The growing global demand for green energy requires the development of innovative solutions. Floating offshore wind turbines (FOWTs) present significant potential by enabling the harvesting of wind in deep-sea waters. However, as this technology is still in its early stages, the impact of the added six degrees of freedom (6-DOF) motion on wake dynamics and power performance remains unclear. Understanding these effects is critical for the design of floating wind farms. In this work, large eddy simulations and an actuator line model are employed to investigate the wake behavior and power output of the IEA-15MW reference turbine mounted on several floating platform concepts. To explore wake interactions in wind farm scenarios, two tandem FOWTs are modelled. The simulations are carried out in AMR-Wind, coupled with OpenFAST for the platform and blades' motion.
Initial cases are conducted with a laminar inflow to isolate fundamental wake mechanisms. Then, a neutral atmospheric boundary layer (ABL) is recreated to perform investigations with realistic offshore conditions.
Platform motions are found to induce velocity fluctuations in the wake and promote vortex-pairing. High-frequency and large-amplitude motions particularly enhance wake recovery in the upstream wake, although this effect is less pronounced in the downstream wake. Among all 6-DOF, surge is identified as the main driver of wake dynamics.
FOWTs generate larger turbulence levels than their fixed counterparts during laminar inflow. Notably, when the downstream turbine moves in phase with the incoming wake, the resulting interaction leads to the superimposition of the wake structures, forming large, separated low-speed regions.
In contrast, under turbulent conditions, FOWTs generate lower turbulence in the near wake, but similar levels further downstream. In these cases, the differences in mean wake velocity between floating and fixed turbines decrease significantly with distance.
The tandem FOWTs are found to produce less total power when operating at rated speed during neutral ABL conditions. However, the downstream FOWTs exhibit power gains of up to 20\%, indicating that larger floating wind farms are likely to generate more electricity than traditional bottom-fixed offshore wind farms. ... Read more

The joint ESA/NASA Mass-change And Geosciences International Constellation (MAGIC) has the objective to extend time-series from previous gravity missions, including an improvement of accuracy and spatio-temporal resolution. The long-term monitoring of Earth’s gravity field carries information on mass change induced by water cycle, climate change and mass transport processes between atmosphere, cryosphere, oceans and solid Earth. MAGIC will be composed of two satellite pairs flying in different orbit planes. The NASA/DLR-led first pair (P1) is expected to be in a near-polar orbit around 500 km of altitude; while the second ESA-led pair (P2) is expected to be in an inclined orbit of 65^◦–70^◦ at approximately 400 km altitude. The ESA-led pair P2 Next Generation Gravity Mission shall be launched after P1 in a staggered manner to form the MAGIC constellation. The addition of an inclined pair shall lead to reduction of temporal aliasing effects and consequently of reliance on de-aliasing models and post-processing. The main novelty of the MAGIC constellation is the delivery of mass-change products at higher spatial resolution, temporal (i.e. subweekly) resolution, shorter latency and higher accuracy than the Gravity Recovery and Climate Experiment (GRACE) and Gravity Recovery and Climate Experiment Follow-On (GRACE-FO). This will pave the way to new science applications and operational services. In this paper, an overview of various fields of science and service applications for hydrology, cryosphere, oceanography, solid Earth, climate change and geodesy is provided. These thematic fields and newly enabled applications and services were analysed in the frame of the initial ESA Science Support activities for MAGIC. The analyses of MAGIC scenarios for different application areas in the field of geosciences confirmed that the double-pair configuration will significantly enlarge the number of observable mass-change phenomena by resolving smaller spatial scales with an uncertainty that satisfies evolved user requirements expressed by international bodies such as IUGG. The required uncertainty levels of dedicated thematic fields met by MAGIC unfiltered Level-2 products will benefit hydrological applications by recovering more than 90 per cent of the major river basins worldwide at 260 km spatial resolution, cryosphere applications by enabling mass change signal separation in the interior of Greenland from those in the coastal zones and by resolving small-scale mass variability in challenging regions such as the Antarctic Peninsula, oceanography applications by monitoring meridional overturning circulation changes on timescales of years and decades, climate applications by detecting amplitude and phase changes of Terrestrial Water Storage after 30 yr in 64 and 56 per cent of the global land areas and solid Earth applications by lowering the Earthquake detection threshold from magnitude 8.8 to magnitude 7.4 with spatial resolution increased to 333 km. ... Read more