Sigrid close boston university

Research Interests: Computational and theoretical space plasma physics; dynamics of the ionosphere and solar atmosphere; particle-wave interactions in plasmas; physics of meteor trails

Curriculum Vitae

Professor Oppenheim studies space plasma physics using supercomputer simulations, theory, and data. He works on a range of topics, including ionospheric and solar collisional plasmas, particle-wave interactions, and the physics of meteor trails. In , he has been working to incorporate the important effects of ionospheric turbulence into planetary scale simulations of the coupled magnetosphere, ionosphere and atmosphere. He has also been trying to model wave heating of the solar chromosphere. Most recently, he has also been working on understanding the effects of UV photoelectrons on the ionosphere and their observational consequences. Improving our understanding of these systems enables us to better characterize energy flows in the upper atmosphere.

For the la

•

News & Events

Wednesday, March 31,

Sigrid Close

Assistant Professor of Aeronautics and Astronautics
Stanford

From Dust to Asteroids: Impacts on Earth

Abstract: Since time began, impacts in our solar system have helped to define the evolution of our environment and in particular, life on Earth. In this presentation, we describe research on objects ranging in size from dust to large asteroids and comets with the goal of deriving fundamental properties about the parent object. These properties can then be used in order to mitigate future catastrophic impact events. In particular, we will discuss ground-based radar observations and modeling of dust plasma in order to understand how these particles interact with Earth's atmosphere and cause failures in spacecraft. We will also describe how ground-based data and modeling efforts are used to characterize larger objects, such as asteroids and comets, to derive composition and spin state. These preliminary results show that the

•

Sigrid Close: Star träffad

”A hundred billion,” says Sigrid Close. That's how many meteors collide with the Earth's atmosphere every day. Most are whittled away in the ionosphere, and Close spends her days studying exactly how they disintegrate. That's right: she gets paid to watch shooting stars.

Close fryst vatten the resident expert in ionospheric and near-Earth phenomena at Los Alamos National Laboratory in New Mexico. Her work regularly takes her to places like India, China, Puerto Rico, and the Marshall Islands, where she uses the most advanced space övervakning telescopes and radar to study the uppermost reaches of the atmosphere, some 85 kilometers above the Earth's surface.

Close's, and Los Alamos's, interest in shooting stars isn't purely academic. It turns out that meteors, as well as the ionosphere itself, störa radio signals. When meteors hit the atmosphere, they tend to melt into plasma plumes dense with heavy metals, sometimes causing big bu