Multi-year fluctuations of temperature and precipitation: The gray area of climate change

The issue of whether the secular climate (twentieth century) is stationary or changing to some new semi-permanent state is clouded by the presence of so-called climate fluctuations. The twentieth century climate record of the United States reveals a substantial number of decadal fluctuations which occur in all seasons for both temperature and precipitation. Recent examples of such behavior include changes in winter and summer temperature variability and increases in transition season precipitation. Statistical evidence suggests that a substantial portion of these fluctuations, even those which are remarkably unusual, are merely manifestations of a stochastic process which possesses weak year-to-year persistence as viewed from an a posteriori perspective. The implications of this result are particularly important with respect to the formulation of physical causes of the fluctuations. The results emphasize the desirability of well-founded clearly-stated a priori theories of climate change as well as the limited usefulness of widely used climate normals.     

Der Aerologische aufbau des Ostasiatischen Monsuns

Zusammenfassung Darstellung des ostasiatischen Monsuns als Erscheinung der Grundschicht. Dieser Monsun über China und Japan ist im Winter sehr flach, nur etwa 1500 m hoch, aufgebaut als Grundschicht vom Normaltyp, der im Falle des Niederschlags nur leicht anschwillt. Der Sommermonsun ist verschieden gestaltet, die Luftmassen, die dem nordpazifischen Hochdruck entströmen, bringen einen Monsun mit stabil geschichteter niedriger Grundschicht von höchstens 2000 m. Der Monsun der tropischen und subtropischen Gegenden entstammt, ist wesentlich feuchter und kann auch höher hinaufreichen. Im ostasiatischen Raum bringt der Sommermonsun trotz seiner Feuchtigkeit keinen Niederschlag von sich aus; dieser fällt nur, wenn sich Depressionen bilden, die Grundschicht sich durch lokale Gewitterbildung auflöst, oder wenn grössere Gebirge zu Steigerungsregen Anlass geben. Hier liegt ein entschiedener Gegensatz zum Regenmonsun des tropischen und subtropischen Asiens.

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Summary Representation of the monsoon in Eastern Asia as a phenomenon of the ground layer. The monsoon over China and Japan is very shallow during the winter, only about 1500 m high and of standart-type ground-layer structure, rising only slightly in the event of precipitation. The summer monsoon is of different structure: ais masses from the North-Pacific high pressure areas produce a monsoon with a stable laminated low ground layer of 2000 m at a maximum. The monsoon originating from tropical and subtropical regions carries considerably more moisture, and can extend to higher levels. In Eastern Asia the summer monsoon, in spite of its high moisture contents, produces no rain by itself, this occurs only when depressions are forming and the ground layer is dissipating because of local thunderstorm activity, or when major mountain ranges are causing an upslope movement. Here is the fundamental difference to the rain monsoon of tropical and subtropical Asia.

     

The economic impacts of banning commercial bottomfish fishing in the Northwestern Hawaiian Islands

This study examines the economic impacts of closing the Northwestern Hawaiian Islands bottomfish fishery, as part of a larger effort to create an effective marine protected area. An overview of the market for NWHI bottomfish in Hawaii is given using input–output data and a fishery closure analysis is conducted using public data on commercial fishing and primary information collected through interviews with wholesalers, restaurants, and retailers. Assuming the worst-case scenario, the wholesale price per pound of Onaga and Opakapaka is estimated to increase by $0.80 and $0.42, respectively. But this is unlikely, as the own-price elasticity of demand for Hawaii-caught bottomfish is found to be highly elastic and there is widespread substitution with imports. The overall economic loss is thus quite small, while the environmental gains of creating the largest marine protected area in the world could be substantial.     

An argument against a type I cometary tail model

This letter represents an abstract of a forthcoming publication in which a type I cometary tail model is explained in terms of observational facts without additional assumptions. It is made clear that essential claims and assertions of the currently discussed magneto-hydrodynamical theory of the tails cannot be brought into agreement with this experimental model.     

AMERICAN ROADS,ROADSIDE AMERICA*

ABSTRACT. Federal support for planning and building roads provided an opportunity to create a new kind of place, the American roadside. The roadside grew up beside the public road as a distinct private space, yet the two were linked as road travelers came to depend on the services provided by people who lived at the road's edge. Federal road-improvement legislation brought discipline to the surveying, construction, and configuration of roads. But roadside structures remained largely the creation of local people, who built a vernacular landscape that was undisciplined and in strong contrast to the road's regimentation. The roadside became a new kind of space occupying the unstable zone between the discipline of the road and the informality of the countryside, a spatial contradiction that gave license to a new, free-wheeling, mercantile logic, an improvisational departure from the staid formality of Main Street.     

乾安县土地利用变化及其生态效应

Based on GIS and statistical methods, with the help of searching historical literatures andcalculating the landscape indices, the land use changes of Qian'an County in both spatial and temporalaspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changesand their ecological effects are discussed too. The main findings of this study are as follows:(1)Landuse changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetlandand water bodies,and an increase in cultivated land, saline-alkali land, and the land for housing andother construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by     

Differences in vegetation characteristics with shoreline position on a tropical pocket beach

ABSTRACT

Composition and richness of coastal vegetation differs with distance from the water and sheltering by topography. Transition from pioneer beach plants to mature forests is expected to be narrow on low wave energy coasts with a tropical climate favorable to vegetation growth. The goal of this paper is to determine whether vegetation on the beach and foredune will be denser and have a greater number of species and more woody shrubs near the water as wave and wind stresses diminish because of favorable shoreline orientation within a pocket beach. Field data on beach width, beach mobility, dune height, vegetation species, vegetation height and percent vegetation cover were collected in Puerto Rico along six cross-shore transects. Beaches are more stable at transects in the lee of an eolianite barrier and a tombolo. The vegetation gradient there is compressed, with denser, taller, more diverse vegetation and more tree species close to the waterline than at more exposed sites. The lack of mobility of the beaches and dunes and lack of geomorphically significant disturbance events is in contrast to the conspicuous feedbacks between overwash, topography, and vegetation on exposed mid-latitude coasts, revealing the need for more study of low-energy beach environments.     

The rheology of cryovolcanic slurries: Motivation and phenomenology of methanol-water slurries with implications for Titan

The Cassini spacecraft has revealed landforms on the surface of Titan suggested to be viscous cryovolcanic flows and possibly eruptive domes. In order to relate those surface features to the processes and chemistries that produced them, it is necessary to construct flow models, which rely on characterization of the rheological properties of the eruptants. This paper describes our initial exploratory attempts to understand the rheological characteristics of cryogenic slurries, using a 40% methanol-water mixture, as a precursor to more detailed experiments. We have devised a new automated cryogenic rotational viscometer system to more fully characterize cryovolcanic slurry rheologies. A series of measurements were performed, varying first temperature, and then strain rate, which revealed development of yield stress-like behaviors, shear-rate dependence, and thixotropic behavior, even at relatively low crystal fractions, not previously reported. At fixed shear rate our data are fit well by the Andrade equation, with the activation energy modified by a solid volume fraction. At fixed temperature, depending on shearing history, a Cross model could describe our data over a wide shear rate range. A Bingham plastic model appears to be a good constitutive model for the data measured at high shear rates when the shear was global. The yield stress like behavior implies that levee formation on cryolava flows is more likely than would be inferred from the previous studies, and may provide a partial explanation for features interpreted as steep-sided volcanic constructs on Titan.