# Tag Info

33

There are many "uncharted waters". Nautical charts have information about water depths, dangers to navigation, aids to navigation, anchorages, and other features. You can see here what might be included in a nautical chart: U.S. Chart No. 1 The area in question is a shallow sea... so boats of different sizes may or may not be able to take certain routes ...

23

Does this huge collective quantity of objects (together with space trash) reflect away enough solar radiation to have a measurable effect? Could this affect Earth's climate, mitigating climate change? No. Suppose, instead of 12,000 tiny satellites, SpaceX was planning on launching 12,000 satellites the size of the International Space Station. The ISS, with ...

16

As the other answer suggests, these are sonar surveys of the ocean depths. But the answer is a bit more complicated. The vast majority of the ocean floor has never been mapped. We really only know about the water depth because the water above the sea floor is lighter than if it were rocks. So a deep ocean produces less gravity than a shallow one. And, ...

14

These are most certainly boundary layer rolls and not gravity waves. While there exists a visual similarity between the two phenomena, and both may exist in similar atmospheric conditions, they can be distinguished by two key characteristics: Unlike gravity waves, which develop in the downwave direction (perpendicular to the crest), boundary layer rolls ...

12

Considering that the Mid-Atlantic ridge was just discovered recently (in geological terms), much of the Earth's water is still unmapped. The surface can be easily mapped by satellites, as said by farrenthorpe. It's just undersea territory which remains a deep mystery (no pun intended). Some question the fact that we can estimate the depth of the Mariana ...

12

Supplementing Wolfgang's answer, here's a National Oceanographic and Atmospheric Administration story that talks about the appearance of ocean-bottom artifacts: With legions of people around the world now exploring the seafloor, many are noticing locations along the ocean bottom marked by mysterious formations of grid-like artifacts. These formations ...

11

A lot depends on the definition of "charted". How much detail must we know for an area to gain this status? As others have said, we have a low-resolution idea of all of the non-ice-covered seabed from satellite altimetry and gravity measurements - but there is a big difference between this, with a resolution measured in miles, and a high-resolution multibeam ...

11

BrO and ClO significantly deplete ozone from the atmosphere. Researchers at Harvard University state: It is a remarkable fact that perhaps the most important observation coupling climate forcing to UV dosage levels at the surface at mid-latitudes is the observation of high (e.g. > 10 ppmv) water vapor and low temperatures (< 210 K) with the ...

10

The structure looks similar to this photograph of a "Japanese land retention system" mentioned in passing towards the bottom of this webpage. From the linked page: Land retention systems in Japan, for example, are often designed as heavy waffle grids which are molded to the topography and cover it to a uniform structural depth. This seems to correspond ...

10

Civilian earth observing SAR satellites do not always operate over empty swaths of oceans (specially in the middle of Indian Ocean) in order to save power. They are not designed to track a fast moving target and have repeat cycle of at least a few days. Then there is the issue of resolution. High res acquisitions modes (with satellites like TerraSAR-X) are ...

9

Given the weather patterns, it looks like Google Earth is generating those cloud overlays from some recent (i.e., the current day) satellite images. That line is suspiciously close to the edge of disc line for Meteosat 8, which is located over the equator at 41.5 °E. I suspect that it's just an artefact of how they're stitching together the various images ...

7

You ask, How to remove these abnormal value for more precise data? The short answer is that you might be able to make your data look more representative of the natural 'truth', but you will probably have to pay for this with some precision. The problem is that the measurement itself is imperfect: this looks like an artifact of the data collection method. ...

7

...measured in mol/m² within the total or tropospheric column. Is it possible to deduce concentrations for a specific slice of the troposphere? Not really, since you have a crucial bit of information missing: the vertical distribution. Your alternatives are: Combine satellite data with a model to estimate near-surface NO₂. The model may be able to ...

7

$\rm \frac{mol}{m^2}$ shows the amount of $\rm{NO_2}$ in the atmosphere over a square meter of surface area - in mols. The molar mass of the $\rm{NO_2}$ is $14+2\cdot 16=46$. It means, the mass of 1 mol of $\rm{NO_2}$ is $\rm{46g}$. The surface area of the Earth is 510million $\rm{km^2}$. Thus, 1 $\rm \frac{mol}{m^2} \rm{NO_2}$ translates to \$\rm{46 \frac{...

6

Yes, mean cloud cover is routinely measured from satellites. Like all satellite data (and in fact all measurements), it does have an uncertainty, but for the purpose of this question the satellite product of mean cloud coverage is good enough. Personally, I would hesitate to trust the data at very high latitudes with frequent cover of snow or ice, because ...

6

As @gerrit pointed out, the Pytroll project has a couple of package which could be useful. To answer your question and get the next overpasses for the next twelve hours above a given location, you can use Pyorbital (https://github.com/pytroll/pyorbital): from pyorbital.orbital import Orbital from datetime import datetime orb = Orbital("SMAP") orb....

5

Thanks for @Kwinkunks's answer. I have read this paper. And this figure may explain something important. What I have already done is plotting the original data like the first subplot. From Destriped - v1.02, the noise data can be shown clearly. Adding another figure to indicate the big importance of induced noise. Huge difference there! So, I'...

5

This is just supplemental information to the accepted answer by @gerrit I took the ESA cloud cover fraction map provided there, and added dots that represent the approximate locations of the ground stations shown in the 2014 map shown in the question, just to get a rough idea. I used the extremely cool Submarine Cable Map site to identify the likely fiber ...

5

An RGB image can not be rendered if you only supply information for one color channel. This is because three channels are needed: Red, Green and Blue. Different software will deal with this invalid input in different ways: Some might set the remaining channels as black (i.e. filling with zero values). In that case the resulting image will be monocromatic. In ...

5

Unfortunately, the older weather satellite data is, the harder it is to read. Perhaps NOAA's Weather and Climate Toolkit can open it. The old stuff usually comes in tightly packed binary formats that may or may not be well documented (these satellites were designed to take pictures of clouds for weather forecasters to use, us future generations were more ...

5

pretext: Seeing this question on the list of network questions caught my interest to the site. I agree with the arguments put forward in the answer by Fred, gravitating on the radical character of halogene oxides listed (e.g., BrO, ClO), where unpaired electrons contribute to reactivity to the specis. Some of them are created in situ under light radiation ...

4

This a great example of "self-organization" in a geomorphological system; this one an oscillating system at a fairly large scale. On a much smaller scale, you find similar structures on sand dune surfaces themselves as well as dry dusty dirt roads: Self organization (and its scaling) is a complex process delicately dependent on just a few variables, in the ...

4

To my understanding, the question refers to studies which aim to estimate pollutant emission fluxes using satellite retrievals of atmospheric constituents. Mathematically, this means estimating the forcing term in an advection-diffusion-reaction system given a set of tracer observations. How well you can localize the emissions depends on the pollutant: for ...

4

Meteosat:- The Meteosat series of satellites are geostationary meteorological satellites operated by EUMETSAT under the Meteosat Transition Programme (MTP) and the Meteosat Second Generation (MSG) program. INSAT:- INSAT-3D is the first Indian geostationary satellite, equipped with sounder instrument that provides frequent good quality atmospheric profiles ...

4

Provide a monthly average in every grid cell, and describe how many measurements were used for each cell. There is no fixed rule for the minimum number of days for reporting a monthly average. A reasonable threshold will depend on the geophysical quantity of interest y, in particular on how much y varies on short and long timescales. If y varies from ...

4

These features are internal gravity waves (IGW) and are characterized by alternating areas of upwards and downwards movement of air parcels. They propagate on a sharp density interface between a relatively dry layer ambient air above and a layer of sea water laden air below. When the moist air rises the cloud is formed above the condensation level and ...

4

The paper basically combines multiple datasets to figure out the changes in ice surface elevation and ice thickness at tidal and multi-year timescales. That way they were able to study grounding line migration, and the melt rate of the glacier and its corresponding ice shelf from above and below. Then they were able to make inferences of the processes ...

4

Unfortunately, your question has no answer. Both have errors. Both can be unreliable. Your choice really depends on how you plan on using them. Satellites instrument contain sources of error, such as bad observations (wildfires in the NIR), mapping problems (especially near the poles), and representation error. Don't underestimate those sources of error- ...

3

Remember the recent disappearance of the Malaysian Airlines flight 370, assumed lost off the coast of Australia? They could not really begin looking for it without first getting a decent map of the ocean floor. It was "uncharted" for the purpose of that search - for most people, "really deep" is all you need to know for practical purposes, but in this case ...

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