Archive for the ‘Uncategorized’ Category

Las imágenes de satélite son como los mapas: están llenas de información útil e interesante, siempre y cuando tengas una clave. Éstas nos pueden mostrar cuánto ha cambiado una ciudad, cuán bien están creciendo nuestros cultivos, dónde arde un fuego o cuando se acerca una tormenta. Para revelar la riqueza de información en una imagen de satélite haz lo siguiente:

1. Busca una escala
2. Busca patrones, formas y texturas
3. Define los colores (incluyendo las sombras)
4. Encuentra el norte
5. Considera tu conocimiento previo

Estos consejos provienen de escritores y visualizadores de NASA Earth Observatory que los utilizan diariamente para interpretar imágenes de satélite. Te ayudarán a orientarte lo suficiente para extraer información valiosa de imágenes de satélite.

Leer más en español.

Este artículo originalmente fue publicado en inglés en NASA Earth Observatory. Traducción al español de Laura Delgado López, IGES.

Unique Perspectives on Precipitation Measurement

November 8th, 2013 by Mike Carlowicz


Following their successful “Let It Snow” photo contest, our colleagues at the soon-to-launch Global Precipitation Measurement (GPM) mission are looking for your best photos and videos of rain, sleet, hail, snow and any other precipitation. They describe their “Unique Perspectives” contest this way:

There are many ways to view precipitation…We’d like to see weather from all angles — far away, up close, above, below and inside. The more creative and unique, the better.  Post your coolest photos and videos of precipitation from unique perspectives, and we’ll choose the best ones to post on the NASA Precipitation Measurement Missions websites…Winning photos will be selected by a group of judges comprised of NASA scientists and outreach personnel, and will be judged based on their creativity and artistic merit.

The new contest runs from November 1 to December 1, 2013, and imagery can be submitted via Flickr, Instagram, or Vimeo. Learn more about the contest and rules by visiting:


Engineer and avid traveler Andrew Bossi had one of the winning entries last spring – this shot of the harbor in Kulusuk, Greenland. His shot became part of an Image of the Day on Earth Observatory.

In between combing your photo archives and setting up your tripod for the perfect precipitation shot, check out this quirky anime cartoon about GPM from the science and outreach team at JAXA, NASA’s partner in the mission. If you don’t speak Japanese, turn on the closed-caption button.




While most of NASA went dark during the government shutdown, life went on at the International Space Station. Throughout October, astronauts Karen Nyberg, Mike Hopkins, and Luca Parmitano sent a steady stream of tweets back to Earth. The most eye-popping of the bunch came from Hopkins, who tweeted this on October 10, 2013: “Saw something launch into space today. Not sure what it was, but the cloud it left behind was pretty amazing.”

It turns out it was a Russian missile launch, according to bloggers at the Russian Nuclear Forces Project. The group noted: “The Strategic Rocket Forces carried out a successful test launch of a Topol/SS-25 missile on October 10, 2013. The missile was launched at 17:39 MSK (13:39 UTC) from Kapustin Yar to the Sary Shagan test site in Kazakhstan. According to a representative of the Rocket Forces, the test was used to confirm characteristics of the Topol missile, to test the systems of the Sary Shagan test site, and ‘to test new combat payload for intercontinental ballistic missiles.’ ”

Hopkins’ colleague, European Space Agency astronaut Luca Parmitano, also captured the remarkable shot below, which shows the missile’s contrail being yanked back and forth by winds at different levels of the atmosphere.  Discovery News, University Today, and Fox News have more coverage.


Shutdown Notice

October 1st, 2013 by Adam Voiland

We’re sorry, but we will not be posting updates to this blog during the government shutdown. Also, all public NASA activities and events are cancelled or postponed until further notice. Rest assured that we will be back as soon as possible! We hope that you will stick with us and we promise more great imagery when we return. Please note that we will not be moderating or posting comments until the shutdown is over.

See you on the other side,

Kevin, Mike, Adam, Holli, Jesse, Rob, and Paul
The Earth Observatory Team

Key Science Points from the 2013 IPCC Report

September 27th, 2013 by Adam Voiland

These key science points were published on September 27, 2013, as “headline statements” by the Intergovernmental Panel on Climate Change (IPCC) as part of the organization’s fifth assessment report. Background links provided by Earth Observatory.

+Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. Read more about global warming.

+Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years. See maps showing global temperature trends.

+Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010 (high confidence). It is virtually certain that the upper ocean (0−700 m) warmed from 1971 to 2010, and it likely warmed between the 1870s and 1971. Read more about Earth’s energy budget.

+Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent (high confidence). Read more about Arctic and Antarctic sea ice.

+The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia (high confidence). Over the period 1901–2010, global mean sea level rose by 0.19 [0.17 to 0.21] m. Read more about sea level rise.

+The atmospheric concentrations of carbon dioxide (CO2), methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. CO2 concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification. Read more about the greenhouse effect.

+Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750. Read more about radiative forcing.

+Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system. Read more about the human fingerprint on the climate system.

+Climate models have improved since the AR4. Models reproduce observed continental-scale surface temperature patterns and trends over many decades, including the more rapid warming since the mid-20th century and the cooling immediately following large volcanic eruptions (very high confidence). Read more about climate models.

+Observational and model studies of temperature change, climate feedbacks and changes in the Earth’s energy budget together provide confidence in the magnitude of global warming in response to past and future forcing. Read more about Earth’s energy budget.

+Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes. This evidence for human influence has grown since AR4. It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century. Read more about the human influence on climate.

+Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions. Read more about greenhouse gases. 

+Global surface temperature change for the end of the 21st century is likely to exceed 1.5°C relative to 1850 to 1900 for all RCP scenarios except RCP2.6. It is likely to exceed 2°C for RCP6.0 and RCP8.5, and more likely than not to exceed 2°C for RCP4.5. Read more about global surface temperatures.

+Warming will continue beyond 2100 under all RCP scenarios except RCP2.6. Warming will continue to exhibit interannual-to-decadal variability and will not be regionally uniform. Read more about the NASA GISS tempearture record.

+Changes in the global water cycle in response to the warming over the 21st century will not be uniform. The contrast in precipitation between wet and dry regions and between wet and dry seasons will increase, although there may be regional exceptions. Read more about the water cycle.

+The global ocean will continue to warm during the 21st century. Heat will penetrate from the surface to the deep ocean and affect ocean circulation. Read more about how oceans absorb heat.

+It is very likely that the Arctic sea ice cover will continue to shrink and thin and that Northern Hemisphere spring snow cover will decrease during the 21st century as global mean surface temperature rises. Global glacier volume will further decrease. Read more about sea ice.

+Global mean sea level will continue to rise during the 21st century. Under all RCP scenarios the rate of sea level rise will very likely exceed that observed during 1971–2010 due to increased ocean warming and increased loss of mass from glaciers and ice sheets. Read more about sea surface temperature.

+Climate change will affect carbon cycle processes in a way that will exacerbate the increase of CO2 in the atmosphere (high confidence). Further uptake of carbon by the ocean will increase ocean acidification. Read more about the ocean’s carbon balance.

+Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond. Most aspects of climate change will persist for many centuries even if emissions of CO2 are stopped. This represents a substantial multi-century climate change commitment created by past, present and future emissions of CO2. Read more about carbon dioxide.

A View Inside Super Typhoon Usagi

September 23rd, 2013 by Adam Voiland


As category 4 Super Typhoon Usagi churned toward Taiwan on September 19, 2013, a satellite orbiting hundreds of miles above used a radar instrument to map the storm’s inner structure. The instrument on the Tropical Rainfall Measuring Mission (TRMM) observed two tall complexes of rain clouds called hot towers in the inner eyewall, a sign that Usagi was a well-organized storm and strengthening.

Tropical cyclone “heat engines” extract heat from the ocean’s surface through evaporation and convert a portion of that energy into destructive winds that circle under the eyewall of the storm. All tropical cyclones have heat engines, but several features detected by TRMM suggested that Usagi’s was running particularly efficiently. Radars almost always see eyewalls in strong tropical cyclones, for instance, but they are rarely as symmetrical as Usagi’s is in the visualization shown above. NASA Goddard Space Flight Center researcher Owen Kelley produced the visualization based on TRMM data from the Precipitation Measurement Missions science team at NASA and from the Japan Aerospace Exploration Agency (JAXA).

In the 3D portion of the image, heavy precipitation is shown in dark red. Light precipitation is gray, green, yellow or light red, with the color reflecting how high the storm has lofted the rain production (higher than 8.5 kilometers is green; above 11.5 kilometers is yellow; and higher than 14 kilometers is red). Note that the underlying image, which shows the temperature of cloud tops, uses a different color scale.  In it, cool cloud tops are pink and white, medium temperature cloud tops are gray and blue, and warm cloud tops are dark gray and black.

Even the heavy precipitation at the base of the eyewall is fairly symmetric, which is somewhat unusual according to Kelley. Tropical cyclone eyewalls that are this symmetric are called “annular,” and they have a tendency to maintain their intensity for longer periods than tropical cyclones with more lopsided eyewalls. At two locations in the inner eyewall, updrafts were strong enough to produce hot towersfeatures that are associated with strengthening cyclones.  A few hours after TRMM collected the data visualized here, Usagi intensified briefly into a category 5 storm, the highest category on the scale. 

Read this Earth Observatory feature and blog post to learn more about how the late Joanne Simpson pioneered the study of hot towers. The video below, produced by NASA Goddard’s Scientific Visualization Studio, offers another view of how hot towers work.

Ocean Revealed or Hidden?

August 9th, 2013 by Holli Riebeek

Yesterday’s Image of the Day — Ocean Revealed — elicited an interesting response from Norman Kuring, a NASA oceanographer who frequently contributes to the Earth Observatory. He notes:

“There have indeed been a number of studies that exploit sunglint for ocean research since Paul Scully-Power made his statement. However, I disagree with the follow-on sentence that, “his observation holds true for satellite observations today.” While sunglint does reveal some information about the ocean beneath, for visible radiometry sensors it usually obscures more than it reveals.”

“We in the ocean-color community often bemoan the fact that the MODIS instruments and VIIRS do not tilt to avoid the worst of the glint field. SeaWiFS, which was primarily an ocean mission, tilted, and the upcoming ocean radiometer on PACE is also planned to be tiltable to avoid the worst of the glint.”

Good point, Norman. Sunglint hides the telltale shades of blue and green that point to phytoplankton growth in the ocean’s surface waters. Here’s a good example, originally published on the Earth Observatory in 2007.


Notice how the bright sunglint obscures the color on the top and right side of the image. (NASA’s Ocean Color web site provides another good example with a more detailed description.) It’s no wonder that oceanographers like Norman cringe at the thought of sunglint in ocean images.

Blazing Hangout

August 7th, 2013 by Mike Carlowicz

Wildfires follow a simple but dangerous equation: Hotter, dryer conditions + more people in the world = a greater likelihood of ferocious wildfires threatening lives and property.

Fires in the western United States are burning earlier, longer and with more intensity, as shown by a decades-long record from ground surveys and NASA satellites. How much of this is due to climate change? And how do scientists see this trend developing in the coming decades, as temperatures rise, seasons shift, and precipitation patterns change?

Join researchers online at 1 p.m. EDT (10 a.m. PDT) on Friday, Aug. 9, for a NASA Google+ Hangout that will explore these questions. The Hangout will feature:

  • Doug Morton, research scientist at NASA’s Goddard Space Flight Center
  • Bill Patzert, research scientist at NASA’s Jet Propulsion Laboratory
  • Elizabeth Reinhardt, national program leader for fire research, research and development, Office of the Climate Change Advisor, U.S. Forest Service

The panelists will take questions from the press and the public during the Hangout. Submit questions on Google+, YouTube, Twitter, Facebook or other social media channels in advance and during the event using the hashtag #NASAFire. The URL for the hangout is

You can also find some background and imagery on wildfires here on the Earth Observatory.

+ Natural Hazards: Fires

+ Natural Disasters and NASA

+ World of Change: Burn Recovery in Yellowstone

+ Aerosols: Tiny Particles, Big Impact

+ Finding a Fire Cloud from Space





NASA astronaut Karen Nyberg took this photograph of moonrise and sunrise over Earth’s limb on August 4, 2013. In a tweet, Nyberg noted that she also saw Jupiter and Mercury as she looked out from the International Space Station, but the glare of the Sun’s light hid them in her photo.

When astronomer and Slate blogger Phil Plait fired up the image processing software on his computer down on Earth, he enhanced the brightness on Nyberg’s photo so that Jupiter and Mercury show up quite nicely. (See the enhanced image below.) Read more about the remarkable photograph on the Bad Astronomy blog.

Follow Nyberg’s Twitter and Pinterst feeds at:


Reader Question: Wild June Weather

July 31st, 2013 by Mike Carlowicz

Periodically, Earth Observatory answers reader questions on this blog. Here’s a recent note from Manny J of New York City:

“I recall that starting on May 15, 2013, the cold did not leave [New York]. In fact, it still felt like winter because it refused to warm up. Then came June 2013, with the sky overcast each and every day, with the humidity very high, hardly any sun except for an occasional peeping through. In fact as of June 30, 2013, there was no summer as summer used to be. The weather pattern was such that I had never seen anything like it. Do you know why?”

We asked Gavin Schmidt, deputy chief of NASA’s Goddard Institute for Space Studies (GISS) and a NYC resident, what he thought:

“The seasonal weather pattern in any particular location is very sensitive to the chaotic dynamics in the atmosphere. Our ability to attribute those changes to either ocean temperature patterns or external drivers is quite limited, and so we can’t provide an answer that can satisfactorily address this question. Things that we can say are caused (statistically) are generally on larger spatial scales and longer time scales.”

In recent years, many readers have asked Earth Observatory if a particular spell of crazy weather is a result of global warming. As Gavin pointed out and many others have explained, weather events and climate are different things. Climate is what you expect to happen, and weather is what actually happens on a  day-to-day, week-to-week time scale. There is inherent chaos and unpredictable variability in weather. Climate, on the other hand, is a matter of trends and long views. What might the season or year look like when compared to the averages of many years?  Is it getting warmer or cooler, wetter or drier? Can that be explained by some physical process?


Above: temperature anomalies for June 2013, as calculated by NASA GISS


There were heat waves, cool spells, and weird weather long before anyone spoke of global warming. And global warming and climate change are not linear, everywhere-the-same patterns. But there is growing evidence that weather extremes are becoming more extreme, the unusual is becoming more usual — and global climate change is a key reason. The Intergovernmental Panel on Climate Change recently published a report on climate extremes, which is also summarized well by Climate Central.

As we explained in a feature story earlier this spring, the behavior of storms is growing more erratic. Other research has shown that heat waves have become more frequent and more likely to break records. This video below shows how the number of deviations from normal — the number of extreme heating or cooling events — has shifted toward more extreme highs and fewer lows.


While Manny and other New Yorkers had an unorthodox June, much of the rest of the United States and the world baked. According the NOAA National Climatic Data Center and meteorologist-blogger Jeff Masters of  Weather Underground, June 2013 was the fifth warmest June on record. July 2013 also was shaping up to be quite hot just about everywhere.