Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observations

<p>The submillimeter-wave radiometer operating in the along-track scanning mode continuously collects brightness temperature (TB) data over a two-dimensional (2D) cloud cross-section as the platform moves forward. TB observations from multiple positions and viewing angles show great promise in...

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Main Authors: Y. Liu, I. S. Adams
Format: Article
Language:English
Published: Copernicus Publications 2025-04-01
Series:Atmospheric Measurement Techniques
Online Access:https://amt.copernicus.org/articles/18/1659/2025/amt-18-1659-2025.pdf
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author Y. Liu
Y. Liu
I. S. Adams
author_facet Y. Liu
Y. Liu
I. S. Adams
author_sort Y. Liu
collection DOAJ
description <p>The submillimeter-wave radiometer operating in the along-track scanning mode continuously collects brightness temperature (TB) data over a two-dimensional (2D) cloud cross-section as the platform moves forward. TB observations from multiple positions and viewing angles show great promise in better constraining the 2D cloud microphysical properties compared to single-angle observations. In this study, we develop two types of tomographic reconstruction algorithms to retrieve 2D ice water content (IWC) profiles using multi-angle TB observations. The one-dimensional (1D) tomographic algorithm performs 1D retrievals beam by beam using each TB observation at a specific sensor position and viewing angle to derive cloud properties along the propagation path. It then integrates the 1D retrieval results to construct 2D cloud cross-section. The 2D tomographic algorithm directly constrains the 2D cloud microphysical properties using multi-angle scanning TB observations. Starting with an initial assumption, the algorithm iteratively refines the 2D cloud microphysical quantities by minimizing discrepancies between TB simulations and observations under prior constraints. Both tomographic algorithms are developed based on a hybrid of Bayesian Monte Carlo integration (MCI) and the optimal estimation method (OEM). A simulation experiment is conducted to evaluate the performance of two tomographic reconstruction algorithms. The experiment demonstrates stable convergence of both tomographic methods, with the 2D tomographic algorithm exhibiting superior performance. The experiment results highlight the significant advantage of using multi-angle observations to constrain 2D cloud structure. Compared to nadir-only retrievals, the tomographic technique provides a detailed reconstruction of ice clouds' inner structure with high spatial resolution. Also, the technique significantly improves retrieval accuracy by correcting systematic biases and reducing the derivation of retrieval errors. Furthermore, the tomography technique effectively increases detection sensitivity for small ice cloud particles.</p>
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issn 1867-1381
1867-8548
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spelling doaj-art-036ca3afdf834f56922e5e953d0230752025-08-20T02:16:29ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482025-04-01181659167410.5194/amt-18-1659-2025Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observationsY. Liu0Y. Liu1I. S. Adams2Goddard Earth Sciences Technology and Research (GESTAR) II, University of Maryland Baltimore County (UMBC), Baltimore, MD 21250, USANASA Goddard Space Flight Center, Greenbelt, MD 20771, USANASA Goddard Space Flight Center, Greenbelt, MD 20771, USA<p>The submillimeter-wave radiometer operating in the along-track scanning mode continuously collects brightness temperature (TB) data over a two-dimensional (2D) cloud cross-section as the platform moves forward. TB observations from multiple positions and viewing angles show great promise in better constraining the 2D cloud microphysical properties compared to single-angle observations. In this study, we develop two types of tomographic reconstruction algorithms to retrieve 2D ice water content (IWC) profiles using multi-angle TB observations. The one-dimensional (1D) tomographic algorithm performs 1D retrievals beam by beam using each TB observation at a specific sensor position and viewing angle to derive cloud properties along the propagation path. It then integrates the 1D retrieval results to construct 2D cloud cross-section. The 2D tomographic algorithm directly constrains the 2D cloud microphysical properties using multi-angle scanning TB observations. Starting with an initial assumption, the algorithm iteratively refines the 2D cloud microphysical quantities by minimizing discrepancies between TB simulations and observations under prior constraints. Both tomographic algorithms are developed based on a hybrid of Bayesian Monte Carlo integration (MCI) and the optimal estimation method (OEM). A simulation experiment is conducted to evaluate the performance of two tomographic reconstruction algorithms. The experiment demonstrates stable convergence of both tomographic methods, with the 2D tomographic algorithm exhibiting superior performance. The experiment results highlight the significant advantage of using multi-angle observations to constrain 2D cloud structure. Compared to nadir-only retrievals, the tomographic technique provides a detailed reconstruction of ice clouds' inner structure with high spatial resolution. Also, the technique significantly improves retrieval accuracy by correcting systematic biases and reducing the derivation of retrieval errors. Furthermore, the tomography technique effectively increases detection sensitivity for small ice cloud particles.</p>https://amt.copernicus.org/articles/18/1659/2025/amt-18-1659-2025.pdf
spellingShingle Y. Liu
Y. Liu
I. S. Adams
Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observations
Atmospheric Measurement Techniques
title Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observations
title_full Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observations
title_fullStr Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observations
title_full_unstemmed Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observations
title_short Tomographic reconstruction algorithms for retrieving two-dimensional ice cloud microphysical parameters using along-track (sub)millimeter-wave radiometer observations
title_sort tomographic reconstruction algorithms for retrieving two dimensional ice cloud microphysical parameters using along track sub millimeter wave radiometer observations
url https://amt.copernicus.org/articles/18/1659/2025/amt-18-1659-2025.pdf
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AT yliu tomographicreconstructionalgorithmsforretrievingtwodimensionalicecloudmicrophysicalparametersusingalongtracksubmillimeterwaveradiometerobservations
AT isadams tomographicreconstructionalgorithmsforretrievingtwodimensionalicecloudmicrophysicalparametersusingalongtracksubmillimeterwaveradiometerobservations