摘要: | 對流層的臭氧對人類的健康,地表植物,和地球的氣候扮演一個非常重要的角色,因此探討臭氧在對流層裡濃度改變的機制是一個非常重要的研究。目前科學界對於控制對流層臭氧濃度的主要過程有兩種理論:分別是平流層主控理論以及對流層光化理論。在過去近20 年有很多的模式分別針對上述兩種理論進行研究,但是直至目前為止還沒有一個能夠被接受的公論。造成此項困難的主要原因是觀測資料缺乏。隨著最近大量觀測資料的產生,以及對流層其他會影響臭氧分佈因素的觀測,結果逐漸產生。我們現在有可能對這個問題進行新的研究,因此本研究主要目的為持續第一年研究工作, 即是整合IMS 三維數值模式與觀測資料(e.g., SHADOZ, MOZAIC)以探討影響對流層臭氧濃度改變的過程。 Tropospheric ozone exerts its influences on human health, terrestrial vegetation, and earth's climate. Two theories are generally employed to explain the origins of elevated ozone in the troposphere. First, transport from the stratosphere to the troposphere is the dominating source of elevated ozone in the troposphere. Second, elevated ozone originated mainly from chemical emissions (e.g. emissions of O3 precursors such as NOx and VOCs from anthropogenic activities, soil, lightning, and biomass burning), followed by photochemistry (photochemical oxidation of CO and hydrocarbons catalysed by HOx and NOx), and transport processes (e.g. large-scale long-range transport, cloud convection, and vertical mixing between the atmospheric boundary layer and free troposphere) within the troposphere itself. It is still a great debate on the contribution of stratosphere and tropospheric photochemistry to the observed ozone variability in the troposphere. The difficulty is due to the lack of the the observational data in verifying model calculations, especially on a three-dimensional and multiyear dimensions. Now with the availability of multiyear observations from projects such as WOUDC, SHADOZ and MOZAIC, together with several new observations from satellite remote-sensing measurements of ground-level fire activities (ATSR), terrestrial vegetation coverage (NDVI), and tropospheric lightning frequency (LIS and OTD), it is now possible to look into this issue with a new perspective that is not able to achieve previously. Here we propose a two-year modelling study of the relative importance of ozone from the stratosphere and the emissions of ozone producing precursors to the ozone levels in the troposphere, by combining three-dimensional modeling techniques with observations from different platforms. The goal of this three-year project is to quantify the contribution of stratosphere and tropospheric photochemistry to the ozone level in different regions of the troposphere, and to find a theory which is able to explain the observed ozone variability. 研究期間:9308 ~ 9407 |