jumps out of the water. Credit: WHOI

Phytoplankton are Part of the Carbon Cycle

Phytoplankton play an important part in the flow of carbon dioxide from the atmosphere into the ocean. Carbon dioxide is consumed during photosynthesis, with carbon being incorporated in the phytoplankton, and as phytoplankton sink a portion of that carbon makes its way into the deep ocean (far away from the atmosphere).

Changes in the growth of phytoplankton may affect atmospheric carbon dioxide concentrations, which impact climate and global surface temperatures. NASA field campaigns like EXPORTS are helping to understand the ocean's impact in terms of storing carbon dioxide.

This moving image shows angled phytoplankton, clear in color moving on a blue background. The image then switches to water. The top is a light blue with dots, while the dark blue underneath represents underwater. The moving dots on the bottom float to the top, to illustrate the carbon cycle. Credit: NASA

Phytoplankton are Key to Understanding a Changing Ocean

NASA studies phytoplankton in different ways with satellites, instruments, and ships. Upcoming missions like Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) - set to launch Jan. 2024 - will reveal interactions between the ocean and atmosphere. This includes how they exchange carbon dioxide and how atmospheric aerosols might fuel phytoplankton growth in the ocean.

Information collected by PACE, especially about changes in plankton populations, will be available to researchers all over the world. See how this data will be used.

The Ocean Color Instrument (OCI) is integrated onto the PACE spacecraft in the cleanroom at Goddard Space Flight Center. Credit: NASA

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