Nicholas Ssessanga

Norwegian version of this page
Room V312
Postal address 4D-Space Space Physics Department of Physics University of Oslo P.O. Box 1048 Blindern N-0316 Oslo

Academic interests

My research interests focus on ionospheric studies, particularly ionospheric tomography, data assimilation, modelling, and data analysis


Fu, W., Ssessanga, N., Yokoyama, T., & Yamamoto, M. (2021). High-resolution 3-D imaging of daytime sporadic-E over Japan by using GNSS TEC and ionosondes. Space Weather, Vol. 19, No 12, e2021SW002878, December 2021. (doi:10.1029/2021SW002878), refereed.

Kim, G.S., Kim, Y.H., Choi, BK. Hong, J. and Ssessanga, N.,  Characterizing ionospheric disturbances caused by the North Korean rocket (Hwasung-15) using a four-dimensional variational (4D-VAR) data-assimilation model. J. Korean Phys. Soc. Vol. 79, No, pp. 785–794, September 2021. (doi:10.1007/s40042-021-00282-0) refereed.

Ssessanga, N., Yamamoto, M. and Saito, S. Assessing the performance of a Northeast Asia Japan-centered 3-D ionosphere specification technique during the 2015 St. Patrick’s day geomagnetic storm. Earth Planets Space Vol. 73, No 124, June 2021. (doi:10.1186/s40623-021-01447-8), refereed.

Ssessanga, N., Yamamoto, M., Saito, S. et al. Complementing regional ground GNSS-STEC computerized ionospheric tomography (CIT) with ionosonde data assimilation.  GPS Solutions, Vol. 25, No 93, April 2021. (doi:10.1007/s10291-021-01133-y), refereed.

Mungufeni, P., Kim, Y.H. and Ssessenga, N., Observations of ionospheric irregularities and its correspondence with sporadic E occurrence over South Korea and Japan, Advances in Space Research, Vol. 67, No 7, April 2021,(doi:10.1016/j.asr.2021.01.013), refereed.

Ssessanga, N., Kim, Y.H., Habarulema, J.B. and Kwak, Y.S., On imaging South African regional ionosphere using 4D‐var technique, Space Weather, Vol. 17, No 11, pp. 1584–1604, October 2019. (doi:10.1029/2019SW002321), refereed.

Mengist, C.K., Ssessanga, N., Jeong, S.H., Kim, J.H., Kim, Y.H. and Kwak, Y.S., Assimilation of multiple data types to a regional ionosphere model with a 3D‐Var algorithm (IDA4D), Space Weather, Vol. 17, No 7, pp. 1018-1039, June 2019. (doi:10.1029/2019SW002159), refereed.

Mengist, C.K., Kim, Y.H., Ssessanga, N. and Kim, J.H., A Data Assimilated Regional Ionosphere Model Using the Total Electron Content from the Korean GPS Network, Journal of Korean Physical Society, Vol. 72, No 7, pp. 826–834, April 2018. (doi:10.3938/jkps.72.826), refereed.

Ssessanga, N., Kim, Y.H., Choi, B. and Chung, J.K., The 4D-var Estimation of North Korean Rocket Exhaust Emissions Into the Ionosphere, Journal of Geophysical Research, Vol. 123, No 3, pp. 2315–2326, March 2018. (doi:10.1002/2017JA024596), refereed.

Yang, Z., Ssessanga, N., Tran, L.T., Bilitza, D. and Kenpankho, P., On improvement in representation of foE in IRI, Advances in space research, Vol. 60, No 2, pp. 347–356, July 2017. (doi:10.1016/j.asr.2016.11.008), refereed.

Ssessanga, N., Kim, Y.H. and Jeong, S.H., A statistical study on the F2 layer vertical variation during nighttime medium-scale traveling ionospheric disturbances, Journal of Geophysical Research, Vol. 122, No 3, pp. 3586–3601, March 2017. (doi:10.1002/2016JA023463), refereed.

Hong, J., Kim, Y.H., Chung, J.K., Ssessanga, N. and Kwak, Y.S., Tomography Reconstruction of Ionospheric Electron Density with Empirical Orthonormal Functions Using Korea GNSS Network, Journal of Astronomy and Space Sciences, Vol. 34, No 1, pp. 7-17, February 2017. (doi:10.5140/JASS.2017.34.1.7), refereed.

Habarulema, J.B. and Ssessanga, N., Adapting a climatology model to improve estimation of ionosphere parameters and subsequent validation with radio occultation and ionosonde data. Space Weather. Vol. 15, No 1, pp.84–89, December 2016. (doi:10.1002/2016SW001549), refereed.

Ssessanga N., Validation of the TEC2F2 model over the African equatorial region, Advances in space research, Vol. 57, No 11, pp.2396–2406, June 2016.  (doi:10.1016/j.asr.2016.03.003), refereed.

Ssessanga, N., McKinnell, L.A. and Habarulema, J.B., Introduction of new data into the South African Ionospheric Map to improve the estimation of F2 layer parameters, Annals of Geophysics, Vol. 58, No 2, A0223, March 2015. (doi:10.4401/ag-6704), refereed.

Ssessanga, N., Kim, Y.H., Kim, E. and Kim, J., Regional optimization of the IRI-2012 output (TEC, foF2) by using derived GPS-TEC, Journal of the Korean Physical Society, Vol. 66, No 10, pp. 1599-1610, June 2015. (doi:10.3938/jkps.66.1599), refereed.

Ssessanga, N., Kim, Y.H. and Kim, E., Vertical structure of medium scale traveling ionospheric disturbances, Geophysical Research Letters, Vol. 42, No 21, pp. 9156–9165, November 2015. (doi:10.1002/2015GL066093), refereed.

Park, W., Lee, J., Yi, Y., Ssessanga, N. and Oh, S., Storm sudden commencements without interplanetary shocks. Journal of Astronomy and Space Sciences, Vol. 32, No 3, pp. 181–187. September 2015. (doi:10.5140/JASS.2015.32.3.181), refereed.

Ssessanga, N., McKinnell, L.A. and Habarulema, J.B., Estimation of foF2 from GPS TEC over the South African region, Journal of Atmospheric and Solar-Terrestrial Physics, Vol. 112, No 0, pp. 20–30, February 2014. (doi:10.1016/j.jastp.2014.02.003), refereed.

 Chartier, A.T., et al, *Ssessanga, N., Ionospheric imaging in Africa, Radio Science, Vol. 49, No 1, pp. 19–27, December 2013. (doi:10.1002/2013RS005238), refereed.


Tags: Space Physics, tomography, Data assimilation, Space Weather,  4DSpace


  • Fu, Weizheng; Yokoyama, Tatsuhiro; Ssessanga, Nicholas; Yamamoto, Mamoru & Liu, Peng (2022). On using a double-thin-shell approach and TEC perturbation component to sound night-time mid-latitude E–F coupling. Earth Planets and Space. ISSN 1343-8832. 74(1). doi: 10.1186/s40623-022-01639-w.
  • Fu, Weizheng; Ssessanga, Nicholas; Yokoyama, Tatsuhiro & Yamamoto, Mamoru (2021). High-Resolution 3-D Imaging of Daytime Sporadic-E Over Japan by Using GNSS TEC and Ionosondes. Space Weather. ISSN 1542-7390. 19(12), p. 1–16. doi: 10.1029/2021SW002878. Full text in Research Archive

View all works in Cristin

Published Jan. 18, 2022 4:19 PM - Last modified Mar. 20, 2022 10:30 PM


Research groups

  • Plasma and space physics