Ozone and water vapor observations in the tropical Pacific

在1998年和1999年期间这种财政支持的基础上，我们在东太平洋的加拉帕戈斯群岛圣克里斯托瓦尔进行了三次观测运动，在太平洋中部的基里巴斯圣诞岛进行了两次观测运动。目前，我们正在对这些活动的数据进行深入分析，目前已经掌握了以下初步知识。通过对比西太平洋圣克里斯托瓦尔和新加坡的数据，我们发现两个站点在北部冬季对流层顶的低压、高海拔和低温特征存在明显的年际变化；然而，从海面温度变化所期望的对应关系并不清楚。圣克里斯托瓦尔的水蒸气测量结果显示，与预期相反，3月份对流层顶周围存在饱和状态的明确证据。9月份有时会出现不饱和的情况，但这是赤道开尔文波向下传播的时期，提供了来自平流层的干燥和富含臭氧的空气入侵。圣克里斯托瓦尔对流层臭氧分布的特征是在3 - 4月接近恒定（约30 ppb）的剖面，但从表面（20ppb）增加到6 - 7公里（50ppb）。这可能表明，由于赤道波活动更加强烈，9月份平流层臭氧泄漏更大。通过科考船的无线电探空仪和臭氧探空仪观测，我们发现了对流层低层的分层结构，最高可达地表约5公里；它们的特点是大气干燥且富含臭氧。在这些层周围，偏北风占主导地位，表明与位于科考船北部的热带辐合带（ITCZ）有关。在圣克里斯托瓦尔和圣诞岛的臭氧数据中也观察到这一特征。

On the basis of this financial support during the period of 1998 and 1999, we have conducted observation campaigns three times at San Cristobal, the Galapagos Islands in the eastern Pacific, and two times at Christmas Island, Kiribati in the central Pacific. We are now making intensive analyses of the data from these campaigns, and have learned the following preliminary knowledge so far.1. By comparing data from San Cristobal with Singapore in the western Pacific, we found at the two stations that there exist clear annual variations of the tropopause properties, such as low pressure, high altitude and low temperature during the northern winter season; however, the correspondence expected from the sea surface temperature variations is not clear.2. Results from water vapor measurements at San Cristobal show, contrary to expectations, clear evidence of saturation conditions around the tropopause in March. Those in September sometimes show unsaturation conditions, but it is a time when downward phase propagation of the equatorial Kelvin wave, providing dry and ozone-rich air intrusion from the stratosphere.3. Tropospheric ozone distribution at San Cristobal is characterized as a near constant (about 30 ppb) profile in March-April, but as a increase up to 6 - 7 km (50ppb) from the surface (20ppb). This may suggest that the stratospheric ozone is leakier in September due tomore vigorous equatorial wave activity.4. Radiosonde and ozonesonde observations from the research vessel, we have found layered structures in the lower troposphere up to about 5km from the surface; these are characterized as a dry and ozone-rich atmosphere. Around these layers, the northerly wind is dominated, suggesting a relation to the Inter-Tropical Convergence Zone (ITCZ) situated north of the research vessel. This feature is also observed in the ozone data at San Cristobal and Christmas island.