Image from TERRA
Tue, 24 Aug 2021 13:05 EDT

Smoke from several large wildfires burning in Northern California can be seen traveling miles into the atmosphere.

Image from TERRA
Fri, 20 Aug 2021 12:00 EDT

Drought is a natural part of the climate cycle, but as Earth’s atmosphere continues to warm due to climate change, droughts are becoming more frequent, severe and pervasive. Ranchers throughout the U.S. are using data from NASA and others to care for their herds and the land during drought conditions.

Image from TERRA
Thu, 19 Aug 2021 12:09 EDT

Evapotranspiration: Watching Over Water Use

Year: 2021

On Wednesday, September 22, 2021, Terra’s Flight Operations Team will be rebooting Terra’s Solid-State Recorder (SSR). Terra’s nominal SSR operations will be offline for approximately 10 – 12 hours. The purpose of the Solid-State Recorder reboot is to restore function to the printed wire assemblies that are currently offline. During this period, many of the instruments will continue to collect data. However, data collected during this period will not be available (except for MODIS direct broadcast data) because the Solid-State Recorder, which stores the data until it can be downlinked, will not be online.

  • MISR – Normal Operations
  • MODIS – Normal Operations (Direct Broadcast will continue to be available)
  • MOPITT – Normal Operations
  • CERES – Safe Mode (no observations); CERES on other platforms ­– Aqua, Suomi National Polar-orbiting Partnership (S-NPP) and NOAA-20 satellites will continue to operate as normal.
  • ASTER – Standby (no observations; nominal maneuver configuration)

Once the solid-state recorder reboot is completed, it is planned that all instruments and data collection will be restored to normal operations, including MODIS and MISR whose data were impacted by the most recent printed wire assembly anomalies in June, 2021.

Two printed wire assemblies (PWA) on the Terra satellite stopped working, resulting in lost data from the Multi-angle Imaging SpectroRadiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) on June 28th and June 29th, 2021.  Radiation from the Sun and deep space likely caused an overcurrent issue that stopped the printed wire assemblies from working.

“We have to manually send the update that says, don’t record to that PWA anymore, but until we do that it keeps trying to save data to the bad PWAs,” says Jason Hendrickson, Terra Flight Systems Manager.  Terra’s flight operations Team quickly worked to initiate commands to mark the printed wire assemblies as bad so that they were no longer used. During the time it took to initiate these commands, both MISR and MODIS lost data. However, repercussions from these non-functioning printed wire assemblies have longer lasting impacts ­– reduced storage capacity of MODIS and MISR data on Terra’s solid-state recorder.

Prior to these printed wire assemblies malfunctioning, fifteen other printed wire assembly stoppages had occurred, each time reducing Terra’s solid-state recorder data storage capacity. However, in 2001, after the first printed wire assembly stopped working, rebooting the solid-state recorder corrected the issue, restoring function. Now with only 43 of 59 printed wire assemblies functioning, data storage capacity has decreased to a critical point for MODIS and MISR.

In a working group meeting held in 2019, this scenario was discussed. All instrument teams made choices about what to do if any more printed wire assemblies stopped working. The options discussed included: downlinking data more frequently, reducing the number of science observations by MISR and MODIS, or rebooting the solid-state recorder in hopes that the printed wire assemblies begin to work again. Weighing the risks and benefits of these courses of action is not taken lightly.

“It takes less time to fill up the storage once we mark the printed wire assembly bad, but the same amount of data is being produced by the instruments as always,” says Dimitrios Mantziaras, Terra Mission Director. To keep all the data that is being produced by the instruments, the data would need to be downlinked more frequently. While this may sound easy, data downlink is limited by the number of passes Terra makes past Tracking and Data Relay Satellites. Without more of these satellites in Terra’s line of sight, data cannot be downlinked more regularly.

Another option is to reduce MODIS and MISR science observations.

“The impact on MODIS data is considered significant,” says Michael King, MODIS Instrument Lead. The MODIS science team is faced with choosing to record data from fewer bands or to accept gaps in their data.

MODIS typically operates with 50% of the orbit recording of daytime bands (all 36 bands), whereas the other 50% of the orbit records only 17 thermal bands (night mode).  The Flight Operations Team can reprogram the percentage split, extending the night mode data collection and decreasing the daytime data collection. This reduces the total amount of data that is collected between data dumps. However, daytime bands are essential for many MODIS data products including: ocean color and ocean optical property products, many atmospheric products, and many land products. Additionally, the daytime bands are important in an early part of data processing that identifies clear sky from clouds.  “The loss of the ability to record these bands and derive the corresponding products will affect time series of Earth observations over the course of the Terra mission, leaving gaps in data in the polar regions,” says King.

Similarly, MISR is faced with reducing about 6 minutes of data per orbit. To mitigate data loss, the MISR science team strategized trimming ascending node data collected near the poles (most, but not all, dayside data are acquired on the descending node when Terra is flying from north to south). “Near the summer and winter solstices the scientific impact is minor, but during fall and spring the required trimming includes either loss of descending node data at high latitudes in both hemispheres or choosing between Arctic or Antarctic coverage,” says David Diner, MISR Principal Investigator. To minimize impacts to the science community that relies on MISR data, the Arctic region — where MISR’s data significantly contributes to measuring sea ice minima, albedo decrease, and support of field campaigns — will be prioritized. “Unfortunately, this will curtail the long-term record of sea ice albedo, anthropogenic aerosol influences, and ice sheet breakup in southern polar regions, which have been the subject of published investigations by the science community,” says Diner.

While these options for data reduction come at costs, the teams are considering rebooting the solid-state recorder, which was done once in 2001. “There is no identifiable risk to doing the reset,” says Kurt Thome, Terra Project Scientist. The successful restart of the solid-state recorder in 2001 brought the first inoperative printed wire assembly back online. If a restart works, then MISR and/or MODIS could continue to collect data as was done prior to the recent malfunctions, potentially even returning Terra’s data storage capacity to the amount it had at launch.

As Terra continues to drift toward it’s expected constellation exit in fall of 2022, the Terra science and Flight Operations Teams continue to preserve Terra’s more than two-decades of data with as much continuity as possible, adding to Terra’s historic long-term data record of Earth observations.

Two printed wire assemblies on the Terra satellite failed, resulting in lost data from the Multi-angle Imaging SpectroRadiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) on June 28th and June 29th. The Terra Flight Operations Team, quickly worked to identify the location of the failures and initiate commands to prevent the solid state recorder from trying to use those locations. Data for both instruments is now continuing to be collected. However, data that is collected may be at a reduced quantity, but not decreased quality.

Comparison of overlapping one-year estimates at 6-month intervals of net top-of-the-atmosphere annual energy flux from CERES (solid orange line) and an in situ observational estimate of uptake of energy by Earth climate system (solid turquoise line).
Credits: NASA/Tim Marvel

Researchers have found that Earth’s energy imbalance approximately doubled during the 14-year period from 2005 to 2019.

Earth’s climate is determined by a delicate balance between how much of the Sun’s radiative energy is absorbed in the atmosphere and at the surface and how much thermal infrared radiation Earth emits to space. A positive energy imbalance means the Earth system is gaining energy, causing the planet to heat up. The doubling of the energy imbalance is the topic of a recent study, the results of which were published June 15 in Geophysical Research Letters.

Scientists at NASA and NOAA compared data from two independent measurements. NASA’s Clouds and the Earth’s Radiant Energy System (CERES) suite of satellite sensors measure how much energy enters and leaves Earth’s system. In addition, data from a global array of ocean floats, called Argo, enable an accurate estimate of the rate at which the world’s oceans are heating up. Since approximately 90 percent of the excess energy from an energy imbalance ends up in the ocean, the overall trends of incoming and outgoing radiation should broadly agree with changes in ocean heat content.

“The two very independent ways of looking at changes in Earth’s energy imbalance are in really, really good agreement, and they’re both showing this very large trend, which gives us a lot of confidence that what we’re seeing is a real phenomenon and not just an instrumental artifact, ” said Norman Loeb, lead author for the study and principal investigator for CERES at NASA’s Langley Research Center in Hampton, Virginia. “The trends we found were quite alarming in a sense.”

Increases in emissions of greenhouse gases such as carbon dioxide and methane due to human activity trap heat in the atmosphere, capturing outgoing radiation that would otherwise escape into space. The warming drives other changes, such as snow and ice melt, and increased water vapor and cloud changes that can further enhance the warming. Earth’s energy imbalance is the net effect of all these factors. In order to determine the primary factors driving the imbalance, the investigators used a method that looked at changes in clouds, water vapor, combined contributions from trace gases and the output of light from the Sun, surface albedo (the amount of light reflected by the Earth’s surface), tiny atmospheric particles called aerosols, and changes in surface and atmospheric temperature distributions.

The study finds that the doubling of the imbalance is partially the result an increase in greenhouse gases due to human activity, also known as anthropogenic forcing, along with increases in water vapor are trapping more outgoing longwave radiation, further contributing to Earth’s energy imbalance. Additionally, the related decrease in clouds and sea ice lead to more absorption of solar energy.

The researchers also found that a flip of the Pacific Decadal Oscillation (PDO) from a cool phase to a warm phase likely played a major role in the intensification of the energy imbalance. The PDO is a pattern of Pacific climate variability. Its fingerprint includes a massive wedge of water in the eastern Pacific that goes through cool and warm phases. This naturally occurring internal variability in the Earth system can have far-reaching effects on weather and climate. An intensely warm PDO phase that began around 2014 and continued until 2020 caused a widespread reduction in cloud coverage over the ocean and a corresponding increase in the absorption of solar radiation.

“It’s likely a mix of anthropogenic forcing and internal variability,” said Loeb. “And over this period they’re both causing warming, which leads to a fairly large change in Earth’s energy imbalance. The magnitude of the increase is unprecedented.”

Loeb cautions that the study is only a snapshot relative to long-term climate change, and that it’s not possible to predict with any certainty what the coming decades might look like for the balance of Earth’s energy budget. The study does conclude, however, that unless the rate of heat uptake subsides, greater changes in climate than are already occurring should be expected.

“The lengthening and highly complementary records from Argo and CERES have allowed us both to pin down Earth’s energy imbalance with increasing accuracy, and to study its variations and trends with increasing insight, as time goes on.” said Gregory Johnson, co-author on the study and physical oceanographer at the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory in Seattle, Washington. “Observing the magnitude and variations of this energy imbalance are vital to understanding Earth’s changing climate.”

Joe Atkinson
NASA’s Langley Research Center
Last Updated: Jun 16, 2021Editor: Joe Atkinson

Link to original article:

Valley Fever is caused by the Coccidioides fungus, which grows in dirt and fields. The fungus, when inhaled, can cause fever, rash and coughing. Dust storms in the Southwestern United States carry these spores in the air, where they can be inhaled and cause illness.

Supported by NASA’s Health and Air Quality (HAQ), NASA researcher Daniel Tong, an associate professor at George Mason University, and his team are studying the impact of dust storms in the southwest U.S on the spread of Valley fever. Using a novel, yet simple technique, Tongs team catches dust using cake pans and marbles. The dust is tested for the Coccidioides fungus. Their research “combines this data with NASA satellite data and high-end computer modeling to enhance current forecasting and surveillance activities related to dust storms and the airborne spread of Valley fever across the southwestern states.” 

Mentions of Terra from NASA articles
NASA Applied Science – Dust Storms, Valley Fever… and Cake Pans

“The on-the-ground measurements were combined with Earth observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard the NASA satellites Terra and Aqua. These satellites monitor vegetation and soil moisture, which can reveal where conditions are ripe for the growth of Coccidioides and the spread of arid dust. MODIS instruments also help track dust storms’ spread by detecting the light reflected from the tiny particles as they are swept across the country. The team also used these data to help “train” their models that assessed long-term trends of dust storms in the region.”

“Tong and his team are combining NASA satellite data and high-end computer modeling with homemade dust catchers made of pans for baking cakes and marbles.” – Dust Storms and Valley Fever in the American West

“While the team gathers data on the ground, NASA satellites are hard at work getting the view from above. Tong’s team uses data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard the NASA satellites Terra and Aqua. These data show likely habitats for this fungus because they monitor vegetation and soil moisture, revealing where conditions are ripe for fungal growth and spread of arid dust”

But tracking dust storms’ movement through air is easier with the help of NASA’s Earth observing instruments – like MODIS – which can also detect the light reflected from the tiny particles as they’re swept across the country. These true color dust observations from MODIS even helped to “train” models developed by the team to assess how the frequency of dust storms is changing.