大气湍流对跨大西洋航班影响将增加 图片来源:Paul Williams/University of Reading, UK 请习惯颠簸的飞行吧。一项新的研究表明:大气湍流的强度和频率对跨大西洋航班的影响在本世纪中叶将有所增加。 研究人员利用全球气候模型来评估晴空湍流——这一现象源自风切变。研究人员特别评估了未来某个时间点上的涡流强度——此时的二氧化碳浓度是人类工业活动开始推进其大幅增长之前的两倍,而根据一个中间路线的排放场景,这一切很可能发生在本世纪50年代的某个时间。 为了便于分析,他们在北大西洋北部的部分地区,模拟了海拔约12千米的大气条件 (这是一个典型的飞机巡航高度),这一地区包括大多数跨大西洋航线。冬季的几个月是这一地区晴空湍流情况最糟糕的时候,而科学家此时测量湍流的21条常用航线中的16条表明:当二氧化碳浓度是工业化前水平的2倍时,飞机震动现象的平均强度(图片描绘了随机抽取的冬季一天的湍流强度)比前者高出了10%~40%,研究人员4月8日在《自然—气候变化》网络版上报告了这一研究成果。 因此,中等或更大湍流的发生频率将增加40%~170%——在强度上乘客将感受到0.5克或更多的加速度,这一强度足以使客舱内的物品被抛起来。由于飞行员需要躲避强湍流,飞行路径将变得更长,这样一来,燃料消耗和二氧化碳排放都将增加——而这可能又将导致更多的湍流。所以请抓紧了。(来源: Intensification of winter transatlantic aviation turbulence in response to climate change renchunxiao 添加于 2013-4-11 15:25:22 67次阅读 | 0次推荐 | 0个评论 Atmospheric turbulence causes most weather-related aircraft incidents1. Commercial aircraft encounter moderate-or-greater turbulence tens of thousands of times each year worldwide, injuring probably hundreds of passengers (occasionally fatally), costing airlines tens of millions of dollars and causing structural damage to planes1, 2, 3. Clear-air turbulence is especially difficult to avoid, because it cannot be seen by pilots or detected by satellites or on-board radar4, 5. Clear-air turbulence is linked to atmospheric jet streams6, 7, which are projected to be strengthened by anthropogenic climate change8. However, the response of clear-air turbulence to projected climate change has not previously been studied. Here we show using climate model simulations that clear-air turbulence changes significantly within the transatlantic flight corridor when the concentration of carbon dioxide in the atmosphere is doubled. At cruise altitudes within 50–75°丠 and 10–60°圠 in winter, most clear-air turbulence measures show a 10–40% increase in the median strength of turbulence and a 40–170% increase in the frequency of occurrence of moderate-or-greater turbulence. Our results suggest that climate change will lead to bumpier transatlantic flights by the middle of this century. Journey times may lengthen and fuel consumption and emissions may increase. Aviation is partly responsible for changing the climate9, but our findings show for the first time how climate change could affect aviation. 作 者: Paul D. Williams1 Manoj M. Joshi2 期刊名称: nature .. 期卷页: 第卷 第期 ~页 学科领域: 地球科学 大气科学 对流层大气物理学 添加人是否为作者: 否 原文链接: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1866.html DOI:
大西洋温度波动引发欧洲气候变化 据《自然—地球科学》上的一项研究显示,上世纪90年代由于气候变化所导致的欧洲夏天的北部暖湿、南部干热的差别或与北大西洋温度波动过程中的变暖阶段有关。在北大西洋温度回落到较冷阶段之前,这种气候格局可能仍将继续存在。 Rowan Sutton与Buwen Dong对北大西洋温度与欧洲气候关联性研究中的观测数据进行分析后发现,上世纪90年代期间,欧洲夏天的气候变化很大,但春季和秋季的气候变化则没那么明显。这种变化与北大西洋的稳定变暖相吻合,也与有记载的大西洋气温数十年的波动格局相关。研究人员表示,这种气候变化对应着海洋变暖。根据较早的一次变化看来,这种温度波动可能会很快地回落到较冷阶段,欧洲气候格局或会产生快速变化。(来源:中国科学报 张笑) Atlantic Ocean influence on a shift in European climate in the 1990s zhangxia111 添加于 2012-10-16 15:03:21 214次阅读 | 0次推荐 | 0个评论 European climate exhibits variability on a wide range of timescales. Understanding the nature and drivers of this variability is an essential step in developing robust climate predictions and risk assessments. The Atlantic Ocean has been suggested as an important driver of variability in European climate on decadal timescales1, 2, 3, 4, 5, 6, but the importance of this influence in recent decades has been unclear, partly because of difficulties in separating the influence of the Atlantic Ocean from other contributions, for example, from the tropical Pacific Ocean and the stratosphere7, 8, 9, 10, 11, 12. Here we analyse four data sets derived from observations to show that, during the 1990s, there was a substantial shift in European climate towards a pattern characterized by anomalously wet summers in northern Europe, and hot, dry, summers in southern Europe, with related shifts in spring and autumn. These changes in climate coincided with a substantial warming of the North Atlantic Ocean13, towards a state last seen in the 1950s. The patterns of European climate change in the 1990s are consistent with earlier changes attributed to the influence of the North Atlantic Ocean4, 6 and provide compelling evidence that the Atlantic Ocean was the key driver. Our results suggest that the recent pattern of anomalies in European climate will persist as long as the North Atlantic Ocean remains anomalously warm. 作 者: Rowan T. Sutton Buwen Dong Affiliations Contributions Corresponding author 期刊名称: 期卷页: 第卷 第期 ~页 学科领域: 地球科学 大气科学 对流层大气物理学 添加人是否为作者: 否 原文链接: http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1595.html DOI: ISBN: 关键词: 相关报道: http://paper.sciencenet.cn/htmlpaper/2012103015434822626323.shtm 备 注:
实行夏令时的哥伦布七点还是天没亮的样子,这里不实行夏令时,五点出头天空就放亮了,看着远方的彩霞,忽然想到应该去看日出,就当晨练吧,赶紧收拾一下出发,向大西洋岸边奔去。结果赶上了日出的尾巴。 Condado Lagoon 沉思者: 水上漂: 飞机飞过椰树 San Antonio Cay 回到酒店。 吃早饭,开会。中午照例拿了盒饭到四楼边吃饭边看风景。 前一天晚上拍的夜景。酒店边上的Convention Center。 San Juan Bay 前一天大西洋边抓拍。