Saturday, April 9, 2016

This is what a scientist sounds like, Dr. Randall on Clouds and such.

In my recent series, "Profiles in Malicious Deception", one of the main characters was the notion that Solar influences and Cosmic Rays somehow control cloud formation via "micro-physical effects".  One Henrik Svensmark and other boosters of this notion go on to claim that clouds are the actual regulators of our planet's temperature, so we need not worry about the gigatons of CO2 we keep adding to our planet's atmospheric carbon cycle at ever faster pace.

It's quite irrational thinking, full of ignored non sequiturs and supported by nothing more than an absolutist self-certainty and ridicule towards all attempts at constructive debate, dialogue, or education.

I'd always intended to follow up with a good YouTube lecture of a scientist explaining the basics about clouds and their role in our global heat and moisture distribution engine.  It took some effort to find and a while to finish my notes, it was worth it, since it makes a heck of a contrast to 1000frolly's presumptuous, insult dripping approach to explaining science.  This man I enjoyed listening to.  Taking notes was an enlightening process rather than the drag 1000frolly's video was.  I've included my notes under his video. 
This is what a scientist sounds like.

Professor David Randall: 
The Role of Clouds and Water Vapor 
in Climate Change

Uploaded on Apr 14, 2011
Dr. David Randall: Professor, Department of Atmospheric Sciences
Colorado State University, Fort Collins, Colorado 

This lecture is part of SFU's 2011 global warming seminar series 
"Global Warming: A Science Perspective".


1:06 - Professor David Randall - Thanks very much for the introduction and for the invitation.  I'm very happy to be here.

Outline of talk
1)  Climate change on the back of an envelope
2)  Climate models
2)  Cloud and water vapor feedbacks

2:10  -   Climate change on the back of an envelope.
Why do we think that more co2 wall make the climate warm up?
Is it because of trends in the observational record (correlation between temps and CO2)?
    No.  That is not the reason.
Is it because of computer climate models?
    No.  That is not the reason.
It is a lot simpler than that.

The climate system does what it does because it's heated.  

There's a pattern of heating and cooling if you change the heating, you change the climate and this is basically why we expect a climate change in response to increasing greenhouse gases.

3:40 - Energy Balance:  Sunshine absorbed - Infrared emitted

4:50 - Increasing CO2 perturbs the Earth's radiation budget:
Considering what happens if there are no feedbacks.
Describing the math.

12:25 -  Given this very simple physical picture it would be very surprising if we didn't see any warming up of the climate, you'd wonder why not.

To go any further than this we need more comprehensive models but before I start talking about more comprehensive models, let me just say that if you ask me personally why am I very confident that our climate is going to warm up in the coming century.  
This is why,  what I just showed you, this is why I believe.

12:50 - Top Ten Things You Need To Know About Climate Models

#1)  The Major Ingredients of Climate Models:
     Atmosphere model
     Ocean model
     Land-surface model
     Sea ice model

Models based on, 
     Partial differential equations,
     Spherical geometry
     Discretization methods
     Time steps of a few minutes
     Very fast computers

14:35 - #2) Atmosphere models contain:
     Carbon, ozone and other chemical species

Process the models compute include:  
     Solar radiation
     Moist convection
     Phase change and other "micro-physics" processes
     Momentum transfer by small scale buoyancy waves 
           (aka gravity waves - though not of the galactic kind.)

17:15 - #3) Grids

17:35 - #4 )Ocean
     Sea Ice
     Various chemical species
     Ocean biology

     Solar radiation
     Momentum transfer by small-scale buoyancy waves
18:35 - #5) Land Surface
     Veggies (role of plants pumping water out of the sub-surface)
     Snow, etc.

19:50 - #6) History of climate modeling
     Richardson, 1922
     Von Neumann & Charney, 1946
     Phillips, 1956
     First global atmospheric models, 1960s
     First global coupled ocean-atmospheric models, 1970s  Manabe -     
     Operational forecasting with global models, late 1970s
     "Serious" land-surface models, 1980s
     IPCC, 1990s
     Currently about 40 models worldwide

Climate Models

General Circulation Models of Climate

Global coupled atmosphere-ocean general circulation models

23:05 - #7) Testing the Models
     Component-level tests
     Weather forecasting
     Simulation of the current climate
     Simulation of past climates

24:45 - #8) An Appetite for FLOPS (floating point operations)
A million million floating point operations are needed to simulate one day. ...

26:10 - #9) What's Missing?
     Ice sheets (being added now)
     Many chemical processes
     Interactive biology on the land surface
          Seasoned greening
          Biome change
     Interactions biology in the ocean

27:40 - #10) Future
     Simulation of ice-age cycles

29:00 - more interactive biology

29:30 - Predictability
A change in the forcing can lead(s) to a change in the climate.
Predicting changes in the forcing can lead to predictable changes in the climate.
Considering various forcings
     The diurnal cycle
     The seasonal cycle
     ice-age cycle
     Volcanic changes in atmospheric composition
     Anthropogenic changes in atmospheric composition

30:55 -  The question is, has a climate model ever made a demonstrably successful prediction?

"The Effects of Doubling the CO2 Concentration on the Climate of a General Circulation Model"  -  Manabe and Wetherald | January 1975

"An attempt is made to estimate the temperature changes resulting from doubling the present CO2 concentration by the use of a simplified three-dimensional general circulation model. This model contains the following simplications: a limited computational domain, an idealized topography, no beat transport by ocean currents, and fixed cloudiness. 

Despite these limitations, the results from this computation yield some indication of how the increase of CO2 concentration may affect the distribution of temperature in the atmosphere. It is shown that the CO2 increase raises the temperature of the model troposphere, whereas it lowers that of the model stratosphere. The tropospheric warming is somewhat larger than that expected from a radiative-convective equilibrium model. 

In particular, the increase of surface temperature in higher latitudes is magnified due to the recession of the snow boundary and the thermal stability of the lower troposphere which limits convective beating to the lowest layer. It is also shown that the doubling of carbon dioxide significantly increases the intensity of the hydrologic cycle of the model."

In summary, Manabe and Wetherald predicted:
     Warming troposphere
     Greater warming near the poles
     Cooling stratosphere
     More rain and higher humidity
All of these things have now happened.

also see: 
Tyndall Lecture: GC43I. Successful Predictions - 2012 AGU Fall Meeting

33:00 - Warming in the Arctic is roughly double that from the whole Earth
34:15 - Sea Ice Melting  (decrease faster than predicted)

35:35 - Forcing and Feedback
Internal processes are part of the climate system.
External processes are unaffected by changes in the climate system.
     The sun
     Human influence(?)
Forcing is due to external processes.
Feedbacks are due to changes
     Albedo feedback
     Stratospheric Cooling

39:30 -  Four-panel graph depicting temps at various altitude over time.
     Lower Stratospheric Cooling  (volcanoes cause heating spike due to aerosols)
     Mid to Upper Troposphere
     Lower Troposphere

41:00 - Column water vapor trend 1968-2004 (kg/m)
     Precipitation map

42:30 - Water vapor feedback
In the tropics the rate of increase of the saturation vapor pressure with temperature is roughly 7 percent per Kelvin.  That's really really fast and it keeps getting steeper.
Water vapor is strong greenhouse gas. . .

44:00 - But, what if there was no CO2? 

     Column Water Vapor
     Surface Temperature
     Planetary Albedo
     Sea Ice Cover
     TOA (top of atmosphere) Net Flux
     Cloud Cover

46:50 - Cloud feedback
... when you think about how clouds affect climate the three big things that matter are:
     Cloud amount
     Cloud Top Height
     Optical properties of the clouds
52:20 - comparing Stratus (low clouds) cover with Sea Surface Temperature 1952-1981
Interesting fact - "this type of cloud cover 'likes' cold water" (52:55) ...
High clouds feedback ...

53:20 - Actual Feedback in Real Climate Change Simulations from 4th IPCC Assessment Report (2007)
     Water vapor - positive
     Clouds - positive
     Albedo - positive
     Lapse rate - negative
     Water pressure and Lapse rate - positive
UPDATE (4/8/16) - a study has been published that indicates previous estimates of the cooling effect of clouds have been too high:
Observational constraints on mixed-phase clouds imply higher climate sensitivity
Tan, Storelvmo, Zelinka | Science  08 Apr 2016: Vol. 352, Issue 6282, pp. 224-227

57:55 - Conclusions
The reasons to expect global warming are neither complicated nor controversial.  They can be summarized on the back of an envelope.

Comprehensive climate models have existed for more than 40 years, and are under intensive development at many centers around the world.

The net effect of many feedbacks in the climate system is to amplify the warming, relative to what would occur with no feedback.

59:20 - Question and Answer

Describes variations in low cloud formation with temp change and with geographic change
The logical disconnect between more evaporation and low clouds - that does not hold because of a variety of geophysical factors.

61:20 - Difference between formation of ocean clouds and land clouds?
A lot has to do with temperature variability of land, compared to the ocean's temperature stability (little change between day and night and over great expanses of surface area.)

62:15 - Reliable cloud cover data available?

Solid global data back to 1950s, early satellites in the 1970s, but reasonably complete global data goes back to the early 1980s.
Limitations of satellites, limitations of surface observations. ...

63:50 - Formation of clouds - influence of the sun and cosmic ray flux?

Clouds are mostly produced because the air is going up.  
As the air rises it's moving to lower pressure, it expands adiabatically that causes it to cool, as it cools the saturation vapor pressure goes down.  
If you cool it enough condensation begins and a cloud forms.

64:40 - Of course, the cloud droplets are nucleated on aerosols, and the presence of aerosols, charged aerosols in particular can be of interest in this context.  There can be solar influences and cosmic-ray influences on the availability of nuclei on which the cloud particles are formed.  But, down here in the lower atmosphere the presence or absence of clouds is never conditioned by the availability of nuclei.  There is always plenty of nuclei.  The presence or absence of clouds is basically produced by how the air is moving.

In the upper troposphere, it's easier to find situations in which the available of nuclei is less and there's more potential for changes in Cirrus cloudiness associated with the availability of suitable ice freezing nuclei.  But, throughout most of the troposphere the availability of nuclei is just not an issue.  

It does matter is how the mass is distributed ...

66:43 ... so the nuclei do have some important influence on the cloud optical properties but they don't determine whether clouds are going to form or not, in any important way in the troposphere.

Uploaded on Apr 14, 2011
The Role of Clouds and Water Vapor in Climate Change
Colorado State University, Fort Collins, Colorado 

This lecture is part of SFU's 2011 global warming seminar series "Global Warming: A Science Perspective".

For more information, visit