At the risk of triggering a new sunspot by talking about it, I’ll cautiously mention that by GMT time midnight tomorrow, August 10th, we will possibly have a 30 day stretch of no sunspots at a time when cycle 24 has been forecast by many to be well underway. Here is the most recent (and auto updating) SOHO MDI image of the sun:
Spotless Days Count
(updated data from Spaceweather.com)
Current Stretch: 29 days
2009 total: 171 days (78%)
Since 2004: 682 days
Typical Solar Min: 485 days
Here is the latest data from NOAA’s Space Weather Prediction Center:
:Product: Daily Solar Data DSD.txt :Issued: 0225 UT 09 Aug 2009 # # Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center # Please send comments and suggestions to SWPC.Webmaster@noaa.gov # # Last 30 Days Daily Solar Data # # Sunspot Stanford GOES10 # Radio SESC Area Solar X-Ray ------ Flares ------ # Flux Sunspot 10E-6 New Mean Bkgd X-Ray Optical # Date 10.7cm Number Hemis. Regions Field Flux C M X S 1 2 3 #--------------------------------------------------------------------------- 2009 07 10 68 13 60 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 11 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 12 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 13 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 14 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 15 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 16 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 17 66 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 18 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 19 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 20 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 21 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 22 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 23 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 24 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 25 69 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 26 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 27 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 28 69 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 29 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 30 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 07 31 69 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 01 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 02 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 03 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 04 66 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 05 66 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 06 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 07 68 0 0 0 -999 A0.0 0 0 0 0 0 0 0 2009 08 08 67 0 0 0 -999 A0.0 0 0 0 0 0 0 0
While it is possible that we’ll see a 30 day stretch of days with no sunspots, we have yet to complete a calendar month without a sunspot.
A year ago in August 2008, we initially had completed a sunspotless calendar month. But, as fate would have it, that distinction was snatched away at the very last moment by the folks in Belgium at SIDC based on one sketch of a plage cum sunspeck from Catainia observatory in Italy.
As Carly Simon once fabulously sung:
I know nothing stays the same
But if youre willing to play the game
Its coming around again
So much for a fantasized “Watts” effect, eh? The last, best hope of the ‘It ain’t the sun, stupid’ coven, gone. So sad.
Richard (22:07:22) :
< In 1880 perihelion would have been on the 15th of December and
< aphelion on the 15th of June.
Where did you get these dates? They are wrong. In 1880 Earth reached
aphelion on July 3, and perihelion occurred on January 1, 1880, and
on January 1, 1881.
Not much different from the present situation.
I calculated them from the fact that in 2000 aphelion was on the 4th of July and this year it seems to be on the 5/6th of July and extrapolated.
Where did you get your figures from? In any case if it was on the 3rd of July in 1880 perihelion should have been on the 3rd of Jan and not the 1st.
Richard (23:33:30) :
< I calculated them from the fact that in 2000 aphelion was on the 4th
< of July and this year it seems to be on the 5/6th of July and extrapolated.
<
< Where did you get your figures from?
You may not extrapolate from dates that are only a few years apart, because there is some scatter in the perihelion/aphelion dates, mainly due to the gravitational action of the Moon. Due to this action, the Earth revolves around the Earth-Moon barycenter, resulting in some "scatter" from the one year to the other in the perihelion/aphelion times. For example, here are the times of the passages of the Earth at perihelion in some years. The times are in UT.
2005 Jan. 2 01 h
2006 Jan. 4 16 h
2007 Jan. 3 20 h
2008 Jan. 2 24 h
2009 Jan. 4 15 h
I am a specialist in mathematical astronomy, and I am making astronomical
calculations since more than 50 years. My figures are obtained from a variety of sources, for example the French analytical planetary theory VSOP87 by
the late Bretagnon, or from the excellent and accurate software Solex by
Aldo Vitagliano.
John C (21:04:19) :
“I decided to check the “3-monthly running mean” (a smoothing technique – no ‘magic’ to it) of sunspot numbers for the past year to see how things were going. …. So I graphed the 3-monthly running means for the period June 2008 through June 2009, for these three sources of sunspot numbers – and the results are intriguing, indeed. It appears we have two successive minima, six or seven months apart – one in August last year, the second either in February (SIDC and IPS figures) or March (SWPC figures)”
===
I htink one problem with all tests and relationships like this is that sunspots themselves are a symptom (an indication, more accurately) of the patterns of magnetic and heat circulation patterns in the sun. The sunspots we see aren’t themselves what is inducing or influencing climate/weather/geomagnetic storms/cosmic ray shielding here.
In my opinion, something else – something more fundamental – is influencing both , or is linking both together. The net result of this solar influence is a sum of a short term 70-80 year cycle (maybe a short term 75 year average period that itself has a true length that oscillates between a 65 year and a 85 year timeframe!) – and a larger, longer 800 year cycle (Roman Warm Period, Dark Ages, Medieval Warm Period, Little Age, Modern Optimum.)
Thow a few orbit pertubations in to get the 10,000 year Ice Ages ….
Jean Meeus – Thank you for that. Is there any way you can explain short term fluctuations of temperature due to the sun?
Richard (04:45:11) :
Jean Meeus – Thank you for that. Is there any way you can explain short term fluctuations of temperature due to the sun?
No. If there are short-term fluctuations in the (global?) temperature,
then certainly they cannot be explained by year-to-year variations in the
Earth-Sun distance. These variations are much too small. For illustration,
here are the times of the least Earth-Sun distances during the years
2000-2009.
The last column gives the least distance between the centers of Earth and
Sun in astronomical units. 1 a.u. is the mean distance between Sun and
Earth. (There is a better, mathematical definition, but this is not to the
point here). Times are in UT.
2000 Jan. 3 05h 0.983321
2001 Jan. 4 09h 0.983286
2002 Jan. 2 14h 0.983290
2003 Jan. 4 05h 0.983320
2004 Jan. 4 16h 0.983265
2005 Jan. 2 01h 0.983297
2006 Jan. 4 16h 0.983327
2007 Jan. 3 20h 0.983260
2008 Jan. 2 24h 0.983280
2009 Jan. 4 15h 0.983273
Jean Meeus (02:19:03) :
Richard (23:33:30) :
resulting in some “scatter” from the one year to the other in the perihelion/aphelion times.
Not to mention the scatter introduced simply by our calendar’s leap year system…
Jean Meeus and Leif – thanks for that.
Yes the Sun-Earth distances and the drift of the aphelion/ perihelion along the seasons are certainly too small to explain the fluctuations of the global temperature on short time scales.
However on larger times scales of a few tens of thousands of years as the aphelion/ perhelion drifts with respect to the solstices (or vice-versa if that is more correct) this would affect our climate.
I read that warmer annual average atmospheric temperatures occur when summers are longer, as opposed to being more intense, because temperature is more sensitive to insolation when the atmosphere is cooler, as dictated by radiative equilibrium.
When autumn and winter occur at perihelion, “as is the case currently in the northern hemisphere, the earth is moving at its maximum velocity and therefore autumn and winter are slightly shorter than spring and summer. Thus, summer in the northern hemisphere is 4.66 days longer than winter and spring is 2.9 days longer than autumn.” – from Wikipedia.
We would therefore naturally assume to be in a warm period.
What puzzles me however is that during the last 700,000 years the interglacials have lasted only about 10,000 years, which is about the length of our present interglacial. When this happened CO2 was rising and continued to rise as the temperatures plunged. Clearly the cause was the sun but how?
Indeed something caused the various warm and cold periods during our present Holocene interglacial. Again the primary cause must have been the sun but again how?
I am inclined to favour solar wind as the explanation of at least small variations of +/- 1.5C – the component directly incident on us.
According to some our interglacial will last about 30-40,000 years more some say even about 100,000 years. But this is based solely on classical variation of insolation due to or changing orbits. This clearly does not take into account the uncertainties and unknowns of our recent past climatic history in which interglacials have lasted only 10,000 years with no satisfactory explanation.