Solar weather watch: Cycle 24

Watching each cycle and trying to relate it to climate is kind of fruitless. Taking the cycles and the average of them is more worthwhile and then seeing what the trend is it is very important.

Interesting, don't let the AGW folks know this. The sun is pretty much benign to them. On a more serious not I think I'm gonna find that report and peruse it.

Don't you think it is a little bit crazy for some people to claim there is very little or no effect from the sun on climate? I don't know the answer as whether it does or not. I would make the over simplified observation that if something stops working I always check the power source first, since the sun is our power source I would think you would check it first.

My whole problem with anyone who makes absolute statements, especially when it comes to something as complicated as climate, is that we don't understand the atmosphere enough to make forecasts about what it is doing. We need to invest much more money into the science, unfortunately we are in a time when science funding is being slashed by people who are to stupid to understand the importance of science.

Actually, I don't know of any scientists who say it has no effect, only that the effect is not significant at this time. There's a big difference in those two statements. When you hear a scientist say "It isn't the sun.", that doesn't equate to "It has no effect.", it means that the sun isn't the dominant factor in driving the changes we see. From peak to trough, the total amount of luminosity change we see from the sun is <0.1% (we measure this directly with satellites and have proxies going back centuries for the effect). The net effect is equivalent to, at most, plus or minus 0.25W/m2 (or the equivalent of putting 1 small Christmas light over the earth every 4 square meters). All alone, by itself, this might be significant. But, when you swamp the atmosphere with excess Tyndall gases like CO2, CH4 and H2O, it is easily dwarfed, as the net effect of those gases are 5-10 times that. I'll go over this subject more in depth when I start the climate history series.

But the sun has become less active in ways other than lumosity. I would assume that would have effects, such as cloud formation, we might not fully appreciate.

I just think we know far to little about how are climate system works to blame every thing on carbon emissions.

My caveat is we should limit those emissions, but keep an open mind as to what is happening. The climate has changed constently through history should we believe it won't continue.

Explain the net effect thing. It looks like a watering down of the WPM to about 250WPM total. Is that about right?

1366W/m2 is the top-of-atmosphere measurement with incoming light perpendicular. If I were to use your figure of a 6W change, to get the net effect of change (or the radiative forcing -- essentially the imbalance of energy hitting the earth through shortwave light and leaving via longwave radiation), we need to take into account:

1) Albedo (for the earth, this is about 70% or .7).
2) The spherical geometry of the earth (we'll need to divide by 4 here).

The equation is:

Radiative Forcing (net effect from above) = Albedo * Change in (TSI)/(Factor for spherical geometry)

or

1.05 W/m2 = .7 * (6/4)

Significant to be sure, assuming 6 W/m2 worth of change at TOA (top of atmosphere). Since we've had our satellites measuring up there though, we've measured about 1.5W/m2 of change from the highest peaks in the 80s-late 90s to the lowest trough (recently -- in 2009). Plugging that in yields 0.26W/m2 worth of radiative forcing -- not all that much.

There is a valid argument that the first half of the 20th century (1900-1940 especially) that the sun significantly contributed to warming in that period. In that era, we have decent evidence that suggests forcing from the sun was probably around half of the total.

If you want to head back further (to say, the Maunder Minimum), radiative forcing changes approaching 1W/m2 probably occurred. Some further reading on TSI back to the 1700s can be had here: sun.stanford.edu/LWS_Dynamo_2009/61797.web.pdf (It's a bit dense -- be warned).

Well, you can say not much, but using your figures the total variation for modern times is only 1.05 WPM, maybe only .7. OK, you say that the sun has played no part in ANY cooling or heating in that period. You would almost have to because that was slight.....right? BTW, stick the highest troughs and lowest stuff where is belongs. We use averaging for a reason. If someone is fiddling with a burner. turning it up and down all the time, the net effect is going to be some average of the cycle. How much has the average cycle dropped in the last round compared to average of the last three? Of course we probably are going to have to wait on that one.

Really, if you at the only data we have on the sun we see only about a slightly different number for average weak solar cycle than the bottoms of swings. Here is the reason why. The quiet solar times were essentially cycles without peaks. So it could be the average cycle was only around 0.25 W weaker than the strongest over the last 500 years. We are lucky this sun is soooo constant.

Also, if it warmed in the first half, why not the second. The cycles, 21 and 22, were essentially as strong as the ones in the early part of the century. Even 20 was what I would considered slightly above neutral to neutral.

BTW, even a 1C change aint much. that's only 0.26% (using the kelvin scale, absolute zero to boiling point).

Don't shoot me for using 30 I know that's a bit high. I am guessing the current earth temperature is probably 20 something. It won't change the percentage thing much.

Here is an interesting overlay. Could we be moving to another minimum? It really takes more than one cycle to be there. We'll see.

Oh crap. bad math again. OK, the lowest is -204C add that to 20c. OK that kicks the 0.7c+ to a whopping 0.31%. DONE Anyway, that is slight in my book.

Yes, we were coming out of the little ice age. A big bump was not totally unexpected. The thing about it is swings tend go go in spurts, not smooth lines. Of course the AGW folks like to point that out as an excuse why the warming has leveled off, but they don't accept that is nature's way also.

Using a percentage for temperature change isn't really a valid way to do comparisons. The reason is due to the Stefan-Boltzmann law, which states that the amount of energy being emitted by a blackbody (of which the Earth is a reasonably close approximate) is proportional to its temperature to the fourth power. In other words, it doesn't take much energy to get from microwave background temperatures (~3K) to say... 50K. It takes a heck of a lot more to get from 200K to 250K (Kelvin = Celsius + 273). Using percentages to do comparisons in this case simply does not work (at all).


Using the Stefan-Boltzmann law (the wikipedia link there actually lays out the entire calculation from start to finish) and an albedo adjustment because the earth isn't a perfect blackbody (again the .7, but this time to the fourth root), it gets you an effective temperature of 255K for Earth (or -18C). This would be the equilibrium temperature of Earth if it had no atmosphere. Tyndall gasses (such as water vapor, carbon dioxide and methane) partially re-radiate outgoing longwave radiation, this keeps the Earth warmer than it otherwise would be (at around 15C or 288K).