Monday, March 19, 2007

Global Temperature Politics Or Science

This is going to be interesting!

This morning I woke up early and while checking my email, this title caught my attention in Space Daily Express newsletter...

After reading the article, I could not stop my self to post this on the blog although, I have already posted one article yesterday...

"The entire debate about global warming is a mirage", this is the opening statement of the news article. Article talks about fundamental of temperature and different averaging methods and other thermodynamics involved in it.

I am posting some of the statements from the news as it is

"global temperature' is thermodynamically as well as mathematically an impossibility"

"It is generally assumed that the atmosphere and the oceans have grown warmer during the recent 50 years. The reason for this point of view is an upward trend in the curve of measurements of the so-called 'global temperature'."

Even more sound statement

"It is impossible to talk about a single temperature for something as complicated as the climate of Earth", Bjarne Andresen says, an expert of thermodynamics. "A temperature can be defined only for a homogeneous system. Furthermore, the climate is not governed by a single temperature. Rather, differences of temperatures drive the processes and create the storms, sea currents, thunder, etc. which make up the climate".

"while it is possible to treat temperature statistically locally, it is meaningless to talk about a a global temperature for Earth"

I like the analogy here...

"The Globe consists of a huge number of components which one cannot just add up and average. That would correspond to calculating the average phone number in the phone book."

Then the news explains some more on averaging methods and finally, makes statement ...

"The currently used method and the consequences drawn from it therefore is more politics than science"

Here is complete news article

The original research is published in Journal of Non-Equilibrium Thermodynamics with even more interesting title 'Does a Global Temperature Exist? ' by professor Christopher Essex, Ross McKitrick and Bjarne Andresen.

The Complete reference to original artilce is

C. Essex, R. McKitrick, B. Andresen: Does a Global Temperature Exist?; J. Non-Equil. Thermod. vol. 32, p. 1-27 (2007). Journal of Non-Equilibrium Thermodynamics.

Some more about Authors ?

Ross McKitrick He is an economist ...
Christopher Essex He is a mathematician ...
Bjarne Andresen He is a professor of physics

Read more comments on the same article

Sunday, March 18, 2007

Transport of Black Carbon and Fine Aerosols

Transport of dust aerosols from Sahara dessert, anthropogenic pollution from Asia, smoke from Canadian and Mexican fires to United States remain areas of research for atmospheric aerosols community.

Recent, research by Renyi Zhang has been in news all over the world. According to his research "pollution from industrial and power plants in China and India. Both countries have seen huge increases in their economies, which means more large factories and power plants to sustain such growth. All of these emit immense quantities of pollution -- much of it soot and sulfate aerosols -- into the atmosphere, which is carried by the prevailing winds over the Pacific Ocean and eventually worldwide."

More Recently, research study by Hadley from Scripps demonstrate that black carbon and fine aerosols transported to North America over Pacific during April 2004.

The abstract read as

"This study presents estimates of long-range transport of black carbon (BC) and aerosol fine mass (diameter less than 2.5 μm) across the Pacific Ocean into North America during April 2004. These transport estimates are based on simulations by the Chemical Weather Forecast System (CFORS) model and evaluated across 130°W, (30°N–60°N) from 26 March through 25 April 2004. CFORS calculates BC transport into North America at 25–32 Gg of which over 75% originates from Asia. Modeled fine aerosol mass transport is between 900 and 1100 Gg. The BC transport amounts to about 77% of the published estimates of North American BC emissions. Approximately 78% of the BC and 82% of the fine aerosol mass transport occur in the midtroposphere above 2 km. Given the relatively large magnitude of the estimated BC transport, we undertake a detailed validation of the model simulations of fine aerosol mass and BC over the west coast of North America. In situ aircraft data were available for the month of April 2004 to assess the accuracy of model simulations of aerosols in the lower troposphere. Aircraft data for aerosol mass collected in the eastern Pacific Ocean during April 2004 as part of the Cloud Indirect Forcing Experiment, as well as surface measurements of fine mass and BC at 30 west coast locations, are compared to CFORS predictions. These surface sites are part of the Interagency Monitoring of Protected Visual Environments (IMPROVE) network. Both the aircraft and the IMPROVE data sets reveal similar patterns of good agreement near and above the boundary layer accompanied by large overprediction within the boundary layer. The observational data validate the CFORS simulations of BC and fine aerosol mass above the boundary layer. The near-surface overprediction does not impair the major conclusions of this study regarding long-range aerosol and BC transport, as most of the long-range transport occurs above 2 km. From this we conclude that the transport of BC from Asia and other regions west is a major source of BC at high elevations over North America. The simulated concentrations of BC between 1 and 3 km, as well as the measured BC concentrations over the elevated IMPROVE sites, range from 0.1 to 0.3 μg/m3. Direct radiative forcing over North America due to the modeled BC concentration between 1 and 15 km is estimated at an additional 2.04–2.55 W/m2 absorbed in the atmosphere and a dimming of −1.45 to −1.47 W/m2 at the surface. The impact of transported BC on the regional radiation budget through direct and indirect effects of the transported BC and other aerosols warrants further study."

Complete Reference:

Sunday, March 11, 2007

Global Dimming: Role of Aerosols

Global dimming is a term coined for reduction in surface reaching solar radiation. Surface observation of solar radiation over different location around the world shows overall decline in the surface reaching solar energy over long period of time. One of the major causes for this dimming is increase in aerosols loading in the atmosphere. There was research study by Alper et al., 2005 published in GRL.

The abstract reads...

‘From the 1950s to the 1980s, a significant decrease of surface solar radiation has been observed at different locations throughout the world. Here we show that this phenomenon, widely termed global dimming, is dominated by the large urban sites. The global-scale analysis of year-to-year variations of solar radiation fluxes shows a decline of 0.41 W/m2/yr for highly populated sites compared to only 0.16 W/m2/yr for sparsely populated sites (less than 0.1 million). Since most of the globe has sparse population, this suggests that solar dimming is of local or regional nature. The dimming is sharpest for the sites at 10°N to 40°N with great industrial activity. In the equatorial regions even the opposite trend to dimming is observed for sparsely populated sites.’

A documentary on global dimming is produced by BBC, for more details follow the link below

Complete Reference:

Alpert, P., P. Kishcha, Y. J. Kaufman, and R. Schwarzbard (2005), Global dimming or local dimming?: Effect of urbanization on sunlight availability, Geophys. Res. Lett., 32, L17802, doi:10.1029/2005GL023320