Thursday, December 2, 2010

Sachs Harbour

I was challenged in this bog By Ian Forrester of lying that the summers in Canada are cooling. He didn't believe me because his faith in AGW requires this to not be true. So he picked a station from here:, Sachs Harbour.

His claim was that when he plotted the max temps from that Excel spreadsheet he got a rising TMax. Hence I was a liar. This individual is quite abusive. Such is the state of mind of True Believers.

So of course one has to check this.

First, the data from this site is aggregated data, monthly averages, with the highest extreme TMax for each month. So we cannot see what is happening daily (such as the number of days of each TMax), but we can look at the highest TMax with this data.

First it must be noted that there are a fair number of missing records, which will tend to skew any trend.

Because Ian seems to be incapable of understanding these graphs, I have to spoon feed him on what these mean. This graph above should have 12 datapoints for each year. Those here that do not show 12 means there is missing data in this station's recordset.

You can see in the late 1980s there is a fair amount of data missing. They have only 7 instead of the 12 required for a complete set.

But we go with what we have. This is the full range of Extreme (highest) TMax for each year:

The top red line is the highest summer Extreme Temp for each year, the blue line is the lowest winter Extreme Temp for each year. Black line is the average.

Doesn't appear to be any increase in the highest TMax in the later years. Missing data at the beginning is obviously causing problems. There is a definite increase until about 1975. But since then, it's not increasing. Highest record temp for this range was 1982 at 24.2C.

Ian seems to think that looking at a subset of the data is "cherry picking". Thus I have to be specific for him to understand that SINCE 1970 is what this graph shows. In other words in the last 40 years there has been no increase in the highest temps. Thus, in spite of increased "global warming" from CO2 emissions, this Arctic location has not seen any of it in the summer high temps.

This is the full range of just summer extreme temps:

Red line is the highest Extreme TMax for the summers, Blue line the lowest Extreme TMax and the black line is the average. Notice missing data is causing the graph to plunge in 1955 and 1960.

How about the winters? Using the monthly averaged TMin we get this:

Red is the highest average TMin, blue is the lowest average TMin and black is the average of the average TMin,

The big jump in the mid 1980's is because of missing data. But the trend is flat until about 1990, and a not as cold trend since. So just like the rest of Canada, Sachs Harbour is showing no increase in summer temps, it's a flat trend. With winters definitely not getting as cold.

Now Ian is on my case about "cheery picking" a range in one graph which I isolated to show what has happened in the last 40 years, no increase in TMax since 1970. What we do not have with this data because it starts at 1955 is what happened prior to this short time frame. So there is no way of knowing what the long term trend is for this location since 1900.

To claim that because the temp increased from 1955 to 1970, just 15 short years, while the rest was flat since shows TMax has an increasing trend in ridiculous at best, and grasping at straws in an attempt to keep the faith alive.

1 comment:

  1. Cherry picking starting points is not science.


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jrwakefield (at) mcswiz (dot) com