Projected climate change in the western North Pacific at the end of the 21st century from ensemble simulations with a high-resolution regional ocean model

ABSTRACT A variant of downscaling is devised to explore the properties of tropical cyclones (TCs) that originate in the open ocean of the western North Pacific Ocean (WestPac) region under extreme climates. This variant applies a seeding strategy in large-scale environments simulated by phase 5 of the Coupled Model Intercomparison Project (CMIP5) climate-model integrations together with embedded integrations of Coupled Ocean–Atmosphere Mesoscale Prediction System for Tropical Cyclones (COAMPS-TC), an operational, high-resolution, nonhydrostatic, convection-permitting numerical weather prediction (NWP) model. Test periods for the present day and late twenty-first century are sampled from two different integrations for the representative concentration pathway (RCP) 8.5 forcing scenario. Then seeded simulations for the present-day period are contrasted with similar seeded simulations for the future period. Reinforcing other downscaling studies, the seeding results suggest that the future environments are notably more conducive to high-intensity TC activity in the WestPac. Specifically, the future simulations yield considerably more TCs that exceed 96-kt (1 kt ≈ 0.5144 m s−1) intensity, and these TCs exhibit notably greater average life cycle maximum intensity and tend to spend more time above the 96-kt intensity threshold. Also, the future simulations yield more TCs that make landfall at >64-kt intensity, and the average landfall intensity of these storms is appreciably greater. These findings are supported by statistical bootstrap analysis as well as by a supplemental sensitivity analysis. Accounting for COAMPS-TC intensity forecast bias using a quantile-matching approach, the seeded simulations suggest that the potential maximum western North Pacific TC intensities in the future extreme climate may be approximately 190 kt.

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Variability of Tropical Cyclone Frequency Over the Western North Pacific in 2018–2020

Frontiers in Climate ◽

10.3389/fclim.2021.770785 ◽

2021 ◽

Vol 3 ◽

Author(s):

Tomomichi Ogata ◽

Yuya Baba

Keyword(s):

Tropical Cyclone ◽

North Pacific ◽

General Circulation ◽

Western North Pacific ◽

Circulation Model ◽

Atmospheric Variability ◽

Convection Scheme ◽

Planetary Scale ◽

Ensemble Simulations ◽

Potential Index

In this study, we examine the tropical cyclone (TC) activity over the western North Pacific (WNP) in 2018–2020 and its relationship with planetary scale convection and circulation anomalies, which play an important role for TC genesis. To determine the sea surface temperature (SST)-forced atmospheric variability, atmospheric general circulation model (AGCM) ensemble simulations are executed along with the observed SST. For AGCM experiments, we use two different convection schemes to examine uncertainty in convective parameterization and robustness of simulated atmospheric response. The observed TC activity and genesis potential demonstrated consistent features. In our AGCM ensemble simulations, the updated convection scheme improves the simulation ability of observed genesis potential as well as planetary scale convection and circulation features, e.g., in September–October–November (SON), a considerable increase in the genesis potential index over the WNP in SON 2018, WNP in SON 2019, and South China Sea (SCS) in SON 2020, which were not captured in the Emanuel scheme, have been simulated in the updated convection scheme.

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Improved Simulation of Tropical Cyclone Responses to ENSO in the Western North Pacific in the High-Resolution GFDL HiFLOR Coupled Climate Model*

Journal of Climate ◽

10.1175/jcli-d-15-0475.1 ◽

2016 ◽

Vol 29 (4) ◽

pp. 1391-1415 ◽

Cited By ~ 48

Author(s):

Wei Zhang ◽

Gabriel A. Vecchi ◽

Hiroyuki Murakami ◽

Thomas Delworth ◽

Andrew T. Wittenberg ◽

...

Keyword(s):

High Resolution ◽

Tropical Cyclone ◽

El Niño ◽

North Pacific ◽

Western North Pacific ◽

El Nino ◽

Walker Circulation ◽

La Niña ◽

Sea Surface ◽

La Nina

Abstract This study aims to assess whether, and the extent to which, an increase in atmospheric resolution of the Geophysical Fluid Dynamics Laboratory (GFDL) Forecast-Oriented Low Ocean Resolution version of CM2.5 (FLOR) with 50-km resolution and the High-Resolution FLOR (HiFLOR) with 25-km resolution improves the simulation of the El Niño–Southern Oscillation (ENSO)–tropical cyclone (TC) connections in the western North Pacific (WNP). HiFLOR simulates better ENSO–TC connections in the WNP including TC track density, genesis, and landfall than FLOR in both long-term control experiments and sea surface temperature (SST)- and sea surface salinity (SSS)-restoring historical runs (1971–2012). Restoring experiments are performed with SSS and SST restored to observational estimates of climatological SSS and interannually varying monthly SST. In the control experiments of HiFLOR, an improved simulation of the Walker circulation arising from more realistic SST and precipitation is largely responsible for its better performance in simulating ENSO–TC connections in the WNP. In the SST-restoring experiments of HiFLOR, more realistic Walker circulation and steering flow during El Niño and La Niña are responsible for the improved simulation of ENSO–TC connections in the WNP. The improved simulation of ENSO–TC connections with HiFLOR arises from a better representation of SST and better responses of environmental large-scale circulation to SST anomalies associated with El Niño or La Niña. A better representation of ENSO–TC connections in HiFLOR can benefit the seasonal forecasting of TC genesis, track, and landfall; improve understanding of the interannual variation of TC activity; and provide better projection of TC activity under climate change.

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A High Resolution Regional Ocean Model For Brazilian Pre-Salt Area: First Validation Results

10.4043/22283-ms ◽

2011 ◽

Author(s):

Jacques P. Schoellkopf

Keyword(s):

High Resolution ◽

Ocean Model ◽

Regional Ocean Model

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Climate change in China in the 21st century as simulated by a high resolution regional climate model

Chinese Science Bulletin ◽

10.1007/s11434-011-4935-8 ◽

2012 ◽

Vol 57 (10) ◽

pp. 1188-1195 ◽

Cited By ~ 109

Author(s):

XueJie Gao ◽

Ying Shi ◽

DongFeng Zhang ◽

Filippo Giorgi

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate Model ◽

21St Century ◽

Climate Model ◽

Regional Climate

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High-resolution IP25-based reconstruction of sea-ice variability in the western North Pacific and Bering Sea during the past 18,000 years

Geo-Marine Letters ◽

10.1007/s00367-015-0432-4 ◽

2015 ◽

Vol 36 (2) ◽

pp. 101-111 ◽

Cited By ~ 25

Author(s):

Marie Méheust ◽

Ruediger Stein ◽

Kirsten Fahl ◽

Lars Max ◽

Jan-Rainer Riethdorf

Keyword(s):

High Resolution ◽

Sea Ice ◽

Bering Sea ◽

North Pacific ◽

Western North Pacific ◽

The Past

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Atmosphere-Driven Cold SST Biases Over The Western North Pacific in The GloSea5 Seasonal Forecast System

10.21203/rs.3.rs-786427/v1 ◽

2021 ◽

Author(s):

Ajin Cho ◽

Hajoon Song ◽

Yong-Jin Tak ◽

Sang-Wook Yeh ◽

Soon-Il An ◽

...

Keyword(s):

Heat Flux ◽

North Pacific ◽

Western North Pacific ◽

Primary Source ◽

Seasonal Forecast ◽

Ocean Model ◽

Sea Surface ◽

Shortwave Radiation ◽

Forecast System ◽

Sst Bias

Abstract The predictability of the sea surface temperature (SST) in seasonal forecast systems is crucial for accurate seasonal predictions. In this study, we evaluate the prediction of SST in the Global Seasonal forecast system version 5 (GloSea5) hindcast with particular interest over the western North Pacific (WNP) in which the SST can modify atmospheric convection and the East Asian weather. GloSea5 has a cold SST bias in the WNP that grows over at least 7 months. The bias originates from the surface heat flux in which the latent heat flux bias shows the biggest contribution. We identify the overestimated cloud in the first few days after initialization that causes insufficient shortwave radiation and negative bias of the surface net heat flux. Uncoupled ocean model experiments infer that the ocean model is unlikely the primary source of the SST bias.

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Modelling climate change impacts on glaciers and water resources in China using OGGM and FUSE

10.5194/egusphere-egu21-12250 ◽

2021 ◽

Author(s):

Dan Goldberg ◽

Louis Kinnear ◽

Florian Kobierska-Baffie ◽

Nans Addor ◽

Helen He ◽

...

Keyword(s):

Climate Change ◽

High Resolution ◽

Water Resources ◽

Mass Loss ◽

Mass Balance ◽

21St Century ◽

General Circulation ◽

Balance Model ◽

High Mountain ◽

Mountainous Regions

<p>Hundreds of millions of people depend strongly on hydrological inputs in the mountainous regions of China and central Asia. Glacier runoff is a major contributor to this hydrological forcing, yet many glaciers in the region have undergone mass loss in recent years and this mass loss is expected to continue or increase in response to climatological change. As such it is important to assess the large-scale response of High Mountain Asia glaciers to climate change , and its effects on hydrology. We present here preliminary modelling investigations of glacier change and hydrological impacts in response to high-resolution climate model projections over the 21st century as a component of the project SWARM (Impacts Assessment to Support WAter Resources Management and Climate Change Adaptation for China). Our model chain consists of i) Open Global Glacier Model (OGGM), which allows for high-resolution glacier flowline modelling of multiple glaciers, and ii) the Framework for Understanding Structural Errors (FUSE) a modular framework for snow and hydrology modelling, which we used to assemble and run three hydrological models over the whole of China. Both FUSE and OGGM are forced by an ensemble of bias-corrected CORDEX-East Asia regional climate models (in turn forced by CMIP5 general circulation models), and outputs of OGGM are provided to FUSE. We discuss our application of OGGM to 80,000 glaciers in Chinese river catchments; our efforts to calibrate the mass balance model using an expanded set of geodetic mass balance constraints; and finally the projections of glacier, snow and streamflow changes in the 21st century. In particular, we discuss the robustness and uncertainties in the projections as sampled by our multi-model ensemble.</p>

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