摘要:

The need for better quantitative understanding of energy fluxes and water exchanges is basic to all climate studies, yet our quantitative knowledge of the global hydrological cycle remains surprisingly poor. Evaporation minus precipitation or, similarly, the net flow of water from land to oceans and the net advection of moisture from the marine atmosphere to the terrestrial atmosphere is known at best to a factor of two to three (J. Schaake, personal communication, 1991). The regional and temporal distribution of the components of the hydrological budget are even more uncertain.Improved understanding of the global hydrological cycle has been limited in part by the absence of reliable global data on such essential quantities as precipitation, evaporation, and atmospheric transport; acquisition of these data is a prerequisite for the study of global energetics and hydrology. Space agencies in the United States, Europe, and Japan have announced plans to launch a series of global Earth observing satellites in the late 1990s to monitor these essential atmospheric and surface parameters and to complement existing operational meteorological and hydrological networks.

ISSN:0002-8606    

DOI:10.1029/91EO00007

年代:1992

数据来源: WILEY

摘要:

Recent JGR policies that encourage special sections and eliminate page charges for author‐produced copy have been a boon forJGR‐Solid Earth, at least if the number of pages published is used as the primary measure of success. On the other hand, these policies have not served the interests of individual subscribers.The merit of the material published in the 8,557 pages of the 1990 volume ofJGR‐Solid Earthis not in question. As a subscriber whose main interest is in seismology, however, I have several measures of the value and cost of the journal besides the number of published pages. These 8,557 pages ofJGR‐Solid Earthoccupy 29 cm of shelf space and weigh 15.7 kg. (The June issue alone weighed 1.9 kg!) These are awkward figures for anyone contemplating a long‐distance move or just taking the most recent issue home for th

ISSN:0002-8606    

DOI:10.1029/91EO00009

年代:1992

数据来源: WILEY

摘要:

The print in the abstract volumes of Eos is too damn small. Although one can read one or two abstracts without much trouble, most people find that the size of the print makes reading several pages of abstracts unnecessarily difficult. Without doubt, age is a factor in my case. But if print that small is not a detriment to communication, why is it not more generally used in publications? Inasmuch as some abstracts are reasonably legible inEos(Vol. 72, No. 44, Supplement), perhaps simply imposing strict standards on author‐prepared copy might suffice. Other remedies (for example, two volumes for the abstracts in a single meeting) will involve greater cos

ISSN:0002-8606    

DOI:10.1029/91EO00011

年代:1992

数据来源: WILEY

摘要:

Sierd Cloetingh joined theTectonicseditorial board as the European editor on January 1.Tectonicsmanuscripts should be sent to one of the following editors: Kevin C. Burke, Editor‐in‐Chief,Tectonics, AGU, 2000 Florida Ave., NW, Washington, DC 20009; Paul Hoffman, North American Editor, Tectonics Office, RR 3 Kemptville, Ontario K0G 1J0; Sierd Cloetingh, European Editor, Vrije Universiteit, Institute for Earth Studies, De Boelelaan 1085, 1081 HV Amsterdam, The Netherla

ISSN:0002-8606    

DOI:10.1029/91EO00014

年代:1992

数据来源: WILEY

摘要:

In this article, we present and discuss some airborne synthetic aperture radar (SAR) observations of the Gulf Stream that were made by the Canada Centre for Remote Sensing (CCRS) during the Surface Wave Dynamics Experiment (SWADE) [seeWeller et al., 1991]. The CCRS CV‐580 aircraft is equipped with a C‐band SAR [seeLivingstone et al., 1988] and was flown on four separate occasions during the third SWADE intensive observation period in February and March 1991.While the purpose of SWADE is to study wind wave dynamics, a northward meander brought the Gulf Stream over the continental shelf and into the SWADE observational area to the east of Wallops Island, Va. The approximate location of the Gulf Stream, based upon an operational oceanographic feature analysis using infrared imagery from the Advanced Very High Resolution Radiometer (AVHRR) and buoy data from the National Oceanic and Atmospheric Administration, is shown in Figur

ISSN:0002-8606    

DOI:10.1029/91EO00016

年代:1992

数据来源: WILEY

摘要:

The study of how contaminants move from the soil surface to the underlying water table—through the realm hydrologists call the vadose zone—is an area of hydrologic research that is just in its infancy. Recent studies seeking to unravel the mysteries of contaminant movement in the vadose zone and predict when, where, and how much groundwater contamination will occur indicate that the flow and transport may be chaotic and hard to measure.Contamination has become a major threat to present and future uses of groundwaters. The vadose zone has gradually be‐come a repository for massive quantities of wastes, which in far too many instances have leached and subsequently recharged aquifers with contaminants. In this zone water enters the Earth's surface via rainfall, irrigation, or snow melt and cycles through porous soils and fractured rocks. Here it may be either intercepted by plant roots and returned to the atmosphere or moves deeper until it recharges underlying aquifers. In the past this process has provided a seemingly endless supply of high‐quality groundwater that has been available for industrial, agricultural, and human cons

ISSN:0002-8606    

DOI:10.1029/91EO30017

年代:1992

数据来源: WILEY

摘要:

NASA's Magellan radar mapping mission to Venus is approaching its third global mapping cycle and continues to return highresolution image, topography, and radiometry data. Nearly 95% of the surface of Venus has been mapped, with excellent performance by the spacecraft and radar systems.Since the 1960s, Earth‐based and orbital radar have been used to map the surface of Venus because of the dense cloud cover that hides the surface. Results from the Earthbased observations were instrumental in defining the gross surface features of parts of the planet, while NASA's Pioneer Venus probe provided a global low‐resolution topographic map. The Soviet Venera missions obtained orbital radar images of about 25% of the planet at a resolution of 1 km. However, these earlier studies did not allow identification of surface processes or the major factors that have shaped the surface of Venus. The Magellan mission, with approximately 100‐m resolution, is providing the first detailed look at this planet to determine its geological evol

ISSN:0002-8606    

DOI:10.1029/91EO40017

年代:1992

数据来源: WILEY