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Showing posts with label Space. Show all posts
Showing posts with label Space. Show all posts

The Future of Earth - Global Warming




Video - The Future of Earth with Global Warming

Abbreviated version of the visualization 'Heating Up,' which depicts climate model projection of 21st century global temperatures. Credit: NASA Scientific Visualization Studio.


“Do we think about the aerosol propellant in our underarm deodorant every day?” Gavin Schmidt, climatologist and director of The Goddard Institute for Space Studies (GISS), asked me. “I don’t think we even have aerosols anymore,” I answered, wondering where he was going with this.

“That’s the point,” he continued, “and nobody cares. Nobody cares where your energy comes from; nobody cares whether your car is electric or petrol. People confuse energy supply with where the energy is supplied from.” He was trying to make the point that as long as people have the things they want, it doesn’t matter, to the vast majority of us, how we get them. This means that as long as the light switch still turns on the lights, most people would barely notice if we were to shift from burning fossil fuels to energy sources with less impact on Earth’s climate (just as people don’t notice that ozone-depleting propellants aren’t used in aerosol cans any more).

I was eager to speak with Dr. Schmidt because of his passion for communicating climate science to public audiences on top of his work as a climatologist. Schmidt is a co-founder and active blogger at Real Climate and was also awarded the inaugural Climate Communications Prize, by the American Geophysical Union (AGU) in 2011. “My goal in communicating,” he explained, “is a totally futile effort to raise the level of the conversation so that we actually discuss the things that matter.”

Since the mere mention of a computer model can cause an otherwise normal person’s face to glaze over, I thought Schmidt, a leader in climate simulations and Earth system modeling, would be the ideal candidate to explain one of the most important, yet probably one of the most misunderstood, instruments scientists have for studying Earth’s climate. See, people commonly confuse climate and weather, and this confusion is perhaps most pronounced when it comes to understanding the difference between a weather forecast and a climate simulation.
Numerical laboratory

Schmidt’s work routine is much like that of any other scientist. He spends a few months preparing experiments, then a few more months conducting the experiments, then a few more months refining and improving the experiments, then a few more months going back and looking at fine details, then a few more months … you get the idea. Climate scientists use complex computer simulations as numerical laboratories to conduct experiments because we don’t have a bunch of spare Earths just lying around. These simulations model Earth’s conditions as precisely as possible. “A single run can take three months on up on super computers,” Schmidt said. “For really long runs, it can take a year.” NASA scientists can reserve time at the NASA Supercomputer Center with High-End Computing Capability to run simulations. Like an astronomer who reserves time on a large telescope to run her experiments, Schmidt books time on these computers to run his.

Schmidt asks the computer to calculate the weather in 20-minute time steps and see how it changes. Every 20 minutes it updates its calculation over hundred-year or even thousand-year periods in the past or the future. “The models that we run process about three to four years of simulation, going through every 20 minute time step, every real day.”

A typical climate simulation code is large, as in 700,000 lines of computer code large. For comparison, the Curiosity Rover required about 500,000 lines of code to autonomously descend safely on Mars, a planet 140 million miles away with a signal time delay of about 14 minutes. The size of a typical app, such as our Earth Now mobile app, is just over 6,000 lines of code. Climate simulations require such a large quantity of code because Earth’s climate is so extraordinarily complex. And, according to Schmidt, “Complexity is quite complex.”

Like a scientist who runs an experiment in a science lab, climate modelers want code that’s consistent from one experiment to another. So they spend most of their time developing that code, looking at code, improving code and fixing bugs.

The model output is compared to data and observations from the real world to build in credibility. “We rate the predictions on whether or not they’re skillful; on whether we can demonstrate they are robust.” When models are tested against the real world, we get a measure of how skillful the model is at reproducing things that have already happened. Then we can be more confident about the accuracy in predicting what’s going to happen. Schmidt wants to find out where the models have skill and where they provide useful information. For example, they’re not very useful for tornado statistics, but they're extremely useful on global mean temperature. According to Schmidt, the credible and consistently reliable predictions include ones that involve adding carbon dioxide to the atmosphere. “You consistently get increases in temperature and those increases are almost always greater over land than they are in the ocean. They’re always larger in the Arctic than in the mid-latitudes and always more in the northern hemisphere than the southern, particularly Antarctica. Those are very, very robust results.”

Lately, his team has been working on improving the code for sea ice dynamics to include the effects of brine pockets (very salty fluid within the ice matrix) as well as the wind moving the ice around. For example, to understand the timeline for Arctic sea ice loss, his team has to work on the different bits of code for the wind, the temperature, the ocean and the water vapor and include the way all these pieces intersect in the real world. After you improve the code, you can see the impact of those improvements.

I asked Schmidt what people’s behavior would look like “if they understood that burning fossil fuels produces carbon dioxide, which causes global warming.” He replied, “People would start focusing on policies and processes that would reduce the amount of fossil fuels without ruining the economy or wrecking society.” Then he added, “I think, I hope! that people will get it before it’s too late.”

I hope so, too...


Gavin Schmidt

Communications Specialist                                           NASA Climate - Earth Right Now
Laura Faye Tenenbaum is a science communicator at NASA's Jet Propulsion Laboratory and teaches oceanography at Glendale Community College.           Contact Laura


A History of the Landsat Science Satellite

Landsat 1 • Landsat 2 • Landsat 3 • Landsat 4 • Landsat 5 • Landsat 6 • Landsat 7 • Landsat 8

From the Beginning

“The Landsat program was created in the United States in the heady scientific and exploratory times associated with taming the atom and going to the Moon,” explains Dr. John Barker. In fact, it was the Apollo Moon-bound missions that inspired the Landsat program. During the early test bed missions for Apollo, photographs of Earth’s land surface from space were taken for the first time.






“This photography has been documented as the stimulus for Landsat,” explains Dr. Paul Lowman, who proposed the terrain photography experiment for the last two Mercury missions, the Gemini missions, and the Apollo 7 and 9 missions.


Thor-Delta rocket prepared to launch Landsat 1, 1972.
Thor-Delta rocket prepared to launch Landsat 1, 1972.

In 1965, director of the U.S. Geological Survey (USGS), William Pecora, proposed the idea of a remote sensing satellite program to gather facts about the natural resources of our planet. Pecora stated that the program was “conceived in 1966 largely as a direct result of the demonstrated utility of the Mercury and Gemini orbital photography to Earth resource studies.”


While weather satellites had been monitoring Earth’s atmosphere since 1960 and were largely considered useful, there was no appreciation of terrain data from space until the mid-1960s.
So, when Landsat 1 was proposed, it met with intense opposition from the Bureau of Budget and those who argued high-altitude aircraft would be the fiscally responsible choice for Earth remote sensing.


Concurrently, the Department of Defense feared that a civilian program such as Landsat would compromise the secrecy of their reconnaissance missions.
Additionally, there were also geopolitical concerns about photographing foreign countries without permission.


In 1965, NASA began methodical investigations of Earth remote sensing using instruments mounted on planes. In 1966, the USGS convinced the Secretary of the Interior, Stewart L. Udall, to announce that the Department of the Interior (DOI) was going to proceed with its own Earth-observing satellite program.


This savvy political stunt coerced NASA to expedite the building of Landsat. But, budgetary constraints and sensor disagreements between application agencies (notably the Department of Agriculture and DOI) again stymied the satellite construction process.
Finally, by 1970 NASA had a green light to build a satellite. Remarkably, within only two years, Landsat 1 was launched, heralding a new age of remote sensing of land from space.


The Landsat satellite record stretches from 1972 to the present. This gallery includes all Landsat images published on the Earth Observatory, Visible Earth, and Landsat Science web sites from all seven Landsat satellites (Landsats 1-8, Landsat 6 failed to achieve orbit). All of the images are in the public domain and may be used with attribution. The correct attribution for imagery obtained from this site is:


“Landsat imagery courtesy of NASA Goddard Space Flight Center and U.S. Geological Survey” or “USGS/NASA Landsat”





More History

 












Learn about the Landsat Legacy project        Landsat Science



Curiosity Mars Rover moves On - Alexander Hills

Within Rover's Reach at Mars Target Area 'Alexander Hills'





This view from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover shows a swath of bedrock called "Alexander Hills," which the rover approached for close-up inspection of selected targets.

The mosaic of six Mastcam frames covers an area about 6 feet (2 meters) across. It shows details within the workspace accessible using the rover's robotic arm from the rover's location when the view was acquired. The component exposures were taken on Nov. 23, 2014, during the 817th Martian day, or sol, of Curiosity's work on Mars. The color has been approximately white-balanced to resemble how the scene would appear under daytime lighting conditions on Earth.

Figure A is an annotated version showing the location of three targets selected for study -- "Aztec," "Agate Hill" and "Cajon" -- and a 50-centimeter (20-inch) scale bar.

The location of Alexander Hills within the "Pahrump Hills" outcrop at the base of Mount Sharp is indicated on an earlier Mastcam view at http://photojournal.jpl.nasa.gov/catalog/PIA19039. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover. Malin Space Science Systems, San Diego, built and operates the rover's Mastcam.

Image Credit: NASA/JPL-Caltech/MSSS

Erosion Resistance at 'Pink Cliffs' at Base of Martian Mount Sharp
Erosion Resistance at 'Pink Cliffs' at Base of Martian Mount Sharp
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Ripples Beside 'Pahrump Hills' Outcrop at Base of Mount Sharp
Ripples Beside 'Pahrump Hills' Outcrop at Base of Mount Sharp
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Erosion Resistance at 'Pink Cliffs' at Base of Martian Mount Sharp
Erosion Resistance at 'Pink Cliffs' at Base of Martian Mount Sharp (Labeled)
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Fine-Grained Rock at Base of Martian Mount Sharp
Fine-Grained, Finely Layered Rock at Base of Martian Mount Sharp
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Fine-Grained Rock at Base of Martian Mount Sharp
Fine-Grained, Finely Layered Rock at Base of Martian Mount Sharp (Labeled)
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NASA - MARS




The Florida Peninsula at Night from Space

                         
                           
Astronauts aboard the International Space Station took this photograph of Florida in October 2014. The peninsula is highly recognizable even at night, especially when looking roughly north, as our map-trained brains expect.



Astronaut photograph ISS041-E-74232 was acquired on October 13, 2014, with a Nikon D3S digital camera using a 24 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by the Expedition 41 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Jacobs at NASA-JSC.



Florida at Night


acquired October 13, 2014 download large image (2 MB, JPEG, 2128x1416)



Illuminated areas give a strong sense of the size of cities. The brightest continuous patch of lights is the Miami-Fort Lauderdale metropolitan area, the largest urban area in the southeastern U.S. and home to 5.6 million people. The next largest area is the Tampa Bay region (2.8 million people) on the Gulf Coast of the peninsula. Orlando, located in the middle, has a somewhat smaller footprint (2.3 million). A nearly straight line of cities runs nearly 560 kilometers (350 miles) along the Atlantic coast from Jacksonville, Florida, to Wilmington, North Carolina.

South of Orlando, the center and southern portions of the peninsula are as dark as the Atlantic Ocean, vividly illustrating the almost population-free Everglades wetland. The lights of Cocoa Beach trace the curved lines of Cape Canaveral and the Kennedy Space Center, an area well known to astronauts. Dim lights of the Florida Keys extend the arc of the Atlantic coast to the corner of the image. The small cluster of lights far offshore is Freeport on Grand Bahama Island (image right). The faint blue areas throughout the image are clouds lit by moonlight.
Instrument(s): 
ISS - Digital Camera
NASA Earth Observatory