Watts Up With That?

UPADATED AT 8:30AM PST Sept 2nd-

More on SIDC’s decision to count a sunspeck (technically a “pore”) days after the fact. NOAA has now followed SIDC in adding a 0.5 sunspot where there was none before. But as commenter Basil points out, SIDC’s own records are in contrast to their last minute decision to count the sunspeck or “pore” on August 21.

There is an archive of the daily SIDC “ursigrams” here:

http://sidc.oma.be/html/SWAPP/dailyreport/dailyreport.html

If you select the ursigrams for August 22 and 23, you get the reported data for the 21st and 22nd:

August 21:

TODAY’S ESTIMATED ISN : 000, BASED ON 07 STATIONS.

SOLAR INDICES FOR 21 Aug 2008
WOLF NUMBER CATANIA : 011
10CM SOLAR FLUX : 067
AK CHAMBON LA FORET : ///
AK WINGST : 004
ESTIMATED AP : 005
ESTIMATED ISN : 000, BASED ON 14 STATIONS.

August 22:

TODAY’S ESTIMATED ISN : 000, BASED ON 11 STATIONS.

SOLAR INDICES FOR 22 Aug 2008
WOLF NUMBER CATANIA : 013
10CM SOLAR FLUX : 068
AK CHAMBON LA FORET : ///
AK WINGST : 003
ESTIMATED AP : 003
ESTIMATED ISN : 000, BASED ON 11 STATIONS.

In both cases, the daily estimated “International Sunspot Number” based on multiple stations, not just the Catania Wolf Number, was 000. So how did SIDC end up with positive values in the monthly report?

UPDATED at 2:42 PM PST Sept 1st –

After going days without counting the August 21/22 “sunspeck” NOAA and SIDC Brussels now says it was NOT a spotless month! Both data sets below have been recently revised.

Here is the SIDC data:
http://www.sidc.be/products/ri_hemispheric/

Here is the NOAA data:
ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/MONTHLY

The NOAA data shows July as 0.5 but they have not yet updated for August as SIDC has. SIDC reports 0.5 for August. It will be interesting to see what NOAA will do.

SIDC officially counted that sunspeck after all. It only took them a week to figure out if they were going to count it or not, since no number was assigned originally.

But there appears to be an error in the data from the one station that reported a spot, Catania, Italy. No other stations monitoring that day reported a spot. Here is the drawing from that Observatory:

ftp://ftp.ct.astro.it/sundraw/OAC_D_20080821_063500.jpg
ftp://ftp.ct.astro.it/sundraw/OAC_D_20080822_055000.jpg

But according to Leif Svalgaard, “SIDC reported a spot in the south, while the spot(s) Catania [reported] was in the north.” This is a puzzle. See his exchange below.

Also, other observatories show no spots at all. For example, at the 150 foot solar solar tower at the Mount Wilson Observatory, the drawings from those dates show no spots at all:

ftp://howard.astro.ucla.edu/pub/obs/drawings/dr080821.jpg

ftp://howard.astro.ucla.edu/pub/obs/drawings/dr080822.jpg

Inquires have been sent, stay tuned.

Here is an exchange in comments from Leif Svalgaard.

——-

REPLY: So What gives Leif….? You yourself said these sunspecks weren’t given a number. I trusted your assessment. Hence this article. Given the Brussels folks decided to change their minds later, what is the rationale ? – Anthony

The active region numbering is done by NOAA, not by Brussels. The Brussels folks occasionally disagree. In this case, they did. Rudolf Wolf would not have counted this spot. Nor would I. What puzzles me is this:
21 7 4 3
22 8 4 4
The 3rd column are ’spots’ in the Northern hemisphere, and the 4th column are ’spots’ in the Southern hemisphere [both weighted with the 'k'-factor: SSN = k(10g+s)]. But there weren’t any in the south. The Catania spot was at 15 degrees north latitude, IIRC. Maybe the last word is not in on this.

——–

Hmm….apparently there’s some backstory to this. There is a debate raging in comments to this story, be sure to check them. – Anthony

# MONTHLY REPORT ON THE INTERNATIONAL SUNSPOT NUMBER #
# from the SIDC (RWC-Belgium) #
#——————————————————————–#

AUGUST 2008

PROVISIONAL INTERNATIONAL NORMALIZED HEMISPHERIC SUNSPOT NUMBERS

Date Ri Rn Rs
__________________________________________________________________

1 0 0 0
2 0 0 0
3 0 0 0
4 0 0 0
5 0 0 0
6 0 0 0
7 0 0 0
8 0 0 0
9 0 0 0
10 0 0 0
11 0 0 0
12 0 0 0
13 0 0 0
14 0 0 0
15 0 0 0
16 0 0 0
17 0 0 0
18 0 0 0
19 0 0 0
20 0 0 0
21 7 4 3
22 8 4 4
23 0 0 0
24 0 0 0
25 0 0 0
26 0 0 0
27 0 0 0
28 0 0 0
29 0 0 0
30 0 0 0
31 0 0 0
__________________________________________________________________

MONTHLY MEAN : 0.5 0.3 0.2

========================================================

ORIGINAL STORY FOLLOWS:

Many have been keeping a watchful eye on solar activity recently. The most popular thing to watch has been sunspots. While not a direct indication of solar activity, they are a proxy for the sun’s internal magnetic dynamo. There have been a number of indicators recently that it has been slowing down.

August 2008 has made solar history. As of 00 UTC (5PM PST) we just posted the first spotless calendar month since June 1913. Solar time is measured by Coordinated Universal Time (UTC) so it is now September 1st in UTC time. I’ve determined this to be the first spotless calendar month according to sunspot data from NOAA’s National Geophysical Data Center, which goes back to 1749. In the 95 years since 1913, we’ve had quite an active sun. But that has been changing in the last few years. The sun today is a nearly featureless sphere and has been for many days:

Image from SOHO

And there are other indicators. For example, some solar forecasts have been revised recently because the forecast models haven’t matched the observations. Australia’s space weather agency recently revised their solar cycle 24 forecast, pushing the expected date for a ramping up of cycle 24 sunspots into the future by six months.

The net effect of having no sunspots is about 0.1% drop in the TSI (Total Solar Irradiance). My view is that TSI alone isn’t the main factor in modulating Earth’s climate. Read the rest of this entry »

A Guest Post By Steve Goddard

In my most recent article in The Register, and also posted here on WUWT, I incorrectly speculated that NSIDC graphs appeared to show less growth in Arctic ice extent than had actually occurred.  My calculations were based on counting ice pixels from Cryosphere Today maps.  Since then, I have had further discussions with Dr. Walt Meier at NSIDC and William Chapman at Cryosphere Today, to try to understand the source of the problem.   Dr. Meier has confirmed that counting pixels provides a “good rough estimate” and that NSIDC teaches pixel counting to CU students as a way to estimate ice extent.  William Chapman has confirmed that the projection used in CT maps is very close to what it appears and to what I had assumed it to be.  It is an astronaut’s view from about 5,000 miles above the north pole.

What I have learned

In 2008, CT and NSIDC maps show excellent agreement – as can be seen in this video which overlays an August 14 NSIDC map on top of the August 14 CT map.  The borders of ice extent are nearly identical in the two maps. (The videos show overlays of the two maps.)

The discrepancy occurred in August, 2007, when agreement between NSIDC and CT was not so good.  The equivalent video from August 15, 2007 shows that the CT map was missing a significant amount of low concentration ice on the Canada/Alaska side.  I have since confirmed from AMSR maps and NASA satellite photos that the NSIDC map is probably more accurate than the CT map.

The reason that CT provides their side-by-side image viewer is apparently to encourage visitors to make a visual comparison of two dates, which is exactly what myself and others here did when we observed the discrepancy vs. NSIDC graphs.  The human brain is quite good at making estimates of relative areas from images, and pixel counting is nothing more than a way to quantify what has already been observed.  Since writing The Register piece I have made adjustments to the CT pixel counts for map distortion, and as I expected that makes the discrepancy slightly larger.

Because CT maps showed less ice in 2007, the increase in 2008 ice extent appears to be much greater. There is little doubt now that the NSIDC reported ice growth is absolutely correct.  But wasn’t the ice supposed to shrink this year due to an excess of “thin first-year ice?”  In May, NSIDC’s mean forecast (based on previous year’s melt) was that Arctic ice extent would be 13% lower than last year.  (NSIDC has more recently posted on their web site some reasons why they believe the May estimates didn’t work out.) Read the rest of this entry »