Isentropic scaling analysis of ozone in the upper troposphere and lower stratosphere

We examine ozone concentrations recorded by 7630 commercial flights from August 1994 to December 1997 for spatial scaling properties. The large amount of data allows an approximately isentropic analysis of ozone variability in the upper troposphere and lower stratosphere. Since ozone is a good passive tracer at cruise altitudes, the results provide a strong diagnostic for scalar advection theories and models. Calculations of structure functions and increment probability distribution functions show that ozone variability scales anomalously from ∼2 to ∼2000 km, although not continuously in this interval. We find no evidence for the simple scaling predicted for smooth advection/diffusion, even at the large scales. At mesoscales the upper tropospheric ozone field is rougher and more intermittent than in the lower stratosphere. Within the troposphere the equatorial ozone field is rougher than at higher latitudes, and the intermittency decreases with increasing latitude. In the stratosphere the intermittency and roughness are greater at high latitudes and over land than at midlatitudes and over the ocean.United States. National Aeronautics and Space Administration (Grant NAG1-2306

General characteristics of tropospheric trace constituent layers observed in the MOZAIC program

We present a statistical study on tropospheric layers as allowed by the most extensive ozone and water vapor database currently available. Considering O₃ and H₂O deviations from an automatically calculated background, we define four types of layers. These tropospheric layers are a common feature, with the percentage of the troposphere occupied by such layers varying from 7% to 33% depending on the region and the season. Most of the layers are found between 4 and 8 km altitude, and the median thickness is about 500 m. At northern midlatitudes we find 4 times more layers in summer than in winter, while in tropical Asia we observe a spring maximum in the occurrence of the layers. The most abundant layer type everywhere is O₃+H₂O− and corresponds to the signature of stratospheric intrusions or continental pollution. This suggests that stratosphere-troposphere exchanges or at least their influence are not negligible in summer at midlatitudes or in the tropics. A complete understanding of the layers could lead to a better empirical assessment of the different tropospheric ozone sources and to an assessment of the potential vorticity fluxes in the troposphere.National Science Foundation (U.S.) (Grant ATM-9910244)United States. National Aeronautics and Space Administration (Grant NAG1-2173

Introducing the atmospheric thermodynamics lidar in Space: ATLAS

International audienceOur understanding of the distribution of heat and water in the atmosphere still shows critical gaps on all temporal and spatial scales. This is mainly due to a lack of accurate measurements of water vapor and temperature profiles - hereafter called thermodynamic (TD) profiles - with high vertical and temporal resolution, especially in the lower troposphere. Accurate, high temporal-spatial resolution observations of TD profiles are essential for improving weather forecasting and re-analyses, for studying land-atmosphere feedback processes and for improving model parameterizations of land- surface and turbulent transport processes in the Atmospheric Boundary Layer. These observational gaps can be addressed with a new active remote sensing system in space based on the Raman lidar technique. Combining vibrational and rotational Raman backscatter signals, simultaneous measurements of water vapour and temperature profiles and a variety of derived variables are possible with unprecedented vertical and horizontal resolution, especially in the lower troposphere. This is the key concept of ATLAS, which was submitted in March 2018 to the European Space Agency in response to the Call for Earth Explorer-10 Mission Ideas in the frame of ESA EOEP. An assessment of the expected performance of the system and the specifications of the different lidar sub-systems has been performed based on the application of an analytical simulation model for space-borne Raman lidar systems. Results from the simulations and technical aspects of the proposed mission will be illustrated at the conference

Introducing the Atmospheric Thermodynamics LidAr in Space – ATLAS

Our understanding of the distribution of heat and water in the atmosphere still shows critical gaps on all temporal and spatial scales. This is mainly due to a lack of accurate measurements of water vapor and temperature profiles -hereafter called thermodynamic (TD) profiles -withhigh vertical and temporal resolution, especially in the lower troposphere. Accurate, high temporal-spatial resolution observations of TD profiles are essential for improving weather forecasting and re-analyses, for studying land-atmosphere feedback processes and for improving model parameterizations of land-surface and turbulent transport processes in the Atmospheric Boundary Layer. These observational gaps can be addressed with a new active remote sensing system in space based on the Raman lidar technique. Combining vibrational and rotational Raman backscatter signals, simultaneous measurements of water vapour and temperature profiles and a variety of derived variables are possible with unprecedented vertical and horizontal resolution, especially in the lower troposphere. This is the key concept of ATLAS, which was submitted in March 2018to the European Space Agency in response to the Call for Earth Explorer-10 Mission Ideas in the frame of ESAEOEP. An assessment of the expected performance of the systemand the specifications of the different lidar sub-systems has been performed based on the application ofan analytical simulation model for space-borne Raman lidar systems. Results from the simulations and technical aspects of the proposed mission will beillustrated at the conference.Peer Reviewe