Carbon historical concentration

When people talk about the Greenhouse Effect , what they are referring to is something extra the effect on the Earth s temperature caused by carbon dioxide concentrations rising above the historic level. Before the Industrial Revolution, the COj level was around 280 ppm, 0.028% of the atmosphere. Daily average CO2 levels (measured at Mauna Loa Observatory in Hawaii) have increased from around 310 ppm (0.031%) in 1958 to 400 ppm (0.040%), first reached on May 9th 2013. 

Once the model was complete, it was adjusted to a steady state condition and tested using historic carbon isotope data from the atmosphere, oceans and polar ice. Several important parameters were calculated and chosen at this stage. Sensitivity analysis indicated that results dispersal of the missing carbon - were significantly influenced by the size of the vegetation carbon pool, its assimilation rate, the concentration of preindustrial atmospheric carbon used, and the CO2 fertilization factor. The model was also sensitive to several factors related to fluxes between ocean reservoirs. 

A. W. King, W. R. Emanuel, and W. M. Post, Projecting future concentrations of atmospheric COi with global carbon cycle models the importance of simulating historical changes. Environmental Management /6 91 (1992). 

The radiocarbon age from Equation (16.2) is expressed in years BP, i.e. Before Present, where Present, by convention, is 1950 AD. Actually, 1950 is considered the reference year in radiocarbon dating, especially due to historical reasons. Following the same convention, in Equation (16.2), when measuring 14/f(t), its value is usually normalized to the concentration of a standard material in 1950 the normalized value is expressed in units of pMC (per cent of Modem Carbon), the standard material being 100 pMC. 

To verify this hypothesis, low volume samplers have been operated in parallel with the air pollution control district s Km samplers. The samples collected were analyzed optically for elemental carbon and by the Gamma Ray Analysis of Light Elements (GRALE) technique for total carbon. These data were used to assess the concentration of elemental and total carbon aerosols present during the winter months in Los Angeles. It was established that the Km samplers can be calibrated to read elemental carbon concentrations. This calibration can be used to reconstruct historical elemental carbon levels at seven sites in Los Angeles. 

A sampling schedule was designed which would encounter peak levels of ambient elemental carbon. Peak levels were of interest for two reasons to insure that filter loadings would be within the appropriate range for maximum analytical sensitivity and to expand the range of values over which the Km samplers could be calibrated. To determine when peak elemental carbon concentrations would be likely to occur, historical data on carbon monoxide... 

Estimation of an Historical Data Base for Elemental Carbon Concentrations... 

Air pollution control agencies in the Los Angeles area have accumulated 22 years of consecutive hourly samples of "particulate matter measured in Km units." It was shown that the historical Km data should be proportional to elemental carbon concentrations present, and the Km samplers were calibrated to read elemental... 

Cass, G. R M. H. Conklin, J. J. Shah, J. J. Huntzicker, and E. S. Macias, Elemental Carbon Concentrations Estimation of and Historical Data Base, Atmos. Environ., 18, 153-162 (1983). Castaldi, M. J., and S. M. Senkan, Real-Time, Ultrasensitive Monitoring of Air Toxics by Laser Photoionization Time-of-Flight Mass Spectrometry, J. Air Waste Manage. Assoc., 48, 77-81... 

Historically, attention on soil organic matter (SOM) has focused on the central role that it plays in ecosystem fertility and soil properties, but in the past two decades the role of soil organic carbon in moderating atmospheric C02 concentrations has emerged as a critical research area.This chapter will focus on the storage and turnover of natural organic matter in soil (SOM), in the context of the global carbon cycle. 

Since ferritic stainless steels contain more carbon than other classes, they are relatively harder to weld and shape than other varieties, which have historically limited their applications. However, since the 1960s, processes such as argon oxygen decarburization have resulted in steels with less carbon, allowing for smaller concentrations of chromium to be used. As a result, the price for ferritic stainless steel has dramatically dropped, and a number of applications now employ these materials - more than 2/3 of which include automotive exhaust systems. 

Two different technologies seem to be the most promising alternatives to reduce gaseous PAH emissions catalytic PAH destruction [6, 7] and PAH adsorption on carbonaceous materials [8, 9]. Historically, carbonaceous materials have been used for the removal of vapor phase organic compounds from about 100 ppmv to 10,000 ppmv concentrations in industrial waste gas streams [10]. Recently, it has been shown that dioxins, furans and PAH, at ppbv or lower coneentrations, can be effectively removed from waste incinerator combustion gases by using carbon injection or carbon bed technology [11]. 

---