Quick primer:
Beryllium-10 is an isotope that is a proxy for the sun’s activity. Be10 is produced in the atmosphere by cosmic ray collisions with atoms of oxygen and nitrogen. Beryllium 10 concentrations are linked to cosmic ray intensity which can be a proxy for solar strength.
One way to capture earth’s record of that proxy data is to drill deep ice cores. Greenland, due to having a large and relatively stable deep ice sheet is often the target for drilling ice cores.
Isotopic analysis of the ice in the core can be linked to temperature and global sea level variations. Analysis of the air contained in bubbles in the ice can reveal the palaeocomposition of the atmosphere, in particular CO2 variations. Volcanic eruptions leave identifiable ash layers.
While it sounds simple to analyze, there are issues of ice compression, flow, and other factors that must be taken into consideration when doing reconstructions from such data. I attended a talk at ICCC 09 that showed one of the ice core operations had procedures that left significant contamination issues for CO2. But since Beryllium is rather rare, it doesn’t seem to have the same contamination issues attached. – Anthony
Be-10 and Climate
Guest post by David Archibald
A couple of years ago on Climate Audit, I undertook to do battle with Dr Svalgaard’s invariate Sun using Dye 3 Be10 data. And so it has come to pass. Plotted up and annotated, the Dye 3 data shows the strong relationship between solar activity and climate. Instead of wading through hundreds of papers for evidence of the Sun’s influence on terrestrial climate, all you have to do is look at this graph.
All the major climate minima are evident in the Be10 record, and the cold period at the end of the 19th century. This graph alone demonstrates that the warming of the 20th century was solar-driven.
The end of the Little Ice Age corresponded with a dramatic decrease in the rate of production of Be10, due to fewer galactic cosmic rays getting into the inner planets of the solar system. Fewer galactic cosmic rays got into the inner planets because the solar wind got stronger. The solar wind got stronger because the Sun’s magnetic field got stronger, as measured by the aa Index from 1868.
Thus the recent fall of aa Index and Ap Index to lows never seen before in living memory is of considerable interest. This reminds me of a line out of Aliens: “Stay frosty people!” Well, we won’t have any choice – it will get frosty.
In about half an hour I have to go with my students to a lab, where we have cloud chambers and we are going to see dirrectly GCR leave little “steam” tracks in methanol. The same thing happens in atmosphere in those layers where the water vapor due to adiabatic cooling reached saturation, but needs something to nucleate the condensation. This is a reversible process and at the same time chaotic. This means that more GCR bring have an enhanced effect. How can this affect the weather? I am going to present here a mechanism. I don’t know the quantitative effect, we might never know it given the high complexity of the situation, but we can’t ignore it.
As we have more GCRs in the atmosphere, we form clouds and precipitation at a lower humidity threshold. What does this mean? It means that clouds are more likely to form where the water evaporates, that is at tropical regions and that humidity has less chances of reaching higher latitudes. This has the effect of increasing the albedo at tropical regions, where the solar irradiation is the most important and of decreasing the humidity at higher latitudes where this enhances the thermal radiation (we all know that water is an important green house gas and more abundant than CO2). Obviously, there are places where increased GCR produce an opposite effect due to geographical particularities, but the general trend is clear.
Again, it is obvious that TSI varies insignificantly with the solar cycle and that the GCR level is modulated by the solar activity. We don’t know though the intrinsic variability in GCR, I am an astrophysicist and we believe that they come from many sources to keep them more or less constant, but isolated events can cause major spikes.
In my oppinion, I think that the GCR level is an important weather regulator, more important than the man made CO2 emissions.
You might be interested in this paper.
Climate Change and the Earth’s Magnetic Poles, A Possible Connection
http://www.akk.me.uk
Abstract:
Many natural mechanisms have been proposed for climate change during the past millennia, however, none of these appears to have accounted for the change in global temperature seen over the second half of the last century. As such the rise in temperature has been attributed to man made mechanisms. Analysis of the movement of the Earth’s magnetic poles over the last 105 years demonstrates strong correlations between the position of the north magnetic, and geomagnetic poles, and both northern hemisphere and global temperatures. Although these correlations are surprising, a statistical analysis shows there is a less than one percent chance they are random, but it is not clear how movements of the poles affect climate. Links between changes in the Earth’s magnetic field and climate change, have been proposed previously although the exact mechanism is disputed. These include: The Earth’s magnetic field affects the energy transfer rates from the solar wind to the Earth’s atmosphere which in turn affects the North Atlantic Oscillation. Movement of the poles changes the geographic distribution of galactic and solar cosmic rays, moving them to particularly climate sensitive areas. Changes in distribution of ultraviolet rays resulting from the movement of the magnetic field, may result in increases in the death rates of carbon sinking oceanic plant life such as phytoplankton.
Author: Kerton, Adrian K.
Source: Energy & Environment, Volume 20, Numbers 1-2, January 2009 , pp. 75-83(9)
Publisher: Multi-Science Publishing Co Ltd
Keywords: MAGNETIC POLES; DRIFT; CLIMATE; COSMIC RAYS
Document Type: Research article
DOI: 10.1260/095830509787689286