Arctic Biosphere-Atmosphere Coupling across multiple Scales (ABACUS).

气候变暖是全球碳循环被破坏的结果。北极已经在显著变暖，预计下个世纪高纬度地区变暖最快、最严重，达到4-7摄氏度。然而，气候、碳循环和全球能源平衡之间存在着复杂的联系，这意味着人们对这些全球变化的细节仍然知之甚少。我们提出了一个关于植物和土壤研究、大气测量、飞机和卫星观测以及建模的重大的、相互关联的方案，以增进我们对北极陆地生物圈对气候变化的反应的了解。我们的总体目标是确定是什么控制了北极生态系统和大气之间碳、水和能量交换的时空变异性。我们的实地考察地点分别位于瑞典阿比斯科(一个重点关注干燥冻土带，另一个重点关注白桦林)和芬兰凯沃(一个重点关注潮湿冻土带，另一个重点关注干燥冻土带)。在凯沃和阿比斯科，卫星图像和飞机飞行都将覆盖10公里×10公里的区域，包括这两个重点区域。该项目有八个工作包：关于植物分配和物候的WP1研究，以及主要群落类型的呼吸-生产比率(通过收获、根系测量和同位素示踪实验)。凋落物的WP2周转，土壤有机质(SOM)，土壤的景观分布(通过土壤调查，同位素标记的凋落物，确定SOM年龄的炸弹C年代)，CH4排放。WP3小室测量土壤和植被在精细尺度上的碳和水交换(分辨率约为1m)。WP4连续测量土壤/植被与大气之间在约100米尺度上的二氧化碳和水分交换，并记录雪深、土壤水分和气候。WP5飞机在两个研究区域进行了测量，记录了二氧化碳和水的交换以及陆地表面和甲烷剖面的图像。这些测量范围将延伸到许多平方公里的区域。WP6通过卫星进行地球观测。我们将把来自几个卫星仪器的观测与实地活动中记录的植物覆盖率的测量联系起来。WP7我们使用模型来连接在不同时间和空间尺度上连接的信息。这些模型代表了我们对该系统的最好理解，我们对照来自舱、塔、飞机或卫星的独立观测来检查和改进我们的理解。我们测试我们是否能够理解来自卫星和飞机的数据，根据在舱和塔上记录的细节，以及WP1和WP2实验。我们将举办一个国际研讨会，与来自世界各地的同事分享我们的想法。我们将以野外测量为基础，通过暑期学校培养研究生，为本科生提供暑期野外体验。

Climate warming is resulting from disruption of the global carbon cycle. The Arctic is already warming significantly, and warming is expected to be fastest and greatest at high latitudes, 4-7 degrees C over the next century. However, there are complex links among climate, the carbon cycle and the global energy balance which mean that the details of such global changes remain poorly understood. We propose a major, linked programme of plant and soil studies, atmospheric measurements, aircraft and satellite observations, and modelling, to improve our understanding of the response of the arctic terrestrial biosphere to climate change. Our overall aim is to determine what controls the temporal and spatial variability of carbon, water and energy exchange between arctic ecosystems and the atmosphere. Our field sites are based at Abisko, Sweden (with one focus area in dry tundra, the other in birch forest), and Kevo, Finland (with one focus on wet tundra, the other on dry tundra). At Kevo and Abisko both satellite imagery and aircraft flights will encompass an area of 10 km x 10 km, including both focus areas. The project has eight work-packages: WP1 Studies on plant allocation and phenology, and respiration-production ratios for major community types (via harvests, root measurement and isotope tracer experiments). WP2 Turnover of litter, soil organic matter (SOM), landscape distribution of soils (via soil surveys, isotope labelled litter, bomb C dating to determine SOM age), CH4 emissions. WP3 Chamber measurements of C and water exchanges from soils and vegetation at fine scales (a resolution of ~1m). WP4 Continuous tower measurements of CO2 and water exchange between the soils/vegetation and the atmosphere at scales of ~100 m, and records of snow depth, soil moisture and climate. WP5 Aircraft measurements over the two study regions, recording CO2 and water exchanges and images of the land surface and profiles of CH4. These measurements will extend over areas of many km squared. WP6 Earth Observation via satellites. We will link observations from several satellite instruments to measurements of plant cover recorded in field campaigns. WP7 We use models to connect the information connected at different time and space scales. The models represent our best understanding of the system, and we check and improve our understanding against independent observations, whether from chambers, towers, aircraft or satellites. We test whether we can understand the data from satellites and aircraft in terms of the detail recorded at the chambers and towers and with the WP1 and WP2 experiments. WP8 We will run an international workshop to share our ideas with colleagues from around the world. We will train post-graduates with a summer-school based around field measurement, and provide undergraduates with summer field experience.