Annual report: The Kjell Henriksen Observatory 2023

Fred Sigernes, Mikko Syrjäsuo, Noora Partamies, Dag Lorentzen, Lisa Baddeley, Katie Herlingshaw, Nina Kristine Eriksen, Charlotte van Hazendonk, Ida Elen Asklund¹ and Gunn Rigmor Aarnes¹

The University Centre in Svalbard (UNIS), Norway
¹ Statsbygg Region North Svalbard, Norway

Name	Position
Fred Sigernes	Prof. Optics and Atmospheric Research / Chief KHO / Adjunct Prof. NTNU
Mikko Syrjäsuo	Department Engineer KHO / SuperDARN / OFS
Noora Partamies	Prof. Middle Atmos. Physics
Dag Arne Lorentzen	Prof. Arctic Geophysics / SuperDARN PI
Lisa Baddeley	Prof. Space physics - Radar applications / SuperDARN Co-I
Katie Herlingshaw	Postdoc. Upper Atmos. Physics
Nina Kristine Eriksen	PhD. Candidate Space Physics
Charlotte van Hazendonk	PhD. Candidate Space Physics
Ida Elen Asklund	Operations Manager Statsbygg
Gunn Rigmor Aarnes	Operations Manager Statsbygg

Table 1. The KHO crew (2023). SuperDARN is abbreviation for the Super Dual Auroral Radar Network radar in Longyearbyen, while OFS means the Operations and Field Safety department at UNIS.

The current crew of KHO is listed above. Fred Sigernes headed and had the daily operational responsibility together with Mikko Syrjäsuo. Ida Elen Asklund and Gunn Rigmor Aarnes are our contacts from the Norwegian Construction and Property Management Department (Statsbygg) in Longyearbyen who owns the building.

KHO serves as the main laboratory for hands on training and teaching of students in the Space physics group at UNIS. Here they are trained on observational techniques, instrument building and introduced to the state-of-the-art facilities for remote observations of the aurora.

Fig. 1. AGF-223 student inspects the CanSat that was launched in November 2023 (Photo Mikko Syrjäsuo).

A grand total of 82.5 ECTS (European Credit Transfer and Accumulation System) have been taught. Table 2 lists 7 relevant courses in space physics and instrumental techniques tied to the observatory.

Code	Course name	ECTS
AGF-216	The Stormy Sun and the Northern Lights	5
AGF-301/801	The Upper Polar Atmosphere	15
AGF-304/804	Radar Diagnostics of Space Plasma	15
AGF-345/845	Polar Magnetospheric Substorms	10
AGF-210	The middle polar atmosphere	15
AGF-223	Remote sensing and space instrumentation	15
TTK-4265	Optical Remote Sensing (NTNU)	7.5

Table 2. Courses in (2023).

During the auroral winter season from November to the end of February, 31 optical instruments operate around the clock. The 16 non-optical instruments run all-year-round 24 hours a day.

22 different institutions from 10 nations are present at KHO.

The instruments at KHO are grouped into mainly five categories (##):

(A) All-sky cameras and narrow field of view imagers

(B) Meridian scanning photometers

(C) Spectrometers / Spectrographs

(D) Scanning / imaging interferometers

(E) Radio or non-optical instrument

A detailed description of the performance and the scientific objective of each instrument are found below.

No.	Instrument	Institution	##	Country
1	All-Sky Imager	University of Oslo (UiO)	A	Norway(NO)
2	All-Sky Video Camera	University Centre in Svalbard (UNIS)	A	NO
3	All-Sky Colour Imager	University College London (UCL)	A	England
4	BACC All-Sky Color Camera	UNIS	A	NO
5	Sony A7s All-sky Camera	UNIS	A	NO
6	All-Sky Airglow Camera	UNIS	A	NO
7	Auroral Spectrograph	National Inst. of Polar Research (NIPR)	C	Japan
8	NIR Spectrograph	NIPR	C	Japan
9	NIR Camera	NIPR	A	Japan
10	Spectrographic Imaging Facilities	University of Southampton	C	England
11	Meridian Scanning Photometer	UNIS	B	USA/NO
12	1/2m Black Ebert-Fastie	UNIS	C	USA/NO
13	1/2m White Ebert-Fastie	UiT-The Arctic University of Norway	C	NO
14	1m Silver Ebert-Fastie	UNIS	C	USA/NO
15	1m Green Ebert-Fastie	UNIS	C	USA/NO
16	Fabry-Perot Interferometer	UCL	D	England
17	Scanning Doppler Imager	UCL	D	England
18	Monochromatic Auroral Imager	Polar Research Inst. of China (PRIC)	A	China
19	Single-wave Auroral Imager	PRIC	A	China
20	Fabry-Perot Interferometer	PRIC	D	China
21	All-Sky Airglow Imager	Kyoto University	A	Japan
22	Hyperspectral tracker	UNIS	C	NO
23	All-Sky hyperspectral camera	UNIS	C	NO
24	Celestron 14" Telescope	UNIS	A	NO
25	Narrow field of view sCMOS tracker	UNIS	A	NO
26	Meridian Imaging Svalbard Spectrograph	UNIS	C	NO
27	The Hot Oxygen Doppler Imager	New Jersey Institute of Technology	D	USA
28	Aurora All-Sky Camera	Korea Polar Research Institute	A	Korea
29	Boreal Auroral Camera Constellation	UNIS	A	NO
30	Fluxgate Magnetometer	UiT	E	NO
31	2-axis Search-coil Magnetometer	Augsburg College and University of New Hampshire	E	USA
32	64-beam Imaging Riometer	UiT	E	NO
33	Auroral Radio Spectrograph	Tohoku University	E	Japan
34	3x GNSS Receivers	Nagoya University	E	Japan
35	HF acquisition system	Institute of Radio Astronomy / UiT	E	Ukraine
36	Scintillation and TEC receiver	University of Bergen	E	NO
37	Fluxgate Magnetometer	PRIC	E	China
38	Induction Magnetometer	PRIC	E	China
39	Polar Research Ionospheric Doppler Experiment	UNIS/Polish research base Hornsund	E	Poland/NO
40	UCB-GNSS receiver	University of Colorado Boulder	E	USA
41	2 x Tracker cameras	UNIS	A	NO
42	Internet radio link-Janssonhaugen	NORSAR	E	NO
43	UHF Ground station	National Institute for Aeronautics	E	Indonesia
44	UHF Ground station	Technische Universität Berlin	E	Germany
45	VHF base station	Kongsberg Satellite Service AS	E	NO
46	Automatic weather station	UNIS	E	NO
47	3xWEB cameras (safety)	UNIS	A	NO

Table 3. Instruments at KHO (2023).

#	Institution	Code	Instruments
1	University Centre in Svalbard (UNIS)	NO	17
2	UiT-The Arctic University of Norway	NO	3
3	University of Oslo (UiO)	NO	1
4	University of Bergen	NO	1
5	NORSAR	NO	1
6	Kongsberg Satellite Service AS	NO	1
7	Augsburg College	US	1
8	University of New Hampshire	US	-
9	University of Colorado Boulder	US	1
10	New Jersey Institute of Technology	US	1
11	University College London (UCL)	UK	3
12	University of Southampton	UK	1
13	National Inst. of Polar Research (NIPR)	JP	3
14	Kyoto University	JP	1
15	Tohoku University	JP	1
16	Nagoya University	JP	1
17	Polar Research Inst. of China (PRIC)	CN	5
18	Korea Polar Research Institute	KR	1
19	Institute of Radio Astronomy	UA	1
20	Polish research base Hornsund	PL	1
21	National Institute for Aeronautics	ID	1
22	Technische Universitat Berlin	DE	1
	Total:	10	47

Table 4. Groups and number of instruments in 2023 .

Figure 3 shows a map of where the instruments are located. Tables 3-4 lists all according to institution and category (##). Note that out of 30 instrument domes; 4 are currently not in use.

The Principal Investigators (PIs) of each instrumental group have been informed according to contracts that there was an increase of 10% on the annual accommodation fee for each instrumental unit / module effective from January 2023.

Major repairs and maintenance of the observatory have been conducted in 2023. A new ventilation system and LED room lights have been installed. The main entrance door has been fixed due to icing and weather damage. The work to install new heat panels has started together with replacing leaking domes. New domes from Talbot design with vertical flange edge are believed to prevent water leakage between dome and roof hatch. Not all domes are replaced due to the arrival of winter before finishing up. The work will continue in spring 2024.

The Silver Bullet spectrometer electrical noise seem to have disappeared after using ferrite rings on signal cable to counter card. Care should be taken to avoid electrical noise in the future.

Two urgent item remain to be fixed. First, the fresh water supply tubes are made of copper and needs to be replaced with stainless steel tubes in order to prevent future erosion and water leaks. This is highly recommended back in 2020 by the chief technician Espen Helgesen at the EISCAT Svalbard radar, where eroded copper pipes caused extensive water damage and total inside renovation and repairs.

Secondly, the UPS system was up for a major 10-year service in 2022. All 256 6V cells were replaced by new ones to secure service lifetime guarantee by the supplier, Schneider Electric. High on the wish list is a diesel emergency generator to secure the battery bank from total drain due to the increasing frequency in unexpected external power failures. One other option could be to connect to the EISCAT emergency generator. This remains to be discussed before a final decision is made.

Instrumental boost Several new groups and instruments have finally joined the observatory after the pandemic. Two high-end interferometer systems, a single wavelength all-sky camera, a Near-InfraRed (NIR) spectrometer, a NIR camera and a GNSS receiver have been installed successfully. See below links for further information. Januar 10, 2023

#	New instruments	Group
1	The Hot Oxygen Doppler Imager (HODI)	NJIT
2	Fabry Perot Interferometer (FPI)	PRIC
3	Single-wavelength Auroral Imager (SAI)	PRIC
4	Near InfraRed Aurora and airglow Spectrograph - 2 (NIRAS-2)	NIPR
5	Near InfraRed Aurora Camera (NIRAC)	NIPR
6	Global Navigation Satellite Systems receiver (GNSS)	UCB

HYPSO-1 First publication! The first scientific paper with data from our hyperspectral imager onboard the HYPSO-1 satellite is now published in Remote sensing. The satellite is one of the smallest of its kind performing ocean spectral scanning with high signal to noise characteristics. Read paper. Januar 28, 2023

Star visit Irish star comedian and UK television presenter Dara Ó Briain has visited our observatory. Katie and Lisa turned the aurora ON, and Dara reported from the roof of KHO that is was a brilliant light show! See tweet here. Januar 29, 2023

Extraterrestrials? FMI is dedicated to operating their BACC #4 camera at Muonio until the very end of the optical season. They do not want to miss a single aurora event even! See image of unexpected guest inspecting the all-sky camera lens here. April 1, 2023

Long-range hyperspectral shooting An experiment to test out telescopes as front optics to our Hyper Spectral Imager version 6 (HSI v6) has started. The aim is to improve the spatial resolution and evaluate a possible design for the next generation HYPSO-3 satellite. Goto Experiment. 25 April, 2023

12 years in service! Version 8.5 of our Aurora Forecast 3D app is now published in Google Play (Android) and App Store (iOS). The work to provide a free of charge mobile auroral forecast service dates back to 2011. It is now downloaded more than 100K+ and is rated above 4 on a 5-point rating scale. More info and computer downloads here. June 2, 2023

New Mega project! In 2023, Katie Herlingshaw received 8 million NOK funding from the Norwegian Research Council for the call for the Researcher Project for Young Talents (see project here). The project is 4-years long and involves data from KHO cameras, spectrographs, and photometers. The target of the grant is to further the understanding of aurora-like features at the polewards edge of the auroral oval and compare them to aurora-like features at the equatorwards edge. Aurora-like means that the features are not caused by particle precipitation, but some other unknown mechanism that is local to the ionosphere. The research will primarily focus on Fragmented Aurora-like Emissions, a small-scale, short-lived phenomenon first documented in the scientific literature over Svalbard using KHO all-sky camera and Meridian Scanning Photometer data in 2021. A new 4-year PhD student, Lena Mielke, has been funded using the research grant and UNIS support to work on the topic and started in March 2024. 4 July, 2023

Aurora Forecast Rocketeer Based on user feedback a new simplified version of the Aurora Forecast app is published today on Apple App Store (iOS) and Google Play (Android). The aim is to provide an easy-to-use app with focus on auroral forecasting using only your phone location sensor. New feature is virtual space travel by rocket to other planets in the solar system. Note that the old 3D app will still be updated. More info and computer downloads here. July 14, 2023

New hyperspectral designs The design to create both a Near Infra-Red (NIR 600 - 1200 nm) and a Short Wave Infra-Red (SWIR 1000 - 1600 nm) Hyper Spectral Imager for the HYPSO-3 satellite mission has started, utilizing new technology, high speed black silicon and indium gallium arsenide image sensors. 24 October, 2023

CanSats, Drones and Spectacular Views Associate prof. Lisa Baddeley reports on AGF-223 field work at KHO where the students launched their own small satellite payload from a drone. Read UNIS newsletter here. 13 November, 2023

Doctora Marie Bøe Henriksen! Salute! Marie Bøe Henriksen has with flying colors defended her PhD thesis titled: "On the Calibration and Optical Performance of a Hyperspectral Imager for Drones and Small Satellites: From First Prototypes to In-Orbit Results ". The defense was at NTNU on Friday 15th of December 2023. Read thesis here. 15 December, 2023

What the heck is that? Today at 08:57 UT, an unidentified object smashed into the field of view of our all-sky cameras. It moved quickly across the sky from the South-East towards North-West horizon, leaving trails of solar illuminated stuff in the upper atmosphere. The object was simultaneously detected from the UiO camera in Ny-Ålesund. We suspect the event to be a Russian rocket that created the Twilight Effect. Read UNIS newletter here. See 30s all-sky movie of the event. 21 December, 2023

Several new groups and instruments have finally joined the observatory after the pandemic. The Hot Oxygen Doppler Imager (HODI) from New Jersey Institute of Technology (NJIT) is a custom made interferometer aimed to study ion-neutral coupling of the F-region plasma to the upper thermosphere.

Likewise, The Polar Research Institute of China (PRIC) has installed a Fabry-Perot interferometer designed by Keo Scientific Ltd. from Canada. The aim is to determine high altitude velocity and density by detecting doppler shifts and broadening of the 557.7 and 630 nm emission lines from airglow and aurora.

The National Institute of Polar Research of Japan (NIPR) has installed the Near InfraRed Aurora Camera (NIRAC) and the Near InfraRed Aurora and airglow Spectrograph-2 (NIRAS-2). The observation focuses on dayside magnetosphere-ionosphere-atmosphere coupling processes by focusing on emission lines in the Near Infra Red (NIR) region of the electromagnetic spectrum.

In addition, the Satellite Navigation and Sensing Laboratory (SeNSe) from the University of Colorado Boulder has installed a next generation Global Navigation Satellite System (GNSS) receiver to study space weather and propagation effects.

Our knowledge in hyperspectral imaging has been exported to NTNU and successfully launched into space onboard the HYPSO-1 (HYPer-spectral Smallsat for ocean Observation) satellite. HYPSO-2 will launch next year with an improved version of our spectral imager. Furthermore, prototype work has started to design a new hyperspectral imager with focus on higher spatial resolution. A Near Infra-Red (NIR) instrument is also planned for atmospheric correction of the data. See highlights above for more information. These instruments are the main payload of the HYPSO-3 satellite planned by NTNU Small Satellite Lab.

Finally, we are pleased to announce that the Longyearbyen Super Dual Auroral Radar Network (LYR-SuperDARN) radar became operational during summer 2023. The radar is now running in a commissioning phase, and has been operating nominally with a 24/7 operational schedule.

Two virtual Windows 2019 servers have been installed to replace our old Windows 2012 R2 server at UNIS. The WEB server now uses the https protocol with encrypted communication. The File server still needs to be implemented to meet todays standards in security.

New network switches are installed. The work that remains is that UNIS IT will test and activate them after our main operation season. All users of the observatory have been notified of the new data regime.

The access to data from KHO is open with lots of quick looks and instrumental snapshots in real-time on the WEB server. Raw data is restricted and available on requests to the PIs of the instruments. Data from UNIS owned instruments are archived to the Norwegian National e-Infrastructure for Research Data (NIRD), UNINETT Sigma 2, using the project Svalbard Space Physics Storage for long-term storage.

The second level of processing raw data is in many cases event based and conducted by students or associated researcher. It requires deep instrumental knowledge, training and programming skills, something our students learn through our courses.

Numerous presentations, visits and interviews have been conducted at KHO over the years. The Aurora Forecast 3D app is rated as 4.1 by 233 reviewers and has reached over 100k+ installs on Google Play for Android. On Apple iOS phones it is rated 4.2 with 1.3k+ users. The app is believed to be popular mainly in the auroral tourist industry and in the amateur radio community. The Facebook page for KHO has 1.7k+ followers.

Katie's new research mega project involves using optical data from KHO and other places in mainland Norway and worldwide. In addition, this project will have a strong involvement with auroral photographers and citizen scientists around the world. To communicate with the public, Katie have done talks and written articles to both to the local community through Artica's Lantern Lecture, Svalbardposten, and blog in addition to reaching a more international community though talks at the Usra Astronomical Society. The project is also timed well as it is occurring alongside an International Space Science Insititute team called the Auroral Research Coordination: Towards Internationalized Citizen Science (ARCTICS). This team contains researchers with expertise in aurora, photographers that capture incredible auroral images, social media group leaders and influencers that can reach large communities of auroral photographers, and people connected to databases that are used to collect and classify different auroral images. A team with these expertise and connections provides valuable collaborations and opportunities to accelerate the project towards its goals.

The main purpose of KHO is to study processes in the magnetospheric cusp all the way throughout the polar cap boundary. Or in other words, what are the effects of the interaction between the Sun and the magnetosphere on our atmosphere? The unique location and the multi-disciplinary instrumental infrastructure such as radars and optics enable us to study the whole atmospheric vertical column to obtain a better understanding of space- and planetary weather.

A vital key in this concept is to upgrade, develop and compare instruments as novel technology and knowledge emerge. Therefore, the aim is to strengthen the co-operation with our existing groups and invite new ones. We wish to be upfront as an attractive partner to large scale rocket and satellite campaigns both on the instrumental and observational side.

The access to internal UNIS research funding is very important. It enables us to preserve the instrumental momentum and helps us keep track of new technology as it arrives. It seeds our research plans and proposals and is therefore strategically important to us. This must not be underestimated compared to our external funding which is more tied up or locked to predefined proposal tasks.

The threats to KHO remain unchanged as identified in the last four-yearly reports. The main threat is the lifetime of Mine 7, which was expected to operate for a maximum of 16 more years. The Norwegian Government decided in October 2023 to outsource coal as fuel for the power plant in Longyearbyen. Consequently, SNSK will close production by 2025. This forces us to evaluate and discuss several scenarios up front.

One immediate question arises: who will fund and maintain the road up to the observatory?

Note that the state of the road from the foot of the mountain and up to Mine 7 is good with new safety car protection. The overall situation has become uncertain and forces us to think on how to adapt to the new state of affairs and politics to secure KHO.

If we stay co- located with the EISCAT Svalbard radar, the access to the mountain keeping the road up the mountain open all year, will most probably increase the operational costs. If we must move due to light pollution, then we will need a new road and infrastructure further away from Longyearbyen and Bolterdalen. One alternative could be to move deep into Adventdalen. Note that this is not compatible with the environmental plan to make inner Adventdalen a conservation area.

The second threat for our operation is the growing number of dog yards by the foot of the mountain and the increasing light pollution they produce. When driving from Longyearbyen into Adventdalen the illumination from these yards look like a small city. This was not the case when we built KHO back in 2008. Numerous attempts through Svalbardposten to encourage to at least turn OFF lights when they are not in use have failed. Dialog is not working even though we have a political consensus from the local government that light pollution should be kept to a minimum. An action plan is needed, or KHO will have to move if the situation continues.

It is a paradox that the tourist industry does not seem to understand the value of dark skies and aurora.

The third, and future concern for our operation is that the local government plans to install a 48-meter-high weather station mast on top of Breinosa to study wind and icing conditions for a possible future wind power plant. The mast is promised to be without a navigation light on top since it will be too close to the field of view of our camera systems. Direct or even atmospheric scattered lamp light in the vicinity of the observatory will destroy our measurements.

In general, the project is characterized by an unrealistic optimism that the wind condition on Svalbard is stable and strong enough to have efficient wind power. The memory of the local politicians seems to lack the fact that KSAT abounded the plans to use wind power on Platåberget after extensive weather mast measurements for one year in 2003/04 by Kjeller Vindteknikk (KVT/FKN/2004/008) - commissioned by Svalbard Samfunnsdrift (SSD). The wind was too unstable and weak for efficient energy production. This was later confirmed by an internal report from UNIS of the weather conditions at Breinosa close to the observatory (2007 - 2010).

In addition, we now know that extreme icing condititions may occur, since it destroyed our SuperDARN radar back in 2018. On the 2 km long, 10 mm diameter ropes that support and keep the masts standing upright, a circular ice cover was formed with a diameter of approximately 50 mm. The total accumulated extra ice mass corresponds to about 20,000 kg, which collapsed the whole radar. The effect was caused by an invasion of super cooled droplets. This does not occur every year, but it does happen!

A future windmill park with navigation lights on top on Breinosa is completely incompatible with KHO existence. It will destroy our light sensitive measurements of aurora and airglow. Furthermore, a windmill within the line-of-sight of the SuperDARN radar will essentially render the radar useless as it receives signals from electrons in the ionosphere. The same applies for the EISCAT radar. A large rotating metal blade in our field of view is not something that can be dealt with.

We will follow the local governments plan to install a windmill park on Breinosa with Argus eyes!

Our concerns should be taken seriously in order to secure our mandate from the Norwegian Parliament to operate an auroral observatory and respect the taxpayer's contribution.

The activity at the KHO has been high in 2023. The observatory has been fully operative since the start of the optical season in November. It is attractive to the space science community with 22 external groups from 10 nations present. 4 new instruments are installed and a new improved SuperDARN radar is now fully operational. The major highlight was Marie Bøe Henriksen PhD defence. 1 PhD, 2 master's and 1 bachelor student used our facilities and data, essential to their graduation. A spaceborne partnership with Cybernetics at NTNU has proven to be vital, especially in terms of student recruitment, teaching and science projects.

1. Marie Bøe Henriksen, PhD, On the Calibration and Optical Performance of a Hyperspectral Imager for Drones and Small Satellites - From First Prototypes to In-Orbit Results, Department of Engineering Cybernetics, Norwegian University of Science and Technology, Norway, 2023.
2. Bas Dol, Master intership, Viability of using images classified by an unsupervised AI for determining patterns in the evolution of auroral morphology, Eindhoven University of Technology, The Netherlands, 2023.
3. Philipp Schneider, Bachelor thesis, Variations in auroral emission intensities, University of Erlangen-Nuremberg, Germany. 2023.
4. Herman Greaker, Master thesis, On the Distribution of Meteoric Smoke Particles above Andøya, Norway, and Estimated Collection During a Summer Rocket Campaign, UiT, Norway, 2023, https://munin.uit.no/handle/10037/32828

1. S. Bakken, M. B. Henriksen, R. Birkeland, D. D. Langer, A. E. Oudijk, S. Berg, Y. Pursley, J. L Garrett, F. Gran-Jansen, E. Honore- Livermore, M. E. Grøtte, B. A. Kristiansen, M. Orlandic, P. Gader, A. J. Sørensen, F. Sigernes, G. Johnsen and T. A. Johansen, HYPSO-1 CubeSat: First Images and In-Orbit Characterization, Remote sensing, 15(3), 755, 2023, https://www.mdpi.com/2072-4292/15/3/755
2. Maetschke, K. N., Kronberg, E. A., Partamies, N., and Grigorenko, E. E., A Possible Mechanism for the Formation of an Eastward moving Auroral Spiral, Frontiers in Astronomy and Space Sciences, 10, 2023, https://doi.org/10.3389/fspas.2023.1240081
3. Juusola, L., Viljanen, A., Partamies, N., Vanhamäki, H., Kellinsalmi, M., and Walker, S., Three principal components describe the spatiotemporal development of meso-scale ionospheric equivalent currents around substorm onsets, Annales Geophysicae, 41, 483-510, 2023, https://doi.org/10.5194/angeo-41-483-2023
4. Nowada, M., Miyashita, Y., Partamies, N., Degeling, A. W., and Shi, Q.-Q., Auroral morphological changes to the formation of auroral spiral during the late substorm recovery phase: Polar UVI and ground all-sky camera observations, Journal of Geophysical Research 128, e2023JA031400, 2023, https://doi.org/10.1029/2023JA031400
5. Kallio, E., Harri, A.M., Knuuttila, O., Alho, A., Järvinen, R., Kauristie, K., Kestilä, A., Kivekäs, J., Koskimaa, P., Lukkari, J.-M., Partamies, N., Ryno, J., and Syrjäsuo, M., Auroral imaging with combined Suomi 100 nanosatellite and ground-based observations: A case study, Journal of Geophysical Research, 128, 2023, https://doi.org/10.1029/2023JA031414
6. Goertz, A., Partamies, N., Whiter, D., and Baddeley, L., Morphological evolution and spatial profile changes of poleward moving auroral forms, Annales Geophysicae, 41, 115-128, 2023, https://doi.org/10.5194/angeo-41-115-2023
7. Whiter, D. K., Partamies, N., Gustavsson, B., and Kauristie, K., The altitude of green OI (557.7 nm) and blue N⁺₂ (427.8 nm) aurora, Annales Geophysicae, 41, 1-12, 2023, https://doi.org/10.5194/angeo-41-1-2023
8. Nina Kristine Eriksen, Dag A. Lorentzen, Kjellmar Oksavik, Lisa Baddeley, Keisuke Hosokawa, Kazuo Shiokawa, Emma Bland, Larry Paxton, Yongliang Zhang, Kathryn McWilliams, Tim Yeoman and David R. Themens, On the Creation, Depletion, and End of Life of Polar Cap Patches, JGR Space Physics, Vol. 128, 12, 2023, e2023JA031739, https://doi.org/10.1029/2023JA031739
9. M. Hamrin, A. Schillings, H. Opgenoorth, S. Nesbit-Östman, E. Krämer, J. Araújo, L. Baddeley, H. Gunell, T. Pitkänen, J. Gjerloev and R. J. Barnes, Space Weather Disturbances in Non-Stormy Times: Occurrence of dB/dt Spikes During Three Solar Cycles, JGR Space Physics, Vol 128, 10, 2023, e2023JA031804, https://doi.org/10.1029/2023JA031804
10. Lisa Baddeley, Dag Lorentzen, Stein Haaland, Erkka Heino, Ingrid Mann, Wojciech Miloch, Kjellmar Oksavik, Noora Partamies, Andres Spicher and Juha Vierinen, Space and atmospheric physics on Svalbard: a case for continued incoherent scatter radar measurements under the cusp and in the polar cap boundary region, Progress in Earth and Planetary Science, 10, 53, 2023, https://progearthplanetsci.springeropen.com/articles/10.1186/s40645-023-00585-9

1. Marie Bøe Henriksen, Fred Sigernes and Tor Arne Johansen, Comparing Filters for Correction of Second Order Diffraction Effects in Hyperspectral Imagers, Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing, ISSN 2158-6276, 2023.
2. Takanori Nishiyama, Masato Kagatani, Senri Furutachi, Yasunobu Ogawa, Takuo Tsuda, Yuki Iwasa, Fuminori Tsuchiya, Peter Dalin, Satonori Nozawa and Fred Sigernes, Initial results of short-wavelength infrared imaging spectrograph and monochromatic imager, NIRAS-2 and NIRAC, installed at KHO/UNIS, Longyearbyen, Svalbard (78.1N, 16.0E), IUGG / IAGA (Aeronomy, Geomagnetism), Berlin, 2023.
3. Sivert Bakken, Fred Sigernes and Tor Arne Johansen, HYPSO-1 Hyperspectral CubeSat: an innovation in optical oceanic exploration (invited), 47th Annual European Meeting on Atmospheric Studies by Optical Methods, Stockholm, Sweden, August 21-24, 2023.
4. Fred Sigernes, The Kjell Henriksen Observatory, Nordic Observatory Meeting NOM-9, Tromsø Geophysical Observatory, The Auroral Observatory, Tromsø, Norway, 16 May, 2023.
5. Gasia Excel, Gerard J Fasel, Abrielle Wang, Yaeji Jang, Sun-Hee Le, Emma Lake, Dora Csonge, Braden Yonano, Aniya Terry, John c Mann, Fred Sigernes and Dag A Lorentzen, Dayside Auroral Expansion Rates for Southward IMF Turnings, Poster, AGU San Francisco, 13 December, 2023.
6. Gasia Excel, Gerard J Fasel, Julia Grace Johnson, Sun-Hee Lee, Jordana Xu, Amiel Silbol, Parker Para, Braden Yonano, Rachel Rodriguez, John c Mann, Fred Sigernes and Dag A Lorentzen, Poleward Moving Auroral Forms and Magnetic Reconnection, Poster, AGU San Francisco, 13 December, 2023.
7. Aidan Hulbert, Thomas Lewer, Gerard J Fasel, Maxwell Fargo, Ethan Swonger, Sun-Hee Lee, Brant Weir, Owen Bradley, Arman Manookian, Braden Yonano, John c Mann, Fred Sigernes and Dag A Lorentzen, Dayside Pulsating Diffuse Aurora and the Interplanetary Magnetic Field, Poster, AGU San Francisco, 13 December, 2023.
8. Chrystal MoserGauthier, Marc Lessard, James H Clemmons, James H Hecht, Douglas G Brinkman, John W Bonnell, Richard L Walterscheid, Anasuya L Aruliah, F. Sigernes, Lisa J Baddeley, Lasse Boy Novock Clausen and Timothy K Yeoman, The Upcoming Rocket Experiment for Neutral Upwelling 3 (RENU-3) Sounding Rocket Mission, Poster, AGU San Francisco, 11 December, 2023.
9. Abrielle Wang, Gerard J Fasel, Audrey Daucher, Andrea Black, Makena Swenski, Sophie Trotter, Braden Yonano, Maame Osei-Tutu, Sun-Hee Lee, John c Mann, Fred Sigernes and Dag A Lorentzen, Dayside Auroral Response to the Solar-Terrestrial Interaction, AGU San Francisco, 13 December, 2023.
10. Eriksen, Nina Kristine, Nishimura, T., Zettergren, Matthew D., Lorentzen, Dag Arne, Oksavik, Kjellmar, Baddeley, Lisa, Shiokawa, Kazuo, Hosokawa, Keisuke, and Bhatt, Asti. Low-Density Ionospheric Polar Cap Patches: Insights on Airglow and Density Variations from Multi-Instrumental Analysis. AGU23, 2023.
11. C. M. van Hazendonk, L. Baddeley, and K. M. Laundal, Poster: Energy deposition of a Pc5 ULF wave in the polar ionosphere measured by EISCAT, EGU General Assembly 2023, Vienna, Austria, April 23-28, 2023.
12. E. Thomas, S. Shepherd and D. Lorentzen, Longyearbyen (LYR) Super Dual Auroral Radar Network (SuperDARN) High Frequency (HF) Radar Ground Scatter Data (2016-2018), NSF Arctic Data Center, 2023.

*Listed presentations and publications do not include all instrumental groups at KHO, only from the KHO crew.