The RADICALS mission will help to address the following questions, which are aligned with the Space Strategy for Canada released by the Canadian government in 2019, and with the Canadian Solar-Terrestrial Science Roadmap of 2020:
- What plasma processes are responsible for the acceleration and loss of energetic particles in space environments?
- What are the physical processes that couple magnetospheres, ionospheres, and atmospheres?
- How are mass, energy, and momentum transported through space environments? What role does multiscale coupling play in space environment dynamics?
- What physical processes cause terrestrial and planetary aurora?
- How does the Sun affect space environments?
- What role do magnetic fields play in the evolution of planetary environments?
- How can we use the space environment as a laboratory?
- How does space weather affect GPS navigation and RF communication?
- How does space weather affect terrestrial weather and climate?
- How does space weather affect the operations of satellites in Earth orbit?
- Can we use our advancing fundamental knowledge of the space environment to improve our ability to predict space weather?
- How does space weather affect the safety and security of Canadians?
To accomplish these high-level objectives, the following specific science goals have been defined:
Energetic particle precipitation (EPP) characterization | What is the relative energetic electron input to the atmosphere at seed energies (~100 keV) and radiation belt energies (~1 MeV)? | Quantify the flux, energy spectrum and spatiotemporal extent of strong (e.g., bounce loss cone-filling) and weak (e.g., drift loss cone-filling) energetic electron precipitation. |
Quantify the contribution of microburst precipitation at seed and radiation belt energies to the overall precipitation budget. | ||
Quantify the rate of backscatter of electrons from the atmosphere at seed and radiation belt energies. | ||
What is the energetic proton input (~1-20 MeV) to the atmosphere from SEP events and from the inner radiation belt? | Quantify the flux, energy spectrum and spatiotemporal extent of strong and weak energetic proton precipitation from SEP events and inner zone protons. | |
Quantify the rate of backscatter of energetic protons from the atmosphere. |
Determining the causes of EPP | What are the dominant direct causes of energetic electron precipitation at seed energies (~100 keV) and radiation belt energies (~1 MeV)? | Determine the prevalence of energy-dependent energetic electron precipitation corresponding to EMIC and whistler-mode (e.g., chorus and hiss) scattering bands. |
Characterize the electromagnetic waves (ULF to VLF) during these energetic electron precipitation events, and in non-events. | ||
Assess the connection between the magnitude of the trapped flux and the rates of strong and weak energetic electron precipitation (cf. Kennel-Petschek) | ||
What are the dominant direct causes of energetic proton precipitation (10s-100s MeV)? | Assess the relationship of polar cap energetic proton precipitation to the occurrence of the SEP events | |
Evaluate the role of magnetic field variations in creating energetic proton precipitation at lower latitudes (e.g., below the magnetic rigidity cutoffs) | ||
Characterize the relationship between electromagnetic waves (ULF to VLF) and energetic proton precipitation from the inner belt |
Parameterization | How effectively can energetic particle precipitation be parameterized? | Evaluate parametrization of EPP flux, spectrum, and spatial extent based on continuously available data, for example ground-based, GEO, and solar wind data. |
Atmospheric Effects | What are the atmospheric effects resulting from energetic particle precipitation? | Assess the relative importance of energetic electron and energetic proton precipitation for NOx and HOx production in the thermosphere and stratosphere and their spatiotemporal scales. |
Assess the relative importance of lower and higher energy electron precipitation for NOx and HOx production in the thermosphere (indirect atmospheric effect) and stratosphere (direct atmospheric effect) and their spatiotemporal scales. |
Space Weather Effects | What are the impacts of space weather resulting from energetic particle precipitation? | Determine the characteristics of the precipitating solar protons that disturb radio frequency transmissions during polar-cap absorption (PCA) events. |
Determine the rates of outer zone radiation belt electron loss as a result of EPP during different geomagnetic conditions for application in radiation belt modeling. |