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Icebergs dot the seascape in Baffin Bay,

Baffin Island, specifically, the largest island in Canada.

“What are we doing all the way out here?” I thought. If I looked out the left side of NASA’s modified G-III aircraft, I could see Canada out the window—Baffin Island, specifically, the largest island in Canada, part of its northeast territory. And if I looked out the right side, I could see the west coast of Greenland. We were pretty much halfway between the two, right in the middle of Baffin Bay, and I was surprised.

Baffin Bay in Eyes on the Earth
Baffin Bay as it appears in NASA's Eyes on the Earth interactive.
I was surprised that it was even possible to see Canada from Greenland. Most maps are so distorted in the high latitudes that both distance and perspective are off, and I hadn’t realized that the two islands were as close as they are to each other – just about 200 miles apart in some places. I also didn’t realize that Oceans Melting Greenland had planned to gather ocean temperature and salinity profiles so far offshore from Greenland’s coastline.

At a glacial pace

I went over to where Flight Engineer Terry Lee kept the map of all the scheduled drop positions and stared at it for a while. She’d marked with a green highlighter the places where she’d already released science probes through a tube in the bottom of the plane. (Hahahah, yes! There’s a hole in the plane through which Aircraft eXpendable Conductivity Temperature Depth (AXCTD) probes leave the aircraft to travel 5,000 feet down to the sea surface and then another 1,000 meters into the ocean, sending back data as they go.)

Baffin Bay map with highlighted drop sites
Lee's map of the scheduled drop sites.
And even though I’d seen this map before, the yellow dots representing scheduled probe drops were right in front of me, out in the middle of the sea, about 100 miles off the coastline. And that confused me because I presumed that this location, this far out at sea, wouldn’t have a layer of fresh water at the sea surface. I figured this far out we’d find salty 3- to 4-degree North Atlantic Ocean Water at the sea surface. So why weren’t we closer to shore where the land ice was melting?

I looked out the window as we flew on. Icebergs dotted the seascape. Each one had once been part of a vast ice sheet that’s been around for hundreds of thousands of years. Each one had moved – at a glacial pace, mind you – from the interior, down through one of the many fjords that slice through the Greenland coastline, and finally out to sea, where they would ultimately melt away. The ‘bergs were large, and it was fun to fly over them and look at their perfect whiteness against the stunning blue sea. All of us would gather on one side of the plane as we passed over a ‘berg, and then quickly jump to the other side to look for it again as we passed by it. But even though there were hundreds of icebergs floating around out there, Baffin Bay is vast — more than 250 thousand square miles. So, in the grand scheme of things, the icebergs seemed inconsequential, incapable of affecting the ocean salinity more than a small amount.

Real-time data

Project Manager Steve Dinardo
Project Manager Steve Dinardo tracks the real-time data coming from the ocean probes.
I was in the midst of pondering all this, not wanting to bother any of the busy team members, when Oceans Melting Greenland Project Manager Steve Dinardo called me over to the bank of computer monitors where he was working. He motioned for me to trade headsets. After I gave him mine and I put on his, I could hear the AXCTD probe sending its signal to the plane as it descended through the water column, and the noise reminded me of the sound a Wookiee from Star Wars makes.

As I was listening, I could see temperature and salinity values arriving in real-time on the monitor. “Wow, no way!” I exclaimed. “That’s insane.” All the way in the middle of Baffin Bay, 100 miles offshore, the ocean was fresher on the surface. I watched the salinity values increase as the probe sank. The temperature profile also reflected a scenario of near-zero-degree water at the surface with 3- to 4-degree ocean water below. That upper layer is Arctic Ocean Water, which is way less salty than the warmer North Atlantic Ocean Water that lies beneath it.

An iceberg
One of the many icebergs we flew by.
And this is the whole point of NASA’s Oceans Melting Greenland mission—to find out how far that warmer North Atlantic Ocean Water has penetrated. Knowing this will help us measure the quantity and rate at which the warmer North Atlantic Ocean Water is melting the Greenland Ice Sheet.

I walked back to look at the yellow dots on the map of the scheduled probe drops one more time. We were as far away from the coast as we would be; the rest of the drops were closer to shore. I wondered how the temperature and salinity profiles in the coastal waters would compare to those from the open ocean.

And the point of the mission flooded my mind again. I looked out the window, across the stretch of Baffin Bay at the Greenland coastline, where groups of icebergs dotted the horizon. In this vast expanse, no one’s done this before, no one knows what this ocean water is like, and we are about to find out.

Find out more about Oceans Melting Greenland.

View and download OMG animations and graphics.

Thank you for your comments.




NASA's Student Airborne Research ProgramYoutube video

NASA's Student Airborne Research Program trains future climate scientists.

We receive a lot of questions, especially from students, asking us for information about how to get a job at NASA. Well, there’s more than one way to get hired here. But one of the most awesome methods we have of training young scientists and preparing them for potential hire here (or a great position anywhere) is by recruiting university undergraduates for our Student Airborne Research Program (SARP)

SARP is our eight-week summer program for college seniors with academic backgrounds in engineering or physical, chemical or biological sciences and an interest in remote sensing. We select about thirty students based on their academic performance, their interest in Earth science and their ability to work in teams. These students receive hands-on research experience on NASA's DC-8 airborne science laboratory. Yup, they get to fly on a modified NASA plane out of NASA’s Armstrong Flight Research Center, in Palmdale, Calif., where they help operate instruments onboard the aircraft and collect samples of atmospheric chemicals.

Did I already say “awesome”? Oh right, I did. Well, I’ll say it again: Awesome.

Many students apply hoping to gain more research experience for graduate school. The whole air sampling team, which is exactly what it sounds like, collects air from around the plane in canisters as it’s flying through different locations and altitudes at different times. The air enters the plane from the outside through an inlet, a pipe sticking out of the plane. The student scientists open the canisters, allowing air from outside the airplane to suck into the can. Then they take the air samples back to the lab at the University of California, Irvine, for analysis and interpretation.

SARP students analyze the air samples for hydrogen, carbon monoxide, carbon dioxide, methane, hydrocarbons, nitrates, oxygenates and halocarbons. Research areas include atmospheric chemistry, air quality, forest ecology and ocean biology.

Once the airborne data has been collected and analyzed, the students make formal presentations of their research results and conclusions. Over the past seven years, the program has hosted 213 students from 145 U.S. colleges and universities. And this year we look forward to helping our latest crop of SARP students gain research experience on a NASA mission, work in multi-disciplinary teams and study surface, atmospheric and oceanographic processes. 

Find out what SARP students thought about their experience here.

Find out more about SARP and other Airborne Science Programs here.

Thank you,


SARP is part of NASA Earth Expeditions, a six-month field research campaign to study regions of critical change around the world.



Credit: Nemeziya / Shutterstock.com.

Cimate change news is intense. Ice caps are melting, the fire season lasts all year long; we have epic storms plus record-breaking floods, droughts and cyclones.

And this year will probably be the Hottest. Year. Ever.

When I interact with the public, I’m bombarded with questions such as “Are we all going to die?” and “How soon will humans go extinct?”

Happy Earth Day, everyone (wipes brow, rolls eyes).

Yet, when I wake up in the morning I'm excited to come to work. I'm energized. I’m amped, really amped. As in, kicking-butt-and-taking-names amped. Why? Because global warming is the greatest challenge of our lives, and challenge is what drives us. Challenge provides us with opportunity, challenge forces us to grow, challenge opens the way for amazing achievement. Challenge is exciting. Without challenge, without struggle, without discomfort, no one would ever advance.

So, when someone gets in my face and is super negative, I try to stay powerful, strong and confident. I tell myself that pressure is okay and I'm going to keep moving no matter what. Because I care about this planet so much that I choose to make a difference.

Yes, carbon dioxide levels are high and increasing rapidly. Yes, future generations will have some extraordinarily difficult challenges to deal with. But denial, avoidance and helplessness aren’t solutions. Can you imagine if we NASA peeps just sat there saying “Oh no, that’s too hard” when faced with huge obstacles? Are you kidding me? Come on! You think it’s easy to build science instruments on satellites and launch them into space? You think it’s easy to measure glaciers melting around the edges of Greenland, or the condition of coral reefs in the Pacific, or plankton blooms across the North Atlantic, or conduct eight field research campaigns in one year?

When the going gets tough—and it does, almost every day—we don’t just stop. We keep working. We know that no successful person got As on every test and that failure and struggle are part of accomplishment. We know that grit and determination will get you everywhere!

In this blog, I write about ocean pollution, sea level rise, climate change and decreasing biodiversity not to scare you, but to empower you, so we can make a difference—you and I, together. Someone reading this blog entry might be the creator of a new breakthrough technology, and then there will be a whole new reality.

So, when you think about the challenge of climate change this Earth Day, consider the possibility of welcoming that challenge. Our shared story could be a story about not giving up, about looking forward to growth, about saying, “Game on.”

Find out more about NASA earth expeditions here.

Join NASA for a #24Seven celebration of Earth Day.

Thank you for caring enough to make a difference and for being powerful in the world.




Earth climate visualization videoYoutube video

“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 for High-End Computing Capability at the NASA Advanced Supercomputing facility and/or the NASA Center for Climate Simulation 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.

› Visit Earth Right Now to comment on this post



Peas with an image of Earth

"Excuse me. What kind of plants are those?"

I was squatting down in my front yard as I do every morning, picking veggies for breakfast, when I heard a voice behind me. I stood up and turned around. It was a neighbor from across the street and three houses down. "They're peas," I told him.

A few years back, we were among the first in our neighborhood to rip out the grass in our parkway so we could plant drought-tolerant succulents and other cool-looking plants instead of boring, old, water-sucking grass. Little did I know that, along with saving money and water, the process also attracted the curiosity of lots of people on our street. We were bucking the trend, breaking the norm, doing something different. And people wanted to hear all about our new way-cooler-looking-than-grass plants.

Then we created a vegetable garden in the front yard. The goal was to have a cool modern-looking yard and have some fun growing and eating good food. We succeeded in harvesting enough kale, tomatoes, artichokes, chard and peas to feast on for many weeks (and I was able to include my own home-grown items in the yummy edible NASA satellite models I made).

But our gardening exploits brought us another unexpected advantage. We were already growing food in our backyard and side yard, but we learned that when you plant cool stuff in the front yard, lots of passersby stop to check it out. It's usually the artichokes that evoke the most frequent comments and questions. I mean, artichokes are weird-looking. (Shhh, don't you dare tell them I said that!) But over the years our vegetable garden has become a magnet that's attracted friendship and community in our neighborhood. And we've seen many other lawns turn into gardens, too.

There's no way to tell what will unfold when you start to do something, even the smallest thing. Actions grow and expand, sort of like the way our peas started out small, crawled past their trellises and are now getting tangled up into each other. What you create in the world can take on a life of its own, beyond what you might ever imagine.

Every Earth Day I write about taking an individual action, and every time I write this I get all kinds of criticism about how doing one small thing isn't enough.

But next time you start to think that your actions are too small to make a difference, think about me and my silly old peas. Remember that I reached down, picked a fresh pea and handed it across the stucco wall to the guy who lives down the street-the guy whom I hadn't yet connected with in all these years; one of the last of my neighbors to reach out. He told me that he and his wife saw our yard and decided to plant a garden as well.

And while you're at it, remember to celebrate Earth Day this year by joining NASA as we all share views of our favorite place on Earth on social media. We hope that if all of us take a moment to acknowledge and remember our planet, we'll feel more connected to it.

You can post photos, Vines and/or Instagram videos. Just be sure to include the hashtag #NoPlaceLikeHome - no matter what social media platform you're using.

You can also get on board now by using our #NoPlaceLikeHome emoji as your profile pic. Join the Facebook or Google+ events and invite your friends to participate. Pledge to spend one day celebrating the planet that over 7 billion people call home.

Find out more at http://www.nasa.gov/likehome/.

Thanks for everything you do to care for our planet.

I look forward to your comments.

- Laura

› Visit Earth Right Now to comment on this post



Animation of the Soil Moisture Active Passive spacecraft spinning its antenna while orbiting Earth.Youtube video

This Thursday, March 19, NASA's latest mission will begin preparation for its next great milestone: making the wicked-amazing antenna rotate.

A number of spacecraft have rotating parts, such as the RapidScat mission and the Global Precipitation Measurement (GPM) mission, but those don't hold a candle to the dynamics of Soil Moisture Active Passive (SMAP).

SMAP's antenna is 20 feet in diameter. The larger the antenna, the more complex its behavior can be, which makes it more difficult to control. Just imagine swinging a 20-foot baseball bat over your head. Yikes!

Right now the antenna is locked in position until the mission "ops" (operations) team completes its checks of the entire instrument's function and confirms operability. They have taken measurements with the radar and the radiometer. They know the instruments are working by comparing the measurements to how they were tested on the ground before launch. The signals look appropriate; they're seeing what's expected. But the antenna's fixed position means it's measuring only a small strip of the ground below.

Once the antenna starts to spin, we'll be able to measure a much larger area and monitor soil moisture around the entire Earth every two to three days.

These are the three steps to achieving "spin up":

1. Engineers unlock the antenna.

2. A few days later, they spin the antenna slowly.

3. They gradually spin it faster.

At each step, they'll verify how it's performing. The engineers will then conduct a more comprehensive checkout of the instrument's systems. With the antenna spinning, they'll get to see the instrument's full performance for the first time.

After the spinning checkouts are completed ... Voilà! Bibbidi bobbidi boo! SMAP will start mapping global soil moisture and return data!

I look forward to your comments.

- Laura

› Visit the Earth Right Now page to join the conversation



Illustration of a bird and outlined wings

Unless you call yourself a rocket scientist, you probably don’t think your daily routine has much in common with flight software engineering. But you would be wrong.

Flight software engineers write computer code for NASA spacecraft, which is complicated because—hello—flying spacecraft into space is complicated.

Flight software runs the instruments and sensors that operate thermal control, spin stabilization on all three axes, uplink and downlink to communicate with spacecraft, data collection and handling, a cruise phase, a descent phase and sometimes a “landing on the surface of a planet” phase. And some of this happens simultaneously. (And I thought feeding the cat and dog at the same time was rough.)

If the spacecraft is far away, like, dude, on Mars or beyond, there’s no controlling it from the ground with a joystick, so the software has to be written to allow the spacecraft to run autonomously.

But the experiences of a flight-software-engineering person* are actually the same as the experiences of a regular-person person, from planning a family reunion, to cleaning the garage, to simply shopping for tonight’s dinner. If you skip the bits about the flying, disregard the software and pay no attention to the engineering, then what you’re left with is some amazingly useful life lessons:

› Continue reading this post on NASA's Global Climate Change website




Screengrab from a time-lapse video of Los Angeles

Illustration of the ground-based instruments and aircraft tracking CO2 in Los Angeles

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.

We arrived in Lima, Peru, late last night and made our way to the United Nations climate conference venue this morning -- an impressive complex known locally as the Pentagonito or “Little Pentagon.” As host country and city, Peru and Lima are representative of several key fronts in the international effort to confront climate change. Peru is home to some of the most significant tropical forests on Earth that are the focus of programs to preserve their vital role in storing carbon and critically endangered ecosystems (more about that tomorrow). With a population approaching 10 million people, Lima itself is a rapidly growing megacity -- one of many in the developing world.

The latter topic is the focus of this post and the event I’m participating in later today at the US Center: “Understanding the Carbon Emissions of Cities.” I’ll be joining colleagues from the US National Institute of Standards and Technology, Arizona State University, Laboratoire Des Sciences du Climat et de l'Environnement (France), and Universidade de São Paulo (Brazil) in presenting the motivation for and recent scientific advances in monitoring urban carbon pollution. There won’t be a live stream but the event will be recorded - keep an eye on the US State Department’s YouTube page where it should be posted this weekend.

So what is “carbon pollution” and why should we care about it? Most of us are familiar with the general topic of air pollution; just ask anybody who has asthma or knows a friend or family member with respiratory problems. Cities are notorious sources of air pollutants or smog -- including visible particles (aerosols) and invisible but caustic ozone. One can find many examples of success stories where air quality has improved in response to clean-air standards as well as horror stories in cities lacking such standards. However, this familiar topic of air quality is mostly limited to short-lived pollutants -- compounds that only persist in the atmosphere for hours or days. Those pollutants are important because of human health impacts but they’re not primary drivers of climate change. Carbon dioxide (CO2) and methane (another carbon-based molecule) on the other hand, are long-lived gases that trap heat in the atmosphere for many years. Once CO2 and methane are in the atmosphere, they remain there for a long time -- centuries, in the case of CO2. Most people are unaware of the presence of CO2 and methane because they’re invisible and odorless and don’t have an immediate impact on health, but those gases are THE big drivers of climate change.

There are many sources of CO2 on Earth, including natural emissions that, prior to the industrial revolution, were balanced by removals from natural carbon scrubbers like forests and oceans. However human activity is rapidly changing the balance of CO2 in the atmosphere, leading to an unprecedented growth rate. Most of these human CO2 emissions come from burning fossil fuels like coal and oil. These fossil emissions are responsible for about 85 percent of humanity’s CO2 footprint today and, globally, they’re continuing to accelerate. So any successful effort to avoid dangerous climate change must have fossil CO2 mitigation at its core. Managing methane is also important given its greater heat trapping potential than CO2.

Why focus on carbon from cities? It turns out that urbanization – the increasing migration of people from rural areas to urban centers – has concentrated over half the world’s population, over 70 percent of fossil CO2 emissions and a significant amount of methane emissions into less than 3 percent of the Earth’s land area! So cities and their power plants represent the largest cause of human carbon emissions. In 2010, the 50 largest cities alone were collectively the third largest fossil CO2 emitter after China and the US – and there are thousands of cities. At the same time, in many cases, emissions from cities are undergoing rapid growth because of urbanization.

But there’s also a silver lining here.

Many cities are beginning to serve as “first responders” to climate change. While national governments continue to negotiate over country-level commitments, mayors of some of the largest cities are already taking action to reduce their cities’ carbon footprints, and they’re working together through voluntary agreements. Additionally, the concentrated nature of urban carbon emissions makes measuring those emissions easier than measuring entire countries.

Measuring the carbon emissions of cities is important (you can’t manage what you can’t measure) and challenging given the number of sources and key sectors and uncertainty about how much each contributes to the total carbon footprint. For example, in a typical city, CO2 is emitted from the transportation sector (cars, trucks, airports, seaports), energy sector (power plants), commercial and industrial sectors (businesses, factories) and residential sector (heating and cooking in homes). Likewise, urban methane sources include landfills, wastewater treatment plants, and leaks in natural gas pipelines. Mayors, regional councils, businesses and citizens have a number of options to reduce their carbon emissions. Measuring the effect of those efforts and understanding where and why they’re not having the intended impact can prove critical to successful mitigation. It also has economic implications -- toward identifying the most cost-effective actions and supporting emissions trading (carbon markets) between cities and other sub-national entities.

How can we measure the carbon emissions of cities? That’s the focus of the Megacities Carbon Project and the topic of our event in Lima today. Briefly, this involves combining data from satellites and surface-monitoring stations that track concentrations of CO2, methane and other gases in the atmosphere over and around cities with other, local data sets that contain information about key sectors. Pilot efforts in Los Angeles, Paris, Sao Paulo and other cities are beginning to demonstrate the utility of these methodologies. Satellites like NASA’s Orbiting Carbon Observatory-2 and other future missions, when combined with a global network of urban carbon monitoring stations, could ultimately play an important role in enabling more effective mitigation action by the world’s largest carbon emitters: cities.


  • Riley Duren

NASA-Generated Damage Map To Assist With Typhoon Haiyan Disaster Response

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.


  • Amber Jenkins

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.


  • Julie Cooper