对地球“两极”臭氧层严重破坏的探究

臭氧是保护地球生物的一道天然屏障.大气中臭氧浓度逐年降低、臭氧层破坏,已引起全世界的广泛关注.通过研究人员长期的观察和分析,地球中、高纬度区上空的臭氧层损耗程度较严重,尤其以两极地区为甚.就臭氧的生成、性质和两极地区特殊的地理气候条件对两极地区臭氧层遭受严重破坏的原因做出探究.     

增强的UV-B辐射对作物的影响

大气中臭氧层的破坏导致到达地表UV-B辐射的增加,对作物产生不同程度的影响.本文讨论了增强的UV-B辐射对作物形态、生理代谢和遗传学效应的影响.     

浅析氮肥对生态环境负效应及对策

综述了国内外有关氮肥消费状况及对生态环境的污染,包括对水体富营养化的 影响;氮肥对地下水的污染;对作物的生长及品质的影响;对大气臭氧层破坏,并提出了防 治氮肥污染的措施。     

反刍动物CH_4调控的研究进展

反刍动物体内CH4的排放,不但导致了饲料能源利用率的下降,而且还会破坏大气臭氧层。笔者综述了反刍动物CH4生成的机制及影响其排放量的因素,并对降低CH4的调控方式做了分析和展望。     

紫外光B对农作物生长的影响

紫外光Ｂ对农作物生长的影响江苏农业科学院遗传所黄少白，戴秋杰环境问题已成为当今人类面临的主要挑战之一。在此问题中由氟利昂和其它化学物质所引起的臭氧层的破坏已成为突出问题之一。根据Ｋｅｒｒ的估计，１９５５－２０６０年臭氧层将减少１６％。在南极圈已有“臭...     

环境激素的危害及预防方法

环境激素是继臭氧层破坏、温室效应之后，又一大世界环境问题。臭氧层破坏、温室效应对生态环境影响是渐进型，对人类社会影响尚有时空上的距离，也给人类社会留有解决问题的时间。随着严格控制破坏程度，可望缓解或维持一定现状。环境激素一经产生，就直接危害野生动物和人类社会，环境激素已发展到威胁人类生存的境地。一、环境激素的由来环境激素是指影响和搅乱生物内分泌系统的有害化学物质的总称。环境激素对生殖系统的影响，最早出现于医学界。随着研究的深入，发现杀虫剂、合成洗涤剂等化工产品和发泡塑料产品及其分解物，部分石油制…     

紫外线辐射对生物的影响

大气臭氧层的破坏引起地表紫外线－－Ｂ（ＵＶ－Ｂ）辐射增加，从而导致对各种 生不良影响，本文主要阐述过量的ＵＶ－Ｂ辐射对人类和某些昆虫的影响，以及抑制和破坏许多睡和水生植物的生长。     

农用溴甲烷的淘汰和代用品的发展前景

溴甲烷是一种被广泛用来杀灭线虫，杂草，昆虫，细菌，真菌和啮齿动物的广谱熏蒸剂，但其对大气臭氧层有显著破坏作用。为了保护地球臭氧层，“蒙特利尔议定书”规定２０１０年内全球将禁产，禁用ＭＢｒ。本文对取代ＭＢｒ的产品和技术作了概述。提出多学科合作研制出新的广谱，经济，实用，且对环境安全的ＭＢｒ代用品将对农业的可持续发展十分重要。     

过量使用化学氮肥的负效应

过量使用化学氮肥的负效应是多方面的,如造成减产;浪费能源;污染环境等。对环境的影响有直接毒杀鱼类;造成水体富营养化;形成酸雨;破坏臭氧层;形成致癌化合物和食物硝酸污染等。     

氮素肥料的环境问题

目前,氮肥的利用率一般较低,其环境问题也比较突出。本文综述了国内外有关氨肥污染方面的研究。内容包括氮肥对地下水的污染;对作物及土壤性质的影响;对大气臭氧层的破坏及对水体富营养化的贡献等。并提出了防治氮肥污染的措施。     

DOAS measurements of tropospheric bromine oxide in mid-latitudes

Episodes of elevated bromine oxide (BrO) concentration are known to occur at high latitudes in the Arctic boundary layer and to lead to catalytic destruction of ozone at those latitudes; these events have not been observed at lower latitudes. With the use of differential optical absorption spectroscopy (DOAS), locally high BrO concentrations were observed at mid-latitudes at the Dead Sea, Israel, during spring 1997. Mixing ratios peaked daily at around 80 parts per trillion around noon and were correlated with low boundary-layer ozone mixing ratios.     

Changes in stratospheric ozone

The ozone layer in the upper atmosphere is a natural feature of the earth's environment. It performs several important functions, including shielding the earth from damaging solar ultraviolet radiation. Far from being static, ozone concentrations rise and fall under the forces of photochemical production, catalytic chemical destruction, and fluid dynamical transport. Human activities are projected to deplete substantially stratospheric ozone through anthropogenic increases in the global concentrations of key atmospheric chemicals. Human-induced perturbations may be occurring already.     

A Reevaluation of the Ozone Budget with HALOE UARS Data: No Evidence for the Ozone Deficit

Recently, additional ozone production mechanisms have been proposed to resolve the ozone deficit problem, which arises from greater ozone destruction than production in several photochemical models of the upper stratosphere and lower mesosphere. A detailed ozone model budget analysis was performed with simultaneous observations of O(3), HCl, H(2)O, CH(4), NO, and NO(2) from the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) under conditions with the strongest photochemical control of ozone. The results indicate that an ozone deficit may not exist. On the contrary, the use of currently recommended photochemical parameters leads to insufficient ozone destruction in the model.     

Chlorine oxide in the stratospheric ozone layer: ground-based detection and measurement

Stratospheric chlorine oxide, a significant intermediate product in the catalytic destruction of ozone by atomic chlorine, has been detected and measured by a ground-based 204-gigahertz, millimeter-wave receiver. Data taken at latitude 42 degrees N on 17 days between 10 January and 18 February 1980 yield an average chlorine oxide column density of approximately 1.05 x 10(14) per square centimeter or approximately 2/3 that of the average of eight in situ balloon flight measurements (excluding the anomalously high data of 14 July 1977) made over the past 4 years at 32 degrees N. We find less chlorine oxide below 35 kilometers and a larger vertical gradient than predicted by theoretical models of the stratospheric ozone layer.     

Antarctic total ozone in 1958

The Antarctic ozone hole results from catalytic destruction of ozone by chlorine radicals. The hole develops in August, reaches its full depth in early October, and is gone by early December of each year. Extremely low total ozone measurements were made at the Antarctic Dumont d'Urville station in 1958. These measurements were derived from spectrographic plates of the blue sky, the moon, and two stars. These Dumont plate data are inconsistent with 1958 Dobson spectrophotometer ozone measurements, inconsistent with present-day Antarctic observations, and inconsistent with meteorological and theoretical information. There is no credible evidence for an ozone hole in 1958.     

植物根际对增强紫外线-B辐射的响应

臭氧层减薄导致地表中波紫外-线B(UV-B,280~320 nm)辐射增强,UV-B辐射能量远高于可见光,并且能被植物体内蛋白质和核酸等生物大分子吸收。当前,植物的UV-B效应研究主要集中在地上部分,对地下部分的研究很少。综述了近年来增强UV-B辐射对植物根际影响的研究进展,主要包括根形态、根系分泌物、根际微生物和根系中矿质营养。并就今后该方面的研究提出建议。     

The role of Br2 and BrCl in surface ozone destruction at polar sunrise

Bromine atoms are believed to play a central role in the depletion of surface-level ozone in the Arctic at polar sunrise. Br2, BrCl, and HOBr have been hypothesized as bromine atom precursors, and there is evidence for chlorine atom precursors as well, but these species have not been measured directly. We report here measurements of Br2, BrCl, and Cl2 made using atmospheric pressure chemical ionization-mass spectrometry at Alert, Nunavut, Canada. In addition to Br2 at mixing ratios up to approximately 25 parts per trillion, BrCl was found at levels as high as approximately 35 parts per trillion. Molecular chlorine was not observed, implying that BrCl is the dominant source of chlorine atoms during polar sunrise, consistent with recent modeling studies. Similar formation of bromine compounds and tropospheric ozone destruction may also occur at mid-latitudes but may not be as apparent owing to more efficient mixing in the boundary layer.     

Stratospheric ozone destruction by man-made chlorofluoromethanes

Calculations indicate that chlorofluoromethanes produced by man can greatly affect the concentrations of stratospheric ozone in future decades. This effect follows the release of chlorine from these compounds in the stratosphere. Present usage levels of chlorofluoromethanes can lead to chlorine-catalyzed ozone destruction rates that will exceed natural sinks of ozone by 1985 or 1990.     

Solar proton event: influence on stratospheric ozone

Large-scale reductions in the ozone content of the middle and upper stratosphere over the polar cap regions were associated with the major solar proton event of 4 August 1972. This reduction, which was determined from measurements with the backscattered ultraviolet experiment on the Nimbus 4 satellite, is interpreted as being due to the catalytic destruction of ozone by odd-nitrogen compounds (NO(x)) produced by the event.     

The sensitivity of polar ozone depletion to proposed geoengineering schemes

The large burden of sulfate aerosols injected into the stratosphere by the eruption of Mount Pinatubo in 1991 cooled Earth and enhanced the destruction of polar ozone in the subsequent few years. The continuous injection of sulfur into the stratosphere has been suggested as a "geoengineering" scheme to counteract global warming. We use an empirical relationship between ozone depletion and chlorine activation to estimate how this approach might influence polar ozone. An injection of sulfur large enough to compensate for surface warming caused by the doubling of atmospheric CO2 would strongly increase the extent of Arctic ozone depletion during the present century for cold winters and would cause a considerable delay, between 30 and 70 years, in the expected recovery of the Antarctic ozone hole.