extracted from weblog three hundred and sixty two published on Thursday 28th December 2006
The Chinook is a mountain wind named after a Native American tribe from the Pacific North-West. They named it snow-eater because of the heat of the wind racing down the eastern slopes of the Rockies. Moist winds sweeping off the Pacific are lifted up over the mountain range, cool and condense into thick clouds and pour with rain. Then the winds become dried out and as they race down the other side of the mountain they warm up and dry even more.
The temperature change is so dramatic that on 14th January 1972 at Loma Montana a 57 Celsius rise was registered from -48C to +9C…a world record for a 24-hour temperature increase. Boulder in Colorado often gets particularly hard hit by Chinooks as the winds are funneled down through nearby canyons. A gust of 143 miles per hour was registered during January 1971 and in January 1982 a Chinook caused more than $10 million of damage.
In my Cloud Cuckoo Land blog I mentioned the scientific problem with Temperature Gauge Data in Temperature-Time Series. I wrote that you can either measure the temperature in the same place for as long as possible…hopefully for centuries...or you measure under similar operant conditions. Here is some of what I wrote.
‘The first course of action seems to make sense because the shape of the landscape affects the local climate. A number this side of the hill will not be the same as one from the other side. But there is a problem. A hundred years ago your measuring point was in the middle of a field five miles out of town. Today it’s in the middle of a shopping centre’.
The operant conditions of your data point matter because built-up environments are typically several degrees warmer. I ended by remarking that ‘even something as simple as collecting data is far from simple’. This data quality effect might be enough to explain the fact that global temperature data from the Northern Hemisphere appears to suggest that it has warmed more than the Southern Hemisphere…something that is puzzling scientists as it is inherently unlikely.
In a scientifically-literate world this 200-word caveat about Data Quality would be unnecessary. But Public Science is now a branch of Public Relations...and truth an early casualty.
The reported average 30-year temperature in Britain from 1961 to 1990 was 9.47 Celsius. Since 1990 every second year has been at least one degree higher than this. The top yearly averages since have been 1995-10.52C; 1997-10.53C; 1999-10.63C; 2002-10.60C; 2003-10.50C; 2004-10.48C and 2006-10.84C.
This year has been particularly warm. July was billed as Britain’s warmest month ever at 19.66 Celsius and we also had the warmest September since 1729 at 16.55C. Globally 2006 will be our sixth warmest year since 1850.
There are Carbonistas who point the finger of suspicion at The Carbon Economy to explain all this but little of their science stands up to rigorous scrutiny.
