A5002938751- Climate variability and models
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Arctic and Antarctic ice dynamics
- Tropical and Extratropical Cyclones Research
- Oceanographic and Atmospheric Processes
- Climate change and permafrost
- Cryospheric studies and observations
- Methane Hydrates and Related Phenomena
- Solar Radiation and Photovoltaics
- Atmospheric Ozone and Climate
- Geological Studies and Exploration
- Marine and coastal ecosystems
- Atmospheric aerosols and clouds
- Energy Load and Power Forecasting
- Climate Change and Health Impacts
- Respiratory viral infections research
- Wireless Signal Modulation Classification
- Integrated Energy Systems Optimization
- Precipitation Measurement and Analysis
- Cardiovascular Disease and Adiposity
- Geophysics and Gravity Measurements
- Reservoir Engineering and Simulation Methods
- demographic modeling and climate adaptation
- Ionosphere and magnetosphere dynamics
University of Tsukuba
2015-2024
University of the Ryukyus
2024
University of Oxford
2013-2020
Naval Research Laboratory Information Technology Division
2017
University of Reading
2016
Met Office
2016
European Centre for Medium-Range Weather Forecasts
2016
National Centre for Atmospheric Science
2016
Lawrence Berkeley National Laboratory
2016
Meteorological Research Institute
2009-2014
A new version of the atmospheric general circulation model Meteorological Research Institute (MRI), with a horizontal grid size about 20 km, has been developed. The previous 20-km model, MRIAGCM3.1, which was developed from an operational numerical weather-prediction provided information on possible climate change induced by global warming, including future changes in tropical cyclones, East Asian monsoon, extreme events, and blockings. For version, MRI-AGCM3.2, we have introduced various...
[1] Eastern Europe and Western Russia experienced a strong heat wave during the summer of 2010. Maximum temperatures exceeded 40°C in early August, resulting over 15,000 deaths many wildfires, inflicting large economic losses on Russia. The resulted from atmospheric blocking that persisted Euro-Russian region late June to August. This study investigates predictabilities extreme blocking-induced surface 2010, using medium-range ensemble forecasts. results show June–August (JJA) 2010 was...
Abstract The International Grand Global Ensemble (TIGGE) was a major component of Observing System Research and Predictability Experiment (THORPEX) research program, whose aim is to accelerate improvements in forecasting high-impact weather. By providing ensemble prediction data from leading operational forecast centers, TIGGE has enhanced collaboration between the meteorological communities enabled studies on wide range topics. paper covers objective evaluation data. For parameters, it...
Future change in the frequency of atmospheric blocking is investigated through present‐day (1979–2003) and future (2075–2099) simulations using 20‐, 60‐, 120‐, 180‐km‐mesh general circulation models (AGCMs) under Intergovernmental Panel on Climate Change Special Reports Emission Scenarios A1B emission scenario, focusing Northern Hemisphere winter (December–February). The results climate reveal that AGCM with highest horizontal resolution required to accurately simulate Euro‐Atlantic...
The aim of this study is to investigate if the representation Northern Hemisphere blocking sensitive resolution in current-generation atmospheric global circulation models (AGCMs). An evaluation conducted how well represented four AGCMs whose horizontal increased from a grid spacing more than 100 km about 25 km. It shown that Euro-Atlantic simulated overall credibly at higher (i.e., better agreement with 50-yr reference climatology created reanalyses ERA-40 and ERA-Interim). improvement seen...
This study assesses the medium‐range flow‐dependent forecast skill of Euro‐Atlantic weather regimes: positive and negative phases North Atlantic Oscillation (NAO+ NAO−), ridge (ATLR), blocking (EABL), for extended winters (November–March) in periods 2006/2007–2013/2014 1985/1986–2013/2014 using The Interactive Grand Global Ensemble (TIGGE) National Oceanic Atmospheric Administration (NOAA)'s Forecasting System (GEFS) reforecast datasets, respectively. models show greater‐than‐observed...
This study undertakes a multi-model comparison with the aim to describe and quantify systematic changes of global energy water budgets when horizontal resolution atmospheric models is increased identify common factors these among models. To do so, we analyse an ensemble twelve atmosphere-only six coupled GCMs, different model formulations resolutions spanning those state-of-the-art i.e. from coarser than 100 km finer 25 km. The main in budget are increase outgoing longwave radiation decrease...
Abstract An extremely strong Arctic cyclone (AC) developed in August 2016. The AC exhibited a minimum sea level pressure (SLP) of 967.2 hPa and covered the entire Pacific sector Ocean on 16 August. At this time, was comparable to observed 2012, terms horizontal extent, position, intensity as measured by SLP. Two processes contributed explosive development AC: growth due baroclinic instability, similar extratropical cyclones, during early phase stage, later nonlinear via merging upper warm...
Global warming projection experiments were conducted using a 20-km mesh global atmospheric model, focusing on the change in rain band of East Asian summer monsoon. To assess uncertainty climate projections, we performed ensemble simulations with 60-km resolution model combining four different SSTs and three initial conditions. In present-day simulations, reproduces monsoon better than lower models terms geographical distribution seasonal march. future simulation by precipitation increases...
High‐latitude climate change is expected to increase the demand for reliable weather and environmental forecasts in polar regions. In this study, a quantitative assessment of skill state‐of‐the‐art global prediction systems regions given using data from THORPEX Interactive Grand Global Ensemble (TIGGE) period 2006/2007–2012/2013. Forecast Arctic comparable that found Northern Hemisphere midlatitudes. However, relative differences quality between different forecasting appear be amplified...
Abstract Future changes in Northern Hemisphere wintertime storm activity as a consequence of global warming are investigated using the AGCM Meteorological Research Institute (MRI-AGCM) with horizontal grid sizes 60 and 20 km. A future (2075–99) climate experiment, which change sea surface temperature (SST) derived from Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel ensemble mean is added to observed SST, compared present-day (1979–2003) experiment. Results three-member...
Abstract Future changes in the frequency of Northern Hemisphere blocking are investigated via large ensemble simulations using a 60 km mesh atmospheric general circulation model prescribed with six future sea surface temperature patterns derived from state‐of‐the‐art climate models under 4 K warmer climate. Our depict wintertime decreasing 16.6% ± 0.7% to 13.1% 2.1% Euro‐Atlantic sector and 17.4% 14.8% 2.4% Pacific sector. This decline is seen affect all durations more than 15 days'...
There is growing evidence that the atmospheric dynamics of Euro-Atlantic sector during winter driven in part by presence quasi-persistent regimes. However, general circulation models typically struggle to simulate these with, for example, an overly weakly persistent blocking regime. Previous studies have showed increased horizontal resolution can improve regime structure a model but so far only considered single with one ensemble member at each resolution, leaving open possibility this may...
This study assesses the forecasting performance of operational medium-range ensemble forecasts: BOM, CMA, CMC, CPTEC, ECMWF, JMA, KMA, NCEP, and UKMO, in terms atmospheric blocking during DJF (December-January-February) 2006/07, 2007/08, 2008/09.The state-of-the-art forecasts performed well simulating frequencies Euro-Atlantic (EA) Pacific (PA) blockings, even after 216-hr lead time, whereas they did not simulate Greenland Ural middle forecast range. The are always able to capture blockings...
[1] The Madden–Julian oscillation (MJO) is the dominant mode of intraseasonal variability in tropics. Accurate simulations MJO are important for studies weather and climate tropics extratropics. This study assesses forecast performance operational medium-range ensemble forecasts, available at THe Observing system Research Predictability EXperiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) data portal, regarding past 3 years. results indicate that ECMWF (European Centre Medium-range...
Accurate predictions of severe weather events are important for the society, economy, and environment in regions affected by such events. In present study, development testing a suite prototype ensemble-based early warning products events, which now routinely available at http://tparc.mri-jma.go.jp/TIGGE/tigge_extreme_prob.html, reported. The based on operational medium-range ensemble forecasts from four leading global numerical centres: European Centre Medium-Range Weather Forecasts, Japan...
Subseasonal-to-seasonal (S2S) forecasts have the potential to provide advance information about weather and climate events. The high heat capacity of water means that subsurface ocean stores re-releases (and other properties) is an important source for S2S forecasts. However, challenging observe, because it cannot be measured by satellite. Subsurface observing systems relevant understanding, modeling, forecasting on timescales will continue evolve with improvement in technological...
Abstract Arctic cyclones (ACs) are a severe atmospheric phenomenon that affects the environment. This study assesses forecast skill of five leading operational medium‐range ensemble forecasts for 10 extraordinary ACs occurred in summer during 2008–2016. Average existence probability predicted was >0.9 at lead times ≤3.5 days. central position error less than half mean radius (469.1 km) 2.5–4.5 pressure 5.5–10.7 hPa such times. Therefore, prediction systems generally predict within 469.1...
[1] How accurate are predictions of climate change from a model which is biased against contemporary observations? If bias can be thought as state-independent linear offset, then the signal derived should not affected substantially by that model's bias. By contrast, if processes cause highly nonlinear, we could expect accuracy to degrade with increasing Since do yet know late 21st Century signal, cannot say at this stage these two paradigms describes best role in studies change. We therefore...
Abstract In the Different Models, Same Initial Conditions (DIMOSIC) project, forecasts from different global medium-range forecast models have been created based on same initial conditions. The dataset consists of 10-day deterministic seven and includes 122 dates spanning one calendar year. All are initialized ECMWF operational analyses to minimize differences due initialization. run at or near their respective resolutions explore similarities between models. main aims this study 1) evaluate...
Abstract This study assesses the subseasonal predictability of weekly mean geopotential height anomaly at 500 hPa and its relationship to teleconnections over Northern Hemisphere in winter. The skill North Pacific, Canada, Greenland is higher than other areas for weeks 3 4 forecasts. These peaks correspond centers action Pacific–North American (PNA) pattern Atlantic Oscillation (NAO). PNA (NAO phase) predictions are better El Niño years lead times 3–4 (2–4 weeks). effects La Niña forcing on...
In this study, Multi-Center Grand Ensembles (MCGEs) were constructed by combining five operational medium-range ensemble forecasts: CMC, ECMWF, JMA, NCEP, and UKMO with equal weights no bias correction. The forecast performance of the MCGEs relative to ECMWF ensemble, having best in world, was investigated using seasonal Root Mean Square Error (RMSE) Ranked Probability Score (RPS) for 500 hPa geopotential height over Northern Hemisphere (20°N-90°N) from December 2006 November 2007.It found...
Future changes in the frequency of Australia–New Zealand (AU; winter and summer) Andes (AN; winter) blockings are investigated via present‐day (1979–2003) future (2075–2099) simulations using 20‐, 60‐, 180‐km‐mesh atmospheric general circulation models (AGCMs) under IPCC SRES A1B emission scenario. The climate reveal that AGCM with highest horizontal resolution is required to accurately simulate AU AN both summer. simulation predicts a significant decrease blocking summer winter, mainly on...
Abstract Atmospheric blocking occurred over the Rocky Mountains at 1200 UTC 15 December 2005. The operational medium-range ensemble forecasts of Canadian Meteorological Center (CMC), Japan Agency (JMA), and National Centers for Environmental Prediction (NCEP), as initialized 10 2005, showed remarkable differences regarding this event. All NCEP members failed to predict correct location blocking, whereas almost all JMA most CMC were successful in predicting location. present study...