Dalton Minimum Returns

Near record- no spot days

http://www.spaceweather.com/

According to NOAA sunspot counts, the longest string of blank suns during the current solar minimum was 52 days back in July, Aug. and Sept. of 2008. If the current trend continues for only four more days, the record will shift to 2009. It's likely to happen; the sun remains eerily quiet and there are no sunspots in the offing. Solar minimum is shaping up to be a big event indeed.

Are Sunspots Disapearing?

Interesting post at spaceweather.com

Sunspots are made of magnetism. The "firmament" of a sunspot is not matter but rather a strong magnetic field that appears dark because it blocks the upflow of heat from the sun's fiery depths. Without magnetism, there would be no sunspots.

That's what makes the following graph a little troubling:

According to Bill Livingston and Matt Penn of the National Solar Observatory in Tucson, Arizona, sunspot magnetic fields are waning. The two respected solar astronomers have been measuring solar magnetism since 1992. Their technique is based on Zeeman splitting of infrared spectral lines emitted by iron atoms in the vicinity of sunspots. Extrapolating their data into the future suggests that sunspots could completely disappear within decades. That would be a bummer for Spaceweather.com.

Don't count out sunspots just yet, however. While the data of Livingston and Penn are widely thought to be correct, far-reaching extrapolations may be premature. This type of measurement is relatively new, and the data reaches back less than 17 years. "Whether this is an omen of long-term sunspot decline, analogous to the Maunder Minimum, remains to be seen," they caution in a recent EOS article.

Forty One days and counting

Here is the latest update from Joseph D’Aleo at ICECAP yesterday. 

Sun Run of 41 Days Without a Spot Now Among the Top 10 Longest

...Thursday, August 20th marked the 41st straight day without a sunspot, one of the longest stretches this solar minimum.

In fact it rises into 10th place among all spotless periods since 1849 (first table here). The total number of spotless days this transition from cycle 23 to 24 is now 694 rapidly approaching the approximate number leading into cycle 15 in the early 1900s (below, enlarged here).

Forty days and counting

Consider this found from spaceweather.com

Spotless Days
Current Stretch: 40 days
2009 total: 182 days (79%)
Since 2004: 693 days

Typical Solar Min: 485 days

Posting has been slow, as we are traveling and WiFi conection are iffy some times. 

Twenty nine days and counting

Russ Steele

By midnight on the 10th of August we will have observed 30 days with a spotless sun. Here are some details from SpeceWeather.com

Daily Sun: 07 Aug 09


The sun is blank--no sunspots. Credit: SOHO/MDI
 
Sunspot number: 0
Spotless Days
Current Stretch: 29 days
2009 total: 171 days (78%)
Since 2004: 682 days
Typical Solar Min: 485 days
explanation | more info
Updated 08 Aug 2009

I wonder if the quiet sun had anything to do with the tomatoes not ripening in Nebraska?

A Sarpy County farmer, master gardener and longtime competitor at the county fair, Green has 67 plants — 27 varieties — this year at his farm outside Springfield, Neb. And they just aren’t ripening.

Blame it on the cool weather, he said. Tomatoes need warm days and warm nights to ripen. So far, though, much of eastern Nebraska is running about 4 to 6 degrees below normal for July.

Kathleen Cue, horticulturist for the University of Nebraska-Lincoln Extension in Douglas and Sarpy Counties, said many common varieties will need a week of sustained warmth to ripen. The lower end of acceptable warmth, she said, is a daytime high in the 70s and nighttime low in the 60s. Noticeably warmer than that would be better for more rapid ripening, she said.

Native to Central and South America, tomatoes need warmth to stimulate fruiting, rather than growing foliage.

With eastern and central Nebraska seeing what could be one of the 10 coolest Julys on record, genuine warmth has been hard to come by. Metro-area temperatures for the rest of this week are forecast to be in the mid-70s to low 80s during the day and upper 50s to low 60s at night.

The type of tomato classified as a determinate, such as Celebrity and Big Boy, are about two weeks behind in ripening and could end up a month behind, Cue said. Determinates tend to be larger and are bred so all the tomatoes on a single plant ripen simultaneously for easy harvesting and shipping, she said.

We used to live in Sarpy County Nebraska in the late 1970s and in the summer the only comfortable place was next to the AC unit in the house. 

Cosmic meddling with the clouds by seven-day magic

The A Science Centric blog has an interesting and perhaps important article on a study by Henrik Svensmark, published in Geophysical Research Letters, on the connection between cosmic rays and cloud cover.  The connection could account for the global warming that takes place during high sunspot activity.

Billions of tonnes of water droplets vanish from the atmosphere, as if by magic, in events that reveal in detail how the Sun and the stars control our everyday clouds. Researchers of the National Space Institute in the Technical University of Denmark (DTU) have traced the consequences of eruptions on the Sun that screen the Earth from some of the cosmic rays - the energetic particles raining down on our planet from exploded stars. 'The Sun makes fantastic natural experiments that allow us to test our ideas about its effects on the climate,' says Prof. Henrik Svensmark, lead author of a report newly published in Geophysical Research Letters. When solar explosions interfere with the cosmic rays there is a temporary shortage of small aerosols, chemical specks in the air that normally grow until water vapour can condense on them, so seeding the liquid water droplets of low-level clouds. Because of the shortage, clouds over the ocean can lose as much as 7 per cent of their liquid water within seven or eight days of the cosmic-ray minimum.

'A link between the Sun, cosmic rays, aerosols, and liquid-water clouds appears to exist on a global scale,' the report concludes. This research, to which Torsten Bondo and Jacob Svensmark contributed, validates 13 years of discoveries that point to a key role for cosmic rays in climate change. In particular, it connects observable variations in the world's cloudiness to laboratory experiments in Copenhagen showing how cosmic rays help to make the all-important aerosols.

You can read the full article here, but it concludes:

The director of the Danish National Space Institute, DTU, Eigil Friis-Christensen, was co-author with Svensmark of an early report on the effect of cosmic rays on cloud cover, back in 1996. Commenting on the latest paper he says, 'The evidence has piled up, first for the link between cosmic rays and low-level clouds and then, by experiment and observation, for the mechanism involving aerosols. All these consistent scientific results illustrate that the current climate models used to predict future climate are lacking important parts of the physics.'