Global atmospheric chemistry climate modeling

全球大气化学气候模拟

• 批准号: 63218943
• 负责人: Dr. Martin Georg Schultz
• 金额: --
• 依托单位: Zentrum für Marine Umweltwissenschaften (MARUM)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/63218943?language=en
• 关键词: Global; atmospheric; chemistry; climate; modeling

Atmospheric chemistry might have played an important role in shaping the climate of the cenozoic era. For example, Sloan and Pollard (1998) explain the so-called "low gradient paradox" (high temperatures in high latitudes) by enhanced methane release from wetlands leading to increased water vapour in the stratosphere and ultimately to warming of the high latitude earth surface. Methane (CH4) is one of the most important greenhouse gases. Its lifetime is predominantly determined by hydroxyl (OH) radicals, so that CH4 both affects and is affected by the atmospheric oxidation (self-cleansing) efficiency. OH in turn is intimately linked to various atmospheric chemistry processes and budgets. Of particular importance are the budgets of NOx (reactive nitrogen species, NO and NO2), biogenic volatile organic compounds (VOCs), carbon monoxide (CO) and ozone. Natural emissions of CH4, NOx, CO and VOCs depend strongly on climatic conditions. In this work package we will estimate the natural emissions of these compounds and their uncertainties for the cenozoic climate. We will use them as input to a set of global atmospheric chemistry simulations in order to assess the strength of the chemistry climate feedback and the potential state of the atmospheric chemical composition under these conditions. The climatic conditions (including inter-annual variability), vegetation patterns and orography will be taken from WP1 and WP5 of this project. The global distribution of potential wetlands and their methane (CH4) emissions at the present-day and during the Cenozoic climate will be estimated using a process-based approach following Kaplan (2002) and Walter et at. (2001), respectively. Other biogenic emission sources and vegetation fires will be estimated via parameterized approaches (Guenther et al., 1995; Thonicke et al., 2001). Budgets of CH4 and global distributions of OH for various climate conditions will be calculated in multidecadal time slice simulations by a general circulation model, which includes a comprehensive representation of tropospheric chemistry.

大气化学可能在新生代气候的形成中发挥了重要作用。例如，Sloan和Pollard（1998年）解释了所谓的“低梯度悖论”（高纬度地区的高温），因为湿地释放的甲烷增加，导致平流层中的水蒸气增加，最终导致高纬度地球表面变暖。甲烷（CH 4）是最重要的温室气体之一。它的寿命主要由羟基（OH）自由基决定，因此CH 4既影响大气氧化（自清洁）效率，又受其影响。OH反过来又与各种大气化学过程和预算密切相关。特别重要的是NOx（活性氮物质，NO和NO2）、生物挥发性有机化合物（VOC）、一氧化碳（CO）和臭氧的预算。甲烷、氮氧化物、一氧化碳和挥发性有机化合物的自然排放在很大程度上取决于气候条件。在这个工作包中，我们将估计这些化合物的自然排放量及其对新生代气候的不确定性。我们将使用它们作为一组全球大气化学模拟的输入，以评估化学气候反馈的强度和在这些条件下大气化学成分的潜在状态。气候条件（包括年际变化）、植被格局和地形将取自本项目WP 1和WP 5。根据Kaplan（2002年）和Walter等人的研究，将使用基于过程的方法估计全球潜在湿地的分布及其在当今和新生代气候期间的甲烷（CH 4）排放量。（2001）。其他生物排放源和植被火灾将通过参数化方法进行估计（Guenther等人，1995; Thonicke等人，2001年）。将通过一个包括对流层化学全面代表性的大气环流模型，在几十年的时间片模拟中计算各种气候条件下的CH 4和OH的全球分布。