World Oceans Day celebrates the global ocean and calls attention to the importance of protecting the chemistry and creatures of this precious resource. We need a healthy ocean to maintain a healthy world.
It takes many techniques to monitor the ocean’s health. Oceangoing research vessels deploy instruments that measure conditions at a range of water depths. Tide gauges along the coasts detect changes in sea level — both short-term changes due to storms and tsunamis and long-term changes due to warming water and melting land ice.
Critical information about the ocean comes from space-based observations. Robotic satellites orbiting hundreds of miles above Earth can monitor sea surface temperatures and the development of large storms.
Digital images taken by crew members on the ISS are also important for ocean monitoring. The astronauts’ photos have the same resolution as the highest-resolution satellite images (6-30 meters per pixel).
Astronauts’ photos of Earth’s oceans are used in research on coral reefs, algal blooms, polar ice shelves, and even “Tahiti’s giant clams,” according to NASA’s ISS Program Science Office. The photos also help corroborate satellites’ indirect measurements of ocean depth.
Apart from their scientific value, the photos are simply beautiful! Explore selected images of the Pacific and Atlantic curated by Windows on Earth. Each day, astronauts photograph specific Earth features at scientists’ request, but they also take many photos just for enjoyment, trying to capture the breathtaking view and share it with the world.
Another ongoing experiment in the ISS National Lab studies how tropical cyclones develop over the oceans. When an astronaut takes a rapid-fire series of photos of a storm, scientists on the CyMISS project select two photos taken from slightly different angles and pair them up to make 3D images. They analyze the image pairs to determine the heights of the cloud tops, which relate to the storm’s intensity. Learn more in the article Disrupting the Way We Understand the World’s Deadliest Storms.
There’s also an ISS experiment that isn’t sponsored by the National Lab, but it’s too cool not to mention! The ICARUS project studies the migration of birds, bats, and insects across the oceans. It has taken a long time to develop radio-transmitting chips small and light enough to place on these animals without hindering their ability to fly. The signals from these miniaturized transmitters are too weak for distant robotic satellites to detect them. But the signals do reach the ISS, which orbits Earth 16 times a day at a conveniently close distance of 250 miles. Whenever the ISS passes within a few hundred miles of a tagged animal, the ICARUS unit logs the data from the animal’s transmitter. ICARUS is revolutionary in its ability to track large numbers of flying animals across the globe!