Image from TERRA
Mon, 30 Oct 2017 12:25 EDT

Former Tropical Storm Saola transitioned into an extra-tropical storm on Oct. 29 as it tracked southeast of the big island of Japan.

Image from TERRA
Tue, 24 Oct 2017 11:36 EDT

When Typhoon Lan made landfall in Japan on Oct. 22, the Global Precipitation Measurement mission core satellite or GPM analyzed the storm and added up the high rainfall that it generated.

Image from TERRA
Tue, 24 Oct 2017 09:22 EDT

A new image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite shows the growing fire scar on the landscape.

Tag: MODIS

MODIS News and Events

Terra showcased in 100 Remote Sensing Uses from GIS Geography

100-remote-sensing-uses-logo-top

Image from GIS Geography. 100 Earth Shattering Uses and Applications of Remote Sensing.

GIS Geography published a list of 100 uses and applications of remote sensing, where data from NASA’s Terra satellite appeared in over 10%.

Listed below are some examples of Terra data uses that made the list (numbered by their original order in the article from GIS Geography):

13. Identifying forest stands and tallying their area to estimate forest supplies (MODIS)

26. Fighting wildfires by planning firefighter dispatch (MODIS)

27. Monitoring air quality in the lower atmosphere (MOPITT)

38. Keeping tabs on the shift from rural to urban growth (MODIS)

39. Quantifying crop conditions with Normalized Difference Vegetation Index (NDVI from MODIS)

59. Monitoring active volcanoes using thermal remote sensing (ASTER, MISR, and MODIS)

66. Looking at the Earth as an art masterpiece NASA’s Earth as Art | NASA Visible Earth

70. Comparing climatic factors from past to present (MODIS, CERES, MOPITT)

75. Studying geology of the Earth’s surface (ASTER, MISR, MODIS)

77. Measuring albedo for Earth’s radiation budget (CERES)

83. Delineating watersheds using DEMs for hydrologists (ASTER)

85. Using a least-cost analysis and vegetation to understand wildebeest migration (NDVI from MODIS)

Read the whole list and learn more about each of the uses and applications of remote sensing at 100 Earth Shattering Remote Sensing Applications Uses from GIS Geography

MODIS Team Lead Selected as 2015 AAAS Fellow

Michael King (500x500)

Washington D.C.—Michael King, Team Leader of the MODIS science team on the Terra and Aqua satellites, of the Laboratory for Atmospheric and Space Physics (LASP), University of Colorado Boulder, was selected as a Fellow of the American Association for the Advancement of Science (AAAS). King was elected as an AAAS Fellow for distinguished contributions to the remote sensing and analysis of clouds and aerosols, and for years of distinguished scientific leadership of the multi-satellite Earth Observing System, which includes Terra.

Read the full release by LASP.

Read more about Dr. Michael King.

Terra on NASA’s Earth Observatory – December

Terra images were featured on NASA’s Earth Observatory this December.

Icebergs Make Waves off South Georgia Island – Features Moderate Imaging Spectroradiometer (MODIS) images showing icebergs floating offshore of South Georgia Island, more than 1,600 kilometers (1,000 miles) east-northeast of South America’s southern tip. The icebergs make waves in the atmosphere.


indonesia_mop_201509Fires Put a Carbon Monoxide Cloud over Indonesia – Measurements of Pollution in the Troposphere (MOPITT) is used to monitor carbon monoxide from fires in Indonesia.


britishcolumbia_tmo_2015333_falsecolorShades of White – MODIS images enable distinction between fog and snow from space


urals_ast_2011194The Ural Mountains – The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) captured images of the Ural Mountains.


ugab_ast_2000350Letter Y: Ugab River, Namibia
The Ugab River looks like a “Y” in the Earth Observatories feature, Reading the ABCs from Space. ASTER on NASA’s Terra satellite captured this false-colored image of the Ugab River running through what appears to be a field of yardangs in northern Namibia.


northpacific_tmo_2009063Letter N for the New Year
Shiptracks in the atmosphere are visible in this image from NASA’s Terra satellite’s Moderate Imaging Spectroradiometer (MODIS) as part of the new feature, Reading the ABCs from Space from NASA’s Earth Observatory. N is for New Year was the final Image of the Day for 2015.

NASA Features from AGU: Terra

The American Geophysical Union recently concluded its Fall meeting in San Fransisco, California from December 14 – 18, 2015.  As part of the meeting contributions to science were featured on NASA.gov.  Data from Terra’s instruments played important roles in collecting data to further research in each of these featured areas.  Read the full features from NASA.gov available at the links below.

El Niño

NASA: Observing the 2015 El Niño – The strongest El Niño since 1997 – 1998 is being monitored for the first time by a host of satellites, including Terra. This video (above) features global data sets from Terra’s instruments and their contribution to El Niño research.

How NASA Sees El Niño Effects From Space – The Moderate Imaging Spectroradiometer (MODIS) contributes to data collection on fires and hurricane monitoring

NASA Examines Global Impact of the 2015 El Niño – El Niño research pulls from data from Terra’s 16 years of data collection, monitoring Earth’s systems from Space

Warming Lakes
Study Shows Climate Change Rapidly Warming World’s Lakes – The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) contributed to this study.

Earthquakes
Studies of Recent and Ancient Nepal Quakes Yield Surprises – The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) contributed to this study.

Sensor Degradation Leads to Calibration Improvements

Changes in the MODIS sensor, not dark ice led scientists to incorrectly determine that the Greenland ice Sheet in the Arctic was darkening. These results and others led to improved calibration corrections in the Collection 6 reprocessing of Moderate Imaging Spectroradiometer (MODIS) data.

A recent study suggested that sensor degradation of the MODIS instrument on NASA’s Terra satellite was responsible for the incorrect data. Ironically, the high quality of the MODIS sensor is what initially led Arctic scientists to look for a subtle change in ice brightness. The data collected by MODIS led researchers to consider that the Greenland ice sheet was darkening from an increase in dark aerosol deposition on the snow. However, ground based measurements showed that there had been little if any change in the color of snow.

Ice darkening could have had big implications for climate researchers. Just like black asphalt absorbs radiation from the sun, resulting in a warmer surface temperature, the darkening of the ice sheet could warm the surface temperature around the snow, increasing snowmelt. This could result a shrinking Greenland ice sheet and have implications on sea level rise.

The combination of a well-understood sensor, high-quality analysis of the satellite data, and coordinated measurements at the surface led to the conclusion that a sensor artifact, a change to an image from defects or degradation of optics, was the culprit this time.

Satellites, like many scientific instruments, need to be calibrated to be able to maintain accuracy. If you’ve ever stepped on a scale and gotten a number that was far too high or too low to be accurate, you’ve been a witness to the degradation of an instrument. Scales can be fixed easily by taring, or resetting the instrument to zero when nothing is being weighed.

Fixing satellite sensor degradation, isn’t quite as easy, but is common practice. The complexity of an instrument like MODIS makes the calibration process much more difficult. Often, there are small instrument effects that are not obvious until many years of data from multiple applications indicate an issue. The dark ice example is one such case.

The vigilance of the MODIS scientists and those working with the instrument calibration led to five previous reprocessings with the sixth currently underway.. Each time the data is reprocessed, degradation of the instruments are taken into account and the data is calibrated based on data collected from other sensors on other satellites as well as from data collected on Earth. MODIS is on-board both Terra and Aqua, when data from these sensors don’t match up the data can be corrected based on data gathered on Earth.

While it may be easy to assume that an aging instrument may be less accurate, in reality the longer the data record that it collects, the more accurate the data can be through reprocessing. Just think, if Terra had only lasted it’s six year design life, instead of going on 16, this error in the data may never have been caught and accounted for in newer data collections.

Thus, while the dark ice example could be considered by some as an indication of a flaw in how satellite data are used, it is, in reality, a success story for how a community of scientists working with groups like the MODIS Characterization and Support Team are striving to get to the right answer.

References:

Sun, J., X. Xiong, A. Angal, H. Chen, A. Wu, and X. Geng, (2014) Time-Dependent Response Versus Scan Angle for MODIS Reflective Solar Bands,IEEE Transactions on Geoscience and Remote Sensing, 52 (6), 3159-3174.

Polashenski, C. M., J. E. Dibb, M. G. Flanner, J. Y. Chen, Z. R. Courville, A. M. Lai, J. J. Schauer, M. M. Shafer, and M. Bergin (2015), Neither dust nor black carbon causing apparent albedo decline in Greenland’s dry snow zone: Implications for MODIS C5 surface reflectance, Geophysical Research Letters, 42.

Atmospheric science: Arctic snow is not becoming dirtier. (2015, 29 October). Nature Research Highlights, Accessed November 25, 2015.