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The Science of Understanding Climate Change

The Science of Understanding Climate Change

We tend to associate NASA with the Apollo landing of humans on the moon, unmanned interplanetary Voyager probes, the orbiting space station and Hubble telescope, the Space Shuttle program, and now Mars exploration. Yet a significant portion of its budget is channeled towards what is generally referred to as the earth observation sciences. NASA engineers together with international teams of scientists, known collectively as GEO or Group on Earth Observations, assemble data to be utilized for a broad range of societal benefits that includes protection of ecosystems, combating desertification, and conserving biodiversity.

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Meet Dr Paul Racette, the principal NASA engineer responsible for overall conceptualization, development, and deployment of highly innovative earth observation remote sensing instruments. He has participated in more than fifteen major field experiments around the world pioneering techniques, and has led the way in collecting rich, scientifically relevant data.

SuperConsciousness spoke with Dr Racette about his passion for this work, and his views on how the more information we have about the environment, the more aware we are, the more responsible as a species we become.

SC: Can you explain your work at NASA in earth observation sciences?

PAUL RACETTE: For about twenty years I’ve worked at NASA’s Goddard Space Flight Center and most of my work has been in the development of earth observation microwave remote sensing instrumentation. I design radiometers and radars used to sense the atmosphere, oceans and land and have developed instruments that are sensitive to the presence of water vapor, atmospheric liquid and ice clouds.

Technically speaking, I have spearheaded technology developments in the millimeter- and submillimeter-wave portion of the electromagnetic spectrum spanning 90 gigahertz, up to a terahertz. Instruments sensing at those wavelengths are sensitive to ice crystals and ice clouds, which are difficult to measure at other frequencies. Infrared frequencies tend not to penetrate the clouds and microwaves are not sufficiently sensitive. This is one of the reasons why microwaves are very useful for earth observation.

SC: How is the ice crystal and ice cloud information used?

RACETTE: Clouds play a very important yet complex role in moderating the earth’s climate, depending upon the height and the types of clouds they are. Clouds can reflect the sunlight and cause a net cooling of the earth’s surface or depending upon where they are in the atmosphere they can also act as a blanket. For instance, you’ve probably experienced a cloudy night in which the clouds trap the heat and it stays warm through the night, or a cloudless night when the temperature will drop.

Interview with NASA Engineer Dr Paul Racette

Infrared frequencies tend not to penetrate the clouds and microwaves are not sufficiently sensitive. This is one of the reasons why microwaves are very useful for earth observation.

Particularly when it comes to ice clouds, we really don’t have a very good handle on the total amount of ice in the atmosphere, its generation or its sublimation, yet that’s how the ice leaves the atmosphere. So there’s one mission called CloudSat that has a 94-gigahertz radar on board to measure cloud profiles. It works by making cloud-profile measurements in a single row. It’s a non-imaging instrument but goes around the earth and samples the clouds and does very well.

The Europeans are collaborating with the Japanese to develop what’s called EarthCare. It’s another radar mission for measuring clouds. And NASA is preparing for a follow-up mission that will measure ice clouds as well, but this will be an imaging system to provide three-dimensional images of the clouds.

SC: How did you become interested in this work?

Interview with NASA Engineer Dr Paul RacetteRACETTE: I grew up in Kansas, a relatively flat state with a whole lot of sky. There, you can see for miles and miles in any given direction and I’ve seen some amazing features in the sky. For me, it’s been a wonderful experience to come to NASA and develop techniques, technologies, and instrumentation for observing the sky.

We need better information about clouds. Certainly there are improvements to be made in short range weather forecasting, but the real driver for me is to improve our understanding of our planet. For example, we really don’t have a good understanding of the amount and distribution of ice there is in the atmosphere, and as such, it creates a level of uncertainty in our climate models. So, the measurements allow us to better understand earth processes and help to reduce the uncertainty of our models for those processes.

There’s certainly a growing awareness of the importance of climate change and the impact climate change has on our lives now, and more importantly will have on future generations. It’s one thing to have people make that connection between the size of car that they drive and the amount of energy used. But the impact on the environment is something really quite different. The reason why we need improved information about the earth is to help guide public policy around development, such as energy policy and the like.

SC: In addition to technology development, you pursued a fellowship path, which included community outreach and education. How does that experience bridge with your work at NASA?

RACETTE: I participated in the NASA Administrators Fellowship Program from 2005 to 2007. I spent the first year at Haskell Indian Nations University where I taught and tutored in the math department. I also developed and taught a course called Earth Exploration which was about looking at earth from space as a form of self-discovery and self-exploration.

The second year, I worked with NASA’s Office of Education and developed partnerships by improving and leveraging NASA’s education programs with other national efforts.

It’s one thing to have people make that connection between the size of car that they drive and the amount of energy used. But the impact on the environment is something really quite different.

Additionally, I was invited to spearhead the online publication, Earthzine, through the IEEE (Institute of Electrical and Electronics Engineers) Committee on Earth Observation and their work towards establishing a comprehensive Global Earth Observing System of Systems. GEOSS is connecting the diverse disciplinary and broad regional types of earth observing systems. Earthzine is an outreach tool that informs the public, the GEO community, and those in position to use earth information in the formation of public policy and land utilization while also creating greater awareness of the social benefits of observing the earth.

SC: How do you see that connecting together earth observation science, technology development, robust data collection, education, public policy, and greater public awareness will serve humanity generally, as well as the United States taxpayers that support your work?

RACETTE: There’s a great deal of uncertainty in the public’s eye and we see this concerning the topic of climate change. There remains significant uncertainty in terms of the magnitude of impact that climate change will have on human civilization, as well as to the extent humans influence earth’s environment.

One of the principle ways that we can reduce the uncertainty, both within the public and within the scientific understanding of environmental change, is through observation. That’s one of the aspects of my work in which I am most passionate. I see earth observation addressing these two issues very succinctly.

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