Article
Environmental Sciences
Jules B. Kajtar, Agus Santoso, Matthew Collins, Andrea S. Taschetto, Matthew H. England, Leela M. Frankcombe
Summary: Climate models show a wide range in simulating the properties of the climate system, with accurate representation of the baseline climate state being crucial for future climate projections. There are significant correlations between baseline temperature, climate variables, and projected global mean temperature changes. Models with cooler initial Southern Ocean tend to exhibit more global warming, while warmer models show the opposite trend.
Article
Engineering, Civil
Kai Xu, Chuanhao Wu, Ce Zhang, Bill X. Hu
Summary: This study assessed the projection and uncertainty of drought characteristics in the Pearl River basin in southern China using three drought indices. The results showed that the uncertainty in projected drought indices was mainly influenced by GCMs and RCPs, with SPI tending to underestimate drought changes. GCMs contributed over 90% of the total uncertainty in drought projections, while RCPs had a limited impact.
JOURNAL OF HYDROLOGY
(2021)
Article
Geosciences, Multidisciplinary
Yuqiong Zheng, Wen Chen, Shangfeng Chen
Summary: The study found that CMIP6 models show improvements in simulating the Pacific meridional mode (PMM) compared to CMIP5, but still significantly underestimate the air-sea coupling strength and coupling persistence time associated with the PMM. There is a large intermodel spread in the relationship between springtime PMM and wintertime ENSO, attributed to bias in simulating the Intertropical Convergence Zone (ITCZ). Models with a stronger climatological ITCZ provide a favorable background for PMM-related sea surface temperature anomalies (SSTAs) to induce stronger atmospheric heating over the subtropical North Pacific, impacting the following-winter ENSO.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Da Yang, Wenyu Zhou, Seth D. Seidel
Summary: Vapour buoyancy has a significant impact on large-scale climate dynamics, making humid air lighter than dry air. However, some climate models fail to accurately represent vapour buoyancy, leading to inaccurate simulations of cloud distributions.
Article
Geosciences, Multidisciplinary
Hengqi Wang, Yiran Peng, Knut von Salzen, Yan Yang, Wei Zhou, Delong Zhao
Summary: This research introduces a numerically efficient aerosol activation scheme and evaluates its performance using cloud data from multiple aircraft campaigns. The study finds that the scheme accurately simulates aerosol activation and cloud droplet number concentration under various meteorological conditions and aerosol regimes. Additionally, an error analysis identifies the key factors that affect the simulation results.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Environmental Sciences
N. Freychet, G. Hegerl, D. Mitchell, M. Collins
Summary: In a warming world, temperature extremes are expected to exhibit noticeable changes, with uncertainties in predictions linked to differences in land-atmosphere feedback across models. This study proposes using the variability of daily surface maximum temperature as a constraint for future projections, indicating that hot extreme changes by the end of the century may be worse than previously estimated, especially for tropical and subtropical regions as well as South and East Asia. Tests with a large multi-model ensemble of climate models suggest that present-day variability of daily maximum temperature can serve as an emergent constraint on the frequency of heat extremes in a warmer climate.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)
Article
Meteorology & Atmospheric Sciences
Yingying An, Xianhong Meng, Lin Zhao, Zhaoguo Li, Shaoying Wang, Lunyu Shang, Hao Chen, Shihua Lyu
Summary: Surface albedo plays a crucial role in the energy and water cycles, and the parameterizations of surface albedo greatly impact the simulation of radiation partition in climate models. In this study, in-situ measurements and MODIS albedo product were used to evaluate the simulated surface albedo by 24 Global Climate Models. The results showed varying monthly albedo among models, with the ensemble mean closer to in-situ measurements. Some models exhibited significant biases in annual surface albedo cycle, and snow albedo parameterization schemes varied in fitting snow albedo attenuation over time in all models.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Xiaofang Feng, Liguan Wu, Chao Wang
Summary: The impact of climate change on tropical cyclone activity is assessed using various approaches, models, and downscaling techniques. The simulation and projection of large-scale circulation patterns are crucial for predicting tropical cyclone activity in a warming climate. This study examines the biases in simulating the western North Pacific monsoon trough (MT), a major circulation system for tropical cyclone formation, based on the output from CMIP6 models. The analysis reveals biases in the exact location and historical changes of the MT, with the simulation of sea surface temperature anomalies in the tropical Pacific being a contributing factor.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Tao Wang, Hua Gong, Yimin Liu, Jianhua Lu
Summary: The spatial pattern of intermodel spread of surface temperature indicates the model biases, with maximum spread in the polar regions and areas with orographic features. Winter amplification exists in the TS-SPREAD over the polar regions, while the maximum spread over the Tibetan Plateau occurs during spring and summer. The interseasonal linkage of processes contributes to the winter amplification of TS-SPREAD over the polar oceans.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Pamela J. Harvey, Stefan W. Grab
Summary: This study investigates the impact of major volcanic eruptions since 1883 on the climate of southern Africa, revealing significant cooling across all sub-regions with observable differences in amplitude, timing, and duration of response. Strongest responses were seen following the Krakatau eruption in all sub-regions, highlighting the varied effects of volcanic forcing on regional climate patterns in southern Africa.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Oceanography
Xinyou Zhang, Yulan Luo, Lin Liu, Xuguang Sun
Summary: This study presents a preliminary assessment of multiple model simulations of tropical Indian Ocean sea surface temperature (SST) warming. Results indicate large discrepancies in the simulations, especially for the eastern equatorial Indian Ocean. The strength of the SST warming trends simulated by the models are weaker than those observed, and significant decadal trend variability is observed only in the southeastern Indian Ocean in observations.
JOURNAL OF OCEAN UNIVERSITY OF CHINA
(2023)
Article
Meteorology & Atmospheric Sciences
Tao Wang, Hua Gong, Yimin Liu, Jianhua Lu
Summary: This study shows that the spatial pattern of intermodel spread of surface temperature (TS-SPREAD) is similar to the absolute error of modeled surface temperature relative to observations, suggesting the possibility of using TS-SPREAD to understand model biases. The regions with maximum TS-SPREAD are located in the northern and southern polar regions, as well as regions with significant orographic features such as the Tibetan Plateau. The study also finds that TS-SPREAD exhibits a winter amplification effect in the polar regions and reaches its maximum during spring and summer over the Tibetan Plateau.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Thierry N. Taguela, Wilfried M. Pokam, Ellen Dyer, Rachel James, Richard Washington
Summary: This study evaluates and compares the simulation of low-level circulation in Central Equatorial Africa using eight climate models from CMIP6 and eight previous models from CMIP5. The results show that while the main characteristics of the simulation are reasonably well depicted, there are some biases. The CMIP5 models generally overestimate the strength of low-level westerlies, while the CMIP6 models show a slight improvement in the simulation of divergent and rotational circulation. The CMIP6 models also exhibit a reduction in the intensity and width of the Congo basin cell, which is associated with the improvement in the simulated low-level westerlies.
Article
Geosciences, Multidisciplinary
Christopher J. Smith, Piers M. Forster
Summary: The suppressed late-20th Century warming seen in CMIP6 is not only caused by a stronger aerosol forcing, but also by weaker greenhouse gas forcing and differences in climate sensitivity between CMIP5 and CMIP6 ensemble. This leads to stronger aerosol cooling over 1960-1990 and stronger greenhouse gas induced warming from 1990, returning the warming post-2000 toward the observed level.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Multidisciplinary Sciences
Budong Qian, Qi Jing, Alex J. Cannon, Ward Smith, Brian Grant, Mikhail A. Semenov, Yue-Ping Xu, Di Ma
Summary: The study assessed the effectiveness of selecting representative subsets of 5 GCMs from a full ensemble of 20 GCMs for projecting crop yields, demonstrating that these subsets could provide accurate estimates of both the mean and spread of the full ensemble. The results showed that the selected subsets outperformed randomly selected subsets in terms of smaller error and larger range.
SCIENTIFIC REPORTS
(2021)
Article
Meteorology & Atmospheric Sciences
Minoru Chikira, Yohei Yamada, Ayako Abe-Ouchi, Masaki Satoh
Summary: The Nonhydrostatic Icosahedral Atmospheric Model (NICAM) coupled with a slab ocean model was used for paleoclimate research for the first time. The model's higher resolution allows for a better representation of narrow precipitation bands and changes in tropical cyclones and monsoons.
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
Md Rezuanul Islam, Masaki Satoh, Hiroshi Takagi
Summary: This study found that storm surge heights have increased in coastal regions of Central Japan, especially Tokyo Bay, over the past 20 years. This increase is attributed to the stronger and larger tropical cyclones during landfall, as well as the increased frequency of cyclones with northeastward tracks. The positive correlation between surge heights and a hazard index further supports these findings.
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
(2022)
Article
Meteorology & Atmospheric Sciences
Shuhei Matsugishi, Masaki Satoh
Summary: In this study, we conducted experiments to investigate the influence of domain size and sea surface temperature on convective self-aggregation. We found that both domain size and sea surface temperature have an impact on the horizontal scale of convective self-aggregation, with larger domains resulting in larger scales of aggregation.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
Masaki Satoh, Shuhei Matsugishi, Woosub Roh, Yasutaka Ikuta, Naomi Kuba, Tatsuya Seiki, Tempei Hashino, Hajime Okamoto
Summary: This collaborative analysis study evaluates cloud microphysics schemes of numerical models for the Tokyo metropolitan area using extensive observation data and focuses on using the dual-polarization Doppler weather radar. Results show that NICAM-DM simulation reproduces comparable polarimetric radar characteristics of rain as the observation, while NICAM-SM and ASUCA-SM overestimate raindrop sizes in stronger rain areas.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Yohei Yamada, Tomoki Miyakawa, Masuo Nakano, Chihiro Kodama, Akiyoshi Wada, Tomoe Nasuno, Ying-Wen Chen, Akira Yamazaki, Hisashi Yashiro, Masaki Satoh
Summary: Typhoon Faxai caused severe damage to Tokyo in 2019. A study was conducted to investigate the predictability of precursor vortex formation and movement using ensemble simulations. Results showed a 70% probability of a Faxai-like vortex approaching Japan two weeks before landfall. The upper-tropospheric vortex played a crucial role in Faxai's track simulation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Shunji Kotsuki, Koji Terasaki, Masaki Satoh, Takemasa Miyoshi
Summary: This study improves precipitation forecasts using GPM DPR data through model parameter estimation. The NICAM-LETKF and GPM DPR observations are used to estimate a model cloud physics parameter related to snowfall terminal velocity. By using a two-dimensional histogram-based parameter estimation method, the gap between simulated and observed data is effectively reduced, leading to improved 6 hr precipitation forecasts.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geosciences, Multidisciplinary
Hao-Yan Liu, Masaki Satoh, Jian-Feng Gu, Lili Lei, Jianping Tang, Zhe-Min Tan, Yuqing Wang, Jing Xu
Summary: This study aimed to explore the predictability of tropical cyclone Freddy in the southern tropical Indian Ocean, and identified three key factors contributing to its limited predictability.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Fredrik Jansson, Martin Janssens, Johanna H. Gronqvist, A. Pier Siebesma, Franziska Glassmeier, Jisk Attema, Victor Azizi, Masaki Satoh, Yousuke Sato, Hauke Schulz, Tobias Kolling
Summary: Small shallow cumulus clouds over tropical oceans have the ability to self-organize into mesoscale patterns. Through simulations and data analysis, we find that the patterns in these clouds vary under different environmental conditions. This research provides a theoretical basis for understanding the coupling between clouds and circulation.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Meteorology & Atmospheric Sciences
Masuo Nakano, Ying-Wen Chen, Masaki Satoh
Summary: Typhoon Krosa formed in the Philippine Sea and made landfall in Japan, but the forecast models failed to accurately predict its track. Through ensemble forecast experiments, it was found that the uncertainty was caused by differences in the size of the typhoon and the retreatment of the western North Pacific subtropical high.
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
(2023)
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
Meteorology & Atmospheric Sciences
Woosub Roh, Masaki Satoh, Tempei Hashino, Shuhei Matsugishi, Tomoe Nasuno, Takuji Kubota
Summary: The Japanese Aerospace Exploration Agency (JAXA) has developed EarthCARE synthetic data, which is simulated using a 3.5 km horizontal-mesh global storm-resolving model. This data is valuable for the development of retrieval algorithms and the timely release of retrieval products after satellite launch. The synthetic data includes information from four EarthCARE instrument sensors and is available in standard and research products.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2023)
Article
Meteorology & Atmospheric Sciences
Minrui Wang, Takashi Y. Nakajima, Woosub Roh, Masaki Satoh, Kentaroh Suzuki, Takuji Kubota, Mayumi Yoshida
Summary: A cloud identification and profiling algorithm is being developed for the multi-spectral imager (MSI) on the EarthCARE spacecraft. The study evaluated the impact of spectral misalignment (SMILE) on the cloud retrieval product. Results showed that the SMILE error had a negligible effect on cloud detection for most cases, but further investigation is needed for land surfaces.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2023)
Article
Meteorology & Atmospheric Sciences
Shinichi Kodama, Masaki Satoh
Summary: In this study, remote precipitation events in Japan were characterized and analyzed. It was found that remote precipitation tended to occur when typhoons were located over the southern or southwestern oceans of Japan and when their tracks were northward or changing to the northeast. The retreat of the subtropical high and the presence of a 200 hPa jet stream entrance were also associated with remote precipitation. Furthermore, the northward water vapor flux and the region of quasi-geostrophic forcing for ascent and frontogenesis played important roles in the occurrence of remote precipitation.
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
(2022)
Article
Meteorology & Atmospheric Sciences
Takahiro Ishiyama, Masaki Satoh, Yohei Yamada
Summary: This study reveals the potential effects of sea surface temperature (SST) warming associated with the Pacific Meridional Mode (PMM) and the Indian Ocean (IO) on tropical cyclone genesis (TCG) in the North Pacific (NP). The results show that warmer SST associated with PMM weakens the monsoon trough in the western North Pacific (WNP) and vertical wind shear over the eastern North Pacific (ENP), leading to a decrease in TCG in the WNP and an increase in TCG in the ENP. Warmer SST over IO weakens the monsoon trough in the WNP, but does not appreciably change the vertical wind shear over the ENP. The study also finds that the anticyclonic anomalies over WNP intensify with SST warming associated with PMM or over IO. Additionally, the cyclonic anomalies over WNP are intensified by warmer SST associated with PMM even in the absence of El Nino forcing.
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
(2022)