Dust flux, Vostok ice core

Dust flux, Vostok ice core
Two dimensional phase space reconstruction of dust flux from the Vostok core over the period 186-4 ka using the time derivative method. Dust flux on the x-axis, rate of change is on the y-axis. From Gipp (2001).

Tuesday, July 21, 2015


This report is driving me crazy. Plus spending spare time with the kids.

Sunday, July 12, 2015

USDX vs gold settling in new area of attraction

For your viewing pleasure, today's chart depicts the USDX index vs gold on a weekly closing basis over the past ten months.

The system seems to be happy in the general area of 0.96 and $1200.

And here is the larger context.

Wednesday, July 8, 2015

Noise reduction and analysis of a long reconstructed record of atmospheric CO2

The CO2 record used last time was presented (largely by interpolation) at 100 year intervals. This provided rather more data than were really needed for the analysis that I had in mind. To produce the plot in yesterday's post, I subsampled the data to produce a record with sample intervals of 1000 years.

The first step is to define regions of stability over each time window. To do this, we reconstruct phase space portraits for each window of data (anywhere from 100 to 200 ky)*.

These graphs have previously been described as looking like they were constructed on an etch-a-sketch. I would say the one on the left looks more like the etch-a-sketch drawings I remember. I would have posted a link to the Zerohedge comments, but the site was down.

Both of the above graphs represent reconstructed phase space plots constructed over a 100-ky window. The one on the left is constructed from a time series with a 100-year sample interval. The one on the right is constructed from a time series with a 1000-year sample window (90% of the data were discarded). At the scale of my investigation, the overall structure of both graphs is the same. The higher resolution data just provides a noisier version of the well-known partially vivisected kangaroo formation.

Many paleoclimate records analyzed in this way commonly show multistability (interpreted as more than one possible equilibria). Multistability may be demonstrated in reconstructed phase space portraits through variable density of observations in phase space.

The above figure shows the successive evolution of the state space through time at 1000 year intervals. Between about 110 and 20 ka, the system evolved through phase space only very slowly--times of slow evolution suggest stability.

Multistability is probably best inferred from phase space density plots. The graph above suggests at least two major areas of stability (perhaps four if you are a splitter rather than a lumper).

Once regions of stability are identified, the next task is characterizing climate by the sequence and timings of the transitions between different regions of stability.

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*Note ky = thousand years (i.e., an interval)
ka = thousand years ago (i.e., a specific time)
Similarly, Ma = million years ago, and My = million years (interval)

Tuesday, July 7, 2015

Stability of atmospheric CO2 over the last 20 million years

I've been playing with a "record" of atmospheric CO2 over the past 20 million years for some time, using the reconstruction of van de Wal et al. (2011). Today's graph is a representation of the various regions of Lyapunov stability teased out from state space reconstructions of segments of the data (windows), ranging from 150 to 250 ky (thousand years) in width.

The red dots all represent regions of stability defined using the methods described here. The blue dot represents approximately today's atmospheric CO2 concentration, which is about where it was 10 million years ago. More later, but I need to go for a walk now.

Wednesday, July 1, 2015

China controls gold

Laws of the People's Republic of China



Regulations of the PRC on the Control of Gold and Silver
(Promulgated June 15, 1983 by the State Council.)
Article 28. When Chinese citizens, foreign nationals or Stateless persons residing in the People's Republic of China wish to leave the People's Republic of China to live permanently abroad the maximum amount per person of gold and silver which may be taken out of the People's Republic of China is:
gold ornaments, 1 liang (31.25 grams)
silver ornaments, 10 liang (312.50 grams)
silver utensils, 20 liang (625 grams)
An inspection shall be made by the People's Republic of China Customs and clearance given only to amounts that conform to regulations.