From the FECYT – Spanish Foundation for Science and Technology via Eurekalert comes this interesting note about solar forcing. It seems there’s a 2.3% per decade increase in solar radiation observed in Spain. Surely this is more than enough to account for the warming there? Cloud cover is said to be the issue, as Dr. Roy Spencer has previously pointed out, it only takes a small amount of cloud cover change to make a warming trend. – Anthony
Spain receives ever more solar radiation
Solar radiation in Spain has increased by 2.3% every decade since the 1980s, according to a study by researchers from the University of Girona and the Federal Institute of Technology (ETH) in Zurich. This increase is linked to the decreased presence of clouds, which has increased the amount of direct radiation reaching us from the Sun.
“The mean annual G series over Spain shows a tendency to increase during the 1985-2010 period, with a significant linear trend of + 3.9 W m-2 [2.3% more] per decade.” This is the main conclusion of a study published in the magazine ‘Global and Planetary Change‘ by researchers from the University of Girona and the Federal Institute of Technology in Zurich (ETH, Switzerland).
The season-by-season data show the same “significant” increase in solar radiation impacting the nation: + 6.5 W/m2 per decade during the summer, + 4.1 W/m2 in autumn, + 3.2 W/m2 in spring and + 1.7 W/m2 in winter.
“These data relate to global solar radiation, in other words the increase in direct radiation reaching us from the Sun plus diffuse radiation which is scattered previously by clouds, atmospheric gases and aerosols,” explains one of the authors, Arturo Sánchez-Lorenzo, currently a postdoctoral researcher at the University of Girona.
What is intriguing is that the scientists found a decrease in the diffuse component, because of which direct radiation has increased to a proportionately higher degree. Only in 1991 and 1992 did diffuse radiation rise, and this was due to the ashes from Mount Pinatubo. In general, however, we can observe a downward trend of – 2.1 W/m2 per decade between 1985 and 2010.
VIDEO: Solar radiation in Spain has increased by 2.3 percent every decade since the 1980s.Click here for more information.
“The explanation lies in the fact that in Spain the amount of cloud has decreased markedly since the 1980s – as we have ascertained through other studies – and the tropospheric aerosol load may also have decreased,” states Sánchez Lorenzo. “It seems to be very simple: fewer clouds result in higher solar radiation on the surface,” he continues.
According to the scientists, this increase may also go hand in hand with more ultraviolet rays, an excess of which presents a health risk, potentially leading to skin cancer.
More global brightening
The increase in global solar radiation is a phenomenon that has been observed in other parts of the world for almost 30 years, especially in developed countries, and it has been named “global brightening”. The fall in the diffuse component has also been observed in Central European and Eastern countries.
The team behind the study has not yet analysed the solar radiation data for 2011-2013 provided by the Spanish State Meteorological Agency, but the data from other European weather stations suggests that this brightening is still on the rise.
“Studies such as these may be of interest to the solar energy industry, especially in countries like Spain, where not only do we already have a lot of direct solar radiation but now we are getting even more,” affirms one of the other authors, Josep Calbó, who is a professor at the University of Girona.
References:
A. Sanchez-Lorenzo, J. Calbó, M. Wild. “Global and diffuse solar radiation in Spain: Building a homogeneous dataset and assessing their trends”. Global and Planetary Change 100: 343–352, 2013.
h/t to Dr. Leif Svalgaard
Ulric Lyons says:
June 19, 2013 at 2:20 am
A lack of strong magnetic storms would then aid the collapse, as would the scarcity of coronal holes, and low plasma speeds, it all adds up.
There is a lack of strong magnetic storms at every minimum and there were more coronal holes in 2008-2009 than in 1996-1997, so it does not add up, but it doesn’t need to: As Solomon’s analysis shows the lack of EUV and the increase of CO2 are enough to explain the difference between the two minima.
Ulric Lyons says:
June 19, 2013 at 2:20 am
low plasma speeds, it all adds up.
To illustrate the non-importance of the solar wind speed take 2003 with the highest yearly average solar wind speed ever measured [543 km/s] and compare with the year before 2002 [440 km/s], yet the thermospheric density in 2003 was only half of that in 2002 in spite of the much higher solar wind speed. There were very large and dark coronal holes in 2003 compared to 2002, so much less EUV which explains why the density in 2003 was only half that of 2002. Again: the solar wind speed is not the determining factor, EUV is. As you could have learned from the Qian/Solomon review [but didn’t].
@Leif
The level of EUV forcing is self evident from the density range from minimum to maximum of each solar cycle. I’m not saying that plasma speed is dominant, but that it is underestimated. For 2003, do we not see a rise in density later in the year as high as 2002?, page 15:
http://www.leif.org/EOS/Thermosphere-Density-Review.pdf
And the rise in plasma velocity was from Autumn 2002:
http://snag.gy/3CPhe.jpg
Leif Svalgaard says:
“there were more coronal holes in 2008-2009 than in 1996-1997”
I know that there were more low latitude CH,s in 2009 than 1996/7, but they were not very frequent or large. Do you have a list of high and low latitude CH’s for 1996/7 to compare total numbers?
Ulric Lyons says:
June 19, 2013 at 5:53 am
I’m not saying that plasma speed is dominant, but that it is underestimated.
Not at all: http://www.leif.org/research/Thermospheric-Density-Speed.png
Ulric Lyons says:
June 19, 2013 at 9:28 am
I know that there were more low latitude CH,s in 2009 than 1996/7, but they were not very frequent or large.
Contradictory statements…
How much longer do we have to walk around in circles?
Leif Svalgaard says:
“How much longer do we have to walk around in circles?”
For as long as you avoid a direct response, i.e.;
do we not see a rise in density later in the year as high as 2002?, page 15:
http://www.leif.org/EOS/Thermosphere-Density-Review.pdf
and; Do you have a list of high and low latitude CH’s for 1996/7 to compare total numbers?
There is no contardiction there, but I could ask the question a different way if you prefer. Were there less high latitude CH’s in 2009 than 1996, and how many CH’s were there in 1996 on average per month of both high and low latitude?
Ulric Lyons says:
June 19, 2013 at 1:14 pm
For as long as you avoid a direct response, i.e.;
do we not see a rise in density later in the year as high as 2002?, page 15:
http://www.leif.org/EOS/Thermosphere-Density-Review.pdf
Assuming you mean Figure 7 on page 161
http://www.leif.org/research/Thermospheric-Density-2002-2006.png
you can see that the rises in the density are due to enhanced EUV [e.g. in red boxes],
so you can stop going in circles.
Perhaps this plot http://www.leif.org/research/Thermospheric-Density-2002-2003.png will make it even clearer. Note the drop in density in the autumn of 2002 and its even more dramatic drop in 2003 as solar wind speed really picks up.
Do you have a list of high and low latitude CH’s for 1996/7 to compare total numbers?
Do you? The experimenters and modelers have done the job for us: “In order to estimate the wavelength dependence of this change, the CHIANTI models [Dere et al., 1997; Landi et al., 2006] of the quiet sun (QS) and coronal hole (CH) differential emission measures (DEMs) were employed. A .50 CH proportion fit the SEM 26–34 nm average measurement for 1996, and a .68 CH proportion fit the SEM 26–34 nm average measurement for 2008”. So no more circles, please.
Leif Svalgaard says:
“you can see that the rises in the density are due to enhanced EUV [e.g. in red boxes]”
You are just being selective with your evidence to attempt to prove your point, and you have missed the target altogether. I said later in the year [2002] not summer time! (red box 1 is ~3 months too early for the rise in density *later* in 2002, i.e. from when the rise in plasma speed occurs. The density is higher at the end of 2002 than in your red box)
http://www.leif.org/research/Thermospheric-Density-2002-2006.png
And red box 2 starts too early for the EUV spikes. The density is rising up to nearly 2002 levels before the rise in EUV.
Also note the drop in speed at the start of 2003: http://snag.gy/3CPhe.jpg
CHIANTI models? I wanted an observational head count, not a model.
Ulric Lyons says:
June 20, 2013 at 3:05 am
And red box 2 starts too early for the EUV spikes. The density is rising up to nearly 2002 levels before the rise in EUV. Also note the drop in speed at the start of 2003:
It would be nice if you would go to the trouble of providing data and times, rather than just words, like in:
Perhaps this plot http://www.leif.org/research/Thermospheric-Density-2002-2003.png will make it even clearer. Note the drop in density in the autumn of 2002 and its even more dramatic drop in 2003 as solar wind speed really picks up.
CHIANTI models? I wanted an observational head count, not a model.
Everything are models these days. The thermospheric density is derived from a model to fit the satellite orbit decays. The EUV flux is derived from a model using the coronal hole fraction, and so on.
Leif Svalgaard says:
“Perhaps this plot http://www.leif.org/research/Thermospheric-Density-2002-2003.png will make it even clearer. Note the drop in density in the autumn of 2002 and its even more dramatic drop in 2003 as solar wind speed really picks up.”
No this plot derived from the satellite drag: http://www.leif.org/research/Thermospheric-Density-2002-2006.png
See the dramatic density rise at the end of 2003, building well before the EUV rise. And also the rise in density in the last 3 months of 2002.
@Leif
Also note the drops in density mid 2004, 2005 and 2006, which have no correlation to any decline in the EUV plot: http://www.leif.org/research/Thermospheric-Density-2002-2006.png
Such a strong drop is not so apparent in mid 2003.
Ulric Lyons says:
June 20, 2013 at 4:36 am
No this plot derived from the satellite drag: http://www.leif.org/research/Thermospheric-Density-2002-2006.png See the dramatic density rise at the end of 2003, building well before the EUV rise.
Not at all, the sharp spike at the end of 2003 was caused by the ‘Halloween’ eent, one of the biggest flares observed and a copious emitter of Xrays and EUV.
The rest of your posts are not substantiated. Make a plot if you must, words don’t cut it.
Leif Svalgaard says:
“Not at all, the sharp spike at the end of 2003 was caused by the ‘Halloween’ eent,”
That’s at the end of October, and yet the density was on a rising trend from mid 2003.
“The rest of your posts are not substantiated. Make a plot if you must,”
Oh yes they are and here’s the plot:
http://www.leif.org/research/Thermospheric-Density-2002-2006.png
@Leif
You are deliberately ignoring:
1) the sharp density rise in the last quarter of 2002
2) the sharp density rises through the second half of 2003
3) the sharp decline in density mid 2004, 2005 and 2006, and lack thereof in 2003
As you continue to deny the observational data, there is no point in continuing this debate.
Ulric Lyons says:
June 20, 2013 at 11:03 am
1) the sharp density rise in the last quarter of 2002
2) the sharp density rises through the second half of 2003
3) the sharp decline in density mid 2004, 2005 and 2006, and lack thereof in 2003
None of these are directly related to solar wind speed, but to increases of Xray and EUV [F10.7]. For example, the spike in October 2003 was caused by a sequence of some of the biggest flares ever with their copious radiation. Helped for a few hours by the extraordinary high solar wind magnetic field and flow pressure.
As you continue to deny the observational data, there is no point in continuing this debate.
Firstly: the density is the output of a model, secondly: this is not a debate, but an attmpts to teach you how this whole things works, but if you continue to flaunt your learning disability, there is, as you suggest, perhaps little point in continuing..:
@Leif
Again, wilfully ignoring the facts, density was rising sharply for several weeks before the 19th of October.
http://www.leif.org/research/Thermospheric-Density-2002-2006.png
“..but if you continue to flaunt your learning disability, there is, as you suggest, perhaps little point in continuing..”
That’s exactly how I feel about you ignoring what the above data shows.
Ulric Lyons says:
June 20, 2013 at 7:12 pm
Again, wilfully ignoring the facts, density was rising sharply for several weeks before the 29th of October.
Again, the facts are that Xray/EUV [as measured by the F10.7 flux] was indeed rising several weeks before the flare, as you can see here [for two different satellites] http://www.leif.org/research/Thermospheric-Density-Fall-2003.png as several active regions were crossing the disk and the X-ray flux increased by a factor of 100. That is what caused the rise in density. A couple of days after the flare, the density also got a boost from the strong magnetic field and flow pressure from the CME that hit the Earth, as I have explained many time now. Don’t miss this opportunity to learn something.
Leif Svalgaard says:
“Again, the facts are that Xray/EUV [as measured by the F10.7 flux] was indeed rising several weeks before the flare, as you can see here [for two different satellites] http://www.leif.org/research/Thermospheric-Density-Fall-2003.pn”
You are showing from September 29th there, which is largely flat for the first three weeks,
and you filtered out the big rise that preceded it, leading up to your 2nd red box.
http://www.leif.org/research/Thermospheric-Density-2002-2006.png
Where’s the effect of the X-flares late May and early June 2003?
Does the proton event effect density?: http://www.lmsal.com/solarsoft/last_events_20031030_1013/index.html
Ulric Lyons says:
June 21, 2013 at 3:19 am
and you filtered out the big rise that preceded it, leading up to your 2nd red box.
Between the two red boxes the density was steadily dropping by almost a factor of ten.
Ulric Lyons says:
June 21, 2013 at 3:19 am
Does the proton event effect density?
Not per se, but it occurs as part of a big flare that does.:
Ulric Lyons says:
June 21, 2013 at 3:19 am
Where’s the effect of the X-flares late May and early June 2003?
Where is the effect of the very high solar wind speed at that time?,
http://hirweb.nict.go.jp/sedoss/solact3/do?d=2003%2c05%2c21
You have to learn to ask meaningful questions, not veiled hints.
Are you saying that there was no density spike at that time corresponding to the very high solar wind speed?
Ulric Lyons says:
June 21, 2013 at 3:19 am
Where’s the effect of the X-flares late May and early June 2003?
Figure 1 of http://www.leif.org/EOS/Thermosphere-Density-Review.pdf shows the typical effect of a big X-flare. About these other [smaller] flares, which dates specifically?
Leif Svalgaard says:
“Between the two red boxes the density was steadily dropping by almost a factor of ten.”
September 2003 is the rise, as I said above, preceding your second red box:
http://www.leif.org/research/Thermospheric-Density-2002-2006.png
Where’s the density spikes from the X-flares late May and early June 2003?
http://www.lmsal.com/solarsoft/latest_events_archive.html