Actually the Amazon takes up 10% of the carbon absorbed by the Earth's land surface with only 5% of the land area--so it's a major source of oxygen. But the Amazon's a pretty complicated place--these maps only show part of what's going on there. Read (shameless plug, but then again the original story is from my site, too) Escape from the Amazon for a few details on the other half of the process.
But there would be lots of happy bacteria munching on all those dead plans, turning them back into carbon dioxide. The Earth's biosphere (in the long term) stabilizes the global climate.
These data are merely a measure of the "carbon fixing" of vegetation: the amount of carbon from the atmosphere used by plants to make bigger plants. The alogorithm is based on the photosynthesis activity of plants. It doesn't include the carbon released back into the atmosphere after a fire, or the carbon dioxide emitted from rotting vegetation (I'm almost positive about the second one, but haven't been able to get in touch with the principal investigator). We (the scientific community & NASA) are still working on figure out carbon sources.
These measurements don't include carbon dioxide emitted from fires--it's just the amount of carbon living plants take in minus the amount they respire.
Many of these types of projects (including this one) are the result of members of congress mandating that NASA spend money on specific projects in their districts. They're called "earmarks" and are a way to avoid the standard review and budgeting process that may weed out frivolous spending.
That said, educational programs like this do serve a useful purpose - they can teach about remote sensing and Earth system science. NASA uses a suite of satellites to monitor the Earth continuously. Applications include mapping, land use/land cover change, global climate studies, atmospheric research, etc. Because the data are complicated, money is needed to process and evaluate it. Data, remote sensing, the electromagnetic spectrum, atmospheric physics, and cartography are all pretty abstract, and something concrete and possibly exciting (or at least interesting enough to attract the press) like the Lewis and Clark Trail is a good way to get people interested.
In any case, the data covering the trail (which the U.S. taxpayer already paid for) will end up being more accesible than otherwise. So it's not a bad investment.
Re:I wonder how much of this is quality . . .
on
Critics Pan Nemesis
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· Score: 1
After the Fox special we got a bunch (i dunno the exact number - maybe 20 to 100) of email along these lines:
When are you going to come clean about all those bogus trips to the moon. The anomalies are so many and obvious that a second grader could figure out the truth. What else do you fake for the billions you waste?
and we're just an Earth science site! earthobservatory.nasa.gov I think it's completely appropriate to have a formal, well-written and documented response. (although badastronomy.com has covered the topic very well already) We also get the occasional "global warming is obvious crap" and "the ozone hole has always been there" type stuff. Should we ignore them too?
although I appreciate the sarcasm, you could at least provide the quote in context. from the next paragraph:
"On the other hand, there are those, some of whom are scientists, who believe that global warming will result in little more than warmer winters and increased plant growth."
especially the graph on the top of the fifth page which shows the "forcings" - amount of energy gained or lost due to various changes in the environment.
The data were collected in May, a little bit of June (instrument issues), and July 2001. The darkest pixel over this period was used (to get rid of clouds missed by the cloud detection algorithm (this accounts for the speckles in the data at highest resolution)
The higher the resolution, the lower the frequency of coverage. Over its 30 year history, Landsat has acquired all of the Earth's surface, but probably not cloud-free, and possibly not in true color. Landsat data is hundreds of dollars per scene ( 190 km on a side) and coverage of the Earth is ~28,000 scenes (~550 MB/scene, but there is overlap between scenes)
Commercial 1 meter (4 meter color) imagery is likely to have collected data over only a small fraction of the Earth, and costs thousands of dollars per scene (tens of kilometers per side)
Anyways an image of the Earth at 30 meter (Landsat true-color) resolution would be ~212,600 by 106,300 pixels - about 68 GB. A bit more than your average PC could handle. I know there are continental scale composites using Landsat data, but I'm not sure about availability.
For now, 1km true-color is the best we can do. But given a bit more time, we may be able to put something together with 250m data.
The ocean water is not actually a true color image - Moderate Resolution Imaing Spectroradiometer (MODIS) surface reflectance data are only processed over land and shallow water regions. [MODIS's data flow is over a Terabyte a day, so the data system (which was designed years ago) has to take some shortcuts.] Over the ocean I used Ocean Color data [a measurement of the amount of chlorphyll in water, used to get an estimate of phytoplankton (which are the base of the marine food chain)] with a color palette that resembled what the ocean should look like.
I did cheat a little in the Bahamas, which are surrounded by shallows whcih appear bright aquamarine in satellite imagery. Rivers with a high sediment load (the Mississippi, Amazon, Yellow, etc.) make the nearby ocean very brown, and this is (regretably) not shown at all in most of the imagery. Incidentally, the sediment also wreaks havoc on the ocean color measurements.
Yup, the MODIS data used to make the Blue Marble are atmospherically corrected. The data are actually a measurement of surface reflectance, which also includes corrections for slope, cloud shadows, aerosols, etc.
By the way, the data for the Blue Marble are corrected for the effects of the atmosphere - including aerosols (some of which are pollution) This is an essential step in the process of using the data to measure properties of the Earth's surface.
We were forced to touch up the clouds - it's impossible for a single polar-orbiting satellite to image all the Earth's clouds at once. (Actually, it's impossible to see all the Earth's clouds at once in visible wavelengths since half is dark at any one time) The cloud map we made has fewer clouds than are visible in real life.
Yes, it is part of our public relations, but I don't think we're being dishonest.
The large 1km images are of the cylindrical equidistant (flat, suitable for spherical mapping in 3D software) projection. They're split into east and west hemispheres because commercial image editing software (i.e. Photoshop) maxes out at 30,000 pixels.
Slashdot Mirror
Coniferous forests do not fix carbon all year long--they shut down during the winter:
o n/
http://earthobservatory.nasa.gov/Study/BOREASCarb
since this is a measure of the carbon fixing of plants, cows, being animals, aren't really relevant.
and yes, methane "emissions" from livestock are still a concern re: global warming.
That's because I'm an idiot and a labelled the scales wrong. Think kg per square meter, not square km. I guess I should go fix it now, huh?
ok, maybe I should have added a ;)
Don't you mean anaerobic?
Actually the Amazon takes up 10% of the carbon absorbed by the Earth's land surface with only 5% of the land area--so it's a major source of oxygen. But the Amazon's a pretty complicated place--these maps only show part of what's going on there. Read (shameless plug, but then again the original story is from my site, too) Escape from the Amazon for a few details on the other half of the process.
But there would be lots of happy bacteria munching on all those dead plans, turning them back into carbon dioxide. The Earth's biosphere (in the long term) stabilizes the global climate.
These data are merely a measure of the "carbon fixing" of vegetation: the amount of carbon from the atmosphere used by plants to make bigger plants. The alogorithm is based on the photosynthesis activity of plants. It doesn't include the carbon released back into the atmosphere after a fire, or the carbon dioxide emitted from rotting vegetation (I'm almost positive about the second one, but haven't been able to get in touch with the principal investigator). We (the scientific community & NASA) are still working on figure out carbon sources.
These measurements don't include carbon dioxide emitted from fires--it's just the amount of carbon living plants take in minus the amount they respire.
But there's no World Trade Center to climb any more. Maybe it should be set in Malaysia with the Petronas Towers?
design and build the instrument
extend the 2nd antenna 60 meters out of the Shuttle payload bay
develop the algorithms to get topographic data out of microwave radar interference patterns
process and calibrate data for 80% of the Earth's land surface at 30 meter resolution
you're hard to please
more info: SRTM: Instruments
Given enough time (heat will speed things up), the crystal structure in diamonds reverts to plain old graphite.
o nd /diamond.htm
http://www.bris.ac.uk/Depts/Chemistry/MOTM/diam
Many of these types of projects (including this one) are the result of members of congress mandating that NASA spend money on specific projects in their districts. They're called "earmarks" and are a way to avoid the standard review and budgeting process that may weed out frivolous spending.
Here's a good article: Pork-barrel projects threatening NASA's core programs
That said, educational programs like this do serve a useful purpose - they can teach about remote sensing and Earth system science. NASA uses a suite of satellites to monitor the Earth continuously. Applications include mapping, land use/land cover change, global climate studies, atmospheric research, etc. Because the data are complicated, money is needed to process and evaluate it. Data, remote sensing, the electromagnetic spectrum, atmospheric physics, and cartography are all pretty abstract, and something concrete and possibly exciting (or at least interesting enough to attract the press) like the Lewis and Clark Trail is a good way to get people interested.
In any case, the data covering the trail (which the U.S. taxpayer already paid for) will end up being more accesible than otherwise. So it's not a bad investment.
How about Gibson, Sterling, and Stephenson?
and we're just an Earth science site! earthobservatory.nasa.gov I think it's completely appropriate to have a formal, well-written and documented response. (although badastronomy.com has covered the topic very well already) We also get the occasional "global warming is obvious crap" and "the ozone hole has always been there" type stuff. Should we ignore them too?
Apparently the Hubble has a max resolution of 280 feet/pixel for the moon (or so):
http://oposite.stsci.edu/pubinfo/pr/1999/14/
the wide field planetary camera 3 is what's on board now, so the res might be higher.
Popular Science has done them, as well. (but the link no longer works)
we do try to be fair.
Another (shorter) summary of the issues involved with global warming is this NASA fact sheet: http://earthobservatory.nasa.gov/Library/GlobalWar ming/
especially the graph on the top of the fifth page which shows the "forcings" - amount of energy gained or lost due to various changes in the environment.
(disclaimer - I worked on the fact sheet)
The data were collected in May, a little bit of June (instrument issues), and July 2001. The darkest pixel over this period was used (to get rid of clouds missed by the cloud detection algorithm (this accounts for the speckles in the data at highest resolution)
The higher the resolution, the lower the frequency of coverage. Over its 30 year history, Landsat has acquired all of the Earth's surface, but probably not cloud-free, and possibly not in true color. Landsat data is hundreds of dollars per scene ( 190 km on a side) and coverage of the Earth is ~28,000 scenes (~550 MB/scene, but there is overlap between scenes)
Commercial 1 meter (4 meter color) imagery is likely to have collected data over only a small fraction of the Earth, and costs thousands of dollars per scene (tens of kilometers per side)
Anyways an image of the Earth at 30 meter (Landsat true-color) resolution would be ~212,600 by 106,300 pixels - about 68 GB. A bit more than your average PC could handle. I know there are continental scale composites using Landsat data, but I'm not sure about availability.
For now, 1km true-color is the best we can do. But given a bit more time, we may be able to put something together with 250m data.
The ocean water is not actually a true color image - Moderate Resolution Imaing Spectroradiometer (MODIS) surface reflectance data are only processed over land and shallow water regions. [MODIS's data flow is over a Terabyte a day, so the data system (which was designed years ago) has to take some shortcuts.] Over the ocean I used Ocean Color data [a measurement of the amount of chlorphyll in water, used to get an estimate of phytoplankton (which are the base of the marine food chain)] with a color palette that resembled what the ocean should look like.
s ets.html
for more info, go here:
What are Phytoplankton?
and to see chlorophyll data dating to 1978, go here (click on the two chlorophyll datasets):
http://earthobservatory.nasa.gov/Observatory/data
I did cheat a little in the Bahamas, which are surrounded by shallows whcih appear bright aquamarine in satellite imagery. Rivers with a high sediment load (the Mississippi, Amazon, Yellow, etc.) make the nearby ocean very brown, and this is (regretably) not shown at all in most of the imagery. Incidentally, the sediment also wreaks havoc on the ocean color measurements.
Yup, the MODIS data used to make the Blue Marble are atmospherically corrected. The data are actually a measurement of surface reflectance, which also includes corrections for slope, cloud shadows, aerosols, etc.
. asp?ProdFamID=2
If you want the specifics, look here:
http://modis-land.gsfc.nasa.gov/products/products
If you want to see more detailed images, we post a NASA Earth science image every day:
http://earthobservatory.nasa.gov/
There's lots of smog and cities.
By the way, the data for the Blue Marble are corrected for the effects of the atmosphere - including aerosols (some of which are pollution) This is an essential step in the process of using the data to measure properties of the Earth's surface.
We were forced to touch up the clouds - it's impossible for a single polar-orbiting satellite to image all the Earth's clouds at once. (Actually, it's impossible to see all the Earth's clouds at once in visible wavelengths since half is dark at any one time) The cloud map we made has fewer clouds than are visible in real life.
Yes, it is part of our public relations, but I don't think we're being dishonest.
The large 1km images are of the cylindrical equidistant (flat, suitable for spherical mapping in 3D software) projection. They're split into east and west hemispheres because commercial image editing software (i.e. Photoshop) maxes out at 30,000 pixels.