The Middle Atmospheric Ozone Response to the 11-Year Solar Cycle

Because of its chemical and radiative properties, atmospheric ozone constitutes a key element of the Earth’s climate system. Absorption of sunlight by ozone in the ultraviolet wavelength range is responsible for stratospheric heating, and determines the temperature structure of the middle atmosphere. Changes in middle atmospheric ozone concentrations result in an altered radiative input to the troposphere and to the Earth’s surface, with implications on the energy balance and the chemical composition of the lower atmosphere. Although a wide range of ground- and satellite-based measurements of its integrated content and of its vertical distribution have been performed since several decades, a number of uncertainties still remain as to the response of middle atmospheric ozone to changes in solar irradiance over decadal time scales. This paper presents an overview of achieved findings, including a discussion of commonly applied data analysis methods and of their implication for the obtained results. We suggest that because it does not imply least-squares fitting of prescribed periodic or proxy data functions into the considered times series, time-domain analysis provides a more reliable method than multiple regression analysis for extracting decadal-scale signals from observational ozone datasets. Applied to decadal ground-based observations, time-domain analysis indicates an average middle atmospheric ozone increase of the order of 2% from solar minimum to solar maximum, which is in reasonable agreement with model results.     

Satellite Measurements of Middle Atmospheric Impacts by Solar Proton Events in Solar Cycle 23

Solar cycle 23 was extremely active with seven of the largest twelve solar proton events (SPEs) in the past forty years recorded. These events caused significant polar middle atmospheric changes that were observed by a number of satellites. The highly energetic protons produced ionizations, excitations, dissociations, and dissociative ionizations of the background constituents in the polar cap regions (>60 degrees geomagnetic latitude), which led to the production of HO_x (H, OH, HO₂) and NO_y (N, NO, NO₂, NO₃, N₂O₅, HNO₃, HO₂NO₂, BrONO₂, ClONO₂). The HO_x increases led to short-lived ozone decreases in the polar mesosphere and upper stratosphere due to the short lifetimes of the HO_x constituents. Polar middle mesospheric ozone decreases greater than 50 % were observed and computed to last for hours to days due to the enhanced HO_x. The NO_y increases led to long-lived polar stratospheric ozone changes because of the long lifetime of the NO_y family in this region. Upper stratospheric ozone decreases of >10 % were computed to last for several months past the solar events in the winter polar regions because of the enhanced NO_y.     

Validation of the operational IASI level 2 processor using AIRS and ECMWF data

The algorithms being implemented in EUMETSAT’s IASI Level 2 Product Processing Facility are validated with real case situations using AIRS data and comparing the retrieved atmospheric states with ECMWF analyses. The tests have been performed for clear-sky ocean scenes during daytime.

The Empirical Orthogonal Function (EOF) retrievals show very good performance, with retrieved atmospheric states standard deviations between 1 and 2 K in temperature and 10% and 20% in relative humidity when compared with ECMWF analysis in the troposphere. The EOF retrievals show relatively smooth profiles.

Results from an iterative retrieval show a standard deviation between 2 and 3 K in temperature and 10% and 30% in relative humidity when compared with ECMWF analyses in the troposphere. They tend to show meteorologically reasonable discontinuities in both temperature and relative humidity. This seems to be the reason why they do not compare as well with ECMWF analyses as the EOF retrievals do. Whether they are closer to reality or not will have to be tested with co-located radiosondes or similar more accurate data, which generally do not exhibit such smooth vertical profiles as ECMWF analyses do.     

卤代烷1211和1301灭火剂替代物的灭火机理,使用情况及评价标准

本文简要论述了卤代烷１２１１和１３０１灭火剂的灭火机理及对臭氧层的破坏机制，介绍了几种欧美广泛采用的卤代烷１２１１和１３０１替代物的性能，并提出了评价卤代烷１２１１和１３０１灭火剂替代物的指标体系。     

A model for calculating the vertical distribution of the atmospheric electric potential in the exchange layer in a maritime clean atmosphere

A theoretical model is developed for calculating the vertical distribution of atmospheric electric potential in exchange layer of maritime clean atmosphere. The transport of space charge in electrode layer acts as a convective generator in this model and plays a major role in determining potential distribution in vertical. Eddy diffusion is the main mechanism responsible for the distribution of space charge in vertical. Our results show that potential at a particular level increases with increase in the strength of eddy diffusion under similar conditions. A method is suggested to estimate columnar resistance, the ionospheric potential and the vertical atmospheric electric potential distribution in exchange layer from measurements of total air-earth current density and surface electric field made over oceans. The results are validated and found to be in very good agreement with the previous aircraft measurements. Different parameters involved in the proposed methodology can be determined either theoretically, as in the present work, or experimentally using the near surface atmospheric electrical measurements or using some other surface-based measurement technique such as LIDAR. A graphical relationship between the atmospheric eddy diffusion coefficient and height of exchange layer obtained from atmospheric electrical approach, is reported.     

The links between atmospheric vorticity,radiation belt electrons,and the solar wind

The links between winter storm intensity and solar wind variations associated with Heliospheric Current Sheet (HCS) crossings are shown to be present in 1997 through 2002 data without the necessity of high stratospheric aerosol loading.     

Improvement of the ADEOS-II/GLI sun-glint algorithm using concomitant microwave scatterometer-derived wind data

The tendency of over-estimation of sun-glint reflectance was found in GLI satellite ocean color data, after applying the traditional sun-glint model of Cox and Munk together with objective analysis wind data. ADEOS-II has provided a good opportunity to improve the glint model using data measured by GLI and SeaWinds, both onboard the satellite. With the help of simultaneous wind measurements achieved by SeaWinds, the Cox and Munk model is re-evaluated using GLI measurements to obtain a new relationship between the surface mean square slope and wind. The new model was found to be very close to the Cox and Munk under moderate wind speed but is much different under calm condition, where it shows similarity to the result reported by Ebuchi and Kizu. It also improves the ocean color data availability and the precision of sun-glint reflectance, based on the evaluation result of the generated Level 3 data products.     

基于FPGA的无人机气压高度测量系统的研究及实现

无人机由于轻巧灵活等特点,在现代战争探测中得到广泛应用。气压高度是控制无人机正常飞行的一个很重要的参数,它是保证无人机完成任务的关键所在。目前,常用的办法是通过测量大气静压来间接测量无人机高度。一个基于FPGA的无人机气压测高系统的实现,较之单片机实现,它具有抗干扰性强,工作稳定可靠等特点。     

空气中一甲肼监测的固体吸附/分光光度法

研究了用固体吸附和分光光度监测空气中一甲肼浓度的方法，试验了标准气、采样管、比色酸度范围、温度、光强和干扰气对测试结果的影响。结果表明：以研制成的固体采样管富集采样，用对二甲氨基苯甲醛作显色剂，在470nm波长，2cm光径的比色皿，采集100L气样时，方法最低检出浓度为0．0031mg／m3，平均变异系数0．036，平均相对误差5．5％，测量范围为0．010mg／m3～2．50mg／m3。     

高层大气模型对空间站轨道漂移和寿命的影响分析

本文以轨道摄动分析方法一阶理论为基础，其中大气阻力摄动采用数值积分方法，给出一种可利用各种大气模型进行轨道摄动分析的计算方法，并利用三种高层大气模型（ＣＩＲＡ—７２，ＣＩＲＡ—８６和ＤＴＭ）和三个太阳活动水平（Ｆ１０．７＝１００，１５０和２００）分析比较了大气阻力振动对高度为４００ｋｍ的空间站轨道漂移和寿命的影响，以及估算修正轨道漂移所需的能量。给出的定量分析结果将为空间站或航天飞行器的轨道设计和能量估算提供依据。