期刊
ATMOSPHERIC CHEMISTRY AND PHYSICS
卷 18, 期 22, 页码 16809-16828出版社
COPERNICUS GESELLSCHAFT MBH
DOI: 10.5194/acp-18-16809-2018
关键词
-
资金
- ATom investigation under the National Aeronautics and Space Administration's (NASA) Earth Venture program [NNX15AJ23G, NNX15AG57A, NNX15AG58A, NNX15AG71A]
- Earth Science Project Office
- Oak Ridge National Laboratory Distributed Active Archive Center
- National Science Foundation
- U.K. Natural Environment Research Council
- Copernicus Atmosphere Monitoring Service (CAMS)
- NASA [NNX15AG58A, 804376, 804137, NNX15AG57A, 804155, NNX15AG71A] Funding Source: Federal RePORTER
- NERC [NE/N018028/1, ncas10003] Funding Source: UKRI
Measurements from actinic flux spectroradiometers on board the NASA DC-8 during the Atmospheric Tomography (ATom) mission provide an extensive set of statistics on how clouds alter photolysis rates (J values) throughout the remote Pacific and Atlantic Ocean basins. J values control tropospheric ozone and methane abundances, and thus clouds have been included for more than three decades in tropospheric chemistry modeling. ATom made four profiling circumnavigations of the troposphere capturing each of the seasons during 2016-2018. This work examines J values from the Pacific Ocean flights of the first deployment, but publishes the complete Atom-1 data set (29 July to 23 August 2016). We compare the observed J values (every 3 s along flight track) with those calculated by nine global chemistry-climate/transport models (globally gridded, hourly, for a mid-August day). To compare these disparate data sets, we build a commensurate statistical picture of the impact of clouds on J values using the ratio of J-cloudy (standard, sometimes cloudy conditions) to J-clear (artificially cleared of clouds). The range of modeled cloud effects is inconsistently large but they fall into two distinct classes: (1) models with large cloud effects showing mostly enhanced J values aloft and or diminished at the surface and (2) models with small effects having nearly clear-sky J values much of the time. The ATom-1 measurements generally favor large cloud effects but are not precise or robust enough to point out the best cloud-modeling approach. The models here have resolutions of 50-200 km and thus reduce the occurrence of clear sky when averaging over grid cells. In situ measurements also average scattered sunlight over a mixed cloud field, but only out to scales of tens of kilometers. A primary uncertainty remains in the role of clouds in chemistry, in particular, how models average over cloud fields, and how such averages can simulate measurements.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据