Photochemical Ozone Budget of the Eastern North Pacific Atmosphere (PHOBEA)

这个项目研究对流层臭氧的形成以及臭氧前体的丰度和来源。对北半球地表和自由对流层臭氧的观测显示春季有极大值。以前在阿拉斯加的测量和模式模拟表明，这个峰值中的一些可以用冬季积累的、人为的臭氧前体的光化学产生来解释。在这方面，最重要的臭氧前体是过氧乙酰硝酸盐（PAN）。测量结果还表明，垂直输送在气团变暖和边界层PAN热分解中起重要作用。这种人为造成的臭氧产生可能有助于臭氧的长期增加，这在春季和夏季已在北半球的几个地点观测到。在这个项目中，臭氧、氮氧化物、总活性氮、PAN、一氧化碳、辐射、氡和活性自由基的地面测量，以及气溶胶特性、紫外线辐射和气象参数将由PI与华盛顿奇卡峰研究基地的其他研究人员合作测量。此外，将在1997年春季与地面测量一起，用飞机测量臭氧、一氧化氮、PAN和一氧化碳的丰度。将采用0维和1维模型。这些数据将提供以下问题的答案：(1)该地区的臭氧预算是什么；(2)什么条件导致气团变暖和PAN成分，导致臭氧形成增强？(3)亚洲排放物对到达美国西海岸的气团有何影响；(4)云型和高度对臭氧/氮氧化物光化学的影响。

9529604 Jaffe This project addresses the formation of tropospheric ozone and the abundance and origin of ozone precursors. Observations of surface and free tropospheric ozone in the northern hemisphere show a spring maximum. Previous measurements in Alaska and model simulations indicate that some of this peak can be explained by photochemical production from winter accumulated, anthropogenic, ozone precursors. In this regard, the most important ozone precursor is peroxyacetyl nitrate (PAN). Measurements also show an important role for vertical transport in warming of air masses and causing thermal decomposition of PAN in the boundary layer. This anthropogenically caused ozone production may contribute to the long-term increases in ozone which have been observed at several northern hemispheric locations during spring and summer. In this project, ground-based measurements of ozone, nitrogen oxides, total reactive nitrogen, PAN, carbon monoxide, radiation, radon, and reactive radical species, as well as aerosol properties, ultraviolet radiation, and meteorological parameters will be measured by the PI in collaboration with other researchers at the Cheeka Peak research site in Washington. In addition, aircraft-borne measurements of the abundance of ozone, nitric oxide, PAN, and carbon monoxide will be performed in the spring of 1997 in conjunction with the ground-based measurements. 0- and 1-dimensional models will be employed. The data will provide answers to questions including: (1) What is the ozone budget in this region; (2) What are the conditions that give rise to air mass warming and PAN composition, leading to enhanced ozone formation; (3) What is the influence of Asian emissions on air masses which arrive at the West Coast of the US; and (4) What is the influence of cloud types and heights on the ozone/nitrogen oxide photochemistry.