Earth Matters

A Watchful Eye on Rio

August 16th, 2016 by Adam Voiland
Many of the Olympic festivities are taking place in Barra da Tijuca, one of the youngest and most affluent neighborhoods in Rio.

Many of the Olympic festivities are taking place in Barra da Tijuca, one of the youngest and most affluent neighborhoods in Rio. Credit: Landsat 8/NASA Earth Observatory.

While gymnasts leap, cyclists pedal, and divers twirl for Olympic gold in Rio de Janeiro, sensors on several NASA Earth Observing satellites are catching glimpses of the city and its surroundings from space. The mix of satellites and sensors in orbit are nearly as varied and diverse as the athletes competing below.

The marathoner among NASA’s fleet would have to be Terra. Despite having a design life of six years, this reliable spacecraft has been in orbit since 2000. The multi-purpose satellite carries five scientific payloads and monitors everything from phytoplankton to forest cover to airborne particles called aerosols.


NASA’s Earth Observing Fleet. Credit: NASA Earth Observing System Project Science Office

The swimmers would have to be Aquarius, Aqua, and the Global Precipitation Measurement (GPM). All three satellites, as their names suggest, specialize in studying water. Aquarius focuses on measuring the ocean’s salinity. Aqua, like Terra, is versatile: It studies water vapor, sea ice, snow ice, clouds, and more. GPM is the newest of the trio. Launched in 2014, it makes global maps of precipitation and sets standards for precipitation measurements worldwide.

The synchronized divers of space would have to be the Gravity Recovery and Climate Experiment (GRACE). While divers seem to temporarily defy gravity with their flips and turns, the pair of GRACE satellites actually measures Earth’s gravity from space.

The GRACE satellites. Credit: NASA

The twin GRACE satellites. Credit: NASA

The archers would be CALIPSO and CloudSat. These two satellites shoot laser pulses (CALIPSO) and radar waves (CloudSat) down toward features in the atmosphere such as clouds and smoke plumes. They measures precisely how long it takes for the light or radio waves to bounce back, making it possible to map the vertical structure of the atmosphere.


Rio at night. Credit: VIIRS/NASA Earth Observatory.

The images above and below offer a glimpse of some of the types of imagery and data that NASA-Earth observing satellites collect. The image at the top of the page shows how Olympic Park in Rio appeared to the Operational Land Imager (OLI), a sensor on Landsat 8. The image immediately above shows Rio at night as seen by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite. The instrument can sense light 100,000 times fainter than conventional visible-light sensors, making it extremely sensitive to moonlight and city lights.


Rio on August 6, 2016. Credit: Worldview/NASA.

The image directly above shows a view of Rio and Guanabara Bay on August 6, 2016, the day after the opening ceremony.  The fourth image (below) shows a view of aerosols observed over Rio by the Multi-Angle Imaging Spectrometer (MISR) on August 2, 2016.


Observations of aerosols over Rio on August 2, 2016. Credit: NASA/Terra/MISR.

Scientists at NASA and officials in the Rio de Janeiro government recently signed an agreement about natural hazards preparedness. The hope is that satellite imagery and data—in conjunction with in situ data from the ground—will help scientists better understand, anticipate, and monitor drought, flooding, and landslides that occur in and around Rio. The collaboration will focus on integrating, visualizing, and sharing relevant data from NASA satellites.


Severe mudslides and landslides affected Rio in 2011. Read more about this image here. Credit: EO-1/NASA Earth Observatory

In a NASA press release, Rio de Janeiro Mayor Eduardo Paes said that his city has historically suffered from massive rainstorms and subsequent floods and landslides, all of which can cause casualties and disrupt the economy. Discussions are underway to address those hazards and to plan future cooperative activities.

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