Jeffrey W. Brosius received his BA in Physics from Franklin and Marshall College in Lancaster, PA, in 1980, and his PhD in Physics from the University of Delaware through the Bartol Research Institute in Newark, DE, in 1985. He has been working in the Solar Physics Laboratory at GSFC since September 1985, employed by Raytheon ITSS (and its various predecessors) until February 2002, and by The Catholic University of America (CUA) ever since. In 2015 he took the role of Deputy PI of the CEPHEUS cooperative agreement between CUA and the Heliophysics Science Division (HSD), and in 2021 he became Deputy PI of the PHaSER cooperative agreement between CUA and HSD. Research interests include solar and stellar flares and transient phenomena, coronal heating, EUV & UV spectroscopy, solar coronal magnetography, nonthermal particle beams, magnetic field extrapolations, and cometary plasma tail phenomena. Brosius has extensive experience analyzing and interpreting observations from the ground (VLA, magnetographs) and from space (SERTS and EUNIS sounding rockets; IUE; SOHO's CDS, EIT, and MDI; TRACE; Yohkoh; RHESSI; Hinode's EIS; SDO's AIA; IRIS; Solar Orbiter's SPICE). He has coordinated numerous observing campaigns, and was a frequent planner of CDS science operations. He is a member of the AAS, SPD, AGU, and IAU.
Jeffrey W Brosius
(ASTROPHYSICIST)
| Email: | jeffrey.w.brosius@nasa.gov |
| Phone: | 301.286.6200 |
| Org Code: | 671 |
| Address: |
NASA/GSFC Mail Code 671 Greenbelt, MD 20771 |
| Employer: | CATHOLIC UNIV OF AMERICA |
Brief Bio
Education
Ph.D.: Physics, University of Delaware and Bartol Research Institute, Newark, DE (1985).
B.A.: Physics, Franklin and Marshall College, Lancaster, PA (1980).
Research Interests
Rapid Cadence EUV Stare Spectroscopy
As a pioneer of rapid cadence EUV stare spectroscopy, Brosius (2001) developed a rapid cadence flare stare study for SOHO’s CDS to detect nonthermal alpha particles during solar flares. Although no such beams were detected, rapid cadence CDS flare stare spectra (e.g., Brosius & Phillips 2004) confirmed theoretical calculations of chromospheric evaporation, and provided strong support for the standard flare model. In subsequent flare stare studies using Hinode/EIS, Brosius (2013) reported the activation of multiple strands in succession within a flaring loop. In further studies using EIS (Brosius, Daw, & Inglis 2016) and IRIS (Brosius & Inglis 2018), quasi-periodic episodes of chromospheric evaporation were attributed to quasi-periodic injections of nonthermal particle beams accelerated during bursty magnetic reconnection. With Solar Orbiter’s SPICE on line, interest in detecting nonthermal protons with rapid cadence EUV flare stare spectra has been rejuvenated (Kerr et al. 2023).
SERTS and EUNIS Sounding Rocket Programs
Since 1992 Dr. Brosius has analyzed and interpreted observations obtained during the 11 flights of the Solar EUV Research Telescope and Spectrograph (SERTS) and Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rockets that took place between 1991 and 2021. Results include spectral line catalogs and measurements of coronal properties such as density, DEM, and nonthermal turbulent velocity (e.g., Brosius et al. 1996; Brosius et al. 2000; Brosius 2024), coordination with the VLA to derive coronal magnetic fields (Brosius & White 2006), and evidence for coronal heating by nanoflares (Brosius et al. 2014). He frequently served as CDS Science Planner to coordinate campaigns with spacecraft and ground-based instruments, wrote and distributed an educational outreach booklet to promote public understanding of solar and stellar spectroscopy, and mentored DC public school teachers at Goddard.
Solar Coronal Heating
Compelling evidence of coronal heating by nanoflares is extensive, faint emission from plasma at flare-like temperatures such as that seen by EUNIS during its 2013 flight (Brosius et al. 2014). This work resulted in a NASA video (https://svs.gsfc.nasa.gov/11613) and press release (August 1, 2014), an article in Science News (by C. Crockett, May 30, 2015), a listing as the 14th top 100 science stories of 2015 in the Jan/Feb 2016 issue of Discover magazine, a Robert H. Goddard Award for Exceptional Achievement for Science in December 2014, and a NASA Agency Group Achievement Award in June 2015. The nanoflare model of coronal heating has also been (and continues to be) investigated using time lags detected in light curves among lines formed at different temperatures derived from rapid cadence stare spectra (Viall, Klimchuk, Chamberlin, & Brosius 2019).
Solar Coronal Magnetic Fields
Brosius developed SOHO JOP 100 to derive coronal magnetic fields based on coordinated measurements of thermal gyroemission obtained with the VLA, and of thermal bremsstrahlung derived from EUV line emission observed with CDS. One particularly exciting campaign featured a large AR sunspot at the west limb, in which Brosius & White (2006) derived field strengths of 1750 G at a height of 8000 km, and 960 G at 12,000 km.
Awards
NASA Agency Group Achievement Award to EUNIS sounding rocket team (June 2015).
Robert H. Goddard Award for Exceptional Achievement for Science to the EUNIS Science Team (December 2014).
NASA Group Achievement Award to the SDO Science Investigation Teams (August 2012).
NASA Agency Group Achievement Award to EUNIS sounding rocket team (April 2009).
Robert H. Goddard Award for Exceptional Achievement for Science to the EUNIS Science Team (September 2008).
John Kershner Scholar Award (May 1980).
The James Hale Steinman Foundation Scholarship (May 1976 - May 1980).
Publications
Refereed
2026. "Spatial variation of energy transport mechanisms within solar flare ribbons.", Nature Astronomy, [10.1038/s41550-025-02747-9] [Journal Article/Letter]
2023. "Prospects of Detecting Nonthermal Protons in Solar Flares via Lyman Line Spectroscopy: Revisiting the Orrall–Zirker Effect.", The Astrophysical Journal, 945 (2): 118 [10.3847/1538-4357/acb92a] [Journal Article/Letter]
2018. "Localized Quasi-periodic Fluctuations in C ii, Si iv, and Fe xxi Emission during Chromospheric Evaporation in a Flare Ribbon Observed by IRIS on 2017 September 9.", The Astrophysical Journal, 867 (2): 85 [10.3847/1538-4357/aae5f5] [Journal Article/Letter]
2016. "Quasi-Periodic Fluctuations and Chromospheric Evaporation in a Solar Flare Ribbon Observed by Hinode/EIS, IRIS, and RHESSI.", The Astrophysical Journal, 830 (2): 101 [10.3847/0004-637x/830/2/101] [Journal Article/Letter]
2014. "PERVASIVE FAINT Fe XIX EMISSION FROM A SOLAR ACTIVE REGION OBSERVED WITH EUNIS-13: EVIDENCE FOR NANOFLARE HEATING.", ASTROPHYSICAL JOURNAL, 790 [10.1088/0004-637X/790/2/112] [Journal Article/Letter]
2012. "CHROMOSPHERIC EVAPORATION IN SOLAR FLARE LOOP STRANDS OBSERVED WITH THE EXTREME-ULTRAVIOLET IMAGING SPECTROMETER ON BOARDHINODE.", The Astrophysical Journal, 762 (2): 133 [10.1088/0004-637x/762/2/133] [Journal Article/Letter]
2006. "Radio Measurements of the Height of Strong Coronal Magnetic Fields Above Sunspots at the Solar Limb.", The Astrophysical Journal, 641 (1): L69-L72 [10.1086/503774] [Journal Article/Letter]
2004. "Extreme‐Ultraviolet and X‐Ray Spectroscopy of a Solar Flare Loop Observed at High Time Resolution: A Case Study in Chromospheric Evaporation.", The Astrophysical Journal, 613 (1): 580-591 [10.1086/422873] [Journal Article/Letter]
2001. "Search for Evidence of Alpha‐Particle Beams during a Solar Flare Observed by the Coronal Diagnostic Spectrometer aboard theSolar and Heliospheric Observatory.", The Astrophysical Journal, 555 (1): 435-439 [10.1086/321438] [Journal Article/Letter]
2000. "Analysis of a Solar Active Region Extreme‐Ultraviolet Spectrum from SERTS‐97.", The Astrophysical Journal, 543 (2): 1016-1026 [10.1086/317153] [Journal Article/Letter]
1996. "Measuring Active and Quiet-Sun Coronal Plasma Properties with Extreme-Ultraviolet Spectra from SERTS.", The Astrophysical Journal Supplement Series, 106 143 [10.1086/192332] [Journal Article/Letter]