NSWP: Equatorial Investigations in the Pacific Sector

NSWP：太平洋地区的赤道调查

• 批准号: 0720396
• 负责人: Roland Tsunoda
• 金额: --
• 依托单位: SRI International
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0720396&HistoricalAwards=false
• 关键词: NSWP; Equatorial; Investigations; Pacific; Sector

This project will address a priority goal of the National Space Weather Program, the need for able short-term forecasts of intense ionospheric irregularities in plasma density that develop in the nighttime equatorial F region (referred to as equatorial spread F, or ESF). Currently, ESF cannot be predicted on a day-to-day basis, even up to less than an hour before the expected first appearance of ESF. There is growing evidence that a key, though unheralded, player may be large-scale wave structure (LSWS) that develops in the bottomside F layer, whereas many previous efforts focused on the post-sunset rise of the F region at dusk. Recent research suggests that measurements of the velocity of the post-sunset rise may be contaminated by the large-scale wave structure, which may help explain why the control of ESF by the post-sunset rise, which holds climatologically, breaks down on a day-to-day basis. This project will investigate the relationships among the large scale wave structure, the post sunset rise, and ESF. The detection and characterization of the large scale wave structures require use of a radar with a steerable beam or sensors spaced closely in longitude. Currently, the only sensors of this kind are the multi-beam radars on the island of Pohnpei and Christmas Island as well as the steerable incoherent-scatter radar ALTAIR located in Kwajalein. The project will use the datasets to perform the following tasks: (1) Use three-beam radar data collected over seven years at Pohnpei, and two-beam radar data collected over four years at Christmas Island, to determine the presence of large scale wave structure and to extract the true post-sunset rise velocity; (2) Operate the recently reconfigured five-beam radar at Pohnpei in order to acquire data which will enable determination of the horizontal wavelength of the large scale wave structure; (3 ) Use all data collected by both radars, each spanning a full solar cycle, to determine short-term and long-term relationships among large scale wave structure, the post-sunset rise, and ESF. The proposed effort is expected to yield the first database with information on large scale waves structure, the post sunset rise, and ESF containing continuous measurements from two locations in the central Pacific sector that span a single, full solar cycle This database can be used for various investigations on time scales from a minute to a full single solar cycle and will be suitable for support of satellite programs such as CHAMP, ROCSAT, DMSP, TIMED, Formosat, and C/NOFS.

该项目将解决国家空间天气计划的一个优先目标，即需要能够对夜间赤道 F 区域（称为赤道扩散 F 或 ESF）中出现的等离子体密度的强烈电离层不规则性进行短期预报。 目前，ESF 无法每天进行预测，甚至在 ESF 首次出现前不到一个小时也是如此。 越来越多的证据表明，一个关键的因素（尽管未被预见）可能是底部 F 层中形成的大规模波浪结构（LSWS），而之前的许多研究都集中在黄昏时 F 区域的日落后上升。 最近的研究表明，日落后上升速度的测量可能受到大规模波浪结构的污染，这可能有助于解释为什么日落后上升对 ESF 的控制（在气候学上是成立的）在日常基础上会崩溃。 该项目将研究大规模波浪结构、日落后上升和 ESF 之间的关系。 大规模波浪结构的检测和表征需要使用具有可操纵波束的雷达或经度上紧密间隔的传感器。 目前，这种类型的传感器仅有波纳佩岛和圣诞岛的多波束雷达以及位于夸贾林岛的可操纵非相干散射雷达 ALTAIR。 该项目将利用这些数据集执行以下任务：（1）利用波纳佩岛七年来收集的三波束雷达数据和圣诞岛四年来收集的两波束雷达数据，确定是否存在大规模波浪结构并提取真实的日落后上升速度； (2) 操作最近在波纳佩重新配置的五波束雷达，以获取能够确定大规模波浪结构的水平波长的数据； (3) 使用两个雷达收集的所有数据（每个数据跨越一个完整的太阳周期）来确定大规模波浪结构、日落后上升和 ESF 之间的短期和长期关系。 拟议的工作预计将产生第一个包含大规模波浪结构、日落后升起和 ESF 信息的数据库，其中包含来自太平洋中部地区两个位置的连续测量，跨越单个完整的太阳周期。该数据库可用于从一分钟到完整的单个太阳周期的时间尺度上的各种调查，并将适用于支持卫星计划，例如 CHAMP、ROCSAT、DMSP、TIMED、Formosat 和 C/NOFS。