Improved understanding of Arctic atmospheric composition and climate through exploitation of satellite observations

通过利用卫星观测提高对北极大气成分和气候的了解

• 批准号: 2443087
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2443087
• 关键词: Improved; understanding; Arctic; atmospheric; composition

Supervisors: Steve Arnold (SEE), Anna Jones (BAS), Richard Pope (NCEO/SEE)The Arctic is undergoing rapid environmental change, and in recent decades has warmed at approximately twice the global mean rate. Radiative forcing (RF) from atmospheric CO2 increases and efficient high latitude climate feedbacks are responsible for the majority of Arctic warming. However, a significant part of the warming has been attributed to effects of changes in atmospheric concentrations of short-lived climate forcers (SLCFs), such as aerosol particles and tropospheric ozone. SLCFs affect Arctic temperatures via local RF produced by changes in their Arctic distributions, but also through RF imposed by changes in their abundances at lower latitudes, and subsequent changes in poleward heat transport. Arctic ozone and aerosol changes in response to natural feedbacks may also be important, for example as oceanic and terrestrial emission sources respond to rapid changes in temperature and ice & snow cover. Anticipated increases in shipping transiting the Arctic pose a further, direct, source of aerosols to the region. A major challenge in attributing changes in Arctic tropospheric composition and climate to remote and local influences from anthropogenic and natural emission sources is a severe paucity of in-situ observations of trace gas and aerosol, particularly over the long-term and through the vertical profile. This project will use satellite observations of tropospheric composition to constrain changes in these anthropogenic and natural influences on the Arctic over recent decades. The project will exploit multiple datasets from both nadir-viewing and limb sounders, and will focus on providing evaluation data for near-surface and upper troposphere composition in the high latitude region. Combining this data synthesis with aircraft & surface data and modeling, will allow new constraints on drivers of multi-annual observed rapid Arctic environmental change. Specific areas of investigation may include:Development of a long-term synthesis of satellite data on Arctic tropospheric composition, through exploitation of multiple sensors over the past 25 years.Evaluation of this long-term data synthesis with available in-situ datasets from aircraft.Use of satellite data time-series in evaluation of long-term chemistry-climate model simulations of Arctic trace gas and aerosol.Combining satellite data and chemistry-climate modeling to produce new estimates of ozone and aerosol radiative effects in the Arctic.Using satellite data to improve understanding of natural emission influences on ozone and aerosol in the Arctic.Using satellite data to improve understanding of long-range transport of trace gases and aerosol from mid-latitudes to the Arctic, and to evaluate these transport pathways in models.Using satellite observations to detect temporal and spatial changes in high latitude local emissions of trace gases influencing the Arctic region.The student will join active research teams in Leeds and BAS, focused on atmospheric chemistry modeling and analysis of satellite and aircraft data. The student will benefit from training in expertise in analysis of large geophysical datasets and remote sensing techniques, as well as numerical atmospheric chemistry-climate modelling. Extended collaborative visits for the student to the British Antarctic Survey will be expected (minimum 3 / yr, 1-2 weeks duration).

主管：史蒂夫·阿诺德（SEE），安娜·琼斯（BAS），理查德·波普（NCEO/SEE）北极正在经历快速的环境变化，近几十年来，北极变暖的速度大约是全球平均速度的两倍。大气CO2增加造成的辐射强迫（RF）和高纬度地区有效的气候反馈是北极变暖的主要原因。然而，变暖的很大一部分是由于大气中短时气候强迫物（SLCFs）浓度变化的影响，如气溶胶颗粒和对流层臭氧。SLCFs通过其北极分布变化产生的局部射频影响北极温度，但也通过其在低纬度丰度变化以及随后的极地热输送变化所施加的射频影响北极温度。北极臭氧和气溶胶响应自然反馈的变化也可能很重要，例如，海洋和陆地排放源响应温度和冰雪覆盖的快速变化。预计过境北极的船舶将增加，这将成为该地区气溶胶的进一步直接来源。将北极对流层组成和气候变化归因于人为和自然排放源的远程和局部影响的一个主要挑战是，对微量气体和气溶胶的现场观测严重缺乏，特别是长期和通过垂直剖面的观测。该项目将利用对流层组成的卫星观测来限制近几十年来对北极的这些人为和自然影响的变化。该项目将利用来自最低点观测和边缘测深仪的多个数据集，并将重点提供高纬度地区近地表和对流层上层成分的评估数据。将这些数据综合与飞机和地面数据和建模相结合，将对多年观测到的北极环境快速变化的驱动因素产生新的限制。具体的调查领域可包括：通过利用过去25年的多个传感器，发展关于北极对流层组成的卫星数据的长期综合。利用飞机上现有的原位数据集对这一长期数据综合进行评估。利用卫星数据时间序列评估北极微量气体和气溶胶的长期化学-气候模式模拟。结合卫星数据和化学-气候模型对北极臭氧和气溶胶辐射效应作出新的估计。利用卫星数据提高对北极自然排放对臭氧和气溶胶影响的认识。利用卫星数据提高对微量气体和气溶胶从中纬度到北极的远距离输送的认识，并在模式中评估这些输送途径。利用卫星观测探测影响北极地区的高纬度地区微量气体排放的时空变化。该学生将加入利兹和BAS的活跃研究团队，专注于大气化学建模和卫星和飞机数据分析。学生将受益于大型地球物理数据集分析和遥感技术的专业知识培训，以及数值大气化学-气候模拟。预计学生将参加英国南极考察队的长期合作访问（至少3次/年，1-2周）。