Janet Machol
Position
Senior Research Scientist
Department
Solar & Terrestrial Physics, NOAA National Centers for Environmental Information
Education
- PhD, Applied Physics, Cornell University, 1993
- BA, Physics and Mathematics, UC Berkeley
Contact
303.497.6686
Publications on the web
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Research Interests
- Improved ultraviolet and X-ray solar irradiance measurements
- Impacts of solar variability on the Earth's upper atmosphere
- Methods to retrieve exospheric density from solar observations
- Development of real-time auroral forecasts
Current Research
I lead our solar irradiance team which works on both the development, calibration and validation of solar irradiance data products for operational space weather and scientific uses as well as space weather research. In particular, our group focuses on measurements from the Extreme Ultraviolet and X-ray Irradiance Sensors (EXIS) aboard the NOAA GOES-R satellites as well as instruments aboard earlier GOES satellites. Scientific GOES data products are available here. I am also the CIRES lead for the NOAA NCEI space weather team.
Upper atmospheric density has major impacts on satellite operations due to satellite drag, but is not well measured. To help improve these measurements and understanding of this region, I lead a project to investigate a new method to determine exospheric hydrogen (H) density measurements from solar extreme ultraviolet observations and to examine the relationship between space weather and the H density distribution.
Prior to joining CIRES/NOAA NCEI, I worked in the CIRES/NOAA CSD atmospheric lidar group where I developed an automated tropospheric water vapor lidar. I also participated in the development and field deployments of other atmospheric lidars. My PhD work involved the development of femtosecond lasers and time-resolved studies of semiconductor nanocrystals.
Honors and Awards
- 2020 CIRES/ NOAA Administrator Award for GOES-R team (team award)
- 2019 GOES-R Program 'Unsung Hero' Award
- 2017 CIRES Gold Medal to match NASA Group Achievement Award (team award)
- 2016 NOAA/NCEI CCOG Team Member of the Year Award (team award)
- 2014 NOAA NGDC Customer Service Excellence Award (team award)
- 2013 US Department of Commerce Certificate of Appreciation (team award)
- 1995 National Research Council Postdoctoral Fellowship
View Publications
- Wauters L; Dominique M; Milligan R; Dammasch IE; Kretzschmar M; Machol J. (Mar 2022). Observation of a Flare and Filament Eruption in Lyman-$alpha $ on 8 September 2011 by the PRoject for OnBoard Autonomy/Large Yield Radiometer (PROBA2/LYRA). Solar Physics: a journal for solar and solar-stellar research and the study of solar terrestrial physics , 297(3). 10.1007/s11207-022-01963-0
- Lean JL; Coddington O; Marchenko S; Machol J; DeLand MT; Kopp G. (Aug 2020). Solar Irradiance Variability: Modeling the Measurements. Earth and Space Science , 7(8). 10.1029/2019EA000645
- Thiemann, EMB; Eparvier, FG; Woodraska, D; Chamberlin, PC; Machol, J; Eden, T; Jones, AR; Meisner, R; Mueller, S; Snow, M; Viereck, R; Woods, TN. (Dec 2019). The GOES-R EUVS model for EUV irradiance variability. JOURNAL OF SPACE WEATHER AND SPACE CLIMATE , 9. 10.1051/swsc/2019041
- Snow, M; Machol, J; Viereck, R; Woods, T; Weber, M; Woodraska, D; Elliott, J. (Nov 2019). A Revised Magnesium II Core-to-Wing Ratio From SORCE SOLSTICE. EARTH AND SPACE SCIENCE , 6(11). 10.1029/2019EA000652
- Machol, J., M. Snow, D. Woodraska, T. Woods, R. Viereck, and O. Coddington. (Jan 2019). An Improved Lyman-alpha Composite. , 6. 10.1029/2019EA000648
- Dominique, M, AN Zhukov, P Heinzel, IE Dammasch, L Wauters, L Dona, S Shestov, M Kretzschmar, J Machol, G Lapenta and W Schmutz. (Nov 2018). First Detection of Solar Flare Emission in Mid-ultraviolet Balmer Continuum. ASTROPHYSICAL JOURNAL LETTERS , 867(2). 10.3847/2041-8213/aaeace
- Chamberlin, PC, TN Woods, L Didkovsky, FG Eparvier, AR Jones, JL Machol, JP Mason, M Snow, EMB Thiemann, RA Viereck and DL Woodraska. (Oct 2018). Solar Ultraviolet Irradiance Observations of the Solar Flares During the intense September 2017 Storm Period. SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS , 16(10). 10.1029/2018SW001866
- Woods, TN, A Caspi, PC Chamberlin, A Jones, R Kohnert, JP Mason, CS Moore, S Palo, C Rouleau, SC Solomon, J Machol and R Viereck. (Feb 2017). New Solar Irradiance Measurements from the Miniature X-Ray Solar Spectrometer Cubesat. ASTROPHYSICAL JOURNAL , 835(2). 10.3847/1538-4357/835/2/122
- Suess, K, M Snow, R Viereck and J Machol. (Feb 2016). Solar Spectral Proxy Irradiance from GOES (SSPRING): a model for solar EUV irradiance. JOURNAL OF SPACE WEATHER AND SPACE CLIMATE , 6. 10.1051/swsc/2016003
- Snow, M, M Weber, J Machol, R Viereck and E Richard. (Jan 2014). Comparison of Magnesium II core-to-wing ratio observations during solar minimum 23/24. JOURNAL OF SPACE WEATHER AND SPACE CLIMATE , 4. 10.1051/swsc/2014001
- Machol, JL, AA Reinard, RA Viereck and DA Biesecker. (Jul 2013). Identification and replacement of proton-contaminated real-time ACE solar wind measurements. SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS , 11(7). 10.1002/swe.20070
- Machol, JL, JC Green, RJ Redmon, RA Viereck and PT Newell. (Mar 2012). Evaluation of OVATION Prime as a forecast model for visible aurorae. SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS , 10. 10.1029/2011SW000746
- Alvarez, RJ, CJ Senff, AO Langford, AM Weickmann, DC Law, JL Machol, DA Merritt, RD Marchbanks, SP Sandberg, WA Brewer, RM Hardesty and RM Banta. (Oct 2011). Development and Application of a Compact, Tunable, Solid-State Airborne Ozone Lidar System for Boundary Layer Profiling. JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY , 28(10). 10.1175/JTECH-D-10-05044.1
- Machol, JL, RD Marchbanks, CJ Senff, BJ McCarty, WL Eberhard, WA Brewer, RA Richter, RJ Alvarez, DC Law, AM Weickmann and SP Sandberg. (Jan 2009). Scanning tropospheric ozone and aerosol lidar with double-gated photomultipliers. APPLIED OPTICS , 48(3). 10.1364/AO.48.000512
- Machol JL; Ayers T; Schwenz KT; Koenig KW; Hardesty RM; Senff CJ; Krainak MA; Abshire JB; Bravo HE; Sandberg SP. (May 2006). Preliminary measurements with an automated compact differential absorption lidar for the profiling of water vapor: errata (vol 43, pg 3110, 2004). Applied Optics , 45(15), 3544-3544. 10.1364/AO.45.003544
- Machol, J.L., T. Ayers, K.T. Schwenz, K.W. Koenig, R.M. Hardesty, C.J. Senff, M.A. Krainak, J.B. Abshire, H.E. Bravo, and S.P. Sandberg. (May 2004). Preliminary measurements with an automated compact differential absorption lidar for the profiling of water vapor. Applied Optics , 43(15). 10.1364/AO.43.003110
- Machol, JL. (Aug 1997). Comparison of the pseudorandom noise code and pulsed direct-detection lidars for atmospheric probing. APPLIED OPTICS , 36(24). 10.1364/AO.36.006021
- MICIC OI; SPRAGUE JR; CURTIS CJ; JONES KM; MACHOL JL; NOZIK AJ; GIESSEN H; FLUEGEL B; MOHS G; PEYGHAMBARIAN N. (May 1995). SYNTHESIS AND CHARACTERIZATION OF INP, GAP, AND GAINP2 QUANTUM DOTS. The Journal of physical chemistry , 99(19). 10.1021/j100019a063
- MACHOL, JL, FW WISE, R PATEL and DB TANNER. (Jun 1994). OPTICAL STUDIES OF IV-VI QUANTUM DOTS. PHYSICA A , 207(1-3). 10.1016/0378-4371(94)90405-7
- MACHOL JL; WISE FW; PATEL RC; TANNER DB. (Jul 1993). VIBRONIC QUANTUM BEATS IN PBS MICROCRYSTALLITES. Physical Review B: Condensed Matter and Materials Physics , 48(4). 10.1103/PhysRevB.48.2819
- PROCTOR RB; MACHOL JL; WISE FW. (Feb 1992). TUNABLE ULTRAVIOLET FEMTOSECOND PULSES AT KILOHERTZ REPETITION RATES. Applied Optics , 31(6). 10.1364/AO.31.000836
