2016年气候趋势继续打破记录导读：根据美国宇航局的地面观测站和卫星数据分析，两个关键的气候变化指标——全球表面温度和北极海冰面积，在2016上半年已打破了多个记录。 根据美国宇航局的地面观测站和卫星数据分析，两个关键的气候变化指标——全球表面温度和北极海冰面积，在2016上半年已打破了多个记录。根据美国宇航局位于纽约的戈达德太空研究所（GISS）的科学家们分析，根据气温记录（最早的记录可追溯到1880年），全球范围内，2016年上半年的每一个月都创下了历史当月温度的最高值。从1月到6月这半年时间里，也创下了地球历史上最热半年的记录，比19世纪末平均温度高出了1.3摄氏度（2.4华氏度）。根据美国宇航局位于马里兰州绿地的戈达德太空飞行中心的科学家们分析，2016年上半年中有五个月的时间，创下了北极海冰面积最小的记录（连续的卫星记录始于1979年）。有一个例外，就是3月，创下了该月海冰面积第二小的记录。虽然这两个关键的气候指标在2016年打破了记录，美国航空航天局的科学家说，最值得关注的是，全球温度和北极海冰几十年的变化趋势一直在持续。这两种趋势都是由大气中浓度不断上升的吸热气体二氧化碳和其他温室气体所驱动的。目前，在夏天融化季节的高峰期，北极海冰面积所覆盖的区域还不到20世纪70年代末和20世纪80年代初覆盖面积的40%。在9月，北极海冰面积年周期循环中的季节性低点，一直以每10年的13.4%的速度在下降。“虽然自10月份开始，厄尔尼诺现象推动了今年冬天热带太平洋地区新的全球气温记录，但是它的基本趋势正在创造这些新的记录数据”GISS主任加文施密特说。之前的厄尔尼诺现象创造了新的气温记录，如1998年。但是在2016年，即使最近厄尔尼诺现象的影响减弱了，全球气温的上升还是远远超过了18年前，因为从在那个时候全球升温就已经开始了。 北极地区变暖超过了全球气温上升趋势的速度，美国宇航局的戈达德研究中心海冰科学家沃尔特迈耶说。“到目前为止，2016年是全球气温创纪录的年份，但是在过去六个月，北极地区的高温纪录甚至更加极端，”迈耶说。“今年，迄今为止这种温暖和不寻常的天气模式导致海冰面积达到创纪录的最低值。”美国宇航局跟踪温度和海冰，以便于了解地球这个系统是如何变化的。除了19个地球观测太空任务外，美国宇航局还向全球各地派出研究人员，让研究人员在更近的范围内调查地球的不同方面。现在，美国宇航局的研究人员正在北极地区工作，以便于更好地了解驱动海冰融化的过程和温度上升对北极生态系统的影响。 上周，美国宇航局的“冰桥行动”项目开始对北极海冰盖表面的融雪坑进行机载测量。融雪坑是融化的冰形成的浅层水。它们暗色的表面能够吸收更多的阳光并加速冰的融化过程。在海冰融化的季节，冰桥行动正在对融雪坑进行大范围观测，这种大规模研究之前从未有过。最新的研究发现，在初夏，融雪坑的形成是年度最小海冰面积的最佳预测指标。“之前没有人从遥感的角度，绘制大范围融雪坑的深度地图，”冰桥项目科学家和NASA戈达德研究中心的海冰专家内森库尔茨说。“我们收集的信息将会显示出，多少水保留在融雪坑中，在海冰表面需要什么样的地形才能存贮水，这有助于提升对融雪坑的研究。”冰桥行动是美国宇航局一项机载测量任务，从2009年开始，每年飞跃两极点的多个地方，目标是对格陵兰岛和南极洲的海冰和冰盖进行连续性的观测。与此同时，美国宇航局的研究人员从今年开始，对阿拉斯加和加拿大近十年的北极生态系统进行多方面的实地研究。北极寒带脆弱性实验（ABoVE）将研究森林、永久冻土和其他生态系统如何应对北极的气温上升，在这里气候变化发生的速度比地球上其他任何地方都要快。ABoVE由12个个独立实验组成，多年来将研究该地区森林的变化，大气和土地、永久冻土之间碳运动的周期，火灾、气候变化和更多其他因素之间的关系。“英文原文”2016 climate trends continue to break recordsTwo key climate change indicators—global surface temperatures and Arctic sea ice extent—have broken numerous records through the first half of 2016， according to NASA analyses of ground-based observations and satellite data.Each of the first six months of 2016 set a record as the warmest respective month globally in the modern temperature record， which dates to 1880， according to scientists at NASA's Goddard Institute for Space Studies (GISS) in New York. The six-month period from January to June was also the planet's warmest half-year on record， with an average temperature 1.3 degrees Celsius (2.4 degrees Fahrenheit) warmer than the late nineteenth century.Five of the first six months of 2016 also set records for the smallest respective monthly Arctic sea iceextent since consistent satellite records began in 1979， according to analyses developed by scientists at NASA's Goddard Space Flight Center， in Greenbelt， Maryland. The one exception， March， recorded the second smallest extent for that month.While these two key climate indicators have broken records in 2016， NASA scientists said it is more significant that global temperature and Arctic sea ice are continuing their decades-long trends of change. Both trends are ultimately driven by rising concentrations of heat-trapping carbon dioxide and other greenhouse gases in the atmosphere.The extent of Arctic sea ice at the peak of the summer melt season now typically covers 40 percent less area than it did in the late 1970s and early 1980s. Arctic sea ice extentin September， the seasonal low point in the annual cycle， has been declining at a rate of 13.4 percent per decade.'While the El Niño event in the tropical Pacific this winter gave a boost to global temperatures from October onwards， it is the underlying trend which is producing these record numbers，' GISS Director Gavin Schmidt said.Previous El Niño events have driven temperatures to what were then record levels， such as in 1998. But in 2016， even as the effects of the recent El Niño taper off， global temperatures have risen well beyond those of 18 years ago because of the overall warming that has taken place in that time.The global trend in rising temperatures is outpaced by the regional warming in the Arctic， said Walt Meier， a sea ice scientist at NASA Goddard.'It has been a record year so far for global temperatures， but the record high temperatures in the Arctic over the past six months have been even more extreme，' Meier said. 'This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year.'NASA tracks temperature and sea ice as part of its effort to understand the Earth as a system and to understand how Earth is changing. In addition to maintaining 19 Earth-observing space missions， NASA also sends researchers around the globe to investigate different facets of the planet at closer range. Right now， NASA researchers are working across the Arctic to better understand both the processes driving increased sea ice melt and the impacts of rising temperatures on Arctic ecosystems.NASA's long-running Operation IceBridge campaign last week began a series of airborne measurements of melt pondson the surface of the Arctic sea ice cap. Melt ponds are shallow pools of water that form as ice melts. Their darker surface can absorb more sunlight and accelerate the melting process. IceBridge is flying out of Barrow， Alaska， during sea ice melt season to capture melt pond observations at a scale never before achieved. Recent studies have found that the formation of melt ponds early in the summer is a good predictor of the yearly minimum sea ice extent in September.'No one has ever， from a remote sensing standpoint， mapped the large-scale depth of melt ponds on sea ice，' said Nathan Kurtz， IceBridge's project scientist and a sea ice researcher at NASA Goddard. 'The information we'll collect is going to show how much water is retained in melt ponds and what kind of topography is needed on the sea ice to constrain them， which will help improve melt pond models.'Operation IceBridge is a NASA airborne mission that has been flying multiple campaigns at both poles each year since 2009， with a goal of maintaining critical continuity of observations of sea ice and the ice sheets of Greenland and Antarctica.At the same time， NASA researchers began in earnest this year a nearly decade-long， multi-faceted field study of Arctic ecosystems in Alaska and Canada. The Arctic-Boreal Vulnerability Experiment (ABoVE) will study how forests， permafrost and other ecosystems are responding to rising temperatures in the Arctic， where climate change is unfolding faster than anywhere else on the planet.ABoVE consists of dozens individual experiments that over years will study the region's changing forests， the cycle of carbon movement between the atmosphere and land， thawing permafrost， the relationship between fire and climate change， and more.