Archives par mot-clé : Sun

Solar Cycle Continues To Be The Weakest In 2 Centuries

by  F.  Bosse and  F. Vahrenholt, August 23, in NoTricksZone


The sun was completely free of spots on 11 days in July. Notable: while during last month the sun’s northern hemisphere was more active (in June all sunspots were in the northern hemisphere), last month the southern hemisphere was the most active part with 60% of the sunspots appearing there. The following diagram shows the course of solar cycle 24 thus far (…)

The Effects of the Bray Climate and Solar Cycle

by Andy May, August 8, 2017 in WUWT


The Bray cycle is about 2450 years from beginning to end and the Bray Lows, which are the coldest portion of the cycle, are the most important events.

The world is currently within the Quaternary Ice Age and nearly as cold as it has ever been. The normal average temperature of the world is around 20°C, some 5°C warmer than today. To keep recent warming in perspective, it is important to understand that even if the worse predictions of the IPCC were to occur, we would only be returning to the average temperature of the last 560 million years

Phanerozoic Global Temperature from Scotese 2015,

link in the post (.pdf)

Does Belgian Holocene speleothem records solar forcing and cold events?

by M. Allan et al., July 11,  2017, in Climate of the Past


We present a decadal-centennial scale Holocene climate record based on trace elements contents from a 65 cm stalagmite (“Père Noël”) from Belgian Père Noël cave. Père Noël (PN) stalagmite covers the last 12.7 ka according to U/Th dating. High spatial resolution measurements of trace elements (Sr, Ba, Mg and Al) were done by Laser- Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Trace elements profiles were interpreted as environmental and climate changes in the Han-sur-Lesse region.

See also here

Closely Coupled: Solar Activity and Sea Level

by David Archibald, July 3, 2017


From a post a couple of days ago: “an F10.7 flux above 100 causes warming and below that level causes cooling.” Greg asked “Can you prove that?” I already had in this WUWT post from 2012. But it is worth revisiting the subject because it answers the big question – If all the energy that stops the Earth from looking like Pluto comes from the Sun, what is the solar activity level that corresponds to our average climate? Because solar activity is falling and climate will follow.

Lowest Solar Activity In 200 Years Accompanied By High Northern Hemispheric Snow And Ice

by P. Gosselin from F. Bosse and F. Vahrenholt, June 18, 2017


In May the sun was very quiet as sunspot number was a mere 18.8, which is only 36% of what is typical for the month this far into the cycle. Seven days saw no sunspot activity at all.

The following chart shows the current cycle, Solar Cycle 24 (red), compared to the mean of the previous cycles (blue) and the similarly behaving SC 5 (black).

It’s clear that the current cycle is significantly weaker than the mean and far weaker than the cycles we saw throughout most of the warming 20th century.

Winning climate strategy demands details

by Michigan State University, June 12, 2017 in ScienceDaily


Scientists at Michigan State University (MSU) show that examining the daily minutia of climate, not just temperature, but also sunshine, precipitation and soil moisture simultaneously all over a country gives a better understanding of how variable a land’s climate can be. That information is crucial when countries are setting policies aimed at growing food, protecting water supplies and the environment and stemming disease outbreaks. The findings were reported in this week’s Scientific Reports.

Indirect Effects of the Sun on Earth’s Climate

by Mike Jonas, June 10, 2017 in WUWT


In this article, I explore the scientific literature on possible solar indirect effects on climate, and suggest a reasonable way of looking at them. This should also answer Leif Svalgaard’s question, though it seems rather unlikely that he would be unaware of any of the material cited here. Certainly just about everything in this article has already appeared on WUWT; the aim here is to present it in a single article (sorry it’s so long). I provide some links to the works of people like Jasper Kirkby, Nir Shaviv and Nigel Calder. For those who have time, those works are worth reading in their entirety.

What Happened to Spot? A Solar Update

by Stephanie Osborn, June 7, 2017


I’ve been keeping a spreadsheet since late last summer, and here are the results, as of June 6th, 2017. (Quick and easy data source, the daily sunspot image archives from Solarham.)

This data (through March; I’ve updated it since then) was posted on Jerry Pournelle’s blog a while back, and it elicited several questions from readers, who didn’t understand the information contained therein. So here is an effort to elaborate on the data, for those of you who aren’t astronomers/ astrophysicists and don’t want to have to keep up with all this stuff.