Detecting climate trends of atmospheric temperature, moisture, cloud, and surface temperature requires accurately calibrated satellite instruments such as the Climate Absolute Radiance and Reflectivity Observatory (CLARREO). Wielicki et al. have studied the CLARREO measurement requirements for achieving climate change accuracy goals in orbit. Our study further quantifies the spectrally dependent IR instrument calibration requirement for detecting trends of atmospheric temperature and moisture profiles. The temperature, water vapor, and surface skin temperature variability and the associated correlation time are derived using Modern Era Retrospective-Analysis for Research and Applications (MERRA) and European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis data. The results are further validated using climate model simulation results. With the derived natural variability as the reference, the calibration requirement is established by carrying out a simulation study for CLARREO observations of various atmospheric states under all-sky. We derive a 0.04 K (=2, or 95% confidence) radiometric calibration requirement baseline using a spectral fingerprinting method. We also demonstrate that the requirement is spectrally dependent and some spectral regions can be relaxed due to the hyperspectral nature of the CLARREO instrument. We further discuss relaxing the requirement to 0.06 K (=2) based on the uncertainties associated with the temperature and water vapor natural variability and relatively small delay in time-to-detect for trends relative to the baseline case. The methodology used in this study can be extended to other parameters (such as clouds and CO) and other instrument configurations.
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http://dx.doi.org/10.1175/JCLI-D-16-0704.1 | DOI Listing |
Eur Radiol
January 2025
Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Objectives: To explore the reproducibility of the 1.5-T MR imaging (MRI)-based R2* method in measuring the liver iron concentration (LIC) across different MRI scanners, scan parameters, and postprocessing techniques.
Materials And Methods: We performed a systematic search of the PubMed, Embase, Medline, Cochrane Library, and Web of Science databases and identified studies that used the 1.
Introduction: Up to 20% of older adults in the United States have mild cognitive impairment (MCI), and about one-third of people with MCI are predicted to transition to Alzheimer's disease (AD) within 5 years. Standard cognitive assessments are long and require a trained technician to administer. We developed the first computerized adaptive test (CAT) based on multidimensional item response theory (MIRT) to more precisely, rapidly, and repeatedly assesses cognitive abilities across the adult lifespan.
View Article and Find Full Text PDFAppl Spectrosc
January 2025
Department of Earth Sciences, Geological Institute, , ETH Zurich, Zurich, Switzerland.
Cavity ring-down spectroscopy (CRDS) is rapidly becoming an invaluable tool to measure hydrogen (δ²H) and oxygen (δO) isotopic compositions in water, yet the long-term accuracy and precision of this technique remain relatively underreported. Here, we critically evaluate one-year performance of CRDS δ²H and δO measurements at ETH Zurich, focusing on high throughput (~200 samples per week) while maintaining required precision and accuracy for diverse scientific investigations. We detail a comprehensive methodological and calibration strategy to optimize CRDS reliability for continuous, high-throughput analysis using Picarro's "Express" mode, an area not extensively explored previously.
View Article and Find Full Text PDFBiomed Chromatogr
February 2025
School of Chemistry & Physics, College of Agriculture, Engineering & Science, Westville Campus, University of KwaZulu-Natal, Durban, South Africa.
A new selective and sensitive high-performance liquid chromatography (HPLC) method was developed for the quantification of potential impurities in fluoxetine hydrochloride. Chromatographic separation was achieved on an end-capped octadecylsilyl silica gel (Gemini-C18 150 mm × 4.6 mm, 3.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, Korea.
Addressing and mitigating decoherence sources plays an essential role in the development of a scalable quantum computing system, which requires low gate errors to be consistently maintained throughout the circuit execution. While nuclear spin-free materials, such as isotopically purified silicon, exhibit intrinsically promising coherence properties for electron spin qubits, the omnipresent charge noise, when converted to magnetic noise under a strong magnetic field gradient, often hinders stable qubit operation within a time frame comparable to the data acquisition time. Here, we demonstrate both open- and closed-loop suppression techniques for the transduced noise in silicon spin qubits, resulting in a more than two-fold (ten-fold) improvement of the inhomogeneous coherence time (Rabi oscillation quality) that leads to a single-qubit gate fidelity of over 99.
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