September 1, 2008

The case of the missing sunspots

Fascinating ongoing discussion at Watts Up with That. Editor Anthony Watts started off by pointing that we have gone one calendar month with no sunspots. Someone wrote in to correct him and let him know that the brief sun-specks that showed up on August 21 and 22 were being counted as full-on sunspots even though their life was only a few tens of hours at best. From Watts Up with That:
Sunspeck counts after all�Sun DOES NOT have first spotless calendar month since June 1913

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.

Later in the post is the original post and it's import on our cooling weather patterns followed by over 150 comments ranging from frothing AGW'rs to people providing links to research on the cooling. A fun read in a barroom brawl sort of way... Posted by DaveH at September 1, 2008 9:23 PM
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