Who Is Richer Game

[Darth Gupta]

Anintroduction traces the evolution of historic preservation in America, highlighting the principal ideas and events that have shaped and continue to shape the movement. The book also describes the workings--legal, administrative, and fiscal--of the layered federal, state, and local government partnership put in place by Congress in 1966. Individual chapters explore the preservation of designed and vernacular landscapes, the relationship between historic preservation and the larger environmental and land-trust movements, the role of new private and nonprofit players, racial and ethnic interests in historic preservation, and the preservation of our intangible cultural values. A concluding chapter analyzes the present state of the historic preservation movement and suggests future directions for the field in the twenty-first century. Contributors include preservationists, local-government citizen activists, an architect, landscape architects, environmentalists, an archaeologist, a real-estate developer, historians, a Native American tribal leader, an ethnologist, and lawyers. About the Author Robert E. Stipe is Emeritus Professor of Design in the Landscape Architecture Department at North Carolina State University. He is coeditor of The American Mosaic: Preserving a Nation's Heritage.

For more information about Robert E. Stipe, visit the Author Page.

"This one serves as a milestone and signpost, indicating both where we are and where we might want to go. . . . A Richer Heritage offers an excellent introduction to the state of the field and how it got there."--Vernacular Architecture Newsletter

"In 2003, a book with the subtitle Historic Preservation in the Twenty-First Century is timely, and the book's title, A Richer Heritage, is justified, as the nation's heritage becomes deeper and richer each year. . . . There is much to spark interest within the pages of A Richer Heritage. The essayists present instructive and interesting material, and Robert E. Stipe, who introduces the work and closes it, chose them well."--North Carolina Historical Review

"The breadth and depth of subject matter enrich our understanding of what it means to preserve, and each author's impassioned approach invites the reader's participation in a meaningful discourse. . . . There can be little doubt that this book can facilitate a critical dialogue among members of the preservation community. Furthermore, its broad scope and provocative content make it a potent addition to preservation literature."--APT Bulletin

"This impressive work is a detailed look at the state of historic preservation in America. It has been assembled by one of the longtime leading figures in the field and includes entries by some of the most important and knowledgeable practitioners. This new volume is fascinating reading for anyone interested in preservation and its history."--William R. Chapman, University of Hawaii at Manoa

"Stipe and his colleagues have succeeded in an immensely challenging task--unraveling the complex field of historic preservation, and, in doing so, examining its strategies, values, and future directions. A Richer Heritage will serve as an invaluable guide for those entering or working in the field, as well as an important source of thought for future generations of preservationists."--Paul W. Edmondson, National Trust for Historic Preservation

A schematic diagram summarizing the main mechanisms of tropical precipitation change in 6 subregions. In area II, the rich-get-richer mechanism tends to yield increased precipitation associated with moisture increase in a climatological convergence region; however, in region IIa this is enhanced by convergence feedback associated with reduced moist stability, while in region IIb the increased depth of convection more than compensates moisture effects causing a weakening of the ascent and reducing precipitation anomalies. Region I has negative precipitation anomalies due substantially to the upped-ante mechanism, in which inflow from less-moistened descent regions reduces the fraction of time that the convective threshold is met, thus tending to shift the margin of the convergence zone. Region III descent zone precipitation increases are associated with either surface fluxes supported by ocean dynamics or warm advection. Descent zone precipitation decreases can occur by the rich-get-richer mechanism (with sign reversed) or balances involving cold advection.

Predicting future temperature changes under global warming is a challenging task, but predicting future precipitation changes may be even more difficult. The agreement among climate model simulations on the spatial distribution of time mean precipitation changes tends to be very poor, especially at a regional scale (e.g., Cubasch et al. 2001; Allen and Ingram 2002; Stott and Kettleborough 2002; Neelin et al. 2006; Meehl et al. 2007). This paper aims to contribute moisture and energy budget analysis of balances and mechanisms contributing to such precipitation changes in the tropics.

In the tropics, at large scales on the annual average, Held and Soden (2006, hereafter HS06) sought robust features among climate models and found a weakening of the tropical circulation, which tends to compensate the effect of the increased atmospheric moisture on tropical precipitation in convergence zones. Chou et al. (2007) studied hemispherical averages of tropical precipitation and found a widening of the seasonal precipitation range between wet and dry seasons to be common among models. For large spatial averages, Neelin et al. (2006) used a measure of the amplitude for the increase and decrease of regional precipitation of each model and found these amplitudes to agree relatively well among climate models even if the locations of the strong changes differed.

Despite these areas where some agreement among climate models and observations can be found, very substantial differences in the geographic distribution of precipitation changes are typical not only at the regional scale but even for relatively large spatial averages (e.g., Allan and Soden 2007, 2008; Chou et al. 2007; Trenberth and Dai 2007; Trenberth et al. 2007; Wentz et al. 2007; Zhang et al. 2007) and in the tropical examples to be examined here.

CN04 emphasizes dynamic feedbacks, such as the convergence feedback, enhancing thermodynamic effects because of the increase in moisture and moisture gradients. HS06 emphasizes the robust aspects of the thermodynamic effects, especially in the annual average, ensemble average, and zonal average. Under the hypothesis that many of the regional discrepancies among climate models are associated with dynamic feedbacks, we use moist static energy (MSE) diagnostics informed by the hypothesized mechanisms of CN04 to examine processes affecting regional tropical precipitation change. We analyze 10 coupled general circulation model (CGCM) simulations in order to seek consistent budgetary balances associated with mechanisms that induce regional change of mean tropical precipitation within and outside the convergence zones. Changes in rainfall distribution characteristics, though important, are not discussed here. In section 2, we briefly describe the data and the moisture and MSE budgets, clarifying the relationship between CN04 and HS06 in terms of these budgets. For reasons outlined below, the analysis carried out separately for tropical convergence zones and subsidence regions, respectively, in sections 3 and 4. The discussion and conclusions are in section 5.

The tropical precipitation change under global warming reveals considerable disagreements among climate models at the regional scale, so attempting to find common features and mechanisms among the models often involves simplification. Here the attempt is made to provide a bridge between the largest-scale, relatively robust aspects and mechanisms that operate at the regional scale. In particular, the effects of dynamic feedbacks associated with changes in circulation appear to be associated with some of the intermodel discrepancy, but also with some of the strongest precipitation anomalies. The focus here is on changes in climatological means. Changes in rainfall characteristics, such as intensity and frequency, are another important aspect, as reviewed in the introduction.

In the convergence zones, three major regions are identified: negative precipitation anomalies with weakened tropical circulation, specifically reduced moisture convergence (area I) and positive precipitation anomalies with enhanced (area IIa) and reduced tropical circulation (area IIb).

The precipitation change is associated with moisture convergence induced by both mean and anomalous vertical velocity, but that which is induced by anomalous vertical velocity is stronger. This is consistent with the convergence feedback contribution to the rich-get-richer mechanism (CN04; Chou et al. 2006): the increased moisture in the lower troposphere destabilizes the atmosphere and increases vertical velocity that is associated with tropical convection.

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