NSWP: Magnetotail State and Dynamics Under Strong Forcing

该项目将调查强烈的太阳风驱动对地球磁层的影响。强驱动产生了各种各样的响应，包括孤立的磁亚暴，磁注入事件和稳定的磁层对流（SMC）。这些响应模式与磁暴有关，磁暴在主相期间通常表现出频繁的亚暴，但有时没有亚暴，或简单激活，或随机亚暴，或亚暴序列。具体的响应模式很可能取决于太阳风的状态和/或磁层的状态。太阳风的突然波动有可能触发从一种模式向另一种模式的转变，本项目的主要目标是确定每种响应模式期间太阳风和磁层的状态。一个变量的瞬时状态由一个动态累积概率分布（cdf）表示，该分布是从集合阵列中计算出来的，其中事件以一个重要的基准时间为中心，例如风暴主相的开始或结束，或者一个特定响应模式的开始。在历元时间中跨阵列推进宽窗口，并且来自所有事件的数据用于计算cdf相对于参考时间的时间变化。太阳风或磁层的状态是由不同重要变量的cdfs等值线图的集合定义的。第二个目标是利用局部线性滤波器来表示太阳风和磁层活动的一般测量之间的耦合。这些滤波器的计算与一种新的技术，确定在一个广泛的时间窗口的中心的线性脉冲响应函数的合奏阵列。滤波器由作为历元时间的函数的响应函数的映射和诸如滤波器面积的时间序列表示。响应的系统性变化应明显表现为预测滤波器大小或形状的变化。第三个目标是确定太阳风触发因素在启动或结束特定响应模式方面的重要性。大量太阳风动态压力脉冲和行星际磁场变化将与磁层响应变化（如亚暴开始和磁层注入开始）相关联。结果将用联合和边际概率分布来描述，其触发延迟时间和相对于货币基金组织先前向南转向的起始延迟时间各不相同，这一项目将增进对磁层对太阳风变化的反应发生变化的物理过程的了解。 这些新的成果将通过创建时间相关的预测过滤器，在预期响应类型和数量方面提高空间气象预报的准确性。研究结果将为太阳风耦合数值模拟提供指导。该项目将提供一个机会，将美国加州大学洛杉矶分校和俄罗斯圣彼得堡州立大学两个主要研究小组的经验和数据资源联合收割机结合起来。彼得堡州立大学。 美国研究小组将对长时间序列进行统计分析，而俄罗斯研究小组将对具体事件进行详细研究。在加州大学洛杉矶分校，该项目将为一些年轻的研究科学家，研究生和本科生提供参与空间天气研究的机会。此外，该项目还将向空间物理学研究界提供将要建立的数据库。 这将使用NASA资助的虚拟磁层天文台来完成。

This project will investigate the effects of strong solar wind driving on Earth's magnetosphere. Strong driving produces a variety of responses including isolated magnetic substorms, sawtooth injection events, and steady magnetospheric convection (SMC). These response modes are associated with magnetic storms which usually exhibit frequent substorms during the main phase, but sometimes have no substorms, or simple activations, or random substorms, or substorm sequences. It is likely that the particular response mode depends on the state of solar wind and/or the state of the magnetosphere. It is possible that sudden fluctuations in the solar wind trigger a transition from one mode to another.The primary objective of this project is to define the state of the solar wind and the magnetosphere during each response mode. The instantaneous state of a variable is represented by a dynamic cumulative probability distribution (cdf) calculated from ensemble arrays with events as rows centered at a significant fiducial time such as the start or end of a storm main phase, or the beginning of a specific response mode. A broad window is advanced across the array in epoch time and data from all events are used to calculate the time variations in the cdf relative to the reference time. The state of the solar wind or magnetosphere is defined by a collection of contour maps of the cdfs for different important variables. A secondary objective is to represent the coupling between the solar wind and common measures of magnetospheric activity using local linear filters. These filters are calculated with a novel technique that determines the linear impulse response function at the center of a broad time window advanced across the ensemble arrays. The filters are represented by maps of the response function as a function of epoch time, and time series such as filter area. Systematic changes in the response should be evident as changes in the size or shape of the prediction filter. The third objective is to determine the importance of solar wind triggers in initiating or ending specific response modes. Large lists of solar wind dynamic pressure pulses and interplanetary magnetic field (IMF) changes will be associated with lists of magnetospheric response changes such as substorm onset and sawtooth injection onsets. Results will be portrayed by joint and marginal probability distributions with variable time delay of trigger and time delay of onset relative to preceding southward turning of the IMF.This project will advance understanding of the physical processes responsible for changes in the magnetosphere's response to changes in the solar wind. The new results will increase the accuracy of space weather forecasts in terms of the type of response expected and quantitatively through the creation of time dependent prediction filters. The results will provide guidance to numerical modelers of solar wind coupling. This project will provide an opportunity to combine the experience and data resources of two major research groups at UCLA in America and the St. Petersburg State University in Russia. The U.S. group will use statistical analysis of long time series while the Russian group will perform detailed studies of specific events. AT UCLA this project will provide an opportunity for several young research scientists, graduate students, and undergraduates to be involved in space weather research. Additionally, the project will make the database that will be created available to the space physics research community. This will be done using the NASA funded Virtual Magnetospheric Observatory.