Month: April 2011

On Earth Day: A Look Back at System Z and the Early Days of EOS

I get plenty of quizzical looks when I tell people I’m a NASA science writer who covers Earth science.

“Earth science? NASA?”

There’s often a pause for a few seconds as the person I’ve told mulls this over. For a surprising number of people, that combination of words doesn’t compute.

Often strings of questions follow: “Oh, so you must write about the Space Shuttle, right? Do you know how long it would take to send astronauts to Mars? Do you think there’s life on Titan?”

When I explain that most of what I write about involves unmanned Earth-observing satellites that monitor less exotic phenomena such as Earth’s weather and climate — not astronauts — it frequently comes as a let-down.

This week, however, I stumbled across a fascinating tidbit of NASA history that reminded me that the line between Earth science and manned spaceflight hasn’t always been so stark.

As I was looking back at the origins of NASA’s current fleet of Earth-observing satellites for a feature story about a soon-to-launch satellite called NPP, I did some reading about an intriguing plan to have manned spaceflight at the center of NASA’s Earth science efforts.

One of the early strategies proposed for monitoring Earth — developed in the late-1970s and early-1980s and dubbed System Z — called for the Space Shuttle to lift a series of Hubble-sized, polar-orbiting Earth-observing platforms into space. 

Spacewalking astronauts would assemble the massive platforms and perform regular maintenance on the instruments. The money for System Z  would have come from  Space Station Freedom (the NASA project that led eventually to the current International Space Station). If implemented, the ambitious plan would have been one of the most expansive projects NASA had ever undertaken and rival the Apollo program in scope and complexity.

Looking back, it was heady stuff. The goal was to make a broad suite of coordinated measurements that would parse out how the many components of the Earth system function as an interconnected whole.

However, the Challenger disaster — and the realization that large platforms were too risky — dealt System Z a serious blow. When NASA abandoned efforts to launch the Space Shuttle from Vandenberg Air Force Base in California, a site  better than Cape Canaveral in Florida for achieving polar orbit, plans for an astronaut-tended Earth-observing platforms faded away as well.

But the dream of having satellites making a broad array of coordinated measurements from polar-orbiting platforms didn’t. It morphed instead, after a decades of downsizing and rescoping, into the current configuration of the Earth Observing System (EOS), a fleet of unmanned spacecraft that is anchored by the medium-sized flagships Terra, Aqua, and Aura. 

Today, more than a decade after the launch of the first EOS flagship, data from EOS satellites have revolutionized earth and climate science. Thousands of technical papers have been published based on EOS data and the satellites have helped pioneer a whole new branch of science called Earth Systems Science. 

Want to learn more about the early days of the EOS program? The NASA Earth Observer newsletter has been running a fascinating series of perspective pieces authored by the people who helped conceive it that make for good Earth Day reading. Here are a few of them:


Imagery
Top: This Earthrise photo was the first view of Earth captured by astronauts in lunar orbit. Credit: NASA
Middle: NASA’s constellation of Earth-observing satellites as of 2011. Credit: NASA
Bottom: An early sketch of “System Z.” Credit: Mark Abbott; Originally published by the Earth Observer


–Adam Voiland, NASA’s Earth Science News Team

Have the Last Four Summers and Winters Felt Warmer?


During a congressional hearing in 1988, Goddard Institute for Space Studies climatologist James Hansen predicted that a perceptive person would be able to notice the climate was changing by the early 21st century. Has his prediction panned out? He digs into the topic in a discussion published this week on his website.


The short answer: yes, depending on where you live, you should be able to tell that in the last four years, for example, summers have been warmer than average. The last four winters have also been noticeably mild in most parts of the world. (Though it’s worth noting that the last two winters in the continental United States have actually been cooler than average).

Read on below to see how Hansen explains it in more detail. (I’ve excerpted some of the more accessible sections of the text and two graphs, but the full discussion is available here as a pdf.)  More context and details about trends in the global surface temperature record are also available.

This past winter, for the second year in a row, seemed pretty extreme in both Europe and the United States. So this is a good time to check quantitatively how seasonal climate change is stacking up against expectations.

People’s perception of climate change may be the most important factor determining their willingness to accept the scientific conclusion that humans are causing global warming (or global climate disruption, as you please). Itis hard to persuade people that they have lying eyes.

In the paperattached to my congressional testimony in 1988 (1) we asserted that theperceptive person would notice that climate was changing by the early21st century. Now we can check the degree to which the real world has lived up to this expectation. The answer will vary from one place to another, so let’s make a global map for this past winter. Each gridbox will be colored red, white or blue, depending on how the local temperature this past winter compared with the categories established by the 1951-1980 climatology.

Figure 7 (above) shows the result for the last four winters (summers in the Southern Hemisphere). To make the maps even more useful we use dark blue and dark red to show those places in which the temperature fell in the extreme (>2 standard deviations) category that occurred only a few percent of the time in the period of climatology1. The extreme cases are important because those are the ones that have greatest practical implications, especially for nature. Species are adapted to climate of the past, so a change to more extreme climates can be detrimental, especially if it occurs so rapidly that species cannot migrate to stay within tolerable climatic conditions.

The numbers on the top of the maps are the percent of the area falling in the five categories: very cold, cold, normal, hot, very hot. In the period of climatology those numbers averaged 2%, 31%, 33%, 31%, 2%, rounded to the nearest percent.

Figure 7 reveals, for example, that the past two winters in Northern Europe both fell in the category of “cold” winters, but not extreme cold. The area hot or very hot (51-73%) far exceeded the area with cold or very cold conditions in all four years (14-27%).

Figure 8 (top) shows results for Jun-Jul-Aug for each of the past four years. In both Jun-Jul- Aug and Dec-Jan-Feb it is apparent that the area falling in either the hot or very hot category totals 64-78% in agreement with our 1988 climate simulations.

The perceptive person who is old enough should be able to recognize that the frequency of unusually mild winters is now much greater than it was in the period 1951-1980. But mild winters may not have much practical impact. So a return to one or two colder than average winters may affect the public’s perception of climate change.

On the other hand, the huge increase in the area with extremely hot summers, from 2-3% in 1951-1980 to as much as 30-40 percent in recent years and most of the land area in 2010. If people cannot recognize that summers are becoming more extreme they may need to have their senses examined or their memories. Perhaps the people who do not recognize climate change are living in air-conditioned environments, which are restricted mainly to one species.

–Adam Voiland, NASA’s Earth Science News Team

Tsunami Hits Home for Goddard Scientist

On March 11, Teppei Yasunari, 31, a visiting scientist at Goddard Space Flight Center, heard that a massive earthquake off the coast of Japan had rocked his homeland and unleashed a deadly tsunami. For Yasunari, an atmospheric scientist who studies the climate effects of tiny airborne particles called aerosols, the frantic days that followed have offered powerful lessons in both patience and science communication as Yasunari grappled with the news that one of his best friends was missing and that a nuclear plant in Fukushima prefecture seemed poised to send a plume of radioactive steam aloft. We sat down with Yasunari to hear his perspective on the disaster.

WoE: You are both an Earth scientist and Japanese. What went through your mind when you heard about the tsunami?

Yasunari: Like everybody, I was shocked. There are no words to describe it. It was hard to believe the video clips I was seeing on the web.

WoE: I know you grew up in Kyoto and Tsukuba, but have you spent any time in Sendai?

Yasunari: Some. I went to undergraduate college in Aomori prefecture, which is not so far from Sendai. I have visited friends who live in Sendai a number of times. 

WoE: Were your friends from college ok?

Yasunari: One of the first things I did after I heard the news was try to contact one of my best friends from Hirosaki University who now lives in Iwate prefecture, which is just immediately north of Miyagi prefecture, the prefecture the earthquake hit the hardest. I tried emailing and calling, but I couldn’t get through. All lines of communication were down. I tried calling friends of friends. Nothing worked. Finally, I registered his name in Google Person Finder.

WoE: How long were you in limbo?

Yasunari: About three days. Finally, I saw something on Person Finder that said he was probably ok. A friend of his from grade school had heard from somebody else that a firefighter had found him. I later heard through Person Finder that he’d been moved to someone’s home, but I still haven’t been able to email or call him. On March 22, I did get an e-mail directly from him. He said his house has been completely destroyed by the tsunami. It was such a relief to have finally heard from him directly.

WoE: I imagine you must have been glued to the Internet looking for information. 

Yasunari: Yes, especially Twitter, Facebook, and Japanese SNS. Since the phone and power is out in some parts of Japan, these sites are often the quickest way to get information. My personal Twitter feed is @TJ_Yasbee.

WoE: Did you look to Twitter for scientific information about what was going on with the earthquake and nuclear plant?

Yasunari: Yes. Actually something surprising happened on Twitter. Since I have studied the long range transport of aerosols, I calculated some air mass transport patterns using the NOAA atmospheric dispersion model called HYSPLIT when I heard about the possibility of a radioactive plume, I wanted to help, so I made some simple figures that showed what direction, based on the model, a plume might move.

WoE: And you tweeted the figures? 

Yasunari: Yes. I only had less than 300 followers at that point. However, a physicist from the University of Tokyo, Ryugo Hayano, saw the figures and contacted me by email. He ended up tweeting his comments with my figure to his more than 40,000 followers. Neither of us could have imagined how quickly that tweet spread. It wasn’t long before newspapers were contacting me to use the figures. I couldn’t believe it.

WoE: Forty-thousand followers is quite a lot for a scientist.

Yasunari: He is well known. He tweets from @hayano. Now he has more than 150,000 followers in just a couple of days because of the earthquake. 

WoE: Did you see a surge of followers on Twitter as well? 

Yasunari: Yes, originally I had about 300. Now I have more than 2,100.

WoE: How did people react to the figures?

Yasunari: The model I made the figures with has quite a coarse resolution, and it can’t show any more than a broad view of how a plume might move. But people in Japan are so worried about the threat of radiation and eager for information that some of them treated it like it was very fine resolution and accurate. 

WoE: So did the newspapers end up using the figure?

Yasunari: In the end, in consultation with a scientist from NOAA, we decided that it would be more confusing than helpful for the public. We asked the newspapers not to use them, and I took them down from Twitter. I learned a lot from this.

WoE: You can’t really delete a tweet, though, can you?

Yasunari: No, but I had tweeted it through Twitpics, and professor Hayano had use a similar site called Plixi, so we were able to take the figures down.

WoE: It certainly raises interesting questions about social media and science communication. Do you wish you had never tweeted the figure in the first place?

Yasunari: Yes and no. The tweet was intended just for my small number of followers, but I never realized how quickly it would spread. Of course, I expected it would spread some, but I didn’t expect it to go viral. In the future, I will be much more aware that the public doesn’t pay much attention to the uncertainties when I show a figure.

At the same time, I wish they would. Twitter and other social media can be a very convenient way for scientists to communicate, so I don’t want to say that scientists should never use social media or have a blog. I guess the best thing to do is try to find a balance between showing too much information and too little.

WoE: What about your family? Were they affected by the earthquake? 

Yasunari: I contacted my family immediately after the earthquake. They were fine because they live in a western part of Japan, about 500 miles away from Sendai. We were extremely lucky. My father, also a scientist, was supposed to be in Sendai on business the day of the earthquake. Fortunately, he canceled the trip the day before he was suppose to leave because he was busy with other things. 

WoE: How lucky. Does your father also study aerosols and climate? 

Yasunari: No, but he is also an atmospheric scientist. He focuses on meteorology and climatology related to Asian monsoons. In fact, he has collaborated with Bill Lau, the chief of the branch I’m in at Goddard. Both Bill Lau and my father are examining the idea that aerosols can have an important impact on the monsoons — a hypothesis called the “elevated heat pump.”

WoE: Is that a topic that you study as well?

Yasunari: In some ways, yes. I recently published a paper that will help quantify how much black carbon and dust are affecting the rate of Himalayan glacier retreat. Another study, led by a scientist from the Pacific Northwest National Laboratory, cited both my paper and my father’s paper at the same time. It was the first time double Yasunari reference in the same paper.

WoE: Thanks for talking to us, and best of luck to your friend.

Yasunari: You’re welcome.  I know Japan will overcome this difficult situation.

Top Image: A United States Air Force satellite observed the widespread loss of electricity in parts of northeastern Japan after the earthquake. The image, a composite, shows functioning electricity from 2010 and 2011. Red indicates power outages detected on March 12, 2011, compared to data from 2010. For more information about the map, please visit this page. Credit: NASA Earth Observatory/NOAA National Geophysical Data Center.

Middle Image: Teppei Yasunari in his office. Credit: NASA/Adam Voiland

Lower Image: A shaking intensity map based on USGS data shows ground motion at multiple locations across Japan during the earthquake. A shaking intensity of VI is considered “strong” and can produce “light damage,” while a IX on the scale is described as “violent” and likely to produce “heavy damage. For more information about the map, please visit this page.  Credit: NASA Earth Observatory/Rob Simmon & Jesse Allen

–Adam Voiland, NASA’s Earth Science News Team