Spectrally resolved outgoing longwave radiation and its applications for the study of climate

Spectrally resolved outgoing longwave radiation and its applications for the study of climate The ERC advanced “IASI-FT” project exploits the space-based instantaneous spectrally resolved observations provided by the family of IASI thermal infrared instruments to (1) monitor atmospheric composition changes and (2) establish climate records. More than 3.5 million of data are available each day, from which near-real-time information on the atmospheric state can be inferred.

Reverberation in Tidal Disruption Events: Dust Echoes, Coronal Emission Lines, Multi-wavelength Cross-correlations, and QPOs

Stellar tidal disruption events (TDEs) are typically discovered by transient emission due to accretion or shocks of the stellar debris. Yet this luminous flare can be reprocessed by gas or dust that inhabits a galactic nucleus, resulting in multiple reverberation signals. Nuclear dust heated by the TDE will lead to an echo at infrared wavelengths (1-10 μm) and transient coronal lines in optical spectra of TDEs trace reverberation by gas that orbits the black hole. Both of these signal have been detected, here we review this rapidly developing field. We also review the results that have been extracted from TDEs with high-quality X-ray light curves: quasi periodic oscillations (QPOs), reverberation lags of fluorescence lines, and cross-correlations with emission at other wavelengths. The observational techniques that are covered in this review probe the emission from TDEs over a wide range of scales: from $\sim 1$ ∼ 1 light year to the innermost parts of the newly formed accretion disk. They provide insights into important properties of TDEs such as their bolometric output and the geometry of the accretion flow. While reverberation signals are not detected for every TDE, we anticipate they will become more commonplace when the next generation of X-ray and infrared instruments become operational.

Miniaturized near-infrared instruments in dairy products or dairy industry: First steps in a long-distance race?

Near-infrared spectroscopy using benchtop instrumentation is widely used in the analysis of dairy products or in the dairy industry. In this paper, we review the use of miniaturized near-infrared instrumentation in dairy products or in the dairy industry, highlighting some strengths and limitations of current devices.

Verification of the AIRS and MLS ozone algorithms based on retrieved daytime and nighttime ozone

Ozone (O3) plays a significant role in weather and climate on regional to global spatial scales. Most studies on the variability in the total column of O3 (TCO) are typically analysed using daytime data. Based on knowledge of the chemistry and transport of O3, significant deviations between daytime and nighttime O3 are only expected either in the planetary boundary layer (PBL) or high in the stratosphere or mesosphere, having little effect on the TCO. Hence, we expect the daytime and nighttime TCO to be very similar. Comparing daytime and nighttime TCOs thus provides an approach to verify the retrieval algorithms of infrared instruments like the Atmospheric InfraRed Sounder (AIRS) and the Microwave Limb Sounder (MLS). Applying this verification on the AIRS and the MLS data we identified inconsistencies in observations of O3 from both satellite instruments. For AIRS, daytime-nighttime differences were found over oceans resembling cloud cover patterns, and over land, mostly over dry land areas, likely related to infrared surface emissivity. These differences point to issues with the representation of both processes in the AIRS retrieval algorithm. For MLS, a major issue was identified with the “ascending-descending” orbit flag, used to discriminate nighttime and daytime MLS measurements. Disregarding this issue, MLS day-night differences were significantly smaller than AIRS day-night differences, providing additional support for retrieval method origin of AIRS day-night TCO differences. MLS day-night differences are dominated by the upper stratospheric and mesospheric diurnal O3 cycle. These results provide useful information for improving infrared O3 products and at the same time will allow study the day-night differences of stratospheric and mesospheric O3.