Factors affecting DLWIR - NREL data (re-analysis)

Data from NREL re-analysed - spread sheet corrected, ULWIR nulling removed as this is basically the same as temperature, latest data added.

Data is dependent on cloud cover. Unfortunately cloud data is only available during daylight. Hours of darkness therefore are not included in this analysis

 The first plot shows the variation with date  (2004 to 2013) Unfortunately the calibration of the pyrgeometer (including device swapping on every calibration) shows up as a signal greater than any trend. The calibration dates are shown as dotted blue lines.

2004 - 2006 31192F3 large error
2006 - 2008 31194F3 10 w/sqm drop
2008 - 2009 31192F3 random 8w/sqm p-p
2009 - 2011 31194F3 10 w/sqm drop
2011 - 2012 31192F3 random 13w/sqm p-p
2012 - 2013 31194F3 random 10w/sqm p-p
It appears that 31194F3 has a drift with time (now possibly corrected)
Also it seems that +-5w/sqm is the expected accuracy for this type of pyrgeometer

Luckily this is the only data extraction that is synchronous with date. Other extraction will tend to remove the drift by averaging. It is significant that the calibration adjustments show up indicating that this spreadsheet successfully sees valid changes of <5w class="goog-spellcheck-word" span="" style="background: none repeat scroll 0% 0% yellow;">sqm

This next plot shows the expected variation of dlwir with temperature.

It should be noted that the drop in value at the high temperature end is most likely due to the small number of results returned and is therefore not valid.

The net plot shows the effect of increasing absolute humidity

 

The following pair show the change with day of the year. Note that temperature effects should have been nulled so the peak should not be due to summer temperature. The second plot compares La Jolla CO2 with the dwlir. The dwlir seems to show the inverse of what would be expected!

Station pressure below, has very little effect on dwlir

Opaque cloud cover increases the dwlir!

Data from:
http://www.nrel.gov/midc/srrl_bms/

Temperature dependence - more analysis of NREL data

This analysis shows the interdependence of temperature and other data.
Temperature may be the cause or the effect!
The second curve on each plot shows the number of results returned. Obviously the more results the more likely the data returned is valid.
All data is averaged with the top and bottom 30% discarded to remove outliers

Temperature is affected negatively by the absolute humidity (gms h2o/cu m). To heat air and water vapour takes more energy than air alone hence the negative slope.

Using the nulling technique produces a plot with little day of year dependence (no annual peak or dip is obvious).
The slope of the line is =0.0001602 per day. This equates to 0.585°C per decade and this is over a period that people say the warming has stopped!

As expected with opaque cloud cover the temperature is negatively correlated.

Temperature with day of year is as expected with a peak at day 200 (19th July) and a minimum at day 40 (9th February). These dates are of course offset from longest/shortest day.

Plots of the nulled variables:

Note that the nulled portion is sometimes limited to less than whole range. In this case a limit is used to only accept data for that nulled range on that variable

Also the nulling process is only used to produce a line of zero slope for each variable - the offset from zero is not relevant as only anomalies are plotted.

Data from:
http://www.nrel.gov/midc/srrl_bms/

Sky Temperature and Thermal Imaging

Sky, High and Low cloud temperatures  as measured on a thermal imaging camera.

These images show the cloud and sky temperatures as measured by a camera with a 2µ to 13µ pass band.

From a previous test done at night the clear sky temperature is less than -40°C (the camera lower limit).

These pictures show that this clear sky value is maintained as expected during daylight (about -43°C).

Cloud temperatures range from -20°C for high light cloud to +1.1°C for low heavy cloud.

The pictures were taken on 21^st December 2012 at approx. 14:00pm  (sunset @ 16:00)
All area temperatures are maximum for that area.
 

 

 

 

These temperatures of course represent what the camera "sees" through its Germanium lense. And as can be seen from the previous thermal camera stuff the camera struggles to measure temperature of gasses - they just do not give black body radiation.

 

Previous posts:

http://climateandstuff.blogspot.co.uk/2012/12/water-vapour-and-thermal-imaging.html

http://climateandstuff.blogspot.co.uk/2012/11/thermal-imaging-how-not-to-measure.html

http://climateandstuff.blogspot.co.uk/2012/05/cool-body-can-transfer-measurable-heat.html

 

 



 

Water Vapour and Thermal imaging

More stuff about thermal imaging.

Looking at the sensitivity spectrum for a FLIR thermal camera much of the CO2 and H2O emission spectra are included but it is not a black body spectrum as the camera expects.

So does this mean that CO2 and water vapour should be less visible to the camera?

For the camera this is important since taking a photo through air which is emitting photons visible to its sensor would make its use limited – you would see the air not the object behind the air.

So a simple test using water vapour was done to see if this was the case

Some videos of a hot plate with 2 wells filled with water, The water is boiling but no hot vapour visible (vapour bubbles show approximately the expected temperature but the only vapour visible is less than 40°C.

If you now place a sheet of paper in the vapour the actual temperature of the vapour as it hits the paper can be seen (greater than 70°C)

Steam shows up at 28C

Shows paper being heated to 75.5C by steam invisible in gap between boiling water amd paper.

Heated plate showing 2 wells with boiling water

These videos show differen views of the hotplate - steam - paper system.

  

Steam visible + paper

Top view of plate, boiling water and paper

side view of plate boiling water and paper

Above videos seem to have problems  so a youtube version:

http://www.youtube.com/watch?feature=player_embedded&v=l3t9XeTIA1w

Conclusion: H2O vapour behaves as expected - despite the temperature being near boiling (100C) it does not appear so to the camera.

WUWT - cherry picking again

Water Vapour
The Watts nail in the coffin of AGW headline:

Another IPCC AR5 reviewer speaks out: no trend in global water vapor

Posted on December 14, 2012by Guest Blogger

New global water vapor findings contradict second draft of IPCC Assessment Report 5 (AR5)

Well, the paper this blogger / expert reviewer is behind a paywall so we have to assume that what he quotes is correct. But a quick search pulls up this paper

http://journals.ametsoc.org/doi/abs/10.1175/BAMS-86-2-245

This from the abstract TPW=total precipitable water:
...Further, we found out that the TPW anomalies are driven by the global surface temperature anomalies, but with a lag.

and from the text:

Time series plots of monthly and annual anomalies of TPW for the two datasets are shown in Figs. 8a and 8b, respectively. Also included in Fig. 8 is the global surface temperature anomaly, computed based on NASA’s Goddard Institute for Space Studies (GISS) global surface temperature data (Hansen et al. 1999).

The first 3 yr (1988–90) and part of 1996 show significant discrepancies between the anomalies of the two TPW datasets. There is, however, a good agreement for most parts of the other years. Linear regressionsbetween the two datasets show a correlation coefficient of 0.66 for the monthly anomalies and 0.74 for the annual anomalies. TPW anomalies are closely correlated to surface temperature anomalies. The correlation with surface temperature is higher for R-2 than for NVAP (Fig. 8d). The maximum cross correlation between TPW and surface temperature is reachedwhen the temperature leads the TPW by 2 months and equals 0.67 for R-2 and0.50 for NVAP. This suggests that precipitable water anomalies are driven by the temperature anomalies.

 

The problem is which cherry to pick?!!!!

 

 

Then of course Watts puts his foot in the wet and smelly with this blog post:

IPCC AR5 draft leaked, contains game-changing admission of enhanced solar forcing – as well as a lack of warming to match model projections, and reversal on ‘extreme weather’

Posted on December 13, 2012by Guest Blogger

So in this headline post we have a total misreading of a document. One of the authors  (and surely he should know) sais so on Australian Radio: .

The leaked IPCC drafts cover a range of subjects from the quality of climate models to measurements of sea level rise and Arctic ice loss.

Professor Steve Sherwood is a director of the Climate Change Research Centre at the University of New South Wales.

He is also a lead author of chapter seven of the IPCC report, which happens to be the one the sceptics are claiming for their side.

But Professor Sherwood is scornful of the idea that the chapter he helped write confirms a greater role for solar and other cosmic rays in global warming.

STEVE SHERWOOD: Oh that's completely ridiculous. I'm sure you could go and read those paragraphs yourself and the summary of it and see that we conclude exactly the opposite, that this cosmic ray effect that the paragraph is discussing appears to be negligible.

MARK COLVIN: They're saying that it is the first indication that the IPCC recognises something called solar forcing.

STEVE SHERWOOD: It's not the first time it recognises it. What it shows is that we looked at this. We look at everything. The IPCC has a very comprehensive process where we try to look at all the influences on climate and so we looked at this one.

And there have been a couple of papers suggesting that solar forcing affects climate through cosmic ray/cloud interactions, but most of the literature on this shows that that doesn't actually work.

MARK COLVIN: So you're saying that you've managed to basically eliminate this idea that sunspots or whatever are more responsible for global warming than human activity.

STEVE SHERWOOD: Based on the peer-reviewed literature that's available now, that looks extremely unlikely.

MARK COLVIN: So what have these people done? Is this just a case of cherry-picking a sentence?

STEVE SHERWOOD: Yeah, it's a pretty severe case of that, because even the sentence doesn't say what they say and certainly if you look at the context, we're really saying the opposite.

http://www.abc.net.au/pm/content/2012/s3654926.htm

It looks as if IPCC has played a blinder.

They can see where the "skeptics" will find inconsitancies and then clarify before publishing and all for free

They also show that sketics cannot read or comprehend!.