Article
Geosciences, Multidisciplinary
Kaori Sato, Hajime Okamoto
Summary: An enhanced understanding of ice-particle microphysics and their formation conditions is necessary for a more accurate representation of ice-phase processes in numerical models. Recent advancements in ice-particle backscattering theories, coupled with space-borne lidar measurements, have enabled a comprehensive exploration of the geographical distribution and seasonal dependence of ice-particle shape categories. This global distribution provides valuable insights into physical processes related to ice cloud particle shape formation, cloud duration, and radiative impacts.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
F. Joseph Turk, Sarah E. Ringerud, Andrea Camplani, Daniele Casella, Randy J. Chase, Ardeshir Ebtehaj, Jie Gong, Mark Kulie, Guosheng Liu, Lisa Milani, Giulia Panegrossi, Ramon Padulles, Jean-Francois Rysman, Paolo Sano, Sajad Vahedizade, Norman B. Wood
Summary: This paper demonstrates the use of near-coincident observations between GPM and CloudSat to extend the capability of representing light rain and cold-season precipitation, through unique triple-frequency data, opening up applications related to cold-season precipitation, ice microphysics, and light rainfall and surface emissivity effects.
Article
Environmental Sciences
Andrzej Z. Kotarba, Mateusz Solecki
Summary: The study evaluated the uncertainties in the CloudSat-CALIPSO dataset and found that estimating a five-year mean cloud amount at every location is impossible. The existing uncertainties are primarily the result of climate-specific factors.
Article
Environmental Sciences
Xiaomei Lu, Yongxiang Hu, Ali Omar, Rosemary Baize, Mark Vaughan, Sharon Rodier, Jayanta Kar, Brian Getzewich, Patricia Lucker, Charles Trepte, Chris Hostetler, David Winker
Summary: Recent studies show that CALIOP aboard the CALIPSO satellite offers valuable information on ocean phytoplankton distributions, but due to polarization crosstalk effects, using crosstalk-corrected signals is recommended to avoid biases in ocean subsurface studies.
Article
Meteorology & Atmospheric Sciences
Yuichiro Hagihara, Yuichi Ohno, Hiroaki Horie, Woosub Roh, Masaki Satoh, Takuji Kubota
Summary: This study investigates the Doppler measurement errors of the EC-CPR on the EarthCARE satellite by increasing the amount of data used and extending the data coverage globally. The errors were evaluated for both low and high pulse repetition frequency settings. The results showed that the errors were significantly reduced after unfolding correction, with the error values ranging from 0.63 m/s to 2.2 m/s for the low PRF setting and from 0.29 m/s to 0.78 m/s for the high PRF setting.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2023)
Article
Optics
Lin Zang, Daniel Rosenfeld, Feiyue Mao, Zengxin Pan, Yannian Zhu, Wei Gong, Zemin Wang
Summary: Monitoring cloud droplet effective radius (re) using CALIOP shows highest accuracy for vertically homogeneous clouds, providing a basis for breakthrough insights in aerosol-cloud interactions (ACI). Global day-night maps of cloud vertical homogeneity and respective re are presented.
Article
Meteorology & Atmospheric Sciences
Andrzej Z. Kotarba
Summary: This study verified the accuracy of cloud parameters calculated based on transect sampling and evaluated the sampling scheme used by the CALIPSO lidar mission. It found that CALIPSO sampling can accurately report mean annual cloud amount, optical thickness, and cloud top height for most locations on Earth, with some areas more affected by transect sampling.
ATMOSPHERIC RESEARCH
(2022)
Article
Meteorology & Atmospheric Sciences
J. -L. f. Li, Kuan-Man Xu, Yu-Cian Tsai, Wei-Liang Lee, Jonathan H. Jiang, Jia-Yuh Yu, Eric Fetzer, Longtao Wu, Graeme Stephens
Summary: This study uses satellite measurements to evaluate the accuracy of CMIP6 models in simulating frozen hydrometeors. The results show that overall the simulations are accurate, but there are still some discrepancies. Further research is needed to improve both models and observational methods due to uncertainty in model physics and observational estimates.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Environmental Sciences
Housseyni Sankare, Jean-Pierre Blanchet, Rene Laprise, Norman T. O'Neill
Summary: Due to the lack of in situ observations, polar clouds are poorly understood compared to lower latitude clouds, but they play a crucial role in climate through thermal radiation emission. Thin Ice Clouds (TIC) dominate in cold polar regions and at high altitudes. They can be classified into two broad categories. This study investigates the capability of the CRCM6 model in simulating cold polar-night clouds over the Arctic Ocean and finds that the model performs well in simulating various cloud properties and types.
Article
Geosciences, Multidisciplinary
Xi Zhao, Xiaohong Liu
Summary: SIP occurs uniformly in both hemispheres and dominates ice formation in moderately cold clouds. It affects global water paths and cloud forcing, improving model agreement with observations.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Jui-Lin F. Li, Wei-Liang Lee, Kuan-Man Xu, Yu-Cian Tsai, Jonathan Jiang, Jia-Yuh Yu, Graeme Stephens, Eric Fetzer, Wei-Ting Chen
Summary: This study uses CloudSat-CALIPSO satellite data to evaluate the modeled cloud fraction in CMIP5 models during a recent historical period. The comparison reveals that most CMIP5 models do not account for precipitating and convective core hydrometeors, leading to significant underestimation of cloud fraction compared to satellite-retrieved data. The underestimation is particularly pronounced in certain regions and altitudes where precipitating ice and convective core hydrometeors play a major role.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geosciences, Multidisciplinary
Goutam Choudhury, Matthias Tesche
Summary: In this study, we present a global multiyear height-resolved data set of aerosol-type-specific cloud condensation nuclei concentrations (n(CCN)) estimated from the CALIPSO satellite's lidar data. The data set covers a large temporal and spatial range and provides valuable information about aerosol-cloud interactions. The complete data set can be accessed at https://doi.org/10.1594/PANGAEA.956215 (Choudhury and Tesche, 2023).
EARTH SYSTEM SCIENCE DATA
(2023)
Article
Computer Science, Artificial Intelligence
Yiying Zhang
Summary: The study introduces a new technique called specular reflection learning to improve the optimization performance of metaheuristic methods, particularly in enhancing the backtracking search algorithm. The effectiveness of specular reflection learning is demonstrated through experiments with various test functions and engineering design problems, showing its superiority over opposition-based learning.
KNOWLEDGE-BASED SYSTEMS
(2021)
Article
Environmental Sciences
Yinghui Liu
Summary: By quantifying the limitations in cloud detection, this study reveals the significant impact of cloud detection uncertainties on radiation flux in the Arctic region.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Meteorology & Atmospheric Sciences
Erica K. Dolinar, James R. Campbell, Jared W. Marquis, Anne E. Garnier, Bryan M. Karpowicz
Summary: We developed a parameterization model for global ice cloud microphysical properties using satellite measurements, allowing for better representation of ice clouds in weather forecasting and climate energy balance studies. By knowing the size of the ice crystals, we can estimate cloud scattering and absorption.
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Tempei Hashino, Gijs de Boer, Hajime Okamoto, Gregory J. Tripoli
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2020)
Article
Geosciences, Multidisciplinary
Kazuaki Kawamoto, Akira Yamauchi, Kentaroh Suzuki, Hajime Okamoto, Jiming Li
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Optics
Yoshitaka Jin, Tomoaki Nishizawa, Nobuo Sugimoto, Shoken Ishii, Makoto Aoki, Kaori Sato, Hajime Okamoto
Article
Optics
Hajime Okamoto, Kaori Sato, Anatoli Borovoi, Hiroshi Ishimoto, Kazuhiko Masuda, Alexander Konoshonkin, Natalia Kustova
Article
Meteorology & Atmospheric Sciences
Woosub Roh, Masaki Satoh, Tempei Hashino, Hajime Okamoto, Tatsuya Seiki
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2020)
Article
Optics
Tomoaki Nishizawa, Yoshitaka Jin, Nobuo Sugimoto, Kaori Sato, Masahiro Fujikawa, Shoken Ishii, Makoto Aoki, Katsuhiro Nakagawa, Hajime Okamoto
Summary: The study developed a 355 nm multiple-field-of-view multiple-scattering polarization lidar to investigate cloud and aerosol microphysics and provide microphysical properties of clouds and aerosols. Aerosol signals and their multiple scattering contributions were generally more pronounced at 355 nm, highlighting the advantage of performing measurements at this wavelength.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2021)
Article
Ecology
M. Koike, K. Goto-Azuma, Y. Kondo, H. Matsui, T. Mori, N. Moteki, S. Ohata, H. Okamoto, N. Oshima, K. Sato, T. Takano, Y. Tobo, J. Ukita, A. Yoshida
Summary: This paper reviews studies of aerosols and clouds performed during the Arctic Challenge for Sustainability (ArCS) project carried out by the National Institute of Polar Research (NIPR) in Japan and collaborating institutions. The research focused on black carbon aerosols, ice nucleating particles, and cloud measurements, emphasizing the importance of accurate measurements and models in understanding the impacts of aerosols and clouds on Arctic climate.
Article
Meteorology & Atmospheric Sciences
M. Kikuchi, H. Okamoto, K. Sato
Summary: The study focuses on horizontal ice plates in clouds using satellite lidar measurements. It shows that tilting affects ice plate detection, decreasing it by 81.7%, with only 30.8% able to be recovered. However, geographical characteristics of ice plates are still preserved during off-nadir periods, hinting at potential undiscovered climatological information on ice plates in future observations.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Geochemistry & Geophysics
Yuichiro Hagihara, Yuichi Ohno, Hiroaki Horie, Woosub Roh, Masaki Satoh, Takuji Kubota, Riko Oki
Summary: This study investigated the impact of horizontal integration and unfolding methods on reducing Doppler measurement errors and simulated Doppler velocities in cirrus cloud and precipitation cases. The results showed that Doppler errors can be significantly reduced by applying appropriate horizontal integration and unfolding methods.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Meteorology & Atmospheric Sciences
Senyi Kong, Kaori Sato, Lei Bi
Summary: The backscattering optical properties of randomly oriented dust particles at a wavelength of 355 nm were comprehensively studied using the super-spheroid dust model. The study found that different super-spheroid dust particles could be used to model the observed characteristics of dust aerosols. The results have important implications for interpreting lidar data from the EarthCARE satellite.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Optics
Yoshitaka Jin, Tomoaki Nishizawa, Nobuo Sugimoto, Satoru Takakura, Makoto Aoki, Shoken Ishii, Akihiro Yamazaki, Rei Kudo, Keiya Yumimoto, Kaori Sato, Hajime Okamoto
Summary: A simple dual-wavelength high-spectral-resolution lidar was developed for continuous observations of aerosol profiles using a scanning interferometer. The system demonstrated robustness through one month of continuous measurements.
Article
Meteorology & Atmospheric Sciences
Yuichiro Hagihara, Yuichi Ohno, Hiroaki Horie, Woosub Roh, Masaki Satoh, Takuji Kubota
Summary: This study investigates the Doppler measurement errors of the EC-CPR on the EarthCARE satellite by increasing the amount of data used and extending the data coverage globally. The errors were evaluated for both low and high pulse repetition frequency settings. The results showed that the errors were significantly reduced after unfolding correction, with the error values ranging from 0.63 m/s to 2.2 m/s for the low PRF setting and from 0.29 m/s to 0.78 m/s for the high PRF setting.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Tomoaki Nishizawa, Yoshitaka Jin, Nobuo Sugimoto, Hajime Okamoto, Masahiro Fujikawa, Shoken Ishii
29TH INTERNATIONAL LASER RADAR CONFERENCE (ILRC 29)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Hajime Okamoto, Kaori Sato, Masahiro Fujikawa, Eiji Oikawa, Tomoaki Nishizawa, Shoken Ishii, Yoshitaka Jin, Makoto Aoki, Nobuo Sugimoto
29TH INTERNATIONAL LASER RADAR CONFERENCE (ILRC 29)
(2020)