When is a record not really a record?

Today the Seattle Times has an article noting that Seattle (Seattle Tacoma Airport) has beat the all-time record for the number of consecutive days of 80F and higher in September.  Today (Monday) should be much cooler since marine air has pushed into western Washington overnight, with low clouds extending to the Cascades.  The heat wave is over.

Here is the plot of the temperatures the last few days.

You will note that on two of the days the temperatures only got to 82F.   Now here is the question.  As I documented in an earlier blog (click here to see it), the third runway has clearly warmed up the temperature sensor at Seattle by roughly 2F.      On the two days SeaTac reached 82 of the now 9 day streak above 80 the neighborhood surrounding SeaTac had highs of 78 and 79, averaged over 4 schools.  That leaves the obvious question:  would Seattle have reached this record if the third runway was not built?  We cannot be sure.

As I have discussed in this blog a number of times, the implications of human-emitted greenhouse gases are profound and substantial warming is pretty much inevitable.  But there IS an issue of our temperature sensors being in places in which development has occurred, as well as sensors that are simply poorly placed.  I don't think we have a clear understanding of the impact of these sensor problems, even though some research has been done on it.

Just to show you the problem, here are pictures of the temperature sensors at three official climatological observing stations in Washington State.  Remember sensors should be over natural vegetated surfaces, away from buildings and concrete/asphalt, and not near heat sources.

Here is Wilbur, Washington.   Breaks every rule....even near the exhaust of an AC unit!  (The temperature unit looks like a set of stacked plates---that is the temperature enclosure)

 Or Dayton, Washington.  Being above gravel is a no-no, and it is close to a building and concrete.

Or Conconully, Washington.  Above rocks and concrete steps.

The problem folks is I could show you dozens more of these for the Northwest and hundreds for the U.S.  Poor siting, not above natural vegetation, too close to buildings, and more.  And it gets worse---there is development/urbanization going in the neighborhoods of many sensors.  Some of the worse problems are at rural sites, so studies that have tried to determine the "true" temperature signal by separating rural from urban sites have often been flawed.

We have a problem.   The U.S. is now establishing a set of primo instruments in virgin locations, but that doesn't help much in documenting past trends.  TThere is little doubt that some records have been influenced by these siting issues.

Now for those global warming skeptics who are smirking about all this, let us make it clear--poor siting does not mean global warming induced by humans is nonsense.  It means we have to be more careful in separating out sensor issues from the real signal.  The real signal is going to get a lot larger,

Finally, any of you living in North Seattle, please keep your eyes out for my lost dog:  more information here.