摘要
采用小间隔O3值作细微天气学分析,定出高原O3低中心和落基山脉O3低槽。根据这些客观实体,明确其基本特征,研究其形成。青藏高原O3低中心常年存在,位于30°N以南,稳定少动,具有年较差小,春浅薄、秋深陷等基本特征。其形成主要靠高山的静力亏损。另一类O3低中心生于6月灭于9月,位于30°N以北,变化多动,是由位于30°N以南的主体低中心派生出来的,但其维持与发展只是部分与100 hPa上的青藏高压及其环流相联系并符合动力-热力观点。落基山脉O3低谷呈现分段低槽型,在山高、紧临大洋地段低槽明显,一年四季存在,夏季低槽分段更为清晰,是由热带、副热带低浓度O3侵袭而来。从整个南北走向来看,静力亏损是其基本成因。为了求出高山静力亏损率的概数,用分布在全球各处高于491 m的22个高山站(含491 m站)直接观测的O3资料,在求出气层O3总量后,根据最小二乘法计算,得到高山每上升1 km O3平均亏损率为4.4 DU。由于这是小尺度的现象,所以对于高山O3低谷,需要采用细微分析方法,研究O3平面场。
In view of the ambiguity of the definition of the ozone low center （trough） above the Tibetan Plateau, we propose a micro-synoptic analysis method to locate the ozone low center above the Tibetan Plateau and the ozone （low） trough above the Rocky Mountains. By using this method the general characteristics and the cause of formation are studied. The ozone low center above the Tibetan Plateau appears very often, and it is stable and rarely movWe find that the cause of There is another kind of ozone low center above the Tibetan Plateau which appears in June and disappears in September. It is unstable and often moving, locating to the north of 30^oN. This center would seem to be derived from the southern low center, and its maintenance and development is related to the Tibetan High Pressure （at 100 hPa level） and atmospheric circulation associated to it. This viewpoint, we think, conforms to the viewpoint of dynamic thermodynamics. The ozone （low） trough above the Rocky Mountains looks as segmental shape. The troug looks more remarkable where the mountain is higher and where the trough is near to the ocean. This trough exists all the year round. But the segmental character appears more remarkable in summer. It seems that there is an intru- sion of low concentration of ozone from tropics and subtropics. We hold that static deficit is the main cause. By the way, it is more preferable to use the micro-scale analysis method to study the two dimensional characters of ozone field. The reason for using such analysis is that the value of static deficit is not large, about 4 DU for every 1 km of ascending where the high mountain reaches the middle troposphere. This is a micro-scale phenomenon in synoptic terminology.
出处
《气候与环境研究》
CSCD
北大核心
2008年第5期617-628,共12页
Climatic and Environmental Research
关键词
青藏高原
臭氧低中心
落基山臭氧低槽
高山静力亏损率
Tibetan Plateau, ozone low center, ozone （low） trough above the Rocky mountains, static depletionabove high mountains
