2001 ISTP Senior Review Proposals The 2001 ISTP Senior Review proposals, detailing science and operations plans for the next four years, are available. ISTP/GGS The ISTP Global Geospace Science (GGS) program consists of three spacecraft missions (Wind, Polar, and Geotail), coordinated ground observing investigations, and theory and modeling investigations. The current proposal spans solar maximum, characterized by powerful transient events and coronal mass ejections, and the approach to solar minimum, characterized by large transient equatorial holes. These latter structures are associated with long-lived, high velocity solar wind streams that produce recurrent geomagnetic storms and which somehow produce the largest fluxes of damaging MeV radiation belt electrons. We propose to take full advantage of the ISTP assets to accomplish the following general goals for the extended phase: We will extend the systems-science approach, describing the dynamic processes associated with the decline of the solar cycle. This will be based on observable quantities and be demonstrable through realistic physical 3D global models of the magnetosphere system. We will understand the dynamic processes associated with the equatorial region of 2-30 RE . We will quantify the relative influences that solar and terrestrial source plasmas have on dynamic equatorial processes. We will determine the equatorial storm plasma injection and loss as a function of solar input. And, we will understand the connection between radiation belt time variations and their direct connection with solar variability. We will investigate the global consequences of magnetic reconnection. We expect to gain an understanding of substorm onset and instability processes associated with the inner magnetosphere. We will establish which are the controlling reconnection processes and quantify their relative importance for system dynamics. Merging versus current disruption? Component versus antiparallel merging? Which are controllers, which act as regulators? Are the fundamental processes different on the dayside, the flanks and in the tail? We will quantify the 3-D structure and evolution of large-scale interplanetary configurations and their interaction with the magnetosphere. The evolution and dynamics of large scale interplanetary structures such as corotating interaction regions (CIRs), magnetic clouds, shocks, flux ropes, etc. will be characterized using new 3-point heliosphere configurations. download .pdf version of ISTP/GGS proposal ISTP/Cluster Cluster is a pioneering, unique, and exciting mission that for the first time in the history of space science has deployed advanced particle and fields experiments on four identical spacecraft. The four spacecraft orbit in a tetrahedral configuration of variable separation allowing separation of space and time as data are collected across plasma boundaries in geospace. Cluster is the culmination of a 15-year joint program between NASA and the European Space Agency to launch a suite of spacecraft designed to explore geospace in unprecedented detail. The high time resolution measurements made by Cluster provide the first clear view of structures in three dimensions, making Cluster the microscope of the International Solar-Terrestrial Physics Program. Cluster's unique capabilities include the ability to use VLBI techniques to determine the location, size, and motions of magnetospheric sources of radio and plasma waves. The wire booms of the Electric Fields and Waves experiment together with the Electron Drift Instrument provide, for the first time, the three vector components of the electric field. Cluster will study the dayside cusp, magnetopause and plasma sheet boundary layer. We will determine the spatial thickness and convective motion of the boundaries between these regions to ascertain the physical processes that lead to the transfer of mass, momentum, and energy across such boundaries. Cluster will probe the geomagnetic tail. Cluster will study the kinetic physics behind the large-scale reconfiguration of plasmas and electromagnetic fields associated with magnetospheric substorms. Cluster will determine how the tail plasma is energized and where it flows. During the summer of 2001, Cluster will move through the geomagnetic tail at 20 RE with a spacecraft separation of ~2000 km. The conjunction of Cluster with Polar, which will also be in the tail at 9 RE, in the vicinity of the Near Earth Neutral Line will be nearly ideal for studying the flow of energy before and during substorm onset. Cluster will help to determine the kinetic structure of interplanetary shocks and the Earth's bow shock. The three-dimensional capabilities enable us to determine the kinetic processes that give rise to these shocks. Cluster will study their spatial structure, how particles are accelerated, and how the observed plasma waves are generated. Cluster will study entry of solar wind plasma into the magnetosheath. The tetrahedral configuration of Cluster and the variable separation of the spacecraft will permit Cluster to study how solar wind particles gain entry into the magnetosheath and magnetosphere. Processes that can be investigated include direct entry through the polar cusp, reconnection, instabilities, boundary layer turbulence, and other processes occurring at the magnetopause. Cluster will investigate the origin of energetic particles in the magnetosphere. We will identify particle storage and acceleration regions and their relationships. Cluster will help to identify the injection mechanisms for different energetic charged particle species into the stable trapping regions during geophysical events. Cluster will study the equatorial magnetosphere. Cluster passes through the equatorial plane at both at apogee and perigee. In the plasmasphere and plasmapause regions Cluster data will characterize the source regions and spatial extents of whistler-mode plasma waves responsible for the acceleration and loss of energetic particles within and immediately outside this boundary, including chorus, plasmaspheric hiss, and lightning-generated whistlers. As Cluster moves through the near-Earth plasma sheet it will determine the shape and plasma flow characteristics of the plasma sheet boundary layer, including the how the boundary layer transitions into the central plasma sheet. Cluster will also study reconnection and particle acceleration processes in the near-Earth plasma sheet. Cluster will investigate the auroral zone. Cluster will determine the flow of plasma from and to the ionosphere during the perigee passes and will determine the spatial scales of acceleration processes occurring within the auroral zone. Cluster, in conjunction with ground-based experiments, will study the low- and mid-latitude projections of boundary field lines that map into the Earth1s auroral zone. download .pdf version of ISTP/Cluster proposal