Comparison of UAH and RSS Time Series with Common Baseline

In this post I set both UAH 5.4 and RSS 3.3 global temperature anomaly series to a common baseline period (1981-2010)  to compare them. Since both the UAH 5.4 and RSS 3.3 series are satellite based , they exhibit striking similarities.

Common Baseline

In this previous post, I showed how to convert temperature anomaly time series from one baseline period to another period.  I then used this technique in this post to directly compare UAH 5.4 (baseline 1981-2010) and GISS.

In this post, I compare the satellite based UAH 5.4 (baseline 1981-2010) and RSS 3.3 (baseline 1979-1998) series.

The offsets are as follows:

• UAH:  -0.000978
• RSS:      0.098772

Since the UAH TLT 5.4 series is based on a 1981-2010 baseline, the offset is nearly zero (-0.00098 versus 0.0). The RSS offset changes the baseline from 1979-1998 to 1981-2010.

Users can reproduce my analysis on their own by downloading my CTS.csv file and applying the offsets to the UAH and RSS series.

Comparison of 1981-2010 Baseline Series

Here is a plot of UAH and RSS 12 month moving averages for 1979 to current: Click to Enlarge

Both 12-month moving average series show similar cyclical patterns with  positive trends. The UAH series shows a slightly higher El Nino response than RSS in in several instances, including the 2010 El Nino cycle.

Here is the monthly trend chart for the 2 series: Click to EnlargeThe 2 satellite  series track each other quite well.

We can examine the delta (delta = UAH – RSS) between the two series to see the actual differences between the series each month. Click to Enlarge.In the 1979 – 2011 period, UAH has been greater than RSS 50.7%.

Here is a scatter plot of the 2 series: Click to Enlarge.

This scatterplot shows that RSS 3.3 and UAH 5.4 are in good agreement when the baselines are set to a common period.

Setting the UAH and RSS series to the same 1981 – 2010 baseline shows how close the 2 satellite series are:

• Both series exhibit strong cyclical patterns, attributable in part to El Nino – La Nina cycles
• Both show upward trend
• Timing of cycles is comparable
• UAH is greater than RSS 50.7 % of months, very close to expected 50% of time

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