By Amber Jenkins

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.

By Erik Conway, writing for My Big Fat Planet

Mars has been a grand scientific mystery ever since the first modern images were beamed back from the Mariner 4 spacecraft in 1965. Those snapshots showed a moon-like, cratered surface — not what we expected. Scientists had assumed that Mars would have an Earth-like atmosphere, composed mainly of nitrogen and with traces of carbon dioxide and water vapor. What they found instead was a cold desert world, one that possessed a thin wisp of an atmosphere containing only carbon dioxide.

Subsequent missions to the Red Planet detected tiny amounts of water vapor in Mars’ atmosphere, and better images began to unveil what looked like river channels and deltas on the surface. Indeed, spacecraft launched in the late 1990s and 2000s found water on Mars in the form of ice, bound into the planet’s soil and in great underground deposits. Water used to flow on the surface of Mars. But how? And where did it all go?

At first sight, the facts defy logic. According to astronomers, the sun used to be dimmer (i.e. colder) than it is now, meaning that Mars (and Earth) should have been colder in the past, not warmer. But observations tell us that it was clearly warmer and wetter on Mars in the past — not colder and more frozen. How did Mars buck the trend and stay toasty in the past? The most likely answer is that it used to have some sort of “super greenhouse effect” going on, the like of which we see on Venus. On Venus, the thick carbon-dioxide-based atmosphere traps the sun’s heat, resulting in surface temperatures that are hot enough to melt lead. Scientists think that early Mars also had a thick, carbon-dioxide-rich atmosphere that provided warming.

That said, in a recent talk at the American Geophysical Union conference in San Francisco, Mars specialist Bruce Jakosky of the University of Colorado pointed out that heat-trapping carbon dioxide alone would not have been sufficient to make Mars warm enough and wet enough to match our observations. Carbon dioxide’s ability to trap heat would have at some point “saturated”, or maxed out. Other greenhouse gases, like methane or ammonia, might have helped trap more heat near the surface of Mars — but they would not have been sufficient either because the sun’s ultraviolet radiation would have destroyed them far too quickly. Ergo, some sort of ultraviolet-absorbing layer high in Mars’ atmosphere would have been needed to help trap the heat. (The Earth’s ozone layer, which dates back to somewhere between 2 and 2.7 billion years ago, performs this service for us now.)

There is, as yet, no evidence of the necessary chemicals on Mars to do this. Jakosky didn’t draw any firm conclusions about how the warmer Mars could have existed. But he did lay out possible future investigations that might help uncover parts of this mystery a little more clearly. One of those includes the MAVEN mission to Mars, scheduled for launch in 2013, which will study how Mars’ atmosphere and climate has changed over time.

As Jakosky has said, in some ways, Mars is a very Earth-like planet. By looking at conditions on other worlds, we can gain insights into how, and why, our own climate is changing here on planet Earth.

You can read more about the Mars Science Laboratory rover here. Scheduled for launch in the fall of 2011, the Curiosity rover will help determine whether Mars has in the past, or does today, harbor life.

This post was written for “My Big Fat Planet,” a blog hosted by Amber Jenkins on NASA’s Global Climate Change site.

By Amber Jenkins

I stumbled upon this video earlier today. It’s Isaac Asimov, famous science fiction writer and biochemist, talking about global warming — back in January 1989. If you change the coloring of the video, the facial hair style, and switch out Asimov for someone else, the video could pretty much have been made today.

Asimov was giving the keynote address at the first annual meeting of The Humanist Institute. “They wanted me to pick out the most important scientific event of 1988. And I really thought that the most important scientific event of 1988 will only be recognized sometime in the future when you get a little perspective.”

What he was talking about was the greenhouse effect, which, he goes on to explain, is “the story everyone started talking about [in 1988], just because there was a hot summer and a drought.” (Sound familiar, letting individual weather events drive talk of whether the Earth’s long-term climate is heating up or cooling down??)

The greenhouse effect explains how certain heat-trapping (a.k.a. “greenhouse”) gases in our atmosphere keep our planet warm, by trapping infrared rays that Earth would otherwise reflect back out into space. The natural greenhouse effect makes Earth habitable — without our atmosphere acting like an electric blanket, the surface of the earth would be about 30 degrees Celsius cooler than it is now.

The problem comes in when humans tinker with this natural state of affairs. Our burning of fossil fuels (coal, oil and gas) constantly pumps out carbon dioxide — a heat-trapping gas — into the atmosphere. Our cutting down of forests reduces the number of trees there are to soak up some of this extra carbon dioxide. All in all, our atmosphere and planet heats up, (by about 0.6 degrees Celsius since the Industrial Revolution) with the electric blanket getting gradually thicker around us.

“I have been talking about the greenhouse effect for 20 years at least,” says Asimov in the video. “And there are other people who have talked about it before I did. I didn’t invent it.” As we’ve stressed here recently, global warming, and the idea that humans can change the climate, is not new.

As one blogger notes, Asimov’s words are as relevant today as they were in 1989. “It’s almost like nothing has happened in all this time.” Except that Isaac Asimov has come and gone, and the climate change he spoke of is continuing.

Asimov’s full speech can be seen here.

This post was written for “My Big Fat Planet,” a blog hosted by Amber Jenkins on NASA’s Global Climate Change site.

By Ed Begley Jr.

A guest blog written for My Big Fat Planet by Ed Begley Jr.

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.

By Stephanie Granger

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