UK greenhouse gas leak detected from space

[Pyrite]

https://www.bbc.co.uk/news/science-environment-66811312
 

A major leak in the UK of the extremely potent greenhouse gas methane has been spotted from space for the first time.
 
Its detection by satellite raises hopes that future leaks can be stopped more quickly.
 
Methane has 28 times the heating potential of CO2 and is a major contributor to global warming.
 
In energy terms, the gas leaked over three months before being stopped could have powered 7,500 homes for a year.
 
The leak from a pipeline in Cheltenham, revealed exclusively to the BBC, was discovered in March. It was detected by Leeds University with the help of specialist satellites.

I'd already heard about this before this press release because of my line of work. It's really promising that leaks such as this can be detected, although it does beg the question of how many of these leaks happen each year and go completely undetected.

[Kyng]

Wow, the fact that it went undetected for three months is quite disturbing - and does raise the question of how many others might not have been found at all.

I suppose this does give us some new means of spotting them - but ideally, we'd have a better way of detecting them from on the ground!

[Pyrite]

I don't actually agree with that last part - if leaks can be easily and rapidly detected from space, then why not go down that route? The only problem I can see is difficulty detecting on cloudy days, but even then you would need a sustained period of cloudy skies to continually block out the signal, and you certainly wouldn't get anywhere near three months of that!

[~ True Legend ~]

I don't actually agree with that last part - if leaks can be easily and rapidly detected from space, then why not go down that route? The only problem I can see is difficulty detecting on cloudy days, but even then you would need a sustained period of cloudy skies to continually block out the signal, and you certainly wouldn't get anywhere near three months of that!

Hopefully such high resolution devices can rise above the clouds. 

As for 3 months of clouds, you never really know with extreme weather events and what not becoming more commonplace. Remember, some tropical countries have a monsoon season. 

We can only hope for the time being.

[Pyrite]

The satellites are above the clouds - that's the whole problem! Satellites detect signatures from the air between themselves and the ground by remote sensing - but clouds will absorb the light that they beam down and as such block the signal.

However, this only occurs completely when clouds are strong, and even in cases of extreme weather you're still able to get some signal.

[~ True Legend ~]

The satellites are above the clouds - that's the whole problem! Satellites detect signatures from the air between themselves and the ground by remote sensing - but clouds will absorb the light that they beam down and as such block the signal.

However, this only occurs completely when clouds are strong, and even in cases of extreme weather you're still able to get some signal.

Well yes, otherwise it’d be too dangerous for planes to fly, right?

[Pyrite]

Not the same thing. The satellite signals we are considering here are wavelengths in the UV to IR, whilst planes mostly rely on radio signals. Satellites also exist much higher up in the atmosphere than planes ever reach. Planes travel in the troposphere, the closest layer to the Earth, where most clouds exist. Most satellites exist in the outermost layers of the atmosphere.

Planes also use weather reports in order to delay or reroute their journeys - I recently flew from Heathrow Airport to Sydney, and the take-off was delayed due to thunderstorms over Germany. Whereas satellites exist above the clouds, so the weather only matters to them in terms of how it can block out the light beams they are transmitting to the Earth's surface and back.

[~ True Legend ~]

Not the same thing. The satellite signals we are considering here are wavelengths in the UV to IR, whilst planes mostly rely on radio signals. Satellites also exist much higher up in the atmosphere than planes ever reach. Planes travel in the troposphere, the closest layer to the Earth, where most clouds exist. Most satellites exist in the outermost layers of the atmosphere.

Planes also use weather reports in order to delay or reroute their journeys - I recently flew from Heathrow Airport to Sydney, and the take-off was delayed due to thunderstorms over Germany. Whereas satellites exist above the clouds, so the weather only matters to them in terms of how it can block out the light beams they are transmitting to the Earth's surface and back.

So, they’re less likely to be negatively impacted by clouds, right ?

[Pyrite]

Physically, perhaps, but in terms of their operation and ability to take data, satellites are more impacted by clouds. Think of it this way - clouds exist between the satellites and the Earth. If the satellites are beaming down light to probe the Earth, clouds will get in the way by absorbing this light. If the satellites are collecting light emitted by the Earth, then once again the clouds get in the way by absorbing light.

[~ True Legend ~]

Physically, perhaps, but in terms of their operation and ability to take data, satellites are more impacted by clouds. Think of it this way - clouds exist between the satellites and the Earth. If the satellites are beaming down light to probe the Earth, clouds will get in the way by absorbing this light. If the satellites are collecting light emitted by the Earth, then once again the clouds get in the way by absorbing light.

Thanks for explaining so patiently ! Would a bit of cloudiness reduce the accuracy by a large margin?