Analysis and modelling of climate-land cover interactions with a carbon cycle perspective

长期以来，气候和碳循环之间的相互作用一直被认为是决定地球气候状态的重要因素。这些复杂的相互作用涉及大气、海洋、海底沉积物、陆地表面和生物群之间的交换，并且通过确定大气中的CO2浓度，在确定地球的辐射预算方面具有根本意义。通过与生物圈的联系，碳循环也对其他与气候有关的参数，如降雨量、地表粗糙度和蒸散量产生重大影响。所有这些相互作用在气候对人为CO2排放的响应中发挥着重要作用，很明显，社会在面对未来气候变化时所需的详细和可靠的预测必须基于对这些气候-碳循环联系的深刻理解。此外，这种理解必须纳入用于生成这些预测的全球和区域模型。最近出现的全球气候-碳循环耦合数值模式是该领域的一个重大进步。这种模式预测技能的关键是它们能够说明植被动态，植被动态通过影响陆地表面和大气之间的物质和能量通量，在广泛的时间和空间尺度上对气候起着重要作用。这项研究提案的长期目标是通过应用和开发气候-碳循环耦合模型，加强我们对植被动态与气候之间相互作用的理解。其短期目标是：㈠通过制定昆虫对中高纬度森林影响的参数，提高现有模型的预测能力-这一进程虽然对这些生态系统的碳收支非常重要，但目前全球模型中没有这一进程;和ii）通过前所未有的大量数值模拟，植被覆盖对气候变化的响应，以及iii）量化人类引起的植被覆盖变化的气候影响，包括在全球循环模式中生成目前尚不存在的造林现实代表性的工作。

Interactions between climate and the carbon cycle have long been recognized as important in determining the Planet's climate state. These complex interactions involve exchanges between the atmosphere, ocean, bottom sediments, land surface and biota and are fundamental, by setting the atmospheric concentration of CO2, in the determination of the Planet's radiative budget. Through its connection to the biosphere, the carbon cycle also has a significant impact on other parameters relevant to climate such as albedo, surface roughness and evapotranspiration. All these interactions play an important role on the climate response to anthropogenic CO2 emissions, and it is clear that the detailed and reliable predictions required by society in the face of future climate change must be based on a solid understanding of these climate-carbon cycle connections. Moreover, this understanding must be incorporated into the global and regional models being used to generate these predictions. The recent advent of numerical coupled global climate-carbon cycle models constitutes a significant advancement for the field. Crucial to the predictive skills of such models is their ability to account for vegetation dynamics which, by influencing fluxes of mass and energy between the land surface and the atmosphere, play an important role in climate over a broad range of temporal and spatial scales. This research proposal is aimed, in the long-term, at enhancing our understanding of the interaction between vegetation dynamics and climate through the application and development of coupled climate-carbon cycle models. Its short-term goals are: i) To increase the predictive skills of current models through the development of a parameterization for insect impact on mid- to high-latitude forests - a process that, although being of great importance to the carbon budget of these ecosystems, is presently absent from global models; and ii) To quantify, through a unprecedentedly large number of numerical simulations, the response of vegetation cover to climate change and iii) To quantify the climatic effects of human-induced vegetation cover change, including work to generate a, presently inexistent, realistic representation of afforestation in a Global Circulation Model.