ASHOE/MAESA ER-2 Aircraft In-Situ Photolysis Rate Data

ASHOE-MAESA_jValue_AircraftInSitu_ER2_Data is the in-situ photolysis rate data for the ER-2 aircraft collected during the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA) suborbital campaign. Data collection for this product is complete.

The ASHOE/MAESA campaign was a multi-organizational effort of NASA, NOAA, and the US Natinal Science Foundation (NSF). The meteorological services of New Zealand, Australia, United Kingdom, and those signatory to the convection governing the European Centre for Medium – range Weather Forecasts (ECMWF) also aided in this mission. ASHOE/MAESA was conducted in four main deployments covering the period from January to November 1994. Its overarching goal was to investigate the causes of long-term reductions of ozone in the wintertime midlatitudes in the southern hemisphere, which had been observed for the last 15 years by ground-based instruments and satellites. ASHOE/MAESA had a secondary objective to obtain measurements for the assessment of the atmospheric effects of supersonic (High Speed Civil Transport) aircrafts.

In order to accomplish these objectives, the ASHOE/MAESA team used the NASA ER-2 aircraft alongside balloons, ground sites, and satellite imagery. A total of 45 flights were conducted, including 26 from Christchurch, New Zealand, 5 from Barber’s Point, Hawaii, and 6 transit flights between Christchurch, Fiji, Hawaii, and California. Some additional flights were flown from California, including surveys up to Alaska and Canada. Most of the flights were flown from Christchurch into the Southern high latitudes to probe the outer regions of the Southern polar vortex. Overall, the latitudinal extent of the ASHOE/MAESA flights was from 70S to 60N. The full payload was included on 32 of the flights, 11 carried the dynamics and radiation configuration, and 2 were test flights for individual instruments. The ER-2 was equipped with 20 instruments, including the Meteorological Measurement System (MMS), the NOAA NOy Instrument (NOAA NOy), Airborne Chromatograph For Atmospheric Trace Species (ACATS), the Airborne Tunable Laser Absorption Spectrometer (ATLAS), and the Wing Tip Air Particulate Sampler (APS). Some of the data collected by these instruments are as follows: temperature, NO, NO2, NOy, CH4, SF6, CHCl3, H2, O3, CO, SO4, and Black Carbon at various wavelengths. Ground sites collected various data on atmospheric temperature, pressure, and ozone mixing ratio. Balloon sondes collected data on atmospheric variables (temperature, pressure, wind direction, etc.). An early version of the Goddard Space Flight Center’s assimilation system was used to monitor meteorological patterns during ASHOE/MAESA to assist in planning the best flight paths. These data, along with satellite data, were used to give global context for local measurements of the ER-2.

ASHOE-MAESA_jValue_AircraftInSitu_ER2_Data 是搭载于ER-2侦察机的原位光解速率数据集，采集自「机载南半球臭氧实验/评估平流层飞行器影响测量（Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft，简称ASHOE/MAESA）」亚轨道观测任务。本产品的数据采集工作已全部完成。

ASHOE/MAESA任务由美国国家航空航天局（NASA）、美国国家海洋和大气管理局（NOAA）以及美国国家科学基金会（National Science Foundation，简称NSF）联合多机构开展。新西兰、澳大利亚、英国的气象服务部门，以及欧洲中期天气预报中心（European Centre for Medium-Range Weather Forecasts，简称ECMWF）的签约气象服务机构亦为本次任务提供了协助。ASHOE/MAESA共分为四个主要部署阶段，实施周期为1994年1月至11月。其核心目标是探究过去15年间由地面仪器与卫星观测到的、南半球冬季中纬度地区臭氧长期亏损的成因；次要目标则是获取测量数据，用于评估超音速（高速民用运输，High Speed Civil Transport）飞行器对大气的影响。

为达成上述目标，ASHOE/MAESA团队依托NASA ER-2侦察机，结合气球探测、地面观测站点与卫星影像开展工作。本次任务共完成45架次飞行，其中26架次从新西兰克赖斯特彻奇起飞、5架次从夏威夷巴伯斯角起飞，另有6架次往返于克赖斯特彻奇、斐济、夏威夷与加利福尼亚之间。另有部分额外飞行架次从加利福尼亚起飞，包括前往阿拉斯加与加拿大的勘测飞行。绝大多数飞行任务从克赖斯特彻奇出发，飞往南极高纬度区域，以探测南极极涡的外围区域。整体而言，ASHOE/MAESA飞行任务的纬度覆盖范围为南纬70度至北纬60度。其中32架次搭载了全套探测载荷，11架次搭载了动力学与辐射探测配置，另有2架次为单台仪器的测试飞行。ER-2侦察机搭载了20台探测仪器，包括气象测量系统（Meteorological Measurement System，简称MMS）、NOAA NOy探测仪、大气痕量物种机载色谱仪（Airborne Chromatograph For Atmospheric Trace Species，简称ACATS）、机载可调谐激光吸收光谱仪（Airborne Tunable Laser Absorption Spectrometer，简称ATLAS）以及翼尖空气颗粒物采样器（Wing Tip Air Particulate Sampler，简称APS）。这些仪器采集的部分数据包括：不同波长下的温度、一氧化氮（NO）、二氧化氮（NO₂）、总活性氮（NOy）、甲烷（CH₄）、六氟化硫（SF₆）、三氯甲烷（CHCl₃）、氢气（H₂）、臭氧（O₃）、一氧化碳（CO）、硫酸盐（SO₄）以及黑碳。地面观测站点采集了大气温度、气压与臭氧混合比等多类数据；气球探空仪则采集了大气变量（温度、气压、风向等）。任务期间，美国戈达德太空飞行中心早期版本的同化系统被用于监测气象模式，以协助规划最优飞行航线。这些数据与卫星数据一同为ER-2的原位测量提供了全球背景参考。