Atmospheric measurements of the carbon cycle

我的研究方向是从大气角度研究碳循环。我的团队测量与碳循环相关的大气微量气体，如二氧化碳（CO2）、甲烷（CH4）、一氧化碳（CO）和羰基硫化物（OCS），目的是量化来自陆地生物圈和城市排放的碳交换。我们的研究重点是改进大气测量本身，以及从这些测量中得出的科学。燃烧化石燃料释放的碳约有一半留在大气中；另一半则以大约相等的比例被海洋和陆地生物圈吸收。在我们目前对全球碳循环的理解中，一个重要的空白是陆地生物圈在从大气中去除碳方面所起的作用，以及在气候变暖加剧的情况下它将发挥的作用。在过去十年中，北美陆地生物圈一直是一个持续的净碳汇，但气候变化、土地利用变化和干扰对未来的影响尚不清楚。例如，加拿大的森林现在被认为是大气中碳的一个小来源。我的研究项目将开发新的大气测量工具，以更好地了解气候变量、野火和其他干扰对大气成分的影响，从而更好地预测未来的变化。众所周知，城市产生了北美约80%的二氧化碳排放量，市政府已经形成了全球联盟，以减少其排放量，通常比联邦政府的同行更快。我们对全球城市对甲烷排放的贡献知之甚少，但它被认为是显著和重要的。大多数城市使用清单来量化排放量，这些清单是根据行业报告编制的。这些清单对于分析行业排放是有用的，但它们不能解释未知或无意的排放。因此，从大气测量中得出的排放量化对于核实排放很重要，但它们提供的关于排放的精确来源的详细信息较少。清单和大气量化共同提供了与排放有关的最有力的政策信息。我的研究项目主要集中在大多伦多地区（GTA），在那里我们开发了一个设施级的CH4排放清单，以及一个密集的地面大气观测站。我们将开发技术，通过我们的大气测量来验证和改进我们的CH4清单，并利用这些技术来评估政策的有效性。我们将运用这些技术量化大多伦多地区的二氧化碳排放量，并与市政府和其他利益相关者合作，将这种网络扩展到其他城市。

My research program focuses on the study of the carbon cycle from the atmospheric perspective. My group measures carbon cycle-relevant atmospheric trace gases, such as carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and carbonyl sulfide (OCS), with the goal of quantifying the exchange of carbon from the terrestrial biosphere and from urban emissions. Our research focuses on improving the atmospheric measurements themselves, and on the science derived from those measurements. About half of the carbon released by burning fossil fuels remains in the atmosphere; the other half is absorbed by the oceans and terrestrial biosphere in approximately equal proportion. A significant gap in our current understanding of the global carbon cycle is the role that the terrestrial biosphere plays in removing carbon from the atmosphere, and the role it will play under increased warming. The North American terrestrial biosphere has been a persistent net carbon sink over the past decade, but future impacts from climate change, land-use change, and disturbance are unclear. Canadian forests, for example, are now thought to be a small source of carbon to the atmosphere. My research program will develop new atmospheric measurement tools to better understand the impacts of climate variables, wildfires and other disturbance on atmospheric composition, which will in turn provide better predictions of future change. Cities are known to produce around 80% of North American CO2 emissions, and municipal governments have formed global coalitions to reduce their emissions, often faster than their federal counterparts. Less is known about the global urban contribution to CH4 emissions, but it is thought to be significant and important. Most cities use inventories to quantify emissions that are compiled from industry reports. These inventories are useful for analysing sectorial emissions, but they cannot account for emissions that are unknown or inadvertent. Therefore, emissions quantification derived from atmospheric measurements is important for verifying emissions, but they provide less detailed information about the precise source of the emission. Together, inventories and atmospheric quantification provide the most powerful policy-relevant information about emissions. My research program focuses on the Greater Toronto Area (GTA), where we have developed a facility-level CH4 emission inventory, and a dense ground-based atmospheric observatory. We will develop techniques for verifying and improving upon our CH4 inventory with our atmospheric measurements, using these techniques to evaluate policy efficacy. We will apply these techniques to quantify CO2 emissions from the GTA and engage municipal governments and other stakeholders to expand this kind of network to other cities.