JPL BLOGS
Inside Views on Outer Space
Hear from scientists, engineers and other experts as they offer a fascinating look at JPL missions, science and history.
JPL | December 4, 2014
Earth Observations to Support Climate Decisions
Riley Duren, chief systems engineer for the Earth Science and Technology Directorate at NASA's Jet Propulsion Laboratory, is reporting from the 2014 United Nations Climate Conference in Lima, Peru.
Today I'm en route to Lima, Peru, to join the United Nations climate conference. This is the 20th Conference of Parties (COP-20) of the UN Framework Convention on Climate Change (UNFCCC). The meeting is intended to set the stage for an international agreement next year between 195 countries on actions to address climate change. For the next two weeks, diplomats, policy makers, scientists, engineers, economists, and representatives of business and non-profit organizations are convening in Lima to discuss a wide range of options to avoid dangerous climate change and/or attempt to manage the impacts to humanity and the other species that share planet Earth. (More background, here)
As it turned out, I managed to miss my flight yesterday as result of the heavy rains and jammed freeways that ensued from the latest "atmospheric river" event in Los Angeles. But I have to admit, I was far more relieved than annoyed by this break (albeit brief) in California's persistent drought - a sentiment shared by all my neighbors and fellow travelers. Yet another reminder of the critical connections between weather, climate, and society, and what's at stake in efforts aimed at planetary stewardship.
Several JPLers are participating in the meeting given the lab's contribution of applying satellite observations to improve scientific understanding of the Earth and support societal decision-making. Collectively, the efforts of us traveling this week span sea, land and air - each reflecting part of NASA's broader mission to study the Earth as an integrated system.
My colleague Dr. Michelle Gierach is part of the NASA delegation at the US Center and will be talking about the ocean and impacts of climate change on key features like the El Nino Southern Oscillation (ENSO). Dr. Sassan Saatchi, who studies forest carbon, will be a panelist at this weekend's Global Landscapes Forum.
My own work these days is mostly focused on heat trapping or "greenhouse" gases in the atmosphere, like carbon dioxide and methane, and understanding the connections with human activity at the scale of countries, states, cities and individual pollution sources. I spend much of my time working with policy makers and scientists to understand stakeholder needs and design monitoring systems that can support practical decision making. It's a big challenge: These monitoring "system of systems" typically require a suite of Earth observing instruments from the ground, air and space - often fused with data from many other information sources. In addition to the technical challenges, after several years in this field, I continue to marvel at the diversity of perspectives, priorities, institutional cultures and ways of thinking, with implications on what data is required. The social dimensions are every bit as important as the bio-geophysical.
I'll say more in subsequent posts about some specific efforts that are underway and how they connect with events at the Lima conference.
TAGS: EARTH, CLIMATE CHANGE
My Big Fat Planet | November 20, 2013
Inside the United Nations Climate Change Conference
Over on My Big Fat Planet, Carmen Boening, a scientist in the Climate Physics Group at NASA's Jet Propulsion Laboratory, is sharing news from the United Nations Climate Change Conference in Poland. Read her reports on the discussions shaping climate change policy and the emotional speech delivered in the wake of Typhoon Haiyan.
Slice of History | July 3, 2013
Seasat Sensors
The Seasat project was a feasibility demonstration of the use of orbital remote sensing for global observation. It was launched on June 26, 1978 and carried five sensors:
-- The Radar Altimeter (ALT) measured wave height at the subsatellite point and the altitude between the spacecraft and the ocean surface. The altitude measurement was precise to within ±10 cm (4 in.). The altitude measurement, when combined with accurate orbit determination information, produced an accurate image of the sea surface topography.
-- The Seasat (Fan-Beam) Scatterometer System (SASS) measured sea surface wind speeds and directions at close intervals from which vector wind fields could be derived on a global basis.
-- The Scanning Multichannel Microwave Radiometer (SMRR) measured wind speed, sea surface temperature to an accuracy of ±2°C, and atmospheric water vapor and liquid water content.
-- The Synthetic Aperture Radar (SAR) was an imaging radar that provided images of the ocean surface from which could be determined ocean wave patterns, water and land interaction data in coastal regions, and radar imagery of sea and fresh water ice and snow cover.
-- The Visual and Infrared Radiometer (VIRR) objective was to provide low-resolution images of visual and infrared radiation emissions from ocean, coastal and atmospheric features in support of the microwave sensors. Clear air temperatures were also measured.
This 1978 illustration was based on a painting, probably by artist Ken Hodges. He created artwork for many different Jet Propulsion Laboratory missions in the 1970s and 1980s, before computer aided animation was used for mission presentations and outreach.
This post was written for “Historical Photo of the Month,” a blog by Julie Cooper of JPL's Library and Archives Group.
TAGS: SEASAT, EARTH, SPACECRAFT, CLIMATE, WEATHER, MISSION,
My Big Fat Planet | February 19, 2013
Ask the Expert - Is It too Late to Reduce Climate Change?
In this new series on "Big Fat Planet," we will answer selected questions about Earth's climate submitted by readers. Recently, a reader asked: "Is there still time to reduce climate change, or is it too late?" The following answer is from Dr. Chip Miller, a researcher specializing in remote sensing of carbon dioxide and other greenhouse gases at NASA's Jet Propulsion Laboratory. He is principal investigator of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) and was deputy principal investigator for NASA's Orbiting Carbon Observatory satellite mission, which was designed to measure atmospheric carbon dioxide from space.
This is a question that has been asked many times and many studies have investigated similar questions: What level of climate change is "acceptable"? What constitutes "dangerous interference" in the climate system?
The short answer is that it's not too late to act, but our past actions may have already locked in certain outcomes and action is needed to avoid more substantial impacts in the future.
In the 1990s and early 2000s it was generally felt that a doubling of carbon dioxide (CO2) in the atmosphere compared to pre-industrial levels -- that is, CO2 concentrations increasing to about 500 parts per million (ppm) - was "acceptable." However, the series of studies from the Intergovernmental Panel on Climate Change (IPCC) has found that as climate models improve, average worldwide surface temperature is projected to increase well beyond the "acceptable" level of 2.0 degrees Celsius (3.6 degrees Fahrenheit) by 2100. (See the IPCC website for the reports and most recent information.)
Jim Hansen (head of NASA's Goddard Institute for Space Studies) has been one of the more outspoken advocates of curtailing CO2 emissions immediately to return atmospheric CO2 levels to about 350 ppm (the level of carbon dioxide that was in the air in the late 1980s). The challenge here is that even if human emissions of CO2 were cut to zero today, there is an inertia in the climate system that would continue for hundreds to thousands of years as the system attempts to re-equilibrate. (See Hansen's Royal Society paper, "Climate change and trace gases," for more details.)
Michael Oppenheimer [Professor of Geosciences and International Affairs at Princeton University] and colleagues have taken a different approach to assessing climate change risk - they define the likelihood of certain environmental outcomes for different levels of atmospheric CO2 accumulation. (See their 2002 Science paper, "Dangerous climate impacts and the Kyoto Protocol," for a look at three potential outcomes at different CO2 levels.)
Further reading:
“Perception of climate change,” J. Hansen, M. Sato & R. Ruedy, Proceedings of the National Academy of Sciences (6 August 2012); doi: 10.1073/pnas.1205276109.
This post was written for "My Big Fat Planet," a blog hosted by Amber Jenkins on NASA's Global Climate Change site.
TAGS: CLIMATE, EARTH, SCIENCE,
My Big Fat Planet | January 10, 2013
In Essence: Science Boiled Down
An interesting recent paper from Dr. Son Nghiem at NASA’s Jet Propulsion Laboratory and colleagues finds that the bottom of the Arctic Ocean controls the pattern of sea ice thousands of feet above on the water’s surface. The seafloor topography exerts its control not only locally, in the Bering, Chukchi, Beaufort, Barents and Greenland Seas, but also spanning hundreds to thousands of miles across the Arctic Ocean.
How? The seafloor influences the distribution of cold and warm waters in the Arctic Ocean where sea ice can preferentially grow or melt. Geological features on the ocean bottom also guide how the sea ice moves, along with influence from surface winds.
Interestingly, the study also links the bottom of the Arctic Ocean with cloud patterns up in the sky. The ocean bottom affects sea ice cover, which affects the amount of vapor coming from the surface of the ocean out into the air, which in turn influences cloud cover.
The researchers, who also come from NASA's Goddard Space Flight Center, the Applied Physics Laboratory and the National/Naval Ice Center in the U.S., use sea ice maps taken from space with NASA’s QuickSCAT satellite, as well as measurements from drifting buoys in the Arctic Ocean. They compare the sea ice and seafloor topography patterns to identify the connection between the two.
Bottom line:
Since the seafloor does not change significantly over many years, sea ice patterns can form repeatedly and persist around certain underwater geological features. So computer models need to incorporate these features in order to improve their forecasts of how ice cover will change over the short- and long-term. This ‘memory’ of the underwater topography could help refine our predictions of what will happen to ice in the Arctic as the climate changes.
Source: “Seafloor Control on Sea Ice,” S. V. Nghiem, P. Clemente-Colon, I.G. Rigor, D.K. Hall & G. Neumann, Deep Sea Research Part II: Topical Studies in Oceanography, Volumes 77-80, pp 52-61 (2012).
This post was written for "My Big Fat Planet," a blog hosted by Amber Jenkins on NASA's Global Climate Change site.
TAGS: EARTH, SCIENCE, CLIMATE,
My Big Fat Planet | January 10, 2013
Pick of the Pics
This is a new image of our planet at night, as taken by a new NASA and National Oceanic and Atmospheric Administration (NOAA) satellite orbiting above us. Scientists recently unveiled this global composite image (and the one below), constructed using cloud-free nighttime images. They show the glow of natural and man-made phenomena across the planet in greater detail than ever seen before. City lights can tell us about how humans have spread across the globe.
Many satellites are equipped to look at Earth during the day, when they can observe our planet fully illuminated by the sun. But with a new sensor onboard the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP) satellite launched last year, scientists now can observe Earth's atmosphere and surface during nighttime hours.
For more Earth at night images, see this article.
This post was written for "My Big Fat Planet," a blog hosted by Amber Jenkins on NASA's Global Climate Change site.
TAGS: EARTH, SCIENCE, CLIMATE,
JPL | December 20, 2010
Red, Red Moon and Other Lunar Eclipse Phenomena
A lunar eclipse occurs when the Earth is positioned between the sun and the moon. Although the Moon passes through the Earth's shadow, the lunar disk remains partially illuminated by sunlight that is refracted and scattered by the Earth's atmosphere.
Refraction is the bending of light that occurs when the rays pass through media of different densities (our atmosphere is more dense near the surface and less dense higher up). Scattering of sunlight by molecules of air also deflects the light into different directions, and this occurs with much greater efficiency at shorter (bluer) wavelengths, which is why the daylight sky appears blue. As we view the sun near sunrise or sunset the light traverses a longer path through the atmosphere than at midday, and when the air is relatively clear, the absence of shorter wavelengths causes the solar disk to appear orange.
Tiny airborne particles, also known as aerosols, also scatter sunlight. The relative efficiency of the scattering at different wavelengths depends on the size and composition of the particles. Pollution and dust in the lower atmosphere tends to subdue the color of the rising or setting sun, whereas fine smoke particles or tiny aerosols lofted to high altitudes during a major volcanic eruption can deepen the color to an intense shade of red.
If you were standing on the Moon's surface during a lunar eclipse, you would see the Sun setting and rising behind the Earth, and you'd observe the refracted and scattered solar rays as they pass through the atmosphere surrounding our planet. Viewed from the Earth, these rays "fill in" the Earth's shadow cast upon the lunar surface, imparting the Moon's disk with a faint orange or reddish glow. Just as we sometimes observe sunrises and sunsets with different shades of orange, pink or red due to the presence of different types of aerosols, the color of the eclipsed lunar disk is also affected by the types of particles that are present in the Earth's atmosphere at the time the eclipse occurs.
TAGS: EARTH, EARTH SCIENCE, GLOBAL CLIMATE CHANGE, GLOBAL WARMING, NASA, LUNAR ECLIPSE
My Big Fat Planet | December 6, 2010
Unchained Goddess: Frank Capra Knew
You might think from the amount of “climate science debate” that is given airtime in the U.S. media that it’s undiscovered territory. But it’s not. The science is very well established and goes back a long way. Global warming is not a new concept.
The Victorians knew about it. John Tyndall (born 1820) knew about it. So did Svante August Arrhenius. In April 1896, Arrhenius published a paper in the London, Edinburgh and Dublin Philosophical Magazine and Journal of Science entitled “On the influence of carbonic acid in the air upon the temperature of the ground.” (Arrhenius referred to carbon dioxide as “carbonic acid” in accordance with the convention of the time.)
Arrhenius’ paper was the first to quantify how carbon dioxide contributed to the greenhouse effect — carbon dioxide warms up the Earth by trapping heat near the surface, a bit like swaddling the planet in an extra blanket. Arrhenius was also the first to speculate about whether changes in the amount of carbon dioxide in the atmosphere have contributed to long-term variations in Earth’s climate. He later made the link between burning fossil fuels and global warming.
Another person who “knew” some time ago was Frank Capra. Graduating from Caltech in 1918, he went on to become a famous filmmaker responsible for “It’s a Wonderful Life” and other movies. But one that stands out, at least for nerds like me or people with an interest in climate change is “Meteora: The Unchained Goddess”, released in 1958.
Made for Bell Labs, this most awesome educational film speaks of “extremely dangerous questions”:
Dr. Frank C. Baxter: “Because with our present knowledge we have no idea what would happen. Even now, man may be unwittingly changing the world’s climate through the waste products of his civilization. Due to our release through factories and automobiles every year of more than six billion tons of carbon dioxide, which helps air absorb heat from the sun, our atmosphere seems to be getting warmer."
Richard Carlson: "This is bad?"
Dr. Frank C. Baxter: "Well, it's been calculated a few degrees rise in the Earth’s temperature would melt the polar ice caps. And if this happens, an inland sea would fill a good portion of the Mississippi valley. Tourists in glass bottom boats would be viewing the drowned towers of Miami through 150 feet of tropical water. For in weather, we’re not only dealing with forces of a far greater variety than even the atomic physicist encounters, but with life itself."
In 1958, they knew about the effects of heating up the planet. In the 1800s they knew about it. Today, the biggest challenge facing climate scientists lies in predicting how much our climate will change in the future. It’s not a trivial task, given how complicated the climate system is — we can barely predict in detail more than a week’s worth of weather. We’re not viewing Miami through bottomed-glass boats yet, but we’re already beginning to see some of the predictions of global warming — melting sea and land ice, sea level rise, more extreme weather events, changes in rainfall and effects on plants and animals — be borne out.
Thanks to OSS and Discovery News for the tip.
This post was written for "My Big Fat Planet," a blog hosted by Amber Jenkins on NASA's Global Climate Change site.
TAGS: EARTH, EARTH SCIENCE, GLOBAL CLIMATE CHANGE, GLOBAL WARMING, NASA
My Big Fat Planet | November 12, 2010
Pulling for the Deniers -- Place Your Bets
I visit the NASA website and review the data. CO2: Up. Ocean and land temperature: Up. Sea level: Up. Polar ice: Down.
Oops.
But, as bizarre as this sounds ... I find myself pulling for the climate change deniers. Wouldn't it be swell if they were right? We could all just relax and ride around in huge cars, and life would be good again.
Like it was in 1970 when I showed up at the first Earth Day. Oh, wait. The smog kind of sucked back then. That might not be the best example.
But, what about the main reason the deniers give not to address climate change?: The cost.
As it turns out, a great example can be found back in smoggy Los Angeles in 1970. Many of us wanted to do something about the horrible choking smog of that era. But, we were told we couldn't afford it.
"We'd love to do something too, Ed, but ... the cost!" Fortunately, we didn't listen to them. Fortunately we also weighed healthcare costs and lost productivity into the equation, and realized the cost of doing nothing was much greater.
And, now, even though we have millions more people in L.A., and four times the cars ... we have far less smog. And, there were many jobs and tremendous wealth created by doing the things that addressed the problem.
Making catalytic converters, combined cycle gas turbines, spray paint booths, and a myriad of other clean technologies of that day - they all created new industries, and brought growth with them.
We have that same choice today. Do we want to accept the costs of doing nothing, and hope that the problem goes away?
So, please, do as I do, and direct everyone you know to reputable sources of climate data, such as NASA's Global Climate Change website. At every talk I give, I make sure that everyone is aware that this information if available. The clock is ticking, and to ignore the science on this one is the worst bet we have ever placed.
Ed Begley Jr. is an Emmy-nominated actor who is active in the environmental community and turns up to Hollywood events on his bicycle. He currently lives near Los Angeles in a self-sufficient home powered by solar energy.
TAGS: EARTH, CLIMATE CHANGE, GLOBAL WARMING, ATMOSPHERE, OCEANS, TEMPERATURE, ENVIRONMENT
JPL | October 15, 2010
Taking On Water Resource Issues
Worldwide today, it is estimated that nearly 1.1 billion people live without access to adequate water supplies and about 2.6 billion people lack adequate water sanitation. Improved understanding of water processes at global and regional scales is essential for sustainability.
Researchers at JPL recently launched the Western Water Resource Solutions website to highlight activities that apply NASA expertise and data to water resource issues in the western United States.
One focus area for this new site is the hydrologic cycle and using global satellite observations of the Earth to improve our understanding of water processes on a regional and local level. The western United States is expected to bear the brunt of impacts to water resource availability because of changing precipitation patterns, increasing temperatures, and a growing population. California is already starting to feel the impacts and is taking action to develop new adaptive management practices to ensure a safe and reliable water supply, while maintaining healthy ecosystems throughout the state.
NASA researchers at Ames Research Center, the Jet Propulsion Laboratory, and Marshall Space Flight Center are currently working with water managers to apply NASA expertise and data to water resource issues in California. The project partners with universities, agencies and other stakeholders, to utilize information from a number of sources, including existing ground observations and models.
This project is only one of several NASA initiatives aimed at providing actionable scientific information on water quality and the water balance worldwide. These other projects include development of better estimates of snow pack, groundwater monitoring, soil moisture and evapotranspiration, water quality, and monitoring fragile levee systems.
In addition to raising awareness about current water resource challenges, the new website highlights NASA's capability to use satellite and airborne data to help solve some of these challenges.
Learn more about the Western Water Resource Solution Group at: http://water.jpl.nasa.gov/
Written as part of Blog Action Day 2010
TAGS: EARTH, CLIMATE, BLOG, ACTION DAY, WATER RESEOURCES, NASA
