Urbanization raises the heat in Orange County, CA

9 08 2008

UPDATE: I personally visited this station today, thanks to a family visit that coincidentally took me to within a couple of miles of this station. It’s on a rooftop at the fire station. I’ll have a complete report tomorrow, but here are some preliminary photos I’m submitting via WiFi at a local Starbucks a short distance away. – Anthony

  
Click thumbnails for larger images

From the Orange County Register:

Urbanization raises the heat in O.C.

August 7th, 2008, 2:00 pm by grobbins

Santa Ana photographed on Oct. 27, 2005

The average annual temperature in Santa Ana has increased by 7.5 degrees in less than a century, a spike largely attributed to urbanization which has seen the city’s population climb from less than 15,000 to more than 350,000. The temperature has gone from a low of 59.7 degrees in 1920 to 67.2 in 1997, with yearly temperatures near the all-time high as recently as 2006.

“Santa Ana now has a lot more buildings, parking lots and streets, which absorb and hold heat, some of it through the night,” says Ivory Small, science officer at the San Diego office of the National Weather Service.

The NWS analyzed the city’s climate and weather based on daily temperature readings from the Santa Ana Fire Station, which has been recording temperatures since 1916. The upward trend is depicted here by Register illustrator Scott Brown.

Warming trend

Forecasters calculated the average yearly temperature by determining the average high and average low temperature for each month. Then they divided those figures by two and got the average monthly temperature. Then they added up the average temperature for January through December of each year and divided by 12, getting the average annual temperature.

Santa Ana’s population has been on a steady, and basically predictable, rise for decades. The average annual temperature also has risen steadily. But the temperature increase didn’t occur in a predictable,  incremental year-by-year pattern. There were lots of hiccups. For example, the average high for 1961 was 64.0 degrees. Three years earlier, the average high was 65 degrees.

Scientists say the average temperature didn’t smoothly rise year-by-year partly due to natural variability. In other words, some years are hotter than others because of  natural fluctuations in weather and climate.

Guy Ball postcard of Santa Ana in 1920s.But over the long-term, the average temperature has been going up in Santa Ana (click to enlarge image of the ‘city” in the 1920s.)

“The increase in temperatures in Santa Ana, as well as an increase in extreme heat days and in heat waves is primarily — about 60 percent — due to the ‘urban heat island effect,’ ” says Bill Patzert, a climatologist at the Jet Propulsion Laboratory in Pasadena. 

“Santa Ana is embedded in the dramatic urbanization or ‘extreme makeover’ of Orange County. More homes, lawns, shopping centers, traffic, freeways and agriculture, all absorbing and retaining solar radiation, making Santa Ana and Orange County warmer.

“On a larger scale, Orange County is atmospherically connected to our ever-expanding and warming Southern California megalopolis. Global warming due to increasing greenhouse gases is responsible for about 40 percent of the overall heating observed in Southern California. “


Comments : 58 Comments »

Categories : climate_change, weather_stations

The view on AGW from the Australian

9 08 2008

Key degrees of difference

Cameron Stewart, Associate editor | August 09, 2008

http://www.theaustralian.news.com.au/story/0,25197,24148862-11949,00.html 

HAS global warming stopped? The question alone is enough to provoke scorn from the mainstream scientific community and from the Government, which says the earth has never been hotter. But tell that to a new army of sceptics who have mushroomed on internet blog sites and elsewhere in recent months to challenge some of the most basic assumptions and claims of climate change science.

Their claims are provocative and contentious but they are also attracting attention, so much sothat mainstream scientists are being forced torespond.

The bloggers and others make several key claims. They say the way of measuring the world’s temperature is frighteningly imprecise and open to manipulation. They argue that far from becoming hotter, the world’s temperatures have cooled in the past decade, contrary to the overwhelming impression conveyed by scientists and politicians.

As such, they say there should be far greater scepticism towards the apocalyptic predictions about climate change. Even widely accepted claims, such as that made by Climate Change Minister Penny Wong that “the 12 hottest years in history have all been in the last 13 years”, are being openly challenged.

“She is just plain wrong,” says Jennifer Marohasy, a biologist and senior fellow of the Institute of Public Affairs. “It’s not a question of debate. What about the medieval warming period? The historical record shows they were growing wine in England, for goodness sake; come on. It is not disputed by anyone that the Vikings arrived in Greenland in AD900 and it was warmer than Greenland is now. What Penny Wong is doing is being selective and saying that is a long time ago.” Read the rest of this entry »


Comments : 137 Comments »

Categories : climate_change