Orals: Fri, 2 May | Room 1.61/62
Earth's energy balance is fundamental to the climate sciences as it regulates the flow of energy in and out of the climate system. Currently, it is positive due to anthropogenic greenhouse gas emissions, leading to increasing temperatures in the atmosphere and oceans, melting of the cryosphere, rising sea levels and more extreme weather around the globe. In recent decades the imbalance has risen dramatically, and in 2023 it reached 1.8 Wm-2, or twice as much as expected.
Monitoring the energy imbalance and the radiation budget components is vital, not only to scientists, but also to guide policy and potentially warn in time in case our projections are wrong. At the same time, NASA's satellites carrying CERES instruments are being decommissioned, and plans are to only launch one Libera instrument to replace them.
I will provide an overview of a new European initiative to directly measure Earth's energy imbalance from space, the Earth Climate Observatory (ECO), which is being developed by ESA within the 12th Earth Explorer program. The mission uses a constellation of satellites each equipped with an innovative combination of multiple wide field of view radiometers and multispectral cameras to increase the accuracy of the delicate balance between incoming and outgoing fluxes.
How to cite: Mauritsen, T.: Earth's energy imbalance rising faster than expected, and we must keep a close watch, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20404, https://doi.org/10.5194/egusphere-egu25-20404, 2025.
Monitoring the Earth Energy Imbalance (EEI) is crucial for predicting climate change and assessing global progress under the Paris Climate Agreement. Currently, the most accurate EEI estimates are derived from in situ observations, with a dominant contribution from the time derivative of the Ocean Heat Content (OHC). These observations, however, require long time periods—typically a decade or more—to yield meaningful insights. In contrast, direct space-based EEI observations have the potential to provide measurements at the annual mean timescale.
To fully understand EEI, it is essential to spectrally separate the Total Outgoing Radiation (TOR) into the two components of the Earth Radiation Budget (ERB): Reflected Solar Radiation (RSR) and Outgoing Longwave Radiation (OLR). This separation is critical for understanding radiative forcing (e.g., aerosol radiative forcing) and climate feedback mechanisms (e.g., ice-albedo feedback), as well as for validating climate models.
The state-of-the-art observation of the RSR is provided by the CERES scanning 3-channel broadband radiometer on the Sun-synchronuous afternoon orbit satellites Aqua, Suomi NPP and NOAA 20.
The Earth Climate Observatory (ECO) mission concept was recently selected by the European Space Agency as one of the 4 candidate Earth Explorer 12 missions, that will be further studied in Phase 0 until mid 2026. The ECO mission proposes an innovative continuity for RSR measurements by replacing the scanning broadband radiometer by a multispectral wide field of view cameras. The wide-field-of-view design enables full angular coverage, significantly reducing the dominant angular conversion error. To leverage this capability, an advanced Deep Learning-based angular conversion method is proposed.
The multispectral bands of the camera are designed to reconstruct the broadband RSR within the state of the art accuracy. Furthermore, the spatial resolution of the cameras will be sufficient to discriminate cloudy from clear-sky scenes. For the calibration of the cameras we propose an on-board shutter for the dark current determination, vicarious calibration for the gain determination, and cross-calibration with the sun-earth radiometer for the final broadband calibration directly tied to the incoming solar radiation.
This mission concept addresses critical challenges in EEI monitoring and represents a significant advancement in Earth Radiation Budget observations. The ECO mission holds the potential to deepen our understanding of climate processes, improve climate models, and provide timely, actionable insights for monitoring climate change.
How to cite: Poyraz, D., Vannerom, D., Schifano, L., Smeesters, L., August, T., and Dewitte, S.: The Earth Climate Observatory space mission concept for innovative continuity in the monitoring of the Earth Reflected Solar Radiation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17026, https://doi.org/10.5194/egusphere-egu25-17026, 2025.
The Earth Energy Imbalance (EEI) is defined as the small difference between the incoming energy the Earth receives from the Sun and the outgoing energy lost by Earth to space. The EEI is accumulated in the Earth climate system and results in global temperature rise. Monitoring the EEI is of prime importance for a predictive understanding of climate change, and for estimating how well humankind is doing in implementing the Paris Climate Agreement.
The current best estimates of the absolute value of the EEI, and of its long term variation are obtained from in situ observations. These observations can only be made over long time periods, typically a decade or longer. In contrast, with direct observations from space, the EEI can in principle be measured at the annual mean time scale. However, this strategy currently faces two fundamental challenges.
The first challenge is that the EEI is the difference between two opposing terms of nearly equal amplitude. Currently, the Incoming Solar Radiation (ISR) and the Total Outgoing Radiation (TOR) are measured with separate instruments, which means that their calibration errors are added and overwhelm the signal to be measured. To make significant progress in this challenge, a differential measurement using identical intercalibrated radiometers to measure both the ISR and the TOR is needed.
The second challenge is that the TOR has a systematic diurnal cycle. Currently, the TOR is sampled from the “morning” and “afternoon” Sun-synchronous orbits, complemented by narrowband geostationary imagers. Recently, the sampling from the morning orbit was abandoned. The sampling of the diurnal cycle can be improved, for example, by using two orthogonal 90° inclined orbits which give both global coverage, and a statistical sampling of the full diurnal cycle at seasonal time scale.
For understanding the radiative forcing and climate feedback, mechanisms underlying changes in the EEI, and for climate model validation, it is necessary to separate the TOR spectrally into the Reflected Solar radiation (RSR) and Outgoing Longwave Radiation (OLR) and to map them at relatively high spatial resolution.
The state-of-the-art observation of the OLR is provided by the CERES scanning 3-channel broadband radiometer aboard the Aqua, Suomi NPP and NOAA 20 satellites. We propose an innovative continuity of those measurements by replacing the radiometer by multispectral wide field of view (FOV) cameras. The wide FOV allows a full angular coverage, providing the potential for a significant reduction of the dominant angular conversion error. To realise this potential we propose to develop an innovative Deep Learning based angular conversion method. The multispectral bands of the camera should allow reconstructing the broadband OLR within the state of the art accuracy. The spatial resolution of the cameras should be sufficient to discriminate cloudy from clear-sky scenes.
How to cite: Vannerom, D., Poyraz, D., Schifano, L., Smeesters, L., August, T., and Dewitte, S.: The Earth Climate Observatory space mission concept for innovative continuity in the monitoring of the Earth Outgoing Longwave Radiation., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16297, https://doi.org/10.5194/egusphere-egu25-16297, 2025.
For 50 years, ONERA has been developing space accelerometers for Geodesy or Fundamental Physics missions: CHAMP, GRACE series, GOCE, MAGIC, MICROSCOPE. For the latest one, the laboratory had the science responsibility and learned better understanding of mission design. By taking advantage of these experiences, we proposed to review the old 80’s concept mission called BIRAMIS aiming at measuring the Earth’s radiative energy imbalance (EEI). The EEI represents the difference between the incoming solar radiation and the outgoing longwave radiation at the top of the atmosphere and is fundamental to estimate the effect of anthropogenic greenhouse gases (GHG) emissions on our climate system.
Currently, EEI is known with a stability of ~+/- 0.2 W/m² over a decade. However, this estimate is biased due to the performance of radiometry and to limited in-flight calibration. Some improvement is brought by using in-situ oceanic and geodetic (gravimetry and altimetry) measurements to estimate the ocean heat uptake. These measurements helps to evaluate EEI with an accuracy of +/- 0.3 W/m² on the time mean.
The accelerometer performances used for the previous missions exhibit resolutions from 10 to 0.1 pico-g. That allows us to imagine a new mission with direct measurements of the radiation pressure on a satellite and to envisage accuracies much better than 0.1 W/m² on the time mean. Decadal-scale variations in EEI induced by solar cycles, volcanic eruptions and variations in GHG emissions could be closely monitored for the benefit of the study of climate change.
How to cite: Rodrigues, M., Christophe, B., Maquaire, K., and Portier, N.: 50 years of legacy in space accelerometer missions for measuring Earth's energy imbalance, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20146, https://doi.org/10.5194/egusphere-egu25-20146, 2025.
Multi-solar cycle observations of sunspot number and location on the solar disk, combined with the occurrence of extreme geomagnetic storms at earth, can be used to identify key points in the solar cycle where the occurrence of extreme space weather events switches on and off. The variable length, approximately 11 year Schwabe cycle can be mapped onto a uniform length cycle (or solar cycle clock) using the Hilbert transform of sunspot number[1,2]. The switch on and off times of geomagnetic activity over each solar cycle can be directly identified from the sunspot number record[3], without requiring a Hilbert transform. This analysis has revealed a sharp switch on and off of geomagnetic activity, with some of the most extreme events occurring close to the switch on/off, rather than at solar maximum[4]. A detailed exploration is made of the locations of individual sunspot groups on the solar disk, hemispheric sunspot numbers, and their correlation with extreme events in the aa record. As well as informing our overall understanding of extreme space weather events, these findings can translate model predictions of sunspot number and morphology into timing of the switch-off and on, offering a route to quantitative estimates of future space weather risk.
[1] Chapman et al Quantifying the solar cycle modulation of extreme space weather GRL (2020) doi:10.1029/2020GL087795
[2] Chapman et al The Sun's magnetic (Hale) cycle and 27 day recurrences in the aa geomagnetic index. Ap. J. (2021) doi: 10.3847/1538-4357/ac069e
[3] Chapman Charting the Solar Cycle, Front. Astron. Space Sci. - Space Physics (2023) doi: 10.3389/fspas.2022.1037096
[4] Chapman et al A solar cycle clock for extreme space weather. Scientific Reports (2024) doi:10.1038/s41598-024-58960-5
How to cite: Chapman, S.: Long term sunspot number records, extreme space weather events at earth seen in the aa index, and their solar cycle modulation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6391, https://doi.org/10.5194/egusphere-egu25-6391, 2025.
Geomagnetic observatories were initially devised to understand the workings of Earth’s dynamo over periods of years to centuries. Those same records contain information on higher frequency variations related to space weather and its interaction with the magnetosphere. The signals are on the order of a few nT or less, so they are often overlooked as noise. By exploiting differences in instrument responses from scalar and vectorial magnetometers (delta F), we show it is possible to extract the frequency content of the magnetic field with periods ranging from 0.1 to 100 seconds. One application demonstrates a nearly simultaneous signal in global observatory data when interplanetary shock fronts have relatively high (ca. >800 km/s) solar wind velocities. These storm events show remarkable similarities in time and space as observed on Earth’s surface. Another application is to stack hourly averages over an entire year. This latter method shows that the maximum amplitude of magnetic field oscillations occurs near solar noon over diurnal periods at all latitudes except in the auroral oval. Seasonal variability is detectable at high latitudes. Long-term trends in field oscillations follow the solar cycle, with maxima occurring during the declining phase when high-speed streams in the solar wind are dominant. A parameter based on solar wind speed and the relative variability of the interplanetary magnetic field correlates robustly with the ground-based measurements. These findings suggest that turbulence in the solar wind, its interaction at the magnetopause, and its propagation through the magnetosphere stimulate magnetic field fluctuations at the ground over a wide frequency range. Delta F therefore allows one to study solar wind phenomena that produce field line oscillations detectable on the Earth’s surface using the publicly available, worldwide database of INTERMAGNET geomagnetic observatories.
How to cite: Gilder, S., Wack, M., Kronberg, E., Lhuillier, F., Smirnov, A., and Wu, Y.: Solar phenomena in geomagnetic observatory records, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17556, https://doi.org/10.5194/egusphere-egu25-17556, 2025.
The vast majority of solar cycle predictions focus on the 11-year sunspot cycle, while space weather and geomagnetic activity predictions are typically made for short time scales, from hours up to a month. Here, we aim to predict geomagnetic activity in the solar cycle time scale. We use a 180-year composite of the geomagnetic aa index and fit each aa cycle between two successive sunspot minima with a parameterized asymmetric Gaussian curve. We show that this curve can be represented with two free parameters and the model closely depicts the cyclic behavior of aa index in about 5-year timescale. However, it is unable to accurately represent shorter term variability.
We show how the two parameters can be forecasted using past aa values and a recently developed sunspot prediction model. Employing these estimated parameter values, we hindcast each past aa cycle from Solar Cycle 10 onwards and make a prediction for Solar Cycle 25, also estimating the uncertainties. Each cycle prediction is made at the time of minimum aa starting the respective cycle.
For Solar Cycle 25, our prediction gives the (5-year smoothed) aa index maximum of 21+/-3 nT, which is slightly higher than, e.g., in Cycle 24 (18.9). However, our model suggests that the overall aa cycle maximum has already been reached quite early in the cycle in July 2022. This suggests that Solar Cycle 25, similarly to Solar Cycles 11 and 13, will probably not have a strong, long-lasting peak of geomagnetic activity in the late declining phase.
How to cite: Asikainen, T., Qvick, T., and Mursula, K.: Solar cycle prediction of geomagnetic activity, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12861, https://doi.org/10.5194/egusphere-egu25-12861, 2025.
Sudden Solar Energetic Particle (SEP) events can have a major impact on technology and humans in space. Therefore forecasts and early warning systems working to support those missions are desirable. One example is REleASE, which utilizes the close correlation of near relativistic electrons and the slower but more hazardous protons.
The original (2009) REleASE system used electron measurements from SOHO/EPHIN. During the HESPERIA project it was expended to include ACE/EPAM. Both systems issue short term warnings before there is a significant flux increase of >20 MeV protons at L1.
We now successfully adapted the method to work with the High Energy Telescope (HET) and the Solar Electron Proton Telescope (SEPT) on board of STEREO-A. The resulting forecasts are publicly available in real time and can be accessed on a dedicated website. Furthermore, we gained valuable insights from adapting the method to the SEPT that uses the magnet/foil technique to separate electrons from ions, which can pose several difficulties.
With now two REleASE systems operational we have the possibility to directly compare forecasts from different points in the heliosphere.
The SOHO/EPHIN and STEREO/SEPT project is supported under Grant 50 OC 2302532 by the German Bundesministerium für Wirtschaft through the Deutsches Zentrum für Luft- und Raumfahrt (DLR). This study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101004159535 (SERPENTINE). The REleASE system is supported by NASA via the grant TXS0150642.
How to cite: Dröge, H., Heber, B., Karavolos, M., Kollhoff, A., Kühl, P., and Malandraki, O.: STEREO REleASE: Solar Energetic Proton forecasting with instruments on STEREO-A, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16017, https://doi.org/10.5194/egusphere-egu25-16017, 2025.
Solar Energetic Ion Events (SEP) can have major impact on technology and human exploration of the Moon and Mars. Therefore warnings of an increased radiation exposure to electronics and astronauts would give sufficient time to take action like moving to a radiation shelter. The Relativistic Electron Alert System for Exploration (REleASE) has been succesfully developed to provide such early warnings for the Earth environment by exploiting the time difference of the arrival of SEP electrons and ions at 1 AU. Interplanetary travel to and from Mars using a Hohmann trajectory is not completely covered by the original REleASE forecast due to the longitudinal seperation between the spacecraft and Earth. The slow STEREO A fly by in 2023 allows to investigate longitudinal dependencies of the REleASE forecast system. Here we investigate three SEP events observed by the Radiation Assessment Detector (RAD) on the Martian surface from September to December 2024 when the magnetic foot point separation in longitude of Mars and STEREO / Earth were between 77 and 36 degree / 96 and 62 degree, respectively. Applying REleASE for the three events we found a better forecast for STEREO closer to the magnetic field line to Mars than for Earth.
The SOHO/EPHIN and STEREO/SEPT project is supported under Grant 50~OC~2302 by the German Bundesministerium für Wirtschaft through the Deutsches Zentrum für Luft- und Raumfahrt (DLR). This study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101004159 (SERPENTINE). The REleASE system is supported by NASA via the grant TXS0150642.
How to cite: Heber, B., Dröge, H., Khaksari, S., Jensen, S., Kollhoff, A., Kühl, P., Löwe, J., Malandraki, O., Tziotziou, K., and Wimmer-Schweingruber, R.: Solar Energetic Proton forecasting for Mars travel using SOHO and STEREO-A REleASE in fall 2024, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16069, https://doi.org/10.5194/egusphere-egu25-16069, 2025.
NASA's Space Weather Research-to-Operations-to-Research program (R2O2R) supports applied space weather research on a range of topics with societal importance: including geomagnetically induced currents and their affects on power grids and pipelines, space weather impacts on satellites and human space exploration, radiation exposure on aircraft, and many more topics. The program has seen changes in the past year to accomodate more collaborative work between space scientists and users impacted by space weather. Among the exciting new initiatives, the program supports Ideas Labs which are small collaborative workshops focused on co-designing R2O2R projects and creating new collaborations. This talk will cover updates to the program, current efforts being supported by NASA, and ways for the international science community to engage in R2O2R.
How to cite: Winter-Baek, L., Shume, E., and Favors, J.: NASA Space Weather Research-to-Operations-to-Research Program, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20557, https://doi.org/10.5194/egusphere-egu25-20557, 2025.
Coronal Mass Ejections (CMEs) are the main drivers of interplanetary shocks and space weather disturbances. One of the key parameters that determine the geo-effectiveness of the CME is its internal magnetic configuration. Strong CMEs directed towards Earth can severely impact our planet, and their prediction can mitigate possible damages. Thus, efficient space weather prediction tools are necessary to produce timely forecasts for the CME's arrival at Earth and their strength upon arrival.
We recently obtained a complete 3D MHD modelling chain from Sun to Earth using COCONUT to reconstruct the coronal model and Icarus to model the inner heliosphere. COCONUT (Perri et al. 2022) is a 3D global MHD model that covers the domain from the solar surface to 0.1 AU. The model is coupled to the heliospheric models EUHFORIA and Icarus. The implemented source terms, such as radiative losses, thermal conduction, and approximated coronal heating, allow bi-modal solar wind configuration at the outer boundary, making the model suitable for space weather purposes.
The novel heliospheric model Icarus (Verbeke et al. 2022, Baratashvili et al. 2022), implemented within the framework of MPI-AMRVAC (Xia et al. 2018), introduces new capabilities to model the heliospheric solar wind and actual CME events. Ideal MHD equations are solved in the co-rotating reference frame with the Sun. Different CME models are injected in the domain superposed on the stationary solar wind. Advanced techniques, such as adaptive mesh refinement and gradual radial grid stretching, are implemented to optimise the simulations. The most significant advantage of the AMR in MPI-AMRVAC is that one can design the refinement criteria according to the purpose of the simulation run.
The obtained fully physics-based MHD chain from Sun to Earth allows the modelling of the CMEs from the solar surface and their dynamic propagation into the heliosphere, paving the way to the most accurate and realistic simulation setups.
How to cite: Baratashvili, T. and Poedts, S.: From Sun to Earth: Exploring the strengths and challenges of the complete MHD modelling chain with COCONUT+Icarus, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6401, https://doi.org/10.5194/egusphere-egu25-6401, 2025.
The solar origins of some geomagnetic storms are ambiguous, which makes the prediction difficult. On March 23, 2023, a severe geomagnetic storm occurred; however, forecasts based on remote-sensing observations failed to predict it. Here, we demonstrate that this storm originates from the faint eruption of a trans-equatorial, longitudinal and low-density magnetic flux rope (FR). Before the eruption, the FR appears as a lengthy strip with weaker coronal emission and no chromospheric signs. Then, the FR’s gentle eruption results in a faint full-halo coronal mass ejection (CME), which is missed by forecasters and not identified in CME catalogs. Clear evidence from both remote-sensing and in-situ observations shows that this FR-containing CME propagates to Earth and causes the geomagnetic storm. Combining magnetic field modeling and in-situ measurements, we reveal that the FR’s southward axial magnetic field is the main cause of the storm. This CME is the stealthiest one reported causing a severe geomagnetic storm, and our study highlights that erupting trans-equatorial FRs can generate major geomagnetic storms in a stealthy way. Characteristic observational signatures of similar eruptions are proposed to help in future forecasts.
How to cite: Teng, W., Su, Y., Ji, H., and Zhang, Q.: Unexpected major geomagnetic storm caused by faint eruption of a solar trans-equatorial flux rope, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3230, https://doi.org/10.5194/egusphere-egu25-3230, 2025.
Recent progress in undersatanding a role of the solar background magnetic field in defining solar activity is presented using eigen vectors derived with Principle Compnent Analysis. This approach revealed a presence of not only 11 year solar cycles but also of grand solar cycles with duration of 330-380 years. We demonstrated that these grand cycles are formed by the interferences of two magnetic waves produced by solar dynamo with dipole magnetic field in two layers of the solar interior with close but not equal frequencies. These grand cycles are always separated by grand solar minima (GSMs) similar to Maunder minimum type, with the modern GSM started in 2020 and to last until 2053. This GSM leads to a reduction of solar irradiance by about 0.22% from the modern level and a decrease of the average terrestrial temperature by about 1.0C in the cycle 26. The reduction of a terrestrial temperature can have important implications for different parts of the planet on growing vegetation, agriculture, food supplies and heating needs in both Northern and Southern hemispheres.
How to cite: Zharkova, V., Zharkov, S., and Shepherd, S.: Modern grand solar minimum and its impact on the terrestrial environment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20202, https://doi.org/10.5194/egusphere-egu25-20202, 2025.
Geomagnetic storms are major disturbances in the near-Earth magnetic environment. A geomagnetic storm can cause electrical power outages on the ground known as the geomagnetically induced currents (GICs). The GICs are directly related to the changes in the geomagnetic field over time and thus, they can be approximated by the time derivative of the geomagnetic field (dH/dt). A geomagnetic storm has three phases: initial phase, main phase and recovery phase. The initial phase of a geomagnetic storm is identified by a strong increase in the positive direction in the magnetic index Dst, known as the Sudden Commencement (SC) following the solar wind compression at the magnetopause. When there is no main phase following the solar wind compression, it is called Sudden Impulse (SI). In this project, it is aimed to study the variations in the geomagnetically induced currents determined by using the ground level magnetic field measurements from Iznik geomagnetic observatory (40.43 N, 29.72 E). The focus is given on the GICs that occur on the ground at different phases of the geomagnetic storm in order to understand the solar wind-magnetosphere connection at these latitudes. Iznik ground level magnetic field data corresponding to 70 magnetic storm events, with 41 SC and 29 SI, were analyzed along with WIND measurements at L1 distance. GICs were calculated using the time derivatives of the ground magnetic field data through Faraday’s induction law. First, statistical properties of the GICs associated with the magnetic storms were determined such as storm phase dependence. Following this, search on the correlation between GICs and solar wind plasma, magnetic field strength and southward IMF Bz were investigated. It was determined that the GICs are stronger and occur more dominantly during the initial phase of the storm corresponding to SC and SI events while those occurring during main phase of the storm are weaker. It was also shown that the GICs during the recovery phase occurred strong and as frequent as the initial phase of the storm. Initial results showed positive correlation with the solar wind plasma pressure, indicating that the GICs recorded over Iznik are mostly associated with the SC/SI events. For selected cases, CalcdeltaB model at NASA/CCMC were used in order to further investigate the occurrence of GICs over Iznik as associated with geomagnetic storms, especially to understand the cause of the Iznik GICs. Comparisons with the model results were made and it was seen that the model results vary from event to event. In this presentation, typical characteristics of the GICs over Iznik, Türkiye and their source of occurrence and initial results from the model comparisons will be discussed in the frame of solar wind-magnetosphere-ground interaction.
How to cite: Dag, R. B. and Kaymaz, Z.: Geomagnetically Induced Currents over Iznik associated with Geomagnetic Storms, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13760, https://doi.org/10.5194/egusphere-egu25-13760, 2025.
Geomagnetic field variations related to magnetospheric Ultra Low Frequency (ULF) waves are frequently observed during geomagnetically active conditions, and they induce geoelectric fields that ultimately drive geomagnetically induced currents (GIC) in power systems. The properties of these waves – including frequency, amplitude, and polarization – vary widely due to many factors including local time, latitude, phase of geomagnetic storm, state of magnetosphere-ionosphere system, and type of solar wind driving condition. Additionally, measurements of geomagnetic fields, geoelectric fields, and GIC with sampling intervals needed to detect many ULF waves (~1s) are sparse during major historical storms. For these reasons, it is challenging to quantitatively assess extreme ULF wave amplitudes and determine which conditions lead to the largest wave fields and GIC. In this research, we use recently improved ground conductivity constraints and an expanded catalog of 1s measurements during past geomagnetic storms to estimate moderate, large, and extreme ULF wave geoelectric field amplitudes, primarily focusing on mid- and low-latitude regions and comparing with direct GIC measurements in several cases. We further describe the conditions that lead to the largest amplitude ULF wave geoelectric fields and GIC.
How to cite: Hartinger, M., Shi, X., Baker, J., and Liu, T.: Geoelectric Fields and Geomagnetically Induced Currents Related to Magnetospheric Ultra Low Frequency Waves, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4883, https://doi.org/10.5194/egusphere-egu25-4883, 2025.
The exosphere is the outermost layer of the terrestrial atmosphere which is mainly comprised of atomic hydrogen (H) and extends from several hundreds of kilometers (~500 km) to several Earth radii (~60 RE). Knowledge of the 3-D structure and spatial distribution of H densities, especially during geomagnetic storms, is crucial to understand (i) the mechanisms that may enhance its permanent escape to space and (ii) its significant role in governing the transient response of the terrestrial plasma environment to space weather. Current analysis of this vast neutral region is carried out via remote sensing measurements of scattered FUV emissions by H atoms, specifically at Lyman-Alpha ~121.6 nm. Zoennchen et al., (2017) and Cucho-Padin & Waldrop., (2019) have conducted multi-event studies of storm-time exospheres using observations from the Lyman-Alpha Detectors (LADs) onboard NASA’s Two-Wide angle Imaging Neutral-atom Spectrometers (TWINS) mission. They found that H densities significantly increased during the main phase of the storm followed by a slow recovery period to quiet-time conditions. Such increase in the number density is theorized to be caused by changes in the temperature and density at its lower boundary, the exobase at ~500 km, during geomagnetic storms. In this work, we investigate the response of the terrestrial exosphere to the geomagnetic superstorm that occurred between May 10-11, 2024, using the Kinetic-based Terrestrial Exospheric (KITE) model which solves the kinetic equation of the H atoms using the finite volume method. Our simulations show a vertical redistribution of atomic H that varies with location. Near the ecliptic plane, there is a depletion of H of up to ~35% with respect to quiet time condition below 3RE altitude, but there is an increase of ~20% above this transition point. Near the north pole, there is a constant increase of atomic H that reaches up to 60% variation at 1.2 RE altitude. We intend to compare these simulations to actual observations of the geocoronal H Lyman-Alpha emission obtained by the Cosmic Origins Spectrograph (COS) instrument onboard the Hubble Space Telescope.
How to cite: Bhattacharyya, D., Cucho-Padin, G., Thiemann, E., Machol, J., Sibeck, D., and France, K.: The dynamic response of the Earth’s exosphere to the 10-11 May 2024 Superstorm, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14868, https://doi.org/10.5194/egusphere-egu25-14868, 2025.
On the May 11th 2024, a succession of CMEs merged in the interplanetary space before striking the Earth. On impact, the interplanetary magnetic field Bz was strongly negative causing an extreme geomagnetic storm, the most intense one seen in the last 20 years. This geomagnetic storm strongly modified fluxes of particles in both the proton and the electron radiation belts. In the case of electrons, this extreme storm led to the direct injection of electrons in the inner belt but also lead to the apparition of multiple electronic belts during the recovery phase. An other implication of this storm was the enhanced electron precipitation flux into the atmosphere. Moreover, solar protons penetrated the magnetosphere causing a Solar Energetic Particle (SEP) event which was measured at geostationary orbit by GOES and in Low Earth Orbit by the EPT. In turn, with those observations and the use of the Atmospheric Radiation Interaction Simulator (AtRIS), the effects of the storm on the atmosphere (ionization and radiation dose rates) are estimated, including the Galactic Cosmic Ray (GCR) Forbush decrease, solar protons and the change in vertical rigidity cutoff. Moreover, observations of atmospheric ozone content from the Aura/MLS instrument show that the event of May 2024 caused a temporary depletion of mesospheric ozone in response to increased ionization rates.
How to cite: Winant, A., Pierrard, V., and Botek, E.: The impact of the May 11th 2024 solar storm on Earth’s environment and atmosphere, combining space borne observations and AtRIS simulations., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15598, https://doi.org/10.5194/egusphere-egu25-15598, 2025.
Well organized and systematic study of sun-earth connection is vital. The fact that the state and conditions of space are influenced by solar activity, makes the space weather domain a field of vibrant research. Solar flares are rapid expulsions of electromagnetic radiation from the Sun's active regions. These complex transient excitations, mainly in soft X-rays (0.1 – 10nm), and extreme ultraviolet (10 – 121.6 nm) resulting in ionospheric response, have been a subject of keen interest over decades. Studies show a clear indication of Coronal Mass Ejections (CMEs) associated with flares and prominences. This is of prime importance, as the research on flare associated CMEs does have some underlying impacts to be revealed. The sudden enhancement of X-ray and extreme ultraviolet irradiance during flares raises the density of the ionosphere through enhanced photoionization. Sudden ionospheric disturbances due to the enhancement of plasma density is crucial and the total electron content (TEC) is a potent measure of the ionospheric response. Present study focuses on the analysis of ionospheric plasma irregularities and TEC variation due to M and X class solar flares in the beginning of solar cycle 25.
We considered intense flares in the period 2019 - 2024, due to the solar activity growth at the ascending part of the solar cycle 25. Out of these, 15 M class and 15 X class flares are chosen to study plasma instabilities and TEC variations. On the basis of multiple observations from GNSS receivers and satellite missions, we present how flare characteristics affect flare responses in the ionosphere and the formation of large-scale travelling ionospheric disturbances, during intense solar flares. The estimation of enhanced TEC (ΔTEC) shows that the peak enhancement in TEC is highly correlated with peak enhancement in X-ray flux during solar flares. Plasma density shows significant escalations on flare days than on non-flare days. More intense X-class flare provoked a more significant response in the ionosphere than the less intense M class flare. In addition to this, our study also expands in relating the same to flare associated CMEs in the given solar cycle. The CMEs whose source regions are known, can be used to draw out valid conclusions on CME - flare association and how this impacts the ionospheric responses. The growing space weather effects has also led to an increase in space weather research that aims to enumerate the sun-earth connection more precisely. The investigation on variation of both TEC and plasma density leads to better understanding of the ionospheric response to flare activity to a remarkable extent.
How to cite: Prasad Revamma, P., Sasidharan Pillai Lekha Kumary, A. T., and Prabhullachandran Sobhanakumari, S.: Study of Ionospheric response to intense Solar Flares in the ascending half of the solar cycle 25 , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-375, https://doi.org/10.5194/egusphere-egu25-375, 2025.
Space weather event catalogs are essential tools for characterizing the near-Earth space environment. From a scientific standpoint, these catalogs provide extensive statistical insights into the physical properties of such events. Operationally, they support forecasting scenarios by offering a basis to assess the diverse impacts these events may have on the near-Earth space environment.
Interplanetary Coronal Mass Ejections (ICMEs) and Stream Interaction Regions (SIRs) are two of the most significant drivers of space weather disturbances. Traditional catalogs of these large-scale solar wind structures are primarily built using in-situ measurements from L1 monitors like WIND, ACE, and DSCOVR. However, these datasets primarily cover the period after 1995, limiting the temporal scope of current catalogs.
Conversely, geomagnetic indices have recorded Earth’s geomagnetic activity for several decades before the advent of the space era. These indices have been shown to respond differently to ICMEs and SIRs (e.g., Benacquista et al., 2017; Bernoux and Maget, 2020), making them a valuable resource for identifying these events in earlier periods.
In this study, we adapt an existing deep learning-based method—originally developed for detecting ICMEs and SIRs using L1 solar wind data—to analyze geomagnetic index measurements. While the geomagnetic-based approach is inherently less precise than its solar wind counterpart, it successfully identifies time intervals likely associated with ICMEs or SIRs
This method is used to extend existing ICME and SIR catalogs back in time to cover the period from 1870 to 1995. Although the resulting extension is not exhaustive, it captures the most geoeffective events, offering a valuable dataset for long-term climatological studies of space weather. This work lays the groundwork for future research aimed at understanding historical space weather trends and their implications for Earth's near-space environment.
This work was supported by both the FARBES (Forecast of Actionable Radiation Belts Scenarios) project, funded by the European Union's Horizon Europe research and innovation programme under grant agreement No 101081772 and ONERA internal fundings, through the federated research project PRF-FIRSTS.
How to cite: Nguyen, G., Bernoux, G., Rüdisser, H., and Gibaru, Q.: Long term-extension of ICMEs and SIRs catalogs with deep learning and geomagnetic indices, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6702, https://doi.org/10.5194/egusphere-egu25-6702, 2025.
Posters on site: Wed, 30 Apr, 10:45–12:30 | Hall X4
The European Space Agency's (ESA) Swarm mission is designed to conduct a highly detailed survey of Earth's geomagnetic field and its changes over time. Launched on November 22, 2013, the mission consists of three identical satellites, Alpha (A), Bravo (B), and Charlie (C), into near-polar Low Earth Orbits (LEO). Swarm A and C fly side-by-side at approximately 470 km above Earth, while Swarm B maintains a higher orbit at around 520 km. Each Swarm satellite has six advanced scientific instruments providing precise measurements: an absolute scalar and vector field magnetometer, a star tracker, an electric field instrument (Langmuir probe and thermal ion imager), a GPS receiver, and an accelerometer. For over a decade and continuing to this day, the Swarm mission has been delivering high-quality data, providing valuable insights into Earth’s magnetic field, ionosphere, and other
dynamic processes in the near-Earth environment.
The Swarm L1b fast-track (FAST) operational chain data are distributed at a significantly faster pace and higher frequency than the standard products (OPER), which typically become available after a delay of three days. FAST data products are designed to minimize the time gap between event occurrence and measurement, providing near real-time access to critical information. This accelerated data delivery enhances the capability to monitor and forecast space weather more effectively. In particular, the Field-Aligned Currents (FAC) and Total Electron Content (TEC) data products rely on L1b products as essential inputs for processing within the GFZ L2 data product chain. Here, we present the fast operational Field-Aligned Currents (FAC) and Total Electron Content (TEC) data products. A comparison with OPER products shows that the FAST data maintains high quality, as it is based on the same algorithms used for the standard OPER products. Despite the faster processing and delivery, the FAST FAC and TEC products offer reliable results that align closely with the operational products. This suggests that the FAST products can be effectively used for real-time space weather monitoring and forecasting while maintaining the accuracy of the information provided.
How to cite: Rauberg, J., Kervalishvili, G., Michaelis, I., Rother, M., and Korte, M.: Swarm Fast-track Field-Aligned Currents (FAC) and Total Electron Content (TEC) data products, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8981, https://doi.org/10.5194/egusphere-egu25-8981, 2025.
Variations in the ionospheric currents can cause rapid disturbances in the magnetic field at the ground level, so called dB/dt spikes, and Geomagnetically Induced Currents (GICs) that can harm human infrastructure. When investigating dB/dt spike occurrence and GIC risks, the focus has typically been on geomagnetic storms. However, recently it has been argued that it is the substorm phenomena which contains the crucial physics for spikes and GICs, and which instead should be in focus. Here we present results from a statistical investigation on the occurrence of spikes in substorms (“substorm spikiness”) as observed in the geomagnetic activity indices SME, SMU, and SML provided by the SuperMAG collaboration. We study the substorm spikiness for different years in the solar cycle and for different levels of geomagnetic disturbance according to the SMR ring current index, and we search for possible solar wind drivers. We investigate both the magnitude and the variability of various potential drivers and conclude that some of the more important drivers are the solar wind speed magnitude and its variability.
How to cite: Hamrin, M., Johansson, C., Nordvall, F., Schillings, A., Pitkänen, T., Araújo, J., Vaverka, J., Opgenoorth, H., and Gjerloev, J.: A Statistical Study of Possible Drivers for Substorm dB/dt Spikiness, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4124, https://doi.org/10.5194/egusphere-egu25-4124, 2025.
Solar activity significantly influences the Earth's magnetosphere and ionosphere, causing current systems and space weather effects. The interaction between rapidly changing magnetic field and the Earth’s conductivity induces an electric field at the surface producing Geomagnetically Induced Currents (GICs) within critical human infrastructure, posing a risk of damage to power lines.
GICs strongly depend on the ground conductivity. Sweden has large spatial variations and complexity in the underlying ground conductivity structure across the country. In order to better understand GICs and for the identification of the worst-case scenarios for Swedish power transmission lines, 3D simulations are essential.
We present results from our GIC simulations, computed using our own 3D FDTD framework employing a Swedish ground conductivity model in high resolution. Compared to previous simulations of the Swedish power grid, ours is High Performance (runs on parallel GPUs), more flexible, and we can simulate the GICs in the time domain, instead of only the frequency domain as has been done before in simplistic approaches. This enables us to study GICs caused by much more realistic ionospheric source currents.
How to cite: Vaverka, J., Araújo, J., Wadbro, E., Opgenoorth, H., and Hamrin, M.: 3D Time Domain Simulation of Geomagnetically Induced Currents in Swedish Power Transmission Lines , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10105, https://doi.org/10.5194/egusphere-egu25-10105, 2025.
Novel remote-sensing techniques can be used to inject vital "oncoming storm" data into upgraded prediction models. Here we present several possibilities being investigated under the auspices of the RISER project, whose goal is to improve space weather forecast times by up to four days, as well as their accuracy. Here, in this early stage of the project one strand is to investigate how best to integrate such new data. We describe how to leverage the capabilities of our existing IONwork software to produce GNSS-based TEC disturbance maps, and use that processed data in concert with information from the heliosphere to create remote-plus-local combined prediction models, comparing both traditional and machine learning techniques. Heliospheric information can be extracted, for example, from L1 monitors: however, within the RISER project we aim at expanding the heliospheric information available by including observations of interplanetary scintillation and corresponding tomographic reconstructions to map solar-wind or CME features structures present in the Sun-Earth interplanetary space. Such extended data will also provide longer lead times than the approximately one hour advance notice given by L1 data, making it easier to create forecasts that are both timely and more accurate.
How to cite: Kinsler, P., Forte, B., Lu, T., Bisi, M., Milan, S., Jackson, D., Fallows, R., Jackson, B., Odstrcil, D., Henley, E., Barnes, D., Chang, O., Bracamontes, M., and Gonzi, S.: Using novel remote sensing techniques to enhance local prediction models of ionosphericresponse to space weather: a RISER project approach, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12224, https://doi.org/10.5194/egusphere-egu25-12224, 2025.
Space weather prediction has become increasingly critical as technological systems—ranging from power grids to satellite communication networks—remain vulnerable to extreme solar activity. Solar flares and coronal mass ejections (CMEs) release high-energy particles and electromagnetic radiation, which can induce geomagnetic storms and disrupt critical infrastructure. Despite significant advances, accurately forecasting the timing, intensity, and impact of these events remains an open challenge due to the complex and non-linear nature of solar activity. Traditional physics-based models, while valuable, are limited by computational constraints and their inability to fully capture the high-dimensional variability of solar phenomena.
Recent progress in machine learning (ML) offers a promising pathway for advancing space weather forecasting by identifying hidden patterns in vast datasets generated by solar observatories. This study utilizes high-resolution, multi-wavelength extreme ultraviolet (EUV) imagery from NASA’s Solar Dynamics Observatory (SDO) and integrates deep learning techniques to improve solar flare prediction. Specifically, convolutional neural networks (CNNs) are employed to extract spatial features of solar flares, while recurrent neural networks (RNNs) model the temporal evolution of solar activity. These models are trained on historical datasets incorporating solar flare images, X-ray flux data, and geomagnetic indices (Dst and Kp) to classify flare intensity and predict potential geomagnetic impacts.
Preliminary results demonstrate that the ML models outperform traditional methods in both detection accuracy and real-time prediction capabilities. Additionally, by leveraging the multi-channel nature of SDO’s EUV imagery, the models can capture complex spatiotemporal dynamics of solar flares, providing a more nuanced understanding of their development. However, key challenges remain, including improving model interpretability, ensuring data completeness, and integrating diverse data sources into operational space weather forecasting frameworks. This study highlights both the potential of machine learning in heliophysics and the ongoing need for interdisciplinary approaches to develop robust and scalable space weather prediction systems.
How to cite: Mauda, N., Landa, V., and Reuveni, Y.: Using SDO Solar Flare Images Along with ML Techniques for Space Weather Prediction, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12821, https://doi.org/10.5194/egusphere-egu25-12821, 2025.
We report on an attempt towards combining the STEREO Relativistic Electron Alert System for Exploration (REleASE) forecasting system with observations of sufficiently bright Type-III radio bursts as a precondition for forecasting. STEREO REleASE forecasts are based on the detection of early arrival of near-relativistic electrons, detected by the Solar Electron Proton Telescope (SEPT) and the High Energy Telescope (HET) onboard STEREO, ahead of more hazardous 21-40 MeV protons from solar energetic particle (SEP) events at STEREO’s current location. These forecasts are complementary to but independent from HESPERIA REleASE forecasts available from L1 supporting the Earth-moon system. While the STEREO REleASE+ system is designed for forecasting locally at STEREO, the current location of the s/c in between Earth L1 and L4 in principle allows for early warnings of Lunar explorers from SEPs originating behind the Sun’s western limb, where source regions are hidden from direct view from the Sun-Earth line. About ¼ of all SEPs affecting Earth originate from there. To improve the STEREO REleASE forecast capabilities, we use a recently developed system that a) automatically identifies Type III radio bursts that are associated with electron beams accelerated in solar eruptive events, and b) sets a condition of the occurrence of a Type-III radio burst associated with significant SEPs (with HET proton fluxes above 0.22 cm-2 s-1 sr-1 MeV-1), thus adding independent evidence of particle escape from the Sun. The STEREO REleASE+ system which builds on the experience of the recent HESPERIA REleASE+ implementation for L1, takes advantage of availability of real-time beacon solar radio observations from STEREO-A/SWAVES and has now been incorporated and running in the HESPERIA framework (https://hesperia.astro.noa.gr). We discuss the techniques used for the automatic detection of Type-III radio bursts, the determination of selection criteria for Type-III bursts as precursors of solar proton events at STEREO’s location and show some representative results of the combined system. Olga Malandraki objects to mandatory EGU membership linked to science presentations.
How to cite: Malandraki, O., Tziotziou, K., Karavolos, M., Droege, H., Heber, B., and Kuehl, P.: STEREO REleASE+: Improving Solar Proton Event Forecasting by means of Automated Recognition of Type-III Radio Bursts, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19494, https://doi.org/10.5194/egusphere-egu25-19494, 2025.
How to cite: Bednorz, S., Pęczek, K., Grzanka, L., Swakoń, J., Galli, A., Sanchez-Cano, B., Barabash, S., Brandt, P., Wurz, P., Nénon, Q., Witasse, O., and Hajdas, W.: Software assisting data analysis of space radiation in spacecraft missions., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18339, https://doi.org/10.5194/egusphere-egu25-18339, 2025.
The Earth Radiation Budget at the Top of the Atmosphere (ToA) governs the status of climate change on our planet. The ERB is the balance between the incoming Total Solar Irradiance (TSI) and total outgoing radiation at the ToA. If more energy is stored in the system the Earth Energy Imbalance is positive and the temperature in the system rises. The Compact Lightweight Absolute RAdiometer (CLARA) experiment onboard the Norwegian micro satellite NorSat-1 is an SI traceable radiometer with the primary science goal to measure TSI from space. Besides TSI, CLARA also measures the terrestrial Outgoing Longwave Radiation (OLR) at the ToA on the night side of Earth. We present the latest status of the data and degradation correction obtained with this SI-traceable radiometer and compare the CLARA TSI and OLR time series with other available observations and reanalysis data. Furthermore, we explore potential synergies with the upcoming TRUTHS mission as well as the Earth Explorer 12 candidate mission ECO.
How to cite: Haberreiter, M., Finsterle, W., and Montillet, J.-P.: Terrestrial Outgoing Longwave Radiation as measured with CLARA onboard NorSat-1, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11228, https://doi.org/10.5194/egusphere-egu25-11228, 2025.
Surface shortwave downward radiation (SWDR) is a key parameter in the Earth's energy budget. Accurate estimation of SWDR is essential for understanding the interactions between the Earth-atmosphere system and global climate change. In particular, the direct and diffuse components of SWDR are critical for applications such as vegetation modeling, carbon cycle simulations, surface albedo estimation, and shortwave radiation correction in complex terrain areas. However, high-precision separation of direct and diffuse SWDR remains lacking. Additionally, current satellite-based SWDR studies often show limited accuracy, especially over highly reflective surfaces such as polar regions, where SWDR is frequently underestimated. This underestimation is attributed to the adjacency effect caused by highly reflective surfaces, which has rarely been quantitatively modeled.
Therefore, this study proposes a framework for shortwave radiation estimation that emphasizes the direct-diffuse SWDR separation and the adjacency effect correction. First, a unified shortwave radiation estimation algorithm is developed, allowing for the simultaneous estimation of total, direct, and diffuse SWDR. Second, an adjacency effect correction scheme is developed, which separately accounts for the influence of direct and diffuse SWDR components. This approach effectively mitigates the underestimation caused by adjacency effects over highly reflective surfaces. The proposed framework is simple and efficient, utilizing only satellite-observed radiance, angle, and elevation as inputs to achieve accurate inversion of total, direct, and diffuse SWDR. Validation using ground-based measurements from global observation networks demonstrates that this framework not only enables high-precision retrieval of SWDR components but also significantly reduces the underestimation caused by the adjacency effect over highly reflective surfaces. This scheme shows substantial potential for generating high-accuracy multi-component shortwave radiation products, advancing global energy budget analysis and related applications.
How to cite: Leng, W., Wang, T., and Xian, Y.: All-Sky Surface Shortwave Downward Radiation Retrieval: Emphasizing Direct-Diffuse Separation and Adjacency Effect Correction, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18765, https://doi.org/10.5194/egusphere-egu25-18765, 2025.
Posters virtual: Thu, 1 May, 14:00–15:45 | vPoster spot 3
EGU25-18737 | Posters virtual | VPS27
Initial Results of Total Solar Irradiance Measurements by DARA-PROBA3Thu, 01 May, 14:00–15:45 (CEST) | vP3.22
The ESA-PROBA3 spacecraft was successfully launched aboard a four-stage PSLV-XL rocket from the Satish Dhawan Space Centre in Sriharikota, India, on Thursday, December 5th, at 11:34 CET (10:34 GMT, 16:04 local time). Formation flying a pair of spacecraft will form an artificial solar eclipse in space, casting a precisely-controlled shadow from the Occulter platform to the Coronograph spacecraft to open up sustained views of the Sun's faint surrounding corona. The payload on the ESA-PROBA3 Occulter spacecraft includes the Digital Absolute Radiometer (DARA) from the Physikalisch Meteorologisches Observatorium, Davos and World Radiation Center (PMOD/WRC). It aims at measuring the Total Solar Irradiance (TSI) in orbit. The destination of the spacecraft is a highly elliptical orbit (600 x 60530 km at around 59 degree inclination). We will present the initial results from this new experiment since its launch.
How to cite: Montillet, J.-P., Finsterle, W., Haberreiter, M., Schmutz, W., Pfiffner, D., Koller, S., and Gander, M.: Initial Results of Total Solar Irradiance Measurements by DARA-PROBA3, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18737, https://doi.org/10.5194/egusphere-egu25-18737, 2025.
