Saturday, March 09, 2013

What is the Rationale behind the supposedly Warming up Trend ?

Hot weather, Heat Wave, Cold Wave, Heavy rains and floods, or drought...the easiest thing is to blame it on Global Warming..or the so called Global Warming (GW). 
New names like Climate Change and The Co2 effect have cropped up to convince and stress upon the belief about the disastrous effects of "GW"

This article will concentrate on the methodoligy of weather station readings and the rationale about how the rise in temperatures have been measured and detemined.

Here is an answer to questions very very frequently asked to me by young meteorologists, keen to devlop and probe into more regions and areas to monitor th weather.
Why not set up more stations world wide and enlarge our meteorology field area ? They ask.

But what's happening ? Weather stations used to monitor near surface temperature for the global climate record are disappearing worldwide at and alarming rate. There are two things going on here: 1) Stations are actually being closed down, particularly in Canada and in Russia in the early 1990′s. 2) Some stations while open, have disappeared off the reporting radar for global temperature metrics such as GISS.

Watch the video here prepared by ( super volunteer and unofficial historian John W. Goetz. It outlines how the worldwide network has grown since the 1890′s, and then dwindled in modern times.

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However, there are ceratin stations which are located much against the WMO norms, and which record and measure higher than actual temperatures, and which remain on roof tops .
Example:Baltimore USHCN station circa 1990′s photo courtesy NOAA.

What is interesting about this station, is that it is a rooftop station, like we’ve seen in San Francisco, Eureka, and many other US cities. Rooftop stations are naturally going to impart a warm bias to the surface temperature records,  for obvious reasons.

Rooftop exposures have an advantage of increased instrument security and good exposure for wind sensors (standard height is about 33 feet). 
However, there are also drawbacks. Exposure for precipitation and temperature instrumentation is clearly non-compliant, being elevated to high above the ground. 

Additionally the instrument exposure is usually over environmentally surfaces like metal, black tar, shingle, stone etc., while at the same time being close to a wide variety of roof surfaces which are subject to change.
Many times, in fact always, we immediately notice that the station in its later years was surrounded by much taller buildings than it was early-on. On top of the rooftop location (pun intended), this represents a pretty dramatic – yet gradual – change in surroundings.
Says Professor Landsburg  reiterating his concern about rooftop exposures with respect to the urban warming issue: “They [rooftop stations] are certainly of little value in a full assessment of the climatic changes brought about by urbanization.”

No argument there. No wonder world averages ar increasing..and far away glaciers and Polar ice is (supposed to be) melting and (supossedly) decling. Thanks to these roof top instruments ? 

What actually we need is only a few very good ground stations might be needed for ground-truth checks. Now a days we come across so much of surface temperature data that are fraught with so many inconsistencies, sloppiness, irregularities and manipulation that they cannot be takien seriously. Satellites are the data source we can rely on.

Contributions and excerpts from Anthony Whatts (Watts Up) and John Goetz, 


sset said...

As given in TOI -> while Artic ice coverage declines, Antartica ice increases ......

Rajan Alexander said...

Here are two links you will really find interesting on the theme:

sset said...

We are happy to hear from Rajesh Sir. Sir pls resend weather terminolgies/models link tutorial. Apologies I lost them. (last year u had shared with us)


sset said...

sorry it is "Rajan Sir" instead of "Rajesh Sir". Anyway I am always thankful to both. Rajan Sir pls share weather terminologies tutorial link.

Outlook for next week till Thursday 29th February: Temperatures expected to rise across Maharashtra and Gujarat. Chance of thunderstorms for...