Laboratory for Atmospheric and Space Physics (LASP)

The dynamics of Earth’s radiation belts remain one of the central challenges in space weather research. Despite decades of satellite observations, predicting when and how the belts will intensify or decay remains difficult. This seminar will discuss recent work combining multi-mission datasets from 36 multi-agency satellites to produce the highest-resolution phase space density (PSD) observations of the outer belt to date, and how these have been used to identify dominant acceleration and loss mechanisms.

Understanding the chemical composition of exoplanet atmospheres is key to identifying habitable worlds and potential biosignatures. Current instruments face challenges in detecting weak atmospheric signals from small-sized exoplanets due to telluric and stellar contamination, spectral overlap, and limited resolution.

We have entered a new era of studying the physics of planetary atmospheres. Powered by new facilities like the James Webb Space Telescope and upcoming 30-meter class telescopes, we can observe exoplanet atmospheres in exquisite detail for the first time. With these measurements, we can test our understanding of the physics and chemistry of atmospheres in exotic environments: heating planets up to thousands of degrees or placing them around stars with very different properties.

Solar irradiance variability models supplement the measurement record by extrapolating the observations to broader spectral range and longer time periods than directly observed. Version 1 of the NASA-NOAA-LASP (NNL) solar irradiance variability models are observation-based models that prescribe change in TSI and SSI based on change in solar magnetic activity features called faculae, that enhance solar irradiance at most wavelengths, and sunspots that reduce solar irradiance.

Mars lacks a global dipole magnetic field like Earth. As a result, the solar wind and interplanetary magnetic field (IMF) directly interact with its upper atmosphere, generating an induced magnetosphere and driving ion escape from the red planet. As a key atmospheric loss process, understanding ion escape is essential for studies of atmospheric evolution and the long-term climate history of Mars.

The evolutionary history, and likely habitability, of exoplanet atmospheres depends on the space weather of their host stars. Understanding the particle environment, including the wind density, magnetic field strength, and velocity field, impinging on exoplanet systems remains a significant open question. This unknown impacts the interpretation of exoplanet atmosphere observations and the ongoing search for biosignatures, with facilities like JWST.

The vicinity of small bodies such as the Moon and asteroids, as well as artificial satellites, forms a “plasma-solid boundary layer” where space plasma and solid surfaces come into direct contact without the mediation of a neutral atmosphere or magnetosphere. The importance of the research subject is being increasingly recognized along with the recent global surge in momentum for manned lunar exploration.

Io, the innermost Galilean satellite of Jupiter, is the most volcanically active body in the Solar System. Its atmosphere is primarily composed of SO₂, S, O, and SO, and is continuously bombarded by plasma from the Io torus at a relative velocity of ~ 60 km/s. As a result of this strong plasma–atmosphere interaction, Io constitutes a major source of neutrals for the Jovian magnetosphere, the ultimate source of its plasma and the main driver of its dynamics.

Many spectroscopic observations in astrophysics, planetary science, heliophysics, and earth science benefit from spatial mapping of some sort. In most cases, this requires slit-stepping a conventional long slit spectrograph or the use of a multi-object or integral-field spectrograph. The relatively low reflectivity of UV mirrors and poor transmission of most dielectrics severely restrict the design space of UV multi-object and integral field spectrographs (MOS and IFS, respectively).

Solar and stellar flares are explosive phenomena in which magnetic energy stored around starspots is suddenly released through magnetic reconnection. The radiation emitted during flares covers a broad range of wavelengths from radio to X-rays, each tracing different aspects of the flare process. In X-rays, the emission arises from hot thermal plasma heated by nonthermal electrons that travel upward from the chromosphere into the corona.