Last week, Digital Journal talked with Anne Douglass, the acting project scientist on the AURA project at the NASA Goddard Space Flight Center. DJ asked Douglas how Earth Systems Science (ESS) played a role in our understanding and interpreting data sent back from Earth-orbiting satellites (EOS).
Douglass explained that the term “Earth System” refers to the four major parts or spheres of the Earth that, working together form a complex system that has sustained life on the planet for millions of years. The four parts are rocks, water, air and life, and they all come together to create an amazingly dynamic global system.
Earth systems science (ESS) is an interdisciplinary field that includes geology, hydrology, biology and many other sciences and disciplines. By studying the Earth as a whole system, we begin to see and understand the interaction between the different systems, getting a clearer picture of what is happening with our climate.
Scientists use words like atmosphere (air), hydrosphere (water), lithosphere or geosphere (rocks), and biosphere (life). In its broadest scale, ESS scientists take a contextual approach to scientific inquiry. This means they study extreme weather events in the context of a changing climate. Everything, from wildfires to volcanic eruptions to loss of biodiversity is studied, with anomalies found in these and other events leading to further studies of the causes and effects they have on our environment.
How ESS and satellite data combine to help in understanding climate change
While reporting on the rising nitrogen dioxide levels in India last week, this Digital Journalist was fascinated by the description of NASA’s Aura atmospheric chemistry satellite and the chemistry and images it has sent back to Earthbound scientists the past 11 years.
Digital Journal asked Douglass to further talk about the launch of Aura and the four high-tech instruments aboard the satellite. The Aura scientist said the satellite was successfully launched on July 15, 2004, from Vandenberg AFB in California using a Boeing Delta II rocket. At that time, Aura (Latin for breeze) joined two sister satellites, Terra, and Aqua, plus 10 additional research satellites.
In launching Aura, NASA scientists were pursuing the answer to three key scientific questions – Is the Earth’s protective ozone layer recovering? What are the processes controlling air quality? How is the Earth’s climate changing? The appropriately named Aura is outfitted with four instruments to survey different aspects of the Earth’s atmosphere. (Remember the four parts of the Earth’s system? Air or atmosphere is one of the systems).
Douglass said the Aura satellite is capable of measuring the atmosphere from the troposphere (where we live) on up to the stratosphere, the home of the ozone layer that protects all life on the planet. Let’s look at the four instruments Aura uses to measure the trace gasses in the atmosphere.
The Microwave Limb Sounder or MLS
The high-tech MLS uses microwave emission in measuring the stratospheric temperature and the constituents that are found in the troposphere. The MLS can also measure upper-level troposphere water vapor if there are tropical cirrus cloud formations. Why is all this important?
For calculating the size and extent of loss in the ozone layer, it is very important. A severe loss of Arctic ozone when there is an abundance of stratospheric chlorine and a slight cooling of the stratosphere could result in an increase in the loss of ozone due to the interaction of chlorine monoxide (ClO) and ozone (O3). The MLS is able to simultaneously provide measurements of upper tropospheric water vapor, ice content, and temperature, under varying conditions.
The HIRDLS or High-Resolution Dynamic Limb Sounder
Using special narrow and more transparent spectral channels, the HIRDLS can cover the Earth both day and night, sending back a complete Earth profile in the space of 12 hours. This instrument stopped working in 2008, but up until that time, it sent back some spectacular imagery, even while it was partially disabled due to the explosive decompression of the launch in 2004.
The launch in 2011 of the Suomi National Polar-orbiting Partnership (Suomi-NPP) also introduced a new second generation of instruments that traced their origins to the Aura and its siblings, so nothing has been lost.
The Tropospheric Emissions Spectrometer or TES
The TES can generate high-resolution, three-dimensional profiles on a global scale for virtually all infrared-active species, from the surface of the planet and on up to the lower stratosphere. So volcanic activity is of special interest to this instrument, as well as fluctuations in infrared activity.
The Ozone Measuring Instrument or OMI
This instrument is self-explanatory, actually. It measures ozone. But it can also measure different aerosol types said Douglass, like smoke, dust, and sulfates, including cloud pressure, and coverage, which provides data for measuring ozone coverage in the troposphere.
Douglass said the OMI is a contribution to the NASA Aura project from the Netherlands’s Agency for Aerospace Programs (NIVR) in collaboration with the Finnish Meteorological Institute (FMI). Douglass also added that NASA is not working alone in their endeavor to learn more about the Earth’s changing climate. It is a collaborative effort between NASA, Europe (ESA-Sentinel-4) and Asia (KARIGEMS).
All the satellite observations from countries around the globe are being supplemented by daily global views from TROPOMI onboard the European Space Agency’s LEO satellite, the Sentinel-5Precurser.
According to the TROPOMI website, The Sentinel-5P mission is will “provide data continuity for the SCIAMACHY instrument aboard the Envisat satellite and NASA’s OMI instrument aboard the Aura satellite in the interim between the end of the Envisat and Aura missions and the launch of Sentinel-5.”
In ending our conversation, Douglass stressed the importance of the need for public understanding of the implications of our changing climate, This Digital Journalist said she found the scientist’s explanations understandable, making it easier to write about the subject.
As Anne Douglass said, if we just take the time to understand what the science is all about, such as Earth Systems Science and what the Earth observation satellites are measuring, then it’s not so hard to see how the parts or spheres of the four Earth systems overlap and interact with each other.
