Development of new retrieval method of tropospheric ozone from MAX-DOAS measurements and its application to long-term MAX-DOAS measurements in China and Germany for the validation of satellite observations and model results of tropospheric ozone

开发基于 MAX-DOAS 测量的对流层臭氧新反演方法及其在中国和德国长期 MAX-DOAS 测量中的应用，以验证对流层臭氧的卫星观测和模型结果

• 批准号: 428994811
• 负责人: Dr. Yang Wang, Ph.D.
• 金额: --
• 依托单位: Forschungsgruppe Satellitenfernerkundung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/428994811?language=en
• 关键词: Development; new; retrieval; method; tropospheric

Tropospheric ozone (O3) plays an important role in controlling the tropospheric chemical composition through various reactions with OH radicals, CO, CH4, NOx, and hydrocarbons. It is a greenhouse gas and pollutant detrimental to human health and crop and ecosystem productivity. However the lack of observations of vertical profiles of tropospheric obscures studies on its impact on the environment, climate, health and ecosystems. Recently developed products of tropospheric ozone derived from satellite observations and chemical transport modelling have large uncertainties and urgently need credible measurements of vertical profiles of tropospheric ozone for validation. Multi axis DOAS (MAX-DOAS) is a state of the art ground-based remote sensing technique to retrieve tropospheric vertical profiles and columns of trace gases (e.g. NO2, BrO, SO2, HCHO, HONO, and CHOCHO) from UV and visible spectra of scattered sunlight. However due to the strong influence of stratospheric O3 on MAX-DOAS measurements, still no satisfactory algorithms for the retrieval of tropospheric ozone profiles from MAX-DOAS measurements exist. In our recent preliminary study, we found that this difficulty could be addressed by the use of external data of stratospheric ozone (Method 1) or by utilising the temperature dependence of the ozone absorption cross section (Method 2), and two corresponding retrieval algorithms of tropospheric ozone from MAX-DOAS measurements have been developed. In this study, we will further improve the Method 1 to make the retrieval independent from external data sets by the use of stratospheric ozone also derived from the MAX-DOAS measurements at high solar zenith angle. The improved method will be validated during two campaigns in China and Germany by comparing them with results from ozone sondes, O3 lidars, Fourier transform spectrometry as well as in-situ O3 measurements. The new method will be evaluated and further improved for situations of strong haze pollutions (low visibility) in China. Then the new method will be adapted and applied for the analysis of long-term measurements of several MAX-DOAS instruments located in Germany and China. A data base of tropospheric ozone profiles will be generated based on the MAX-DOAS measurements in the North China Plain region and Yangtze River delta region, China and in Mainz, Germany. The data base will be used to validate satellite products and model simulations of tropospheric ozone, and characterize its temporal-spatial variation, the effects of regional transport, and to identify sources of tropospheric ozone. In addition to method 1, also method 2 (utilising the temperature dependence of O3 absorptions) will be further improved.

对流层臭氧（O3）通过与OH自由基、CO、CH 4、NOx和碳氢化合物的各种反应，在控制对流层化学组成方面起着重要作用。它是一种温室气体和污染物，对人类健康、作物和生态系统生产力有害。然而，由于缺乏对流层垂直廓线观测，因此无法研究对流层对环境、气候、健康和生态系统的影响。最近通过卫星观测和化学传输模型制作的对流层臭氧产品具有很大的不确定性，迫切需要对对流层臭氧垂直分布进行可靠的测量，以供验证。多轴DOAS（MAX-DOAS）是一种利用太阳光散射的紫外和可见光谱反演对流层痕量气体（如NO2、BrO、SO2、HCHO、HONO和CHOCHO）垂直廓线和气柱的地面遥感技术。但是由于平流层O3对MAX-DOAS测量的影响很大，目前还没有一种令人满意的算法来从MAX-DOAS测量中反演对流层臭氧廓线。在我们最近的初步研究中，我们发现，这一困难可以通过使用平流层臭氧的外部数据（方法1）或通过利用臭氧吸收截面的温度依赖性（方法2）来解决，并且已经开发了两种相应的对流层臭氧反演算法。在这项研究中，我们将进一步改进的方法1，使反演独立于外部数据集，通过使用平流层臭氧也来自MAX-DOAS测量在高太阳天顶角。改进后的方法将在中国和德国的两次活动中通过与臭氧探空仪、O3激光雷达、傅里叶变换光谱仪以及现场O3测量结果的比较进行验证。新方法将在中国强灰霾污染（低能见度）的情况下进行评估和进一步改进。然后，新的方法将适应和应用于位于德国和中国的几个MAX-DOAS仪器的长期测量的分析。利用MAX-DOAS在中国华北平原、长江三角洲和德国美因茨的观测资料，建立对流层臭氧廓线数据库。该数据库将用于验证对流层臭氧的卫星产品和模型模拟，并确定其时空变化的特征、区域传输的影响以及确定对流层臭氧的来源。除了方法1之外，方法2（利用O3吸收的温度依赖性）也将被进一步改进。