全球气候变化对水稻生产的影响

水稻作为世界第二大粮食作物,我国第一大粮食作物,其产量和品质的形成是品种遗传特性和环境条件综合作用的结果。20世纪以来,由于人类活动的加剧,全球气候变化加快,作为水稻生长的环境因素,气候变化对水稻生产将产生很大的影响。本文结合国内外最新研究资料,主要从气候变暖、二氧化碳浓度升高、臭氧破坏等三个方面介绍气候变化对水稻产量和品质的影响,以便进一步探讨影响机理和采取相应的措施减小环境变化对水稻生产带来的负面影响,发挥其正向效应。     

Modern global climate change

Modern climate change is dominated by human influences, which are now large enough to exceed the bounds of natural variability. The main source of global climate change is human-induced changes in atmospheric composition. These perturbations primarily result from emissions associated with energy use, but on local and regional scales, urbanization and land use changes are also important. Although there has been progress in monitoring and understanding climate change, there remain many scientific, technical, and institutional impediments to precisely planning for, adapting to, and mitigating the effects of climate change. There is still considerable uncertainty about the rates of change that can be expected, but it is clear that these changes will be increasingly manifested in important and tangible ways, such as changes in extremes of temperature and precipitation, decreases in seasonal and perennial snow and ice extent, and sea level rise. Anthropogenic climate change is now likely to continue for many centuries. We are venturing into the unknown with climate, and its associated impacts could be quite disruptive.     

全球气候变化对中国农业的影响

The present paper shows possible effects that global climate change affects China''s agriculture.As a result,its bad effects are more than good effects.     

Observed impact of snow cover on the heat balance and the rise of continental spring temperatures

Analysis of satellite-derived snow cover, radiative balance, and surface air temperature over Northern Hemisphere extratropical land shows that the retreat of the Northern Hemisphere's extent of spring snow cover over the past 20 years parallels a change in the influence of snow cover on the radiative balance and an observed increase of spring temperatures over the same area. These results help explain why the long-term (20th century) increase in surface air temperature over Northern Hemisphere land has been greater in spring than in any other season relative to the interannual variability.     

祁连山区春季积雪对河西春小麦生育期的影响

利用祁连山区14个气象站1961—2005年的春季极端最大、极端最大平均、最大平均积雪深度和河西6地春小麦生育期资料,分析了时间变化规律和积雪对春小麦生育期的影响。结果表明,极端最大、极端最大平均和最大平均积雪深度的三阶曲线总体呈高—低—高—低的趋势,60、80年代增加,70、90年代减小。河西春小麦生育期提前趋势最明显的是抽穗期,其次是拔节期和成熟期。极端最大、极端最大平均和最大平均积雪深度与河西春小麦多数生育期为正相关。极端最大积雪深度与敦煌春小麦生育期相关最显著的是播种期,其次是3叶期;与张掖春小麦生育期相关最显著的是开花期,其次是孕穗期、乳熟期和成熟期;与武威春小麦相关最显著的是开花期。极端最大平均积雪深度与武威春小麦相关最显著的是开花期和成熟期。最大平均积雪深度与敦煌春小麦播种期和3叶期为正相关;与张掖春小麦相关最显著的是开花期,其次是孕穗期、抽穗期、成熟期;与武威春小麦相关较显著的是抽穗期、开花期、成熟期。     

Properties of the background global aerosol and their effects on climate

Properties of the aerosols above Hawaii, Alaska, and the South Pole are derived from sun photometry at several wavelengths. The mass loading of aerosol material is several milligrams per square meter. At the South Pole the mean particle radius is 0.04 micrometer; at Hawaii in March 1975 there was a thin volcanic layer with a mean particle radius of 0.1 micrometer. The aerosols cause heating of the earth-atmosphere system at the poles and cooling at low latitudes.     

青藏高原植被覆盖变化及气候驱动因子分析

利用青藏高原2001—2015年的MODIS归一化植被数据集、地表温度数据集和317个气象站的气温、降水量数据,分析了归一化植被指数(NDVI)与气温、降水量及地温的相关性,讨论了3种气候因子的联合驱动机制。结果表明,青藏高原植被覆盖呈由东向西、自南向北的递减状态,且总体上呈波动增长趋势;青藏高原植被覆盖与降水量、气温及地温均呈正相关,与气温相关性最强;青藏高原植被增长的首要驱动因子是热量,且降水量与热量对植被生长的驱动作用呈互补性。     

Applying MODIS data to monitor snow cover in cultivated land in Henan Province

[目的]探讨利用MODIS数据监测河南省耕地雪盖的可行性,为减灾抗灾提供技术支持.[方法]利用多天的MODIS数据,通过计算归一化差分积雪指数,结合第2、4波段的波谱信息及植被指数,将雪、云与其他地物分开,再结合MODIS的云掩膜数据去除云的影响,实现雪盖的提取.[结果]2008年1月16、29、31日耕地积雪覆盖面积分别占全省耕地面积的13.04％、68.43％和65.23％,主要集中分布在黄河以南粮食主产区,且呈由西向东逐渐推移发展趋势.[结论]在基础地理信息数据辅助下,利用MODIS数据进行大面积雪情监测是可行的,监测结果得到地面调查支持,可进行业务化运作.将遥感监测结果和基础地理信息数据相结合,进行各种专题图的制作,可为减灾抗灾提供技术支持.     

MODIS数据在河南省耕地雪盖监测中的应用

[目的]探讨利用MODIS数据监测河南省耕地雪盖的可行性,为减灾抗灾提供技术支持.[方法]利用多天的MODIS数据,通过计算归一化差分积雪指数,结合第2、4波段的波谱信息及植被指数,将雪、云与其他地物分开,再结合MODIS的云掩膜数据去除云的影响,实现雪盖的提取.[结果]2008年1月16、29、31日耕地积雪覆盖面积分别占全省耕地面积的13.04%、68.43%和65.23%,主要集中分布在黄河以南粮食主产区,且呈由西向东逐渐推移发展趋势.[结论]在基础地理信息数据辅助下,利用MODIS数据进行大面积雪情监测是可行的,监测结果得到地面调查支持,可进行业务化运作.将遥感监测结果和基础地理信息数据相结合,进行各种专题图的制作,可为减灾抗灾提供技术支持.     

The rise of global mean sea level as an indication of climate change

Rising mean sea level, it is proposed, is a significant indicator of global climate change. The principal factors that can have contributed to the observed increases of global mean sea level in recent decades are thermal expansion of the oceans and the discharge of polar ice sheets. Calculations indicate that thermal expansion cannot be the sole factor responsible for the observed rise in sea level over the last 40 years; significant discharges of polar ice must also be occurring. Global warming, due in some degree presumably to increasing atmospheric carbon dioxide, has been opposed by the extraction of heat necessary to melt the discharged ice. During the past 40 years more than 50,000 cubic kilometers of ice has been discharged and has melted, reducing the surface warming that might otherwise have occurred by as much as a factor of 2. The transfer of mass from the polar regions to a thin spherical shell covering all the oceans should have increased the earth's moment of inertia and correspondingly reduced the speed of rotation by about 1.5 parts in 10(8). This accounts for about three quarters of the observed fractional reduction in the earth's angular velocity since 1940. Monitoring of global mean sea level, ocean surface temperatures, and the earth's speed of rotation should be complemented by monitoring of the polar ice sheets, as is now possible by satellite altimetry. All parts of the puzzle need to be examined in order that a consistent picture emerge.     

Smoke and pollution aerosol effect on cloud cover

Pollution and smoke aerosols can increase or decrease the cloud cover. This duality in the effects of aerosols forms one of the largest uncertainties in climate research. Using solar measurements from Aerosol Robotic Network sites around the globe, we show an increase in cloud cover with an increase in the aerosol column concentration and an inverse dependence on the aerosol absorption of sunlight. The emerging rule appears to be independent of geographical location or aerosol type, thus increasing our confidence in the understanding of these aerosol effects on the clouds and climate. Preliminary estimates suggest an increase of 5% in cloud cover.     

Soil carbon sequestration impacts on global climate change and food security

The carbon sink capacity of the world's agricultural and degraded soils is 50 to 66% of the historic carbon loss of 42 to 78 gigatons of carbon. The rate of soil organic carbon sequestration with adoption of recommended technologies depends on soil texture and structure, rainfall, temperature, farming system, and soil management. Strategies to increase the soil carbon pool include soil restoration and woodland regeneration, no-till farming, cover crops, nutrient management, manuring and sludge application, improved grazing, water conservation and harvesting, efficient irrigation, agroforestry practices, and growing energy crops on spare lands. An increase of 1 ton of soil carbon pool of degraded cropland soils may increase crop yield by 20 to 40 kilograms per hectare (kg/ha) for wheat, 10 to 20 kg/ha for maize, and 0.5 to 1 kg/ha for cowpeas. As well as enhancing food security, carbon sequestration has the potential to offset fossil fuel emissions by 0.4 to 1.2 gigatons of carbon per year, or 5 to 15% of the global fossil-fuel emissions.     

2种常用的全球土地利用/覆被历史数据集在中国区域的精度评价

【目的】分析全球土地利用/覆被历史数据集在中国区域的精度。【方法】分别搜集耕地、草地的统计资料和空间数据以及林地的统计资料,采用升尺度方法对耕地和草地的空间数据进行处理,分析全球土地利用/覆被历史数据集SAGE和HYDE 3.1与我国统计资料中耕地、林地和草地面积的差异。【结果】SAGE数据集中耕地、草地和林地面积与我国统计数据相差较大,HYDE 3.1数据集中耕地和草地面积与我国统计数据虽然相近,但其反映的耕地和草地面积变化趋势以及空间分布与我国实际情况存在较大差距。【结论】鉴于全球土地利用/覆被历史数据集SAGE和HYDE 3.1在我国的精度较低,因此有必要依据国内的历史统计资料,重建一套适用于中国的高精度土地利用数据集,以服务于我国气候变化研究。     

秸秆覆盖对降雨入渗影响的试验研究

为研究作物秸秆覆盖对改善农田自然降水利用效果的作用 ,采用人工降雨的方法模拟小雨、中雨和大雨 3种不同降雨强度 ,对雨后玉米、小麦秸秆覆盖地与裸地 0～ 2 0cm土层土壤含水率分布情况进行了试验。结果表明 :小雨后 ,由于秸秆覆盖阻滞入渗的作用 ,秸秆覆盖地 0～ 5cm土层土壤含水率短时间内低于裸地 ,但降雨后 2 4h玉米秸秆覆盖地已与裸地持平 ,以后逐渐高于裸地 ,降雨后 5 2h小麦秸秆覆盖地已高于裸地 ,且裸地水分蒸发量高于秸秆覆盖地 ;中雨后 ,秸秆覆盖阻滞入渗作用表现在土壤 5～ 2 0cm土层 ;大雨后 ,秸秆覆盖阻滞入渗作用表现在10～ 2 0cm土层。秸秆的吸水性会暂时阻滞雨水的入渗 ,但随着时间的延长 ,以及秸秆覆盖抑制水分蒸发的作用 ,秸秆覆盖地雨水入渗效果均高于裸地 ,秸秆覆盖在降雨小的情况下仍然有利于雨水的利用。     

The persistently variable "background" stratospheric aerosol layer and global climate change

Recent measurements demonstrate that the "background" stratospheric aerosol layer is persistently variable rather than constant, even in the absence of major volcanic eruptions. Several independent data sets show that stratospheric aerosols have increased in abundance since 2000. Near-global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about -0.1 watt per square meter, reducing the recent global warming that would otherwise have occurred. Observations from earlier periods are limited but suggest an additional negative radiative forcing of about -0.1 watt per square meter from 1960 to 1990. Climate model projections neglecting these changes would continue to overestimate the radiative forcing and global warming in coming decades if these aerosols remain present at current values or increase.     

The greenhouse theory of climate change: a test by an inadvertent global experiment

Since the dawn of the industrial era, the atmospheric concentrations of several radiatively active gases have been increasing as a result of human activities. The radiative heating from this inadvertent experiment has driven the climate system out of equilibrium with the incoming solar energy. According to the greenhouse theory of climate change, the climate system will be restored to equilibrium by a warming of the surfacetroposphere system and a cooling of the stratosphere. The predicted changes, during the next few decades, could far exceed natural climate variations in historical times. Hence, the greenhouse theory of climate change has reached the crucial stage of verification. Surface warming as large as that predicted by models would be unprecedented during an interglacial period such as the present. The theory, its scope for verification, and the emerging complexities of the climate feedback mechanisms are discussed.