# Author Archives: mrooijer

## Why validation in Principle Components Analysis?

I have written an analysis and replication of the following figure in M&M05: It is known – in some circles- that this figure is misleading. What I have not seen yet is that the figure should have looked like this: … Continue reading

## Where was that “hiatus”?

Some people are still believing that the global temperature somehow has not increased, or increased less than expected in the last 18 years. Nothing is further from the truth: taking the average of the four most commonly used surface temperature … Continue reading

## Takens Theorem

A famous dynamical system is the Lorenz butterfly. It is a curve that moves in time through the (X,Y,Z)-space and that is attracted by a strange attractor. # discrete simulation of the Lorenz system # N is some large number s = … Continue reading

## 18 years hiatus?

Regression is: Anomaly= a+ b*(months since 1-1-1997)/120 + c*ENSO(lag=3) + d*TSI(ssp-proxy with lag=3) + e*volcanic_areasols(lag=6) The confidence intervals are the standard CI’s corrected for auto-correlation. Notice the larger uncertainty in the coefficients for the satellite-data, caused by higher auto-correlation and bigger swings … Continue reading

## Global Temperature Applet

I made an applet in R with Shiny: explore the global temperature trends and the various factors that influence the variations. Click the picture below to go to the applet. This is a work in progress. Comments, questions, etc. can … Continue reading

## It has not stopped

And finally the series until end 2013 from Berkeley:

## GISS Global temperatures: reporting history

GISS Global Sea and Land Surface Temperatures as they were reported in 1981, 1995, 2003 and today. The line are 5 years averages, or, more accurate, 60 months averages. Sources: 1981: Hansen e.a (image copy) 1995: Steve Mcintyre (monthly anomaly) 2003: … Continue reading