Aerosols (small particles in the air) have profound impacts on clouds such that they reflect more solar radiation back to space, exerting an overall cooling effect on the Earth. This this project, we will establish a novel framework to optimize the methodology used for estimating aerosol-cloud interactions (ACI) from satellites. In combination with new satellites PACE and EarthCARE, we will determine the optimized satellite-based ACI and then use it to constrain current climate models. The project is a crucial step towards confident predictions of future climate, especially important given the context of continuously decreasing aerosol emissions in our warming world.

This project aims to improve our understanding of Jupiters atmosphere, which is vital for studying gas giants. We will explore the possibility of a stable layer in Jupiters atmosphere using a numerical general circulation model that may explain its unique features. NASAs Juno mission has shown that Jupiters jet streams reach deep into its atmosphere, but the reasons for their cutoff are still a mystery. We will investigate how different configurations of this stable layer could influence jet streams and examine factors like a unique phase of helium and temperature changes that might support its existence.

Aerosolen spelen een cruciale rol in de stralingsbalans van de aarde. Sinds het industriële tijdperk hebben de toegenomen emissies van aerosolen bijgedragen aan afkoeling van de atmosfeer, wat de opwarming door broeikasgassen gedeeltelijk heeft gecompenseerd. Aangezien klimaatmodellen de belangrijkste instrumenten zijn voor het voorspellen van toekomstige klimaatveranderingen, is het essentieel om hun vermogen te verbeteren om de samenstelling, fysieke en stralingskenmerken van aerosolen en hun interacties met wolken nauwkeuriger te vertegenwoordigen. Dit project heeft als doel deze uitdagingen aan te pakken door geavanceerde satellietwaarnemingen te combineren met innovatieve technieken in klimaatmodellering.

The Laser Interferometry Space Antenna (LISA), scheduled for launch in the mid-2030s, will measure gravitational waves (GWs) that have about 105 times longer wavelengths than can be measured with ground-based GW detectors. This opens up a new discovery window on (astro)physics that can be probed with GWs. It brings into view the merging of supermassive black holes at the nuclei of galaxies or stellar-sized compact objects falling into those, tens of thousands of white dwarf binaries in our Galaxy, cosmology, and the early stages of merging binary neutron stars and stellar-sized black holes. Early access to this exciting opportunity for the Dutch community and crucial involvement in this innovative technological challenge motivate this proposal. LISA is in principle an interferometer like the LIGO and Virgo detectors on Earth, but now the end stations are 2.5 million km apart in space. This necessitates several additional techniques to make it work as an interferometer. One of those techniques concerns novel quadrant InGaAs photodiodes (QPDs) with high sensitivity so that the sub-nanoWatt 1064-nm laser light can be discerned after interference with the local microWatt laser signal. Unique expertise at SRON and Nikhef makes it possible to develop these demanding QPDs with their large sensitive area, low-noise and large bandwidth. Together with Dutch industry, SRON and Nikhef are developing QPDs for LISA and have completed promising first prototypes as part of the phase A study of LISA. Here, we propose to develop the QPDs to the required performance and mature the design to flight-readiness. This involves design refinements, technology simulations, two epitaxy rounds, processing of wafers to QPDs, performance and reliability testing of QPDs, packaging procedures, assembly with front-end electronics and housing, verification and full-system testing in a complete optical bench.

The question ‘are we alone?’ is a central question in astronomy. It has become even more relevant due to the recent discovery of planets within the habitable zone of their star. Since life changes the composition of the planet’s atmosphere, its signatures can be measured in the spectrum of that atmosphere. However, an Earth-like planet around a Sun-like star is very faint. The solution is to use a coronagraph, which supresses the starlight, but not the planet. Still, the signal from the planet is less than 1 photon/pixel/second. A crucial technology is therefore a noiseless, photon-counting detector, which ideally resolves the energy of each photon. Established detectors based on photoconductor technology have too high noise, and energy information is lost due to the high bandgap. I propose the next generation camera in which every pixel resolves the energy of each incoming photon, using microwave kinetic inductance detectors (MKIDs). Each pixel is a superconducting resonator, in which a single photon creates thousands of excitations. The resonator response is a direct measure of the photon energy. The theoretical energy resolution of >70 (at 400 nm - 2.5 μm) allows to distinguish the main molecular lines associated with life without additional optics. On top of that these detectors are dark- and read noise free. The main challenge I will face is reaching the energy resolution of >70. Large MKID cameras have been demonstrated, but with an energy resolution <10. I will deepen the understanding of the device physics to increase the detector response, starting from my experience with the most sensitive terahertz MKIDs. As an intermediate step I will acquire practical experience through a 2000 pixel lab demonstrator with an energy resolution ≥20, which can right away function as a wavefront sensor or as a fringe sensor in optical interferometry.