Magnetospheric substorm research using VLF/ELF radiowave observations at Casey

Metadata record for data from ASAC Project 1324See the link below for public details on this project.---- Public Summary from Project ----Huge amounts of energy from the solar wind (the Suns expanding atmosphere), are stored in the magnetosphere (Earth's outer atmosphere), and released in geomagnetic storms that affect space and ground engineering systems (power systems, communications satellites, etc.). VLF radiowave observations at Casey will help us understand a fundamental sub-process: the substorm.From the project webpage:This project records very low frequency and extremely low frequency (300 Hz to 10 kHz) radio waves produced naturally in 'geospace' and received on the ground at high latitudes; the characteristics of these waves are used to study physical processes which occur in the magnetosphere, and in particular the substorm process. A VELOX (VLF/ELF Logger Experiment) instrument recording these fascinating waves has been operating at Halley Research Station, Antarctica, for several years. We are now in the process of setting up a global network of such systems --- VELOXnet. The substorm project is part of the British Antarctic Survey's research programme on Magnetic Reconnection, Substorms and their Consequence A local copy of this dataset is maintained at the Australian Antarctic Data Centre. The dataset contains all VELOX data collected at Casey (in the period 2001-2005) in binary format, plus a batch file and exe file for converting the data to ascii format. A copy of the data manual describing the data is also included.Taken from the 2008-2009 Progress Report:The objectives of the research are:The purpose of the project is to observe high energy radiation belt particles at low altitudes, using the VLF system operating at Casey. The software in this system will be enhanced to allow the detection of energetic particle precipitation events occurring in the region between Australia and Antarctica. This work will (1) form part of the WARP project undertaken by BAS during 2005-2010, (2) provide input into the Australian Antarctic Science Program - through the Space and Atmospheric Sciences program: solar variability and weather, (3) provide input into the Particle Precipitation Effects on the Middle Atmosphere project proposed by the University of Otago to the New Zealand Marsden Fund.With the VLF system in this configuration it will become part of the world-wide group of receivers looking at energetic precipitation events into the atmosphere. The network of receivers is known as Antarctic/Arctic Radiation-belt Dynamic Deposition VLF Atmospheric Research Kartell (AARDDVARK).This research continues the work of the project started in 2001, but includes some small, easily achieved adjustments of the system software (done via the internet link) to extend the scientific capability of the instrument. The research will include several new members of the scientific team: Prof Fred Menk, Dr Craig Rodger, and Dr Mark Cliverd.Progress against objectives:In the last 12 months (April 2008 to March 2009) the project has formed part of the WARP project undertaken by BAS during 2005-2010, and generated two publications for the AAD publications database. Taken from the 2009-2010 Progress Report:Progress against objectives:In the last 12 months the AARDVARK receiver at Casey has continued to operate and provide good quality data. No significant system issues have occurred. Work has been undertaken to compare energetic electron precipitation events observed by the AARDVARK network in 2009. The focus is on simultaneous events observed at Casey (AAD) and Scott Base (Antarctica New Zealand and Otago University, Dunedin, NZ). Additional supporting event data has come from the riometer located at Macquarie Island.Taken from the 2010-2011 Progress Report:Progress against objectives:The VLF system at Casey has run continuously throughout 2010/11. There have been no hardware, software, or data transfer issues. Despite the very low levels of solar variability and geomagnetic storms some examples of energetic electron precipitation events have been observed. In contrast to previous publications we have been able to analyse 2009 and 2010 events using radio wave phase measurements, following the successful upgrade of the system in Feb 2009. The event data are being combined with, and compared against, similar observations made from the New Zealand Scott Base, riometer absorption measurements from Macquarie Island, and THEMIS satellite observations. Detailed comparisons between ground-based and space-based instrumentation will provide new insight into the way energetic electrons are precipitated into the upper atmosphere. Publication of the results of this study are expected in 2011.

本元数据记录对应ASAC 1324号项目的数据集，项目公开详情请参阅下方链接。
—— 项目公开摘要 ——
太阳风（太阳扩张的大气层）携带的巨量能量会存储于磁层（地球外层大气）之中，并在地磁暴期间释放，进而对航天与地面工程系统（电力系统、通信卫星等）造成影响。在凯西站开展的甚低频（VLF）无线电观测，将助力我们理解亚暴这一基础物理过程。

项目网页内容如下：
本项目记录了在‘地球空间’中自然产生、并在高纬度地面接收的甚低频（VLF）与极低频（ELF，300 Hz至10 kHz）无线电波；通过分析这些电波的特征，可研究磁层内发生的物理过程，尤其是亚暴过程。一台用于记录这类电波的VELOX（甚低频/极低频记录实验）仪器，已在南极哈雷研究站运行多年。目前我们正着手搭建此类仪器的全球组网——VELOXnet。

亚暴项目是英国南极调查局（British Antarctic Survey, BAS）‘磁重联、亚暴及其影响’研究计划的组成部分。本数据集的本地副本由澳大利亚南极数据中心（Australian Antarctic Data Centre, AAD）托管。本数据集包含2001年至2005年在凯西站采集的所有VELOX二进制格式数据，以及用于将数据转换为ASCII格式的批处理文件与可执行（exe）文件。此外还附带了数据说明手册副本。

以下内容节选自2008-2009年度进展报告：
本研究的目标如下：本项目旨在借助凯西站的甚低频系统，观测低高度轨道的高能辐射带粒子。本项目将对系统软件进行升级，以实现对澳大利亚与南极之间区域内高能粒子沉降事件的探测。
此项研究工作将：(1) 纳入英国南极调查局（BAS）2005年至2010年实施的WARP项目；(2) 通过空间与大气科学项目（聚焦太阳变异性与天气）为澳大利亚南极科学计划提供支撑；(3) 为奥塔哥大学向新西兰马斯登基金申请的‘中层大气粒子沉降效应’项目提供数据输入。
该配置后的甚低频系统将加入全球观测大气高能粒子沉降事件的接收站网络。该接收站网络被称为南极/北极辐射带动态沉降甚低频大气研究联盟（Antarctic/Arctic Radiation-belt Dynamic Deposition VLF Atmospheric Research Kartell, AARDDVARK）。
本研究延续了2001年启动的项目工作，同时将通过远程互联对系统软件进行少量易于实现的调整，以拓展仪器的科研能力。本研究团队将新增3名成员：弗雷德·门克教授（Fred Menk）、克雷格·罗杰博士（Craig Rodger）以及马克·克利弗德博士（Mark Cliverd）。

目标完成进展：在2008年4月至2009年3月的12个月周期内，本项目作为英国南极调查局2005-2010年WARP项目的组成部分推进，并在澳大利亚南极数据中心（AAD）的出版物数据库中新增两篇刊发成果。

以下内容节选自2009-2010年度进展报告：
目标完成进展：在过去12个月中，凯西站的AARDDVARK接收站持续稳定运行并产出高质量数据，未出现重大系统故障。项目团队开展了针对2009年AARDDVARK网络观测到的高能电子沉降事件的对比分析工作，重点聚焦凯西站（AAD）与斯科特基地（新西兰南极考察队、奥塔哥大学，达尼丁，新西兰）观测到的同步事件。辅助事件数据来自麦夸里岛的电离层吸收计（riometer）。

以下内容节选自2010-2011年度进展报告：
目标完成进展：2010/2011财年期间，凯西站的甚低频系统始终持续运行，未出现硬件、软件或数据传输相关问题。尽管太阳变异性与地磁暴活动水平极低，项目团队仍观测到了多起高能电子沉降事件。得益于2009年2月完成的系统升级，本次研究可利用无线电波相位测量手段分析2009年与2010年的事件数据，这与此前的研究成果有所不同。目前团队正将事件数据与新西兰斯科特基地的同类观测、麦夸里岛的电离层吸收计测量数据以及THEMIS卫星观测数据进行整合与对比。地基与天基观测仪器的详细对比分析，将为高能电子沉降进入高层大气的机制提供全新认知。本研究成果预计将于2011年刊发。