Friday, August 06, 2010

Why you should read Rabett Run

and why Tony Watts is dangerous.

A late comment on a recent puzzler newly brings this reply

Rachel said...

Thank you very much all of you, I had a take-home test in oceanography and "skin altitude" is NOWHERE on the Internet except for on this forum, and I needed the definition for a high point question. So thank you, and a very interesting discussion.

jre provided the answer before the question was asked

The lapse rate is indeed central to the greenhouse effect. To my mind, the best concise discussion of why this is so is David Archer's. To paraphrase:
1) Once you know insolation, emissivity and albedo, you can ring up Stefan and Boltzmann and know the earth's skin temperature.
2) Skin altitude is determined by absorption, reflection and re-radiation by wavelength at all altitudes. In general, higher IR opacity results in higher skin altitude.
3) Surface temperature may be found by taking the skin temperature (known from radiative equilibrium) and the skin altitude (known from atmospheric radiative properties), then sliding down to the surface at a constant lapse rate. Higher skin altitude + constant lapse rate -> higher surface temperature.

Armed with these few concepts and a clear mental picture of the atmospheric temperature profile, such as the one you have kindly provided, anyone can explain the greenhouse effect to a climate skeptic. For all the good it will do you.

But this also points to the value of informative blogs (see left hand side) and the danger of disinformative blogs. What do we need to do the honest broker asks?

19 comments:

Anonymous said...

Is Mr. Archer's discussion found in his book, Global Warming: Understanding the Forecast, or is this from an essay available on the interweb? I would like to follow up on this.

Patrick Cottentail

Lionel A Smith said...

Patrick

Yes, David Archer describes lapse rate and skin temperature in that book. 'The Long Thaw' is also recommended reading for other aspects.

David B. Benson said...

That is indeed clever.

Thanks to all (who did so) for bringing it forward.

Anonymous said...

http://www.science20.com/chatter_box/blog/spitting_graves

Patrick Lockerby has a different opinion to Tony Watts on the discovery of the Investigator, Robert McLure's ship. The link that Watts provided does not tell the story true.

Regards Little Mouse

Anonymous said...

Watts has no sense of shame. That is why he is so useful to McIntyre.

Rattus Norvegicus said...

Yeah, I posted I comment (hey, it was approved in unmolested form) which pointed out the problems. What is really amazing is the continuing discussion of Gavin Menzies' fiction about the Chinese fleet sailing through the arctic in the 15th century. Aside from the fact that it has no evidence...

Anonymous said...

Patrick

GLOBAL WARMING.....UNDERSTANDING THE FORECAST
By David Archer

Watch the Video Lectures.
Relive those classroom days.

Sorry I can't name the Chapter. I didn't get that far.



http://geoflop.uchicago.edu/forecast/docs/lectures.html

Anonymous said...

I realise space is limited on your LHS, Eli, and is real estate best reserved for truly informative stuff, but what about a list of blogs, under a suitable title (Trash, Rubbish, Pseudobabble,...), to be avoided? Without links of course. But you could "linkify" them by using the HTML "a, /a" tags without setting the urls therin, making them look the real thing.

Those in the know, of course, know what to avoid, or partake with a salt mine or two, but a continuous advertising campaign against those blogs showing disinformation, ineptitude, calumny, distortion, misdirection, etc. must have some didactic value.

Cymraeg llygoden

anonymouse1 said...

hi, i am trying to find a good article on how funding/grant applications work in climate science. I remember reading a good article on this that but cannot remember where it was.

simon evans said...

@anonymouse1

try these blog entries, but remember funding for climate science goes much like funding for any other science.

http://profmandia.wordpress.com/2010/03/11/taking-the-money-for-granted-%e2%80%93-part-i/
http://profmandia.wordpress.com/2010/03/22/taking-the-money-for-granted-%e2%80%93-part-ii/

Ron Broberg said...

Skin altitude is determined by absorption, reflection and re-radiation by wavelength at all altitudes.

Got math?

ie ... is there a straight-forward formula for this (like Stefan-Boltzmann) or is the skin alt laboriously determined through numerical computation?

captdallas2 said...

I find it amusing that the skeptics are trying to prove the greenhouse effect to the skeptics. Oh, wait a minute, I am considered to be a skeptic, though I always thought I was a realist.

EliRabett said...

Anon 5:54 (please take a name:) Watts is not fronting for McIntryre, he is fronting for Pielke Sr. Just follow how the surface station picture gallery started.

CapitalistImperialistPig said...

"skin temperature" is a new one on me. It sounds an awful lot like what we used to call "effective radiating temperature." What's the difference?

EliRabett said...

Hank, this probably goes back about 8 years when Blue Cross of MD and DC was trying to cash out with management making off with the rainy day fund.

http://baltimorechronicle.com/bluecrossAbell_jan02.html

EliRabett said...

Ray P sends a note and a publication date:

Note that there is some confusion floating around regarding "skin temperature" vs. "radiating temperature," especially because as often applied to solids the term "skin temperature" is actually the "radiating temperature." David sometimes uses skin temperature as synonymous with radiating temperature, but in usual atmospheric parlance the skin temperature is the temperature of a two-sided blackbody (i.e. optically thin slab) in equilibrium with the outgoing radiation -- the temperature of the skin of the atmosphere. That differs from the radiating temperature by a factor of 1/2**(1/4). If you google "radiating temperature" you'll find a lot more on that. There's an extensive discussion of all this in my climate book (on track to go on sale in December!) for those who don't mind "death by theoretical physics," as Eli so kindly puts it.

--Raypierre

Patrick said...

David Archer's lectures are also available on youtube. I mention this because the link from his web page is not working.

Patrick Cottentail

Anonymous said...

What does (1/2)**(1/4) mean? Base and exponent?

Ignorant Bunny

EliRabett said...

1/2 aka 0.5 to the power 1/4 aka 0.25 base 10 = .841