WE PROPOSE TO INVESTIGATE THE ENERGY BUDGET AND HEATING PROCESSES IN CMES AS THEY EXPAND FROM THE SOLAR SUR…

Assistance award details

Assistance award identifier

ASST_NON_80NSSC19K0853_080

FAIN

80NSSC19K0853

Recipient

SMITHSONIAN INSTITUTION

Awarding agency

National Aeronautics and Space Administration

Funding agency

National Aeronautics and Space Administration

Assistance listing (CFDA)

43.001

Total obligated

$605,361

Period

Jun 1, 2019 – May 31, 2022

Fiscal year

2019

Place of performance state

MA

Source file

FY2019_All_Assistance_Full_20261006.zip

Description

WE PROPOSE TO INVESTIGATE THE ENERGY BUDGET AND HEATING PROCESSES IN CMES AS THEY EXPAND FROM THE SOLAR SURFACE TO A FEW SOLAR RADII. WE HAVE SHOWN THAT THE ERUPTING GAS IS STRONGLY HEATED AS SEEN DRAMATICALLY WHEN PROMINENCE MATERIAL CHANGES FROM ABSORPTION TO EMISSION AS THE STRUCTURE RISES. THE INTEGRATED HEATING CAN BE COMPARABLE TO THE KINETIC ENERGY OF THE CME WHICH IN TURN IS COMPARABLE TO THE ENERGY EMITTED BY THE FLARE. IN SOME CASES THAT HEAT IS QUICKLY RADIATED AWAY AND THE GAS REMAINS COOL WHILE IN OTHERS THE GAS REACHES CORONAL OR FLARE TEMPERATURES. THAT HEATING HAS ONLY BEEN INVESTIGATED IN A HANDFUL OF EVENTS THUS FAR. UV SPECTRA FROM SOHO/UVCS COMBINED WITH TIME-DEPENDENT IONIZATION CALCULATIONS CONSTRAINED THE HEAT REQUIRED TO MATCH THE TEMPERATURE AND IONIZATION STATE. HINODE/EIS EUV SPECTRA DETERMINED THE RADIATIVE LOSSES WHICH DOMINATE OVER ADIABATIC EXPANSION AT HIGH DENSITIES. AND IONIZATION STATES MEASURED WITH ACE/SWICS WERE COMBINED WITH TIME-DEPENDENT IONIZATION CALCULATIONS TO SHOW THAT THE CONTINUED HEATING MUST BE COMPARABLE TO THE CME KINETIC ENERGY. POSSIBLE HEATING MECHANISMS INCLUDE HYDRODYNAMIC SHOCKS HEATING BY MHD WAVES AND THERMAL CONDUCTION BUT EACH HAS BEEN SHOWN TO BE INADEQUATE IN AT LEAST ONE CASE. THEREFORE THE THERMAL ENERGY PROBABLY COMES FROM THE MAGNETIC FREE ENERGY OF THE ERUPTING STRUCTURE. INDEED AN EXPANDING COMPLEX MAGNETIC STRUCTURE MUST DISSIPATE MAGNETIC ENERGY IN ORDER TO CONSERVE MAGNETIC HELICITY BUT THE PARTITION OF ENERGY AMONG KINETIC ENERGY THERMAL ENERGY AND ENERGETIC PARTICLES IS NOT KNOWN. MOREOVER IT IS NOT EVEN KNOWN WHETHER THE MAGNETIC ENERGY DISSIPATION THAT DOMINATES CME HEATING OCCURS IN THE CURRENT SHEET OR IN DISTRIBUTED REGIONS OF MHD TURBULENCE. WE PROPOSE TO USE UVCS AIA LASCO AND ACE/ULYSSES DATA TO DETERMINE THE HEATING RATES IN THE EXPANDING GAS. WE WILL EMPLOY METHODS WE HAVE PREVIOUSLY USED BUT WITH IMPORTANT EXTENSIONS. WE DO NOT EXPECT TO HAVE ALL THESE DATA SETS AND