No2onoo2

Considering natural stratospheric ozone production destruction as a balanced cycle, the NO* reaction sequence is responsible for approximately half of the loss in the upper stratosphere, but much less in the lower stratosphere (Wennberg et al., 1994). Since this is a natural steady-state process, this is not the same as a long term 03 loss. The principal source of NO to the stratosphere is the slow upward diffusion of tropospheric N20, and its subsequent reaction with O atoms, or photolysis...

Patricia C Henshaw Robert J Charlson and Stephen J Burges

It is hard to imagine any part of the Earth system that is more essential than or that has as many different functions as the water of the hydrosphere. In particular, the presence of a mobile liquid phase, with its long list of special chemical and physical properties, must be clearly identified as the main feature of Earth that separates it from the other terrestrial planets or from any known astronomical object. Close to home, the terrestrial planets, Earth, Mars, and Venus are presumed to...

Ch2o o2 co2 h2o

A small fraction (less than 1 ) of the fixed carbon produced by photosynthesis is buried and physically removed from any potential reaction with oxygen (until the buried material is brought to the surface - at a much later time). Thus, the oxygen in our contemporary atmosphere is the consequence of many millions of years of fixed carbon burial. More details on this topic can be found in Chapters 8 and 11. The high concentration of oxygen in the atmosphere plays a central role in the...

Sucrose

Fig. 3-11 Carbohydrates in (a) 3-, 5-, and 6-carbon sugars (monosaccharides), (b) oligosaccharides, and (c) polysaccharides. (Reprinted with permission from W. K. Purves and G. H. Orians, Life The Science of Biology, pp. 63-81, Copyright 1987 by Sinauer Associates, Inc., Sunderland, MA.) of the valence electrons of carbon and may also participate in hydrogen bonds. Hydrogen bonds also involve nitrogen and oxygen and are important in determining the structures of DNA and many other molecules....

Properties of and Transfers between the Key Reservoirs

Part Two of this book focuses on the major spheres that deliver and receive the chemical constituents moving through the Earth system. This part is loosely organized in terms of the speed at which material is processed by a particular sphere. However, since the hydrologic cycle has traditionally served as a paradigm for considering mass balance in the elemental biogeo-chemical cycles, we begin by providing basic information on how the hydrosphere works in Chapter 6. Earth is a unique planet in...

Samuel S Butcher and Sharon E Anthony

This chapter applies the physical chemistry taught in the first year of undergraduate chemistry to chemical problems in the natural environment and introduces key chemical concepts to use and keep in mind for the rest of this book. The material in this chapter is especially important to consider when utilizing the modeling techniques presented in Chapter 4. There are two principal chemical concepts we will cover that are important for studying the natural environment. The first is...

Info

Known accessible reserves of fossil carbon (Keeling and Bacastow, 1977). If all fluxes are proportional to the reservoir contents, the percentage change in reservoir content will be equal for all the reservoirs. The non-linear relations discussed above give rise to substantial variations between the reservoirs. Note that the atmospheric reservoir is much more significantly perturbed than any of the other three reservoirs. Even in the case with a 6000 Pg input, the carbon content of the oceans...

C

The steady-state flux from the atmosphere to the ocean across the layer is given by Fick's First Law This treatment may be compared with that given in Chapter 4. The top of the stagnant film is assumed to have a gas concentration in equilibrium with the overlying air (i.e., Cg KHPg). The unknown values are the flux and the thickness of the diffusive layer z. The thickness z has been determined by analyses of isotopes (14C and 222Rn) that can be used to obtain the flux (Broecker and Peng, 1974...

Daniel A Jaffe

In most natural systems available or fixed nitrogen is usually the limiting factor in plant growth. This realization led to the invention and massive use of nitrogen fertilizers during the 20th century and ever increasing crop yields per acre of farmed land. Without this use of nitrogenous fertilizers, the Earth could not support its current population of six billion people (Smil, 1997). At the same time, the widespread use of fossil fuels releases not only carbon dioxide, but nitrogen oxides...

Biogeochemical Cycles

Biogeochemical cycles are the backbone of Earth system science and are the major focus of this book. In this part, we will use the background provided in Part One, along with the information on the major reservoirs provided in Part Two to tell a cohesive story about five biogeochemical cycles those of carbon (Chapter 11), nitrogen (Chapter 12), sulfur (Chapter 13), phosphorus (Chapter 14), and the trace metals (Chapter 15). The goal of each one of these chapters is to provide an overview of the...