Reported here are O3 data recorded during the 1977 and 1978 Gametag field experiments. Nearly two thirds of these data were recorded in the free troposphere over the altitude range of 5–6.5 km. The remaining one third were collected in the atmospheric boundary layer, typically 0.3–1 km above the surface terrain. The latitude range covered by these measurements was 58°S to 70°N and involved flight operations over northern Canada, Alaska, the southeastern/central Pacific (northern hemisphere), and the central/western Pacific in the southern hemisphere. This data base is unique in that all ozone measurements were recorded on the same set of three ozone analyzers, on a single aircraft platform, and over a short time span. Key observations include (1) systematically higher average free tropospheric O3 levels in the northern versus southern hemisphere with the global minimum in ozone occurring at tropical latitudes; (2) extensive O3 layering within the free troposphere over large geographical areas of the northern hemisphere and, to a much lesser extent, remote areas of the southern hemisphere; (3) boundary‐layer O3 concentration levels which were consistently lower than free tropospheric O3 levels in remote areas of the northern hemisphere but only slightly lower than those levels observed in the southern hemisphere; and (4) the finding in April/May 1978 of a latitudinal zone, 13°S to 2°N, virtually devoid of boundary layer O3. A comparison of these data with those of other investigators, together with a discussion of the relevancy of these observations to our present understanding of the tropospheric O3 budget, is presented.
Presented in this paper are the H2O data collected during the 1977 and the 1978 Gametag (Global Atmospheric Measurements Experiment of Tropospheric Aerosols and Gases) field experiments. These data primarily reflect sampling occurring during the horizontal flight legs, involving altitudes of 5–6.5 km (free troposphere) and those in the atmospheric boundary layer at altitudes of ≤2 km. The latitude range covered was 70°N to 58°S. Approximately two thirds of the data were recorded over the open Pacific Ocean with the remaining one third being recorded over continental areas (e.g., Canada and Alaska). The H2O results show that very large variations in the level of this trace gas can occur within the free troposphere over very small geographical distances. They also indicate that over some regions of the Pacific Ocean very low levels of H2O can be found even at tropical and subtropical latitudes. The comparison of Gametag data with existing global dew point compilations suggests that some of the radiosonde middle tropospheric dew point profiles may be significantly in error, the radiosonde results being too high. Comparisons of the Gametag O3 and dew point/H2O data have shown that for the middle troposphere these two variables very frequently are negatively correlated. Comparisons between O3 and CO, when carried out within a given hemisphere, do not show a significant negative or positive correlation. On the basis of our findings, we have concluded that stratospheric/tropospheric dynamic exchange processes, directly and/or indirectly, play a controlling role in defining the tropospheric O3 source strength.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.