CHAMOS

2023 (3)

Kalakoski, N., P.T. Verronen, M.E. Szeląg, and C.H. Jackman, Global ozone loss following extreme solar proton storms based on the July 2012 coronal mass ejection, Nature Sci. Rep., 13, 13873, 2023. DOI: 10.1038/s41598-023-40129-1

Chapman-Smith, K., A. Seppälä, C.J. Rodger, A. Hendy and C. Forsyth, Observed loss of polar mesospheric ozone following substorm-driven electron precipitation, Geophys. Res. Lett., 50, e2023GL104860, 2023. DOI: 10.1029/2023GL104860

Sarris T., Palmroth M.,... Clilverd M.,... Verronen, P.T., et al., Plasma-neutral interactions in the lower thermosphere-ionosphere: The need for in situ measurements to address focused questions, Front. Astron. Space Sci., 9:1063190, 2023. DOI: 10.3389/fspas.2022.1063190

2022 (7)

Nilsen, K., A. Kero, P.T. Verronen, M.E. Szeląg, First analysis of direct satellite-borne observations of ozone impact by the November 2001 solar proton event, J. Geophys. Res. Atmos., 127, e2022JD036904, 2022. DOI: 10.1029/2022JD036904

Szeląg, M.E., D.R. Marsh, P.T. Verronen, A. Seppälä, and N. Kalakoski, Ozone impact from solar energetic particles cools the polar stratosphere, Nature Commun., 13, 6883, 2022. DOI: 10.1038/s41467-022-34666-y

Lucilla Alfonsi, ..., Carl-Fredrik Enell, ..., Antti Kero, et al., Review of Environmental Monitoring by Means of Radio Waves in the Polar Regions: From Atmosphere to Geospace, Surv. Geophys., , 2022. DOI: 10.1007/s10712-022-09734-z

Baumann, C., Kero, A., Raizada, S., Rapp, M., Sulzer, M. P., Verronen, P. T., and Vierinen, J., Arecibo measurements of D-region electron densities during sunset and sunrise: implications for atmospheric composition, Ann. Geophys., 40, 519-530, 2022. DOI: 10.5194/angeo-40-519-2022

Bernhardt, P.A., M. Hua, J. Bortnik, Q. Ma, P.T. Verronen, M.P. McCarthy, D.L. Hampton, M. Golkowski, M.B. Cohen, D.K. Richardson, A.D. Howarth, H.G. James, and N.P. Meredith, Active Precipitation of Radiation Belt Electrons using Rocket Exhaust Driven Amplification (REDA) of Man-Made Whistlers, J. Geophys. Res. Space, 127, e2022JA030358, 2022. DOI: 10.1029/2022JA030358

Thomas, N., Kero, A., Miyoshi, Y., Shiokawa, K., Hyötylä, M., Raita, T., et al., Statistical survey of Arase satellite data sets in conjunction with the Finnish riometer network, J. Geophys. Res. Space, 127, e2022JA030271, 2022. DOI: 10.1029/2022JA030271

Newnham, D.A., M.A. Clilverd, W.D.J. Clark, P.T. Verronen, and A.E.E. Rogers, Ground-based Ku-band microwave observations of ozone in the polar middle atmosphere, Atmos. Meas. Tech., 15, 2361-2376, 2022. DOI: 10.5194/amt-15-2361-2022

2021 (9)

Sinnhuber, M., H. Nesse Tyssøy, T. Asikainen, S. Bender, B. Funke, K. Hendrickx, J. Pettit, T. Reddmann, E. Rozanov, H. Schmidt, C. Smith-Johnsen, T. Sukhodolov, M.E. Szeląg, M. van de Kamp, P.T. Verronen, J.M. Wissing, O.S. Yakovchuk, Heppa III intercomparison experiment on medium-energy electrons, part II: Model-measurement intercomparison of nitric oxide (NO) during a geomagnetic storm in April 2010, J. Geophys. Res. Space, 127, e2021JA029466, 2021. DOI: 10.1029/2021JA029466

Hendry, A.T., A. Seppälä, C.J. Rodger, and M.A. Clilverd, Impact of EMIC-wave driven electron precipitation on the radiation belts and the atmosphere, J. Geophys. Res., 126, e2020JA028671, 2021. DOI: 10.1029/2020JA028671

Gordon, E.M., A. Seppälä, B. Funke, J. Tamminen, and K.A. Walker, Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss, Atmos. Chem. Phys., 21, 2819-2836, 2021. DOI: 10.5194/acp-21-2819-2021

Nesse Tyssøy, H., M. Sinnhuber, T. Asikainen, S. Bender, M.A. Clilverd, B. Funke, M. van de Kamp, J.M. Pettit, C.E. Randall, T. Reddmann, C.J. Rodger, E. Rozanov, C. Smith-Johnsen, T. Sukhodolov, P.T. Verronen, J.M. Wissing, O. Yakovchuk, HEPPA III intercom- parison experiment on medium-energy electrons, part I: Estimated ionization rates during a geomagnetic active period in April 2010, J. Geophys. Res. Space, 127, e2021JA029128, 2021. DOI: 10.1029/2021JA029128

Verronen, P. T., Kero, A., Partamies, N., Szeląg, M. E., Oyama, S.-I., Miyoshi, Y., and Turunen, E., Simulated seasonal impact on middle atmospheric ozone from high-energy electron precipitation related to pulsating aurorae, Ann. Geophys., 39, 883-897, 2021. DOI: 10.5194/angeo-39-883-2021

Nilsen, K., A. Kero, P.T. Verronen, M.E. Szeląg, N. Kalakoski, J. Jia, Sensitivity of middle atmospheric ozone to solar proton events: A comparison between a climate model and satellites, J. Geophys. Res. Atmos., 126, e2021JD034549, 2021. DOI: 10.1029/2021JD034549

Guttu, S., Y. Orsolini, F. Stordal, O.H. Otterå, N.-E. Omrani, N. Tartaglione, P.T. Verronen, C.J. Rodger, M.A. Clilverd, Impacts of UV Irradiance and Medium-Energy Electron Precipitation on the North Atlantic Oscillation during the 11-year solar cycle, Atmosphere, 12, 1029, 2021. DOI: 10.3390/atmos12081029

Miyoshi, Y., K. Hosokawa, S. Kurita, S.-I. Oyama, Y. Ogawa, S. Saito, I. Shinohara, A. Kero, E. Turunen, P.T. Verronen, S. Kasahara, S. Yokota, T. Mitani, T. Takashima, N. Higashio, Y. Kasahara, S. Matsuda, F. Tsuchiya, A. Kumamoto, A. Matsuoka, T. Hori, K. Keika, M. Shoji, M. Teramoto, S. Imajo, C. Jun, and S. Nakamura, Penetration of MeV electrons into the mesosphere accompanying pulsating aurorae, Nature Sci. Rep., 11, 13724, 2021. DOI: 10.1038/s41598-021-92611-3

Palmroth, M., Grandin, M., Sarris, T., Doornbos, E., Tourgaidis, S., Aikio, A., Buchert, S., Clilverd, M.A., Dandouras, I., Heelis, R., Hoffmann, A., Ivchenko, N., Kervalishvili, G., Knud- sen, D.J., Kotova, A., Liu, H.-L., Malaspina, D.M., March, G., Marchaudon, A., Marghitu, O., Matsuo, T., Miloch, W.J., Moretto-Jorgensen, T., Mpaloukidis, D., Olsen, N., Papadakis, K., Pfaff, R., Pirnaris, P., Siemes, C., Stolle, C., Suni, J., van den IJssel, J., Verronen, P.T., Visser, P., and Yamauchi, M., Lower thermosphere-ionosphere (LTI) quantities: Current status of measuring techniques and models, Ann. Geophys., 39, 189-237, 2021. DOI: 10.5194/angeo-2020-42

2020 (8)

Häkkilä, T., P.T. Verronen, L. Millan, M.E. Szeląg, and N. Kalakoski, and A. Kero, Odd hydrogen response thresholds for indication of solar proton and electron impact in the mesosphere and stratosphere, Ann. Geophys., 38, 1299-1312, 2020. DOI: 10.5194/angeo-38-1299-2020

Jia, J., A. Kero, N. Kalakoski, M.E. Szeląg, and P.T. Verronen, Is there a direct solar proton impact on lower stratospheric ozone?, Atmos. Chem. Phys., 20, 14969-14982, 2020. DOI: 10.5194/acp-20-14969-2020

Gordon, E.M., A. Seppälä, and J. Tamminen, Evidence for energetic particle precipitation and quasi-biennial oscillation modulations of the Antarctic NO2 springtime stratospheric column from OMI observations, Atmos. Chem. Phys., 20, 6259-6271, 2020. DOI: 10.5194/acp-20-6259-2020

Tesema, F., Partamies, N., Nesse Tyssoy, H., Kero, A., and Smith-Johnsen, C., Observations of electron precipitation during pulsating aurora and its chemical impact, J. Geophys. Res. Space, 125, e2019JA027713, 2020. DOI: 10.1029/2019JA027713

Kalakoski, N., P.T. Verronen, A. Seppälä, M.E. Szeląg, A. Kero, and D.R. Marsh, Statistical response of middle atmosphere composition to solar proton events in WACCM-D simulations: importance of lower ionospheric chemistry, Atmos. Chem. Phys., 20, 8923-8938, 2020. DOI: 10.5194/acp-20-8923-2020

Verronen, P.T., D.R. Marsh, M.E. Szeląg, and N. Kalakoski, Magnetic-local-time dependency of radiation belt electron precipitation: impact on ozone in the polar middle atmosphere, Ann. Geophys., 38, 833-844, 2020. DOI: 10.5194/angeo-38-833-2020

Clilverd, M.A., C.J. Rodger, M. van de Kamp, and P.T. Verronen, Electron precipitation from the outer radiation belt during the St Patricks Day storm 2015: Observations, modelling, and validation, J. Geophys. Res. Space, 125, e2019JA027725, 2020. DOI: 10.1029/2019JA027725

Palmroth, M., M. Grandin, M. Helin, P. Koski, A. Oksanen, M. A. Glad, R. Valonen, K. Saari, E. Bruus, J. Norberg, A. Viljanen, K. Kauristie, and P.T. Verronen, Citizen scientists discover a new auroral form: Dunes provide insight into the upper atmosphere, AGU Advances, 1, e2019AV000133, 2020. DOI: 10.1029/2019AV000133

2019 (2)

Newnham, D.A., Clilverd, M.A., Kosch, M., Seppälä, A., and Verronen, P.T., Simulation study for ground-based Ku-band microwave observations of ozone and hydroxyl in the polar middle atmosphere, Atmos. Meas. Tech., 12, 1375-1392, 2019. DOI: 10.5194/amt-12-1375-2019

Heino, E., P.T. Verronen, A. Kero, N. Kalakoski, and N. Partamies, Cosmic Noise Absorption During Solar Proton Events in WACCM-D and Riometer Observations, J. Geophys. Res. Space, 124, 1361-1376, 2019. DOI: 10.1029/2018JA026192

2018 (6)

Oyama, S., T. T. Tsuda, K. Hosokawa, Y. Ogawa, Y. Miyoshi, S. Kurita, A. E. Kero, R. Fujii, Y. Tanaka, A. Mizuno, T. Kawabata, B. Gustavsson and T. Leyser, Auroral molecular-emission effects on the atomic oxygen line at 777.4 nm, Earth, Planets and Space, 70:166, 2018. DOI: 10.1186/s40623-018-0936-z

van de Kamp, M., Rodger, C.J., Seppälä, A., Clilverd, M.A., and Verronen, P.T., An updated model providing long-term datasets of energetic electron precipitation, including zonal dependence, J. Geophys. Res. Atmos., 123, 9891-9915, 2018. DOI: 10.1029/2017JD028253

Newnham, D.A., M.A. Clilverd, C.J. Rodger, K. Hendrickx, L. Megner, A.J. Kavanagh, A. Seppälä, P.T. Verronen, M.E. Andersson, D.R. Marsh, T. Kovacs, W. Feng, and J.M.C. Plane, Observations and modelling of increased nitric oxide in the Antarctic polar middle atmosphere associated with geomagnetic storm driven energetic electron precipitation, J. Geophys. Res. Space, 123, 6009-6025, 2018. DOI: 10.1029/2018JA025507

Orsolini, Y.J., C. Smith-Johnsen, D.R. Marsh, F. Stordal, C.J. Rodger, P.T. Verronen, and M.A. Clilverd, Mesospheric nitric acid enhancements during energetic electron precipitation events simulated by WACCM-D, J. Geophys. Res. Atmos., 123, 6984-6998, 2018. DOI: 10.1029/2017JD028211

Andersson, M.E., P.T. Verronen, D.R. Marsh, A. Seppälä, S.-M. Päivärinta, C.J. Rodger, M.A. Clilverd, N. Kalakoski, M. van de Kamp, Polar ozone response to energetic particle precipitation over decadal time scales: the role of medium-energy electrons, J. Geophys. Res. Atmos., 123, 607-622, 2018. DOI: 10.1002/2017JD027605

Seppälä, A., E. Douma, C.J. Rodger, P.T. Verronen, M.A. Clilverd, and J. Bortnik, Electron microburst events: modeling the atmospheric impact, Geophys. Res. Lett., 45, 2018. DOI: 10.1002/2017GL075949

2017 (5)

Denton, M. H., R. Kivi, Th. Ulich, C. J. Rodger, M. A. Clilverd, R. B. Horne, and A. J. Kavanagh, Solar proton events and stratospheric ozone depletion over Northern Finland, J. Atmos. Sol. Terr. Phys., in press, 2017. DOI: 10.1016/j.jastp.2017.07.003

Grandin, M., A. Kero, N. Partamies, D. McKay, D. Whiter, A. Kozlovsky, and Y. Miyoshi, Observation of pulsating aurora signatures in cosmic noise absorption data, Geophys. Res. Lett., 44, 5292-5300, 2017. DOI: 10.1002/2017GL073901

Oyama, S., Kero, A., Rodger, C.J., Clilverd, M.A., Miyoshi, Y., Partamies, N., Turunen, E., Raita, T., Verronen, P.T. and Saito, S., Energetic electron precipitation and auroral morphology at the substorm recovery phase, J. Geophys. Res. Space Phys., 122, 2017. DOI: 10.1002/2016JA023484

Matthes, K., Funke, B., Andersson, M.E., Barnard, L., Beer, J., Charbonneau, P., Clilverd, M.A., Dudok de Wit, T., Haberreiter, M., Hendry, A., Jackman, C.H., Kretschmar, M., Kruschke, T., Kunze, M., Langematz, U., Marsh, D.R., Maycock, A., Misios, S., Rodger, C.J., Scaife, A., Seppälä, A., Shangguan, M., Sinnhuber, M., Tourpali, K., Usoskin, I., van de Kamp, M., Verronen, P.T. and Versick, S., Solar Forcing for CMIP6, Geosci. Model Dev., 10, 2247-2302, 2017. DOI: 10.5194/gmd-10-2247-2017

Funke, B., Ball, W., Bender, S., Gardini, A., Harvey, V.L., Lambert, A., Lopez-Puertas, M., Marsh, D.R., Meraner, K., Nieder, H., Päivärinta, S.-M., P ́erot, K., Randall, C.E., Reddmann, T., Rozanov, E., Schmidt, H., Seppälä, A., Sinnhuber, M., Sukhodolov, T., Stiller, G.P., Tsvetkova, N.D., Verronen, P.T., Versick, S., von Clarmann, T., Walker, K.A., and Yushkov, V., HEPPA-II model-measurement intercomparison project: EPP indirect effects during the dynamically perturbed NH winter 2008-2009, Atmos. Chem. Phys., 17, 3573-3604, 2017. DOI: 10.5194/acp-17-3573-2017

2016 (4)

Rogers, N.C., Kero, A., Honary, F., Verronen, P.T., Warrington, E.M. and Danskin, D.W., Improving the twilight model for polar cap absorption nowcasts, Space Weather, 14, 950-972, 2016. DOI: 10.1002/2016SW001527

van de Kamp, M., A. Seppälä, M.A. Clilverd, C.J. Rodger, P.T. Verronen, and I.C. Whittaker, A model providing long-term datasets of energetic electron precipitation during geomagnetic storms, J. Geophys. Res. Atmos., 121, 12520-12540, 2016. DOI: 10.1002/2015JD024212

Turunen, E., Kero, A., Verronen, P.T., Miyoshi, Y., Oyama, S. and Saito, S., Mesospheric ozone destruction by high-energy electron precipitation associated with pulsating aurora, J. Geophys. Res. Atmos., 121, 11852-11861, 2016. DOI: 10.1002/2016JD025015

Clilverd, M.A., C. J. Rodger, M. E. Andersson, P. T. Verronen, and A. Seppälä, Linkages between the radiation belts, polar atmosphere and climate: electron precipitation through wave particle interactions, chapter in Waves, Particles and Storms in Geospace, edited by G. Balasis, I. A. Daglis, and I. R. Mann, Oxford University Press, ISBN: 9780198705246, 2016.

2015 (7)

Verronen, P. T. and C. J. Rodger, Atmospheric ionization by energetic particle precipitation, in Earth's climate response to a changing Sun, edited by T. Dudok de Wit et al., EDP Sciences (www.edpsciences.org), ISBN: 978-2-7598-1733-7, 2015.

Baumann, C., M. Rapp, M. Anttila, A. Kero, and P. T. Verronen, Effects of meteoric smoke particles on the D-region ion-chemistry, J. Geophys. Res., 120, 2015. DOI: 10.1002/2015JA021927

Clilverd, M. A., R. Duthie, R. Hardman, A. T. Hendry, C. J. Rodger, T. Raita, M. Engebretson, M. R. Lessard, D. Danskin, and D. K. Milling, Electron precipitation from EMIC waves: a case study from 31 May 2013, J. Geophys. Res., 120, 3618-3631, 2015. DOI: 10.1002/2015JA021090

Neal, J. J., C. J. Rodger, M. A. Clilverd, N. R. Thomson, T. Raita, and Th. Ulich, Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations, J. Geophys. Res., 120, 2194-2211, 2015. DOI: 10.1002/2014JA020689

Seppälä, A., M. A. Clilverd, M. J. Beharrell, C. J. Rodger, P. T. Verronen, M. E. Andersson and D. A. Newnham, Substorm-induced energetic electron precipitation: Impact on atmospheric chemistry, Geophys. Res. Lett., 42, 2015. DOI: 10.1002/2015GL065523

Miyoshi, Y., S. Oyama, S. Saito, S. Kurita, H. Fujiwara, R. Kataoka, Y. Ebihara, C. Kletzing, G. Reeves, O. Santolik, M. Clilverd, C. J. Rodger, E. Turunen, and F. Tsuchiya, Energetic electron precipitation associated with pulsating aurora: EISCAT and Van Allen Probe observations, J. Geophys. Res. Space Physics, 120, 2015. DOI: 10.1002/2014JA020690

Verronen, P.T., Andersson, M.E., Kero, A., Enell, C.-F., Wissing, J.M., Talaat, E.R., Kauristie, K., Palmroth, M., Sarris, T.E. and Armandillo, E., Contribution of proton and electron precipitation to the observed electron concentration in October-November 2003 and September 2005, Ann. Geophys., 33, 381-394, 2015. DOI: 10.5194/angeo-33-381-2015

2014 (5)

Andersson, M.E., Verronen, P.T., Rodger, C.J., Clilverd M.A., and Seppälä A., Missing driver in the Sun-Earth connection from energetic electron precipitation impacts mesospheric ozone, Nature Commun., 5:5197, 2014. DOI: 10.1038/ncomms6197

Seppälä A. and Clilverd M.A., Energetic particle forcing of the Northern Hemisphere winter stratosphere: comparison to solar irradiance forcing, Front. Physics, 2:25, 2014. DOI: 10.3389/fphy.2014.00025

Kero, A., J. Vierinen, D. McKay-Bukowski, C.-F. Enell, M. Sinor, L. Roininen, and Y. Ogawa, Ionospheric electron density profiles inverted from a spectral riometer measurement, Geophys. Res. Lett., 41, 2014. DOI: 10.1002/2014GL060986

Andersson, M.E., Verronen, P.T., Rodger, C.J., Clilverd, M.A., and Wang S., Longitudinal hotspots in the mesospheric OH variations due to energetic electron precipitation, Atmos. Chem. Phys., 14, 1095-1105, 2014. DOI: 10.5194/acp-14-1095-2014

Arnone, E., A. K. Smith, C.-F. Enell, A. Kero, and B. M. Dinelli, WACCM climate chemistry sensitivity to sprite perturbations, J. Geophys. Res. Atmos., 119, 6958-6970, 2014. DOI: 10.1002/2013JD020825

2013 (6)

Baumann, C., Rapp, M., Kero, A., and Enell, C.-F., Meteor smoke influences on the D-region charge balance - review of recent in situ measurements and one-dimensional model results, Ann. Geophys., 31, 2049-2062, 2013. DOI: 10.5194/angeo-31-2049-2013

Seppälä, A., H. Lu, M. A. Clilverd, and C. J. Rodger, Geomagnetic activity signatures in wintertime stratosphere wind, temperature, and wave response, J. Geophys. Res., 118, 2169-2183, 2013. DOI: 10.1002/jgrd.50236

Verronen, P.T., Andersson, M.E., Rodger, C.J., Clilverd, M.A., Wang S., and Turunen, E., Comparison of modeled and observed effects of radiation belt electron precipitation on mesospheric hydroxyl and ozone, J. Geophys. Res., 118, 11419-11428, 2013. DOI: 10.1002/jgrd.50845

Cresswell-Moorcock, K., C. J. Rodger, A. Kero, A. B. Collier, M. A. Clilverd, I. Häggström, and T. Pitkänen, A reexamination of latitudinal limits of substorm-produced energetic electron precipitation, J. Geophys. Res., 118, 2013. DOI: 10.1002/jgra.50598

Newnham D. A., P. J. Espy, M. A. Clilverd, C. J. Rodger, A. Seppälä, D. J. Maxfield, P. Hartogh, K. Holmen, and R. B. Horne, Observations of nitric oxide in the Antarctic middle atmosphere during recurrent geomagnetic storms, J. Geophys. Res., 118, 2013. DOI: 10.1002/2013JA019056

Päivärinta, S.-M., Seppälä, A., Andersson, M., Verronen, P. T., Thölix, L., and Kyrölä, E., Observed effects of solar proton events and sudden stratospheric warmings on odd nitrogen and ozone in the polar middle atmosphere, J. Geophys. Res., 118, 6837-6848, 2013. DOI: 10.1002/jgrd.50486

2012 (3)

Andersson, M. E., Verronen, P. T., Wang S., Rodger, C. J., Clilverd, M. A., and Carson, B. R., Precipitating radiation belt electrons and enhancements of mesospheric hydroxyl during 2004-2009, J. Geophys. Res., 117, D09304, 2012. DOI: 10.1029/2011JD017246

Rodger, C. J., Clilverd, M. A., Kavanagh, A. J., Watt, C. E. J., Verronen, P. T. and Raita, T., Contrasting the responses of three different ground-based instruments to energetic electron precipitation,, Radio Sci., 47, RS2021, 2012. DOI: 10.1029/2011RS004971

Clilverd, M. A., Rodger, C. J., Rae, I. J., Brundell, J. B., Thomson, N. R., Cobbett, N., Verronen, P. T., Menk, F. W., Combined THEMIS and ground-based observations of a pair of substorm-associated electron precipitation events, J. Geophys. Res., 117(A2), A02313, 2012. DOI: 10.1029/2011JA016933

2011 (5)

C.-F. Enell, B. Gustavsson, B. U. E. Brändström, T. Sergienko, P. T. Verronen, P. Rydesäter, and I. Sandahl, Tomography-like retrieval of auroral volume emission ratios for the 20080131 Hotel Payload 2 event, Geosci. Instrum. Method. Data Syst. Discuss., 2, 1-21, 2011. DOI: 10.5194/gid-2-1-2012

Salmi, S.-M., Verronen, P. T., Thölix, L., Kyrölä, E., Backman, L., Karpechko, A. Yu., and Seppälä, A., Mesosphere-to-stratosphere descent of odd nitrogen in February-March 2009 after sudden stratospheric warming, Atmos. Chem. Phys., 11, 4645-4655, 2011. DOI: 10.5194/acp-11-4645-2011

Baumgaertner, A. J. G., Seppälä, A., Jöckel, P., and Clilverd, M.A., Geomagnetic activity related NOx enhancements and polar surface air temperature variability in a chemistry climate model: Modulation of the NAM index, Atmos. Chem. Phys., 11, 4521-4531, 2011. DOI: 10.5194/acp-11-4521-2011

Newnham, D., Espy, P., Clilverd, M. A., Rodger, C.J., Seppälä, A., Maxfield, D., Hartogh, P., Holmen, K., and Horne, R., Direct observations of nitric oxide produced by energetic electron precipitation into the Antarctic middle atmosphere, Geophys. Res. Lett., 38, L20104, 2011.

Verronen, P.T., Rodger, C.J., Clilverd, M.A. and Wang, S., First Evidence of Mesospheric Hydroxyl Response to Electron Precipitation from the Radiation Belts, J. Geophys. Res., 116, D07307, 2011. DOI: 10.1029/2010JD014965

2010 (3)

Clilverd, M. A., C. J. Rodger, S. Dietrich, T. Raita, T. Ulich, E. Clarke, A. W. P. Thomson, and A. J. Kavanagh, High-latitude geomagnetically induced current events observed on very low frequency radio wave receiver systems., Radio Sci., 45, RS2006 1-11, 2010.

Clilverd, M.A., C. J. Rodger, R. Gamble, Th. Ulich, T. Raita, A. Seppälä, J. Green, N. Thomson, J-A Sauvaud, M. Parrot, Ground-based estimates of outer radiation belt energetic electron precipitation fluxes into the atmosphere, J. Geophys. Res., 115, A12304 1-11, 2010.

Rodger C. J., Clilverd M. A., Seppälä A., Thomson N. R., Gamble R. J., Parrot M., Sauvaud J., Ulich Thomas, Radiation belt electron precipitation due to geomagnetic storms: Significance to middle atmosphere ozone chemistry, J. Geophys., 115, A11320 1-12, 2010.

2009 (5)

Clilverd, M. A., A. Seppälä, C. J. Rodger, M. G. Mlynczak, and J. U. Kozyra, Additional stratospheric NOx production by relativistic electron precipitation during the 2004 spring NOx descent event, J. Geophys. Res., 114, A04305, 2009. DOI: 10.1029/2008JA013472

Clilverd, M. A., C. J. Rodger, N. R. Thomson, J. B. Brundell, Th. Ulich, J. Lichtenberger, N. Cobbett, A. B. Collier, F. W. Menk, A. Seppälä, P. T. Verronen, and E. Turunen, Remote sensing space weather events: the AARDDVARK network, Space Weather, 7, S04001, 2009. DOI: 10.1029/2008SW000412

Seppälä, A., C. E. Randall, M. A. Clilverd, E. Rozanov, and C. J. Rodger, Geomagnetic activity and polar surface air temperature variability, J. Geophys. Res., 114, A10312, 2009. DOI: 10.1029/2008JA014029

Arnone, E., A. Kero, C-F Enell, M. Carlotti, Craig J. Rodger, E. Papandrea, N. F. Arnold, B. M. Dinelli, M. Ridolfi and E. Turunen, Seeking sprite-induced signatures in remotely sensed middle atmosphere NO2: latitude and time variations, Plasma Sources Sci. Technol., 18, 034014 10pp, 2009. DOI: 10.1088/0963-0252/18/3/034014

Turunen, E., P. T. Verronen, A. Seppälä, C. J. Rodger, M. A. Clilverd, J. Tamminen, C. F. Enell and Th. Ulich, Impact of different precipitation energies on NOx generation during geomagnetic storms, J. Atmos Sol.-Terr. Phys, 71, 1176-1189, 2009. DOI: 10.1016/j.jastp.2008.07.005

2008 (12)

Verronen, P.T., B. Funke, M. Lopez-Puertas, G. B. Stiller, T. von Clarmann, N. Glatthor, C.-F. Enell, E. Turunen and J. Tamminen, About the increase of HNO3 in the stratopause region during the Halloween 2003 solar proton event, Geophys. Res. Lett., 35, L20809, 2008. DOI: 10.1029/2008GL035312

Kero, A., C.-F. Enell, A. J. Kavanagh, J. Vierinen, I. Virtanen, and E. Turunen, Could negative ion production explain the polar mesosphere winter echo (PMWE) modulation in active HF heating experiments?, Geophys. Res. Lett., 35, L23102, 2008. DOI: 10.1029/2008GL035798

Kero, A., Ionospheric D-region studies by means of active heating experiments and modelling, PhD thesis, University of Oulu, Sodankylä geophysical observatory publications, No. 102, 2008.

Rodger, C. J., P. T. Verronen, M. A. Clilverd, A. Seppälä, and E. Turunen, Significance of the Carrington Event Solar Proton Event to the neutral atmosphere, J. Geophys. Res., 113, D23302, 2008. DOI: 10.1029/2008JD010702

Seppälä, A., M. A. Clilverd, C. J. Rodger, P. T. Verronen, and E. Turunen, The Effects of Hard Spectra Solar Proton Events on the Middle Atmosphere, J. Geophys. Res., 113, A11311, 2008. DOI: 10.1029/2008JA013517

Neubert, T., M. Rycroft, T. Farges, E. Blanc, O. Chanrion, E. Arnone A. Odzimek, N. Arnold, C.-F. Enell, E. Turunen, T. Bösinger, Mika, C. Haldoupis, R. J. Steiner, O. van der Velde, S. Soula, P. Berg, F. Boberg, P. Thejll, B. Christiansen, M. Ignaccolo, M. F¨llekrug, P. T. Verronen, J. Montanya, and N. Crosby, Recent results from studies of electric discharges in the mesosphere, Surveys in Geophysics, vol. 29, no. 2, pp. 71-137, 2008. DOI: 10.1007/s10712-008-9043-1

Kero, A., J. Vierinen, C.-F. Enell, I. Virtanen, and E. Turunen, New incoherent scatter diagnostic methods for the heated D-region ionosphere, Ann. Geophys., 26, 2273-2279, 2008.

Enell, C.-F, P. T. Verronen, M. J. Beharrell, J. P. Vierinen, A. Kero, A. Seppälä, F. Honary Th. Ulich, and E. Turunen, Case study of the mesospheric and lower thermospheric effects of solar x-ray flares: Coupled ion-neutral modelling and comparison with EISCAT and riometer measurements, Ann. Geophys., 26, 2311-2321, 2008.

Rodger, C. J., T. Raita, M. A. Clilverd, A. Seppälä, S. Dietrich, N. R. Thomson, and Th. Ulich, Observations of relativistic electron precipitation from the radiation belts driven by EMIC Waves, Geophys. Res. Lett., 35, L16106, 2008. DOI: 10.1029/2008GL034804

Rodger, C. J, A. Seppälä, and M. A. Clilverd, Significance of Transient Luminous Events to Neutral Chemistry: Experimental Measurements, Geophys. Res. Lett., 35, L07803, 2008. DOI: 10.1029/2008GL033221

Enell, C.-F., E. Arnone, T. Adachi, O. Chanrion, P. T. Verronen, A. Seppälä, T. Neubert, T. Ulich, E. Turunen, Y. Takahashi, and R.-R. Hsu, Parameterisation of the chemical effect of sprites in the middle atmosphere, Ann. Geophys., 26, 13-27, SRef-ID: 1432-0576/angeo/2008-26-13, 2008.

Arnone, E., A. Kero, B. Dinelli, C. Enell, N. F. Arnold, E. Papandrea, C. J. Rodger, M. Carlotti, M. Ridolfi, and E. Turunen, Seeking sprite-induced signatures in remotely sensed middle atmosphere NO2, Geophys. Res. Lett., 35, L05807, 2008. DOI: 10.1029/2007GL031791

2007 (11)

Clilverd, M. A., C. J. Rodger, R. M. Millan, J. G. Sample, M. Kokorowski, M. P. McCarthy, Th. Ulich, T. Raita, A. J. Kavanagh, and E. Spanswick, Energetic particle precipitation into the middle atmosphere triggered by a coronal mass ejection, J. Geophys. Res., 112, A11210, 2007. DOI: 10.1029/2007JA012395

Kero, A., C.-F. Enell, Th. Ulich, E. Turunen, M. T. Rietveld, and F. H. Honary, Statistical signature of active D-region HF heating in IRIS riometer data from 1994-2004,, Ann. Geophys., 25, 407-415, 2007.

Seppälä, Annika, Observations of production and transport of NOx formed by energetic particle precipitation in the polar night atmosphere, PhD thesis, University of Helsinki, Finnish Meteorological Institute Contributions, No. 62, 2007.

Clilverd, M. A., Seppälä, A., Rodger, C. J., Thomson N.R., Lichtenberger, J., and Steinbach, P., Temporal variability of the descent of high-altitude NOx, J. Geophys. Res., 112, A09307, 2007. DOI: 10.1029/2006JA012085

Clilverd, M.A., Rodger, C.J., Moffat-Griffin, T. and Verronen, P.T., Improved dynamic geomagnetic rigidity cutoff modeling: testing predictive accuracy, J. Geophys. Res., 112, A08302, 2007. DOI: 10.1029/2007JA012410

Rodger, C.J., Clilverd, M.A., Nunn, D., Verronen, P.T., Bortnik, J. and Turunen, E., Storm time, short-lived bursts of relativistic electron precipitation detected by subionospheric radio wave propagation, J. Geophys. Res., Vol. 112, A07301, 2007. DOI: 10.1029/2007JA012347

Rodger, C.J., Enell, C.F., Turunen, E., Clilverd, M.A., Thomson, N.R. and Verronen, P.T., Lightning-driven inner radiation belt energy deposition into the atmosphere: Implications for ionisation-levels and neutral chemistry, Ann. Geophys., 25, 1745-1757, 2007.

Rodger, C.J., M. A. Clilverd, N. R. Thomson, R. J. Gamble, A. Seppälä, E. Turunen, N. P. Meredith, M. Parrot, J. Sauvaud, and J. Berthelier, Radiation belt electron precipitation into the atmosphere: recovery from a geomagnetic storm, J. Geophys. Res., 112, A11307, 2007. DOI: 10.1029/2007JA012383

Seppälä, A., Clilverd, M. A., and Rodger, C. J., NOx enhancements in the middle atmosphere during 2003-2004 polar winter: The relative significance of Solar Proton Events and the Aurora as a source, J. Geophys. Res., 112, D23303, 2007. DOI: 10.1029/2006JD008326

Seppälä, A., Verronen, P.T., Clilverd, M.A., Randall, C.E., Tamminen, J., Sofieva, V., Backman, L., and Kyrölä, E., Arctic and Antarctic polar winter NOx and energetic particle precipitation in 2002-2006, Geophys. Res. Lett.,, Vol. 34, No. 12, L12810, 2007. DOI: 10.1029/2007GL029733

Verronen, P.T., Rodger, C.J., Clilverd, M.A., Pickett, H.M. and Turunen, E., Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl, Ann. Geophys., Vol.25, pp. 2203-2215, http://direct.sref.org/1432-0576/angeo/2007-25-2203, 2007.

2006 (8)

Verronen, P.T., Seppälä, A., Kyrölä, E., Tamminen, J., Pickett, H.M. and Turunen, E., Production of Odd Hydrogen in the Mesosphere During the January 2005 Solar Proton Event, Geophys. Res. Lett., 33, 24, L24811, 2006. DOI: 10.1029/2006GL028115

Clilverd, M.A., Seppälä, A., Rodger, C. J., Thomson, N.R., Verronen, P., Turunen, E., Ulich, Th., Lichtenberger, J., and Stienbach, P., Modeling polar ionospheric effects during the October-November 2003 solar proton events., Radio Sci., 41, RS2001, 2006. DOI: 10.1029/2005RS003290

Clilverd, Mark A., Seppälä, Annika, Rodger, Craig J., Verronen, Pekka T., Thomson, Neil R., Ionospheric evidence of thermosphere-to-stratosphere descent of polar NOx, Geophys. Res. Lett., Vol. 33, No. 19, L19811, 2006. DOI: 10.1029/2006GL026727

Rodger, C.J., Clilverd, M.A., Ulich, Th., Verronen, P.T., Turunen, E., Thomson, N.R., The Atmospheric Implications of Radiation Belt Remediation, Ann. Geophys., 24, 2025-2041, SRef-ID: 1432-0576/ag/2006-24-2025, 2006.

Rodger, C.J., Clilverd, M.A., Verronen, P.T., Ulich, Th., Jarvis, M.J. and Turunen, E., Dynamic geomagnetic rigidity cutoff variations during a solar proton event, J. Geophys. Res., 111, A04222, 2006. DOI: 10.1029/2005JA011395

Seppälä, A., P.T. Verronen, V.F. Sofieva, J. Tamminen, E. Kyrölä, C. J. Rodger, and M.A. Clilverd, Destruction of the Tertiary Ozone Maximum During a Solar Proton Event, Geophys. Res. Lett., 33, L07804, 2006. DOI: 10.1029/2005GL025571

Verronen, P.T., Ulich, Th., Turunen, E., and Rodger, C.J., Sunset transition of negative charge in the D-region ionosphere during high-ionization conditions, Ann. Geophys., 24, 187-202, 2006.

Verronen, P.T., Ionosphere-Atmosphere Interaction During Solar Proton Events, PhD thesis, University of Helsinki, Finnish Meteorological Institute Contributions, No. 55, 2006.

2005 (3)

Clilverd, M. A., Rodger, C. J., Ulich, Th., Seppälä, A.,Turunen, E., Botman, A., and Thomson, N., Modelling a large solar proton event in the southern polar cap, J. Geophys. Res., 110, A09307, 2005. DOI: 10.1029/2004JA010922

Enell, C.-F., Kero, A., Turunen, E., Ulich, Th., Verronen, P.T., Seppälä, A., Marple, S., Honery, F., and Senior, A., Effects of D-region RF heating studied with the Sodankylä Ion Chemistry model, Ann. Geophys., 23, 1575-1583, 2005.

Verronen, P.T., Seppälä, A., Clilverd, M.A., Rodger, C.J., Kyrölä, E., Enell, C.F., Ulich, Th., and Turunen, E., Diurnal variation of ozone depletion during the October-November 2003 solar proton events, J. Geophys. Res., 110, A09S32, 2005. DOI: 10.1029/2004JA010932

2004 (1)

Seppälä, A., Verronen, P.T., Kyrölä, E., Hassinen, S., Backman, L., Hauchecorne, A., Bertaux, J.L., and Fussen, D., Solar Proton Events of October-November 2003: Ozone depletion in the Northern hemisphere polar winter as seen by GOMOS/Envisat, Geophys. Res. Lett., 31, L19107, 2004. DOI: 10.1029/2004GL021042

2002 (1)

Verronen, P. T., Turunen, E., Ulich, Th., and Kyrölä, E., Modelling the effects of the October 1989 solar proton event on mesospheric odd nitrogen using a detailed ion and neutral chemistry model, Ann. Geophys., 20, 1967-1976, 2002.