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Climate change in the 21st century simulated by HadGEM2-AO under representative concentration pathways 总被引：2，自引：0，他引：2
Hee-Jeong Baek Johan Lee Hyo-Shin Lee Yu-Kyung Hyun ChunHo Cho Won-Tae Kwon Charline Marzin Sun-Yeong Gan Min-Ji Kim Da-Hee Choi Jonghwa Lee Jaeho Lee Kyung-On Boo Hyun-Suk Kang Young-Hwa Byun 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(5):603-618
We present climate responses of Representative Concentration Pathways (RCPs) using the coupled climate model HadGEM2-AO for the Coupled Model Intercomparison Project phase 5 (CMIP5). The RCPs are selected as standard scenarios for the IPCC Fifth Assessment Report and these scenarios include time paths for emissions and concentrations of greenhouse gas and aerosols and land-use/land cover. The global average warming and precipitation increases for the last 20 years of the 21st century relative to the period 1986-2005 are +1.1°C/+2.1% for RCP2.6, +2.4°C/+4.0% for RCP4.5, +2.5°C/+3.3% for RCP6.0 and +4.1°C/+4.6% for RCP8.5, respectively. The climate response on RCP 2.6 scenario meets the UN Copenhagen Accord to limit global warming within two degrees at the end of 21st century, the mitigation effect is about 3°C between RCP2.6 and RCP8.5. The projected precipitation changes over the 21st century are expected to increase in tropical regions and at high latitudes, and decrease in subtropical regions associated with projected poleward expansions of the Hadley cell. Total soil moisture change is projected to decrease in northern hemisphere high latitudes and increase in central Africa and Asia whereas near-surface soil moisture tends to decrease in most areas according to the warming and evaporation increase. The trend and magnitude of future climate extremes are also projected to increase in proportion to radiative forcing of RCPs. For RCP 8.5, at the end of the summer season the Arctic is projected to be free of sea ice. 相似文献
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Climate change detection, attribution, and prediction were studied for the surface temperature in the Northeast Asian region using NCEP/NCAR reanalysis data and three coupled-model simulations from ECHAM4/OPYC3, HadCM3, and CCCma GCMs (Canadian Centre for Climate Modeling and Analysis general circulation model). The Bayesian fingerprint approach was used to perform the detection and attribution test for the anthropogenic climate change signal associated with changes in anthropogenic carbon dioxide (CO2) and sulfate aerosol (SO42-) concentrations for the Northeast Asian temperature. It was shown that there was a weak anthropogenic climate change signal in the Northeast Asian temperature change. The relative contribution of CO2 and SO42- effects to total temperature change in Northeast Asia was quantified from ECHAM4/OPYC3 and CCCma GCM simulations using analysis of variance. For the observed temperature change for the period of 1959-1998, the CO2 effect contributed 10%-21% of the total variance and the di 相似文献
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We present an analysis of a high resolution multi-decadal simulation of recent climate (1971–2000) over the Korean Peninsula
with a regional climate model (RegCM3) using a one-way double-nested system. Mean climate state as well as frequency and intensity
of extreme climate events are investigated at various temporal and spatial scales, with focus on surface air temperature and
precipitation. The mother intermediate resolution model domain encompasses the eastern regions of Asia at 60 km grid spacing
while the high resolution nested domain covers the Korean Peninsula at 20 km grid spacing. The simulation spans the 30-year
period of January 1971 through December 2000, and initial and lateral boundary conditions for the mother domain are provided
from ECHO-G fields based on the IPCC SRES B2 scenario. The model shows a good performance in reproducing the climatological
and regional characteristics of surface variables, although some persistent biases are present. Main results are as follows:
(1) The RegCM3 successfully simulates the fine-scale structure of the temperature field due to topographic forcing but it
shows a systematic cold bias mostly due to an underestimate of maximum temperature. (2) The frequency distribution of simulated
daily mean temperature agrees well with the observed seasonal and spatial patterns. In the summer season, however, daily variability
is underestimated. (3) The RegCM3 simulation adequately captures the seasonal evolution of precipitation associated to the
East Asia monsoon. In particular, the simulated winter precipitation is remarkably good, clearly showing typical precipitation
patterns that occur on the northwestern areas of Japan during the winter monsoon. Although summer precipitation is underestimated,
area-averaged time series of precipitation over Korea show that the RegCM3 agrees better with observations than ECHO-G both
in terms of seasonal evolution and precipitation amounts. (4) Heavy rainfall phenomena exceeding 300 mm/day are simulated
only at the high resolution of the double nested domain. (5) The model shows a tendency to overestimate the number of precipitation
days and to underestimate the precipitation intensities. (6) A CSEOF analysis reveals that the model captures the strength
of the annual cycle and the surface warming trend throughout the simulated period. 相似文献
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Suryun Ham Song-You Hong Yign Noh Soon-Il An Young-Hwa Byun Hyun-Suk Kang Johan Lee Won-Tae Kwon 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(4):457-463
This paper investigates the effects of river discharge on simulated climatology from 1979 to 1988 using the Hadley Centre Global Environmental Model version 2. Two experiments are performed with and without the inclusion of Total Runoff Integrating Pathways. The results show that the inclusion of flow routing can lead to the decrease of salinity over the coastal region due to freshwater. This reduction results in a shallower mixed layer depth, which in turn leads to the weakening of trade winds and a decrease in vertical mixing in the ocean. The enhanced sensible and latent heat fluxes over warmed SST improve the simulated precipitation and thermodynamic circulation. As a result, the experiment with flow routing is capable of improving the large-scale climate feature with an increase in precipitation over the eastern tropical equatorial Pacific region. 相似文献
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Hyun-Suk Koo Hae-Dong Kim Won-Tae Yun Soon-Hwan Lee 《Asia-Pacific Journal of Atmospheric Sciences》2010,46(1):53-64
The urbanization of Daegu metropolitan region has progressed rapidly over the last 100 years, but changing land-use resulting from that urbanization has also caused the regional circulations to evolve. The effect of 100 years of urbanization on the regional circulations was simulated for the analysis using an A2C (Atmosphere to Computational Fluid Dynamics) model. Calm synoptic conditions and a stable lapse rate were assumed for the initial model atmosphere, with a horizontal grid resolution of 1 km. The simulation demonstrated that land-use changes have affected the Daegu metropolitan area’s regional circulations by deepening the convective boundary layer (CBL) over the urbanized area, resulting in deviations from mean surface temperature and surface wind fields. The last 100 years have seen the following changes in the region: 1) the urbanized area has increased by around 15 times, while the number of forests and paddy fields has rapidly decreased; 2) surface wind speeds have decreased by about 25% and 35% during the day and at night, respectively, and severe changes in wind direction have been noted over the urbanized areas; 3) regional warming has been around 1.5°C and 4°C in the daytime and early morning hours, respectively (in particular, warming in the early morning hours suggests the presence of overnight heat islands), and 4) sensible heat flux and CBL height have increased by about 40 W m?2 and 500 m for the period, respectively. 相似文献
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Hydroclimatological response to dynamically downscaled climate change simulations for Korean basins 总被引：1，自引：1，他引：0
Eun-Soon Im Il-Won Jung Heejun Chang Deg-Hyo Bae Won-Tae Kwon 《Climatic change》2010,100(3-4):485-508
We investigated the hydrological response to climate change simulations for three basins in South Korea. To provide fine-scale climate information to the PRMS hydrological model, an ECHO-G B2 simulation was dynamically downscaled using the RegCM3 double-nested system implementing two different convection schemes, namely, the Grell and the MIT-Emanuel (EMU) schemes. The daily minimum and maximum temperatures and precipitation from the nested domain for a grid spacing of 20 km are used as the input for the PRMS run. Two sets of multi-decadal simulations are performed over a reference period (1971–2000) and a future period (2021–2050). We focus on the differences of hydrological impacts in response to both simulations with different performances. Based on the validation of the reference simulations, the EMU simulation shows considerable improvement compared to the Grell simulation, indicating a reduction in the cold and dry biases during summer. This improvement is directly reflected in the hydrological simulation of evapotranspiration and runoff. However, using the RCM simulations without bias-correction showed the limitations of hydrologic simulation, especially snowmelt. Despite large differences in both reference simulations, the change signals of temperature and precipitation derived from the differences between the reference and future simulations show a similar pattern and sign. However, the differences in monthly change in precipitation and temperature between Grell and EMU caused the relatively large differences in runoff changes in the study areas. 相似文献
8.
Surface and upper-level features associated with wintertime cold surge outbreaks in South Korea 总被引：1，自引：0，他引：1
The surface and upper-level features associated with a sharp drop of wintertime daily temperature over South Korea is investigated in this study. This sharp drop in daily temperature is called a cold surge and is one of the most hazardous weather phenomena in East Asian winters. An upper-level baroclinic wave of 60°wavelength propagating eastward at a phase speed of 12°longitude per day across the continent of northern China from the west of Lake Baikal toward the eastern coast of China causes the outbreak of cold air over South Korea. The cooling associated with the upper-level baroclinic wave is found at all altitudes under the geopotential height-fall center near the tropopause. The development in the ridge seems to derive the early evolution of the eastward-propagating sinusoidal wave, whereas the trough is connected directly with the tropospheric temperature-drop. An enhancement of the wintertime East Asian jet stream after the outbreak of a cold surge is a response to the steep temperature gradient associated with the developing baroclinic wave. 相似文献
9.
An analysis of simulated future surface climate change over the southern half of Korean Peninsula using a RegCM3-based high-resolution
one-way double-nested system is presented. Changes in mean climate as well as the frequency and intensity of extreme climate
events are discussed for the 30-year-period of 2021–2050 with respect to the reference period of 1971–2000 based on the IPCC
SRES B2 emission scenario. Warming in the range of 1–4°C is found throughout the analysis region and in all seasons. The warming
is maximum in the higher latitudes of the South Korean Peninsula and in the cold season. A large reduction in snow depth is
projected in response to the increase of winter minimum temperature induced by the greenhouse warming. The change in precipitation
shows a distinct seasonal variation and a substantial regional variability. In particular, we find a large increase of wintertime
precipitation over Korea, especially in the upslope side of major mountain systems. Summer precipitation increases over the
northern part of South Korea and decreases over the southern regions, indicating regional diversity. The precipitation change
also shows marked intraseasonal variations throughout the monsoon season. The temperature change shows a positive trend throughout
2021–2050 while the precipitation change is characterized by pronounced interdecadal variations. The PDF of the daily temperature
is shifted towards higher values and is somewhat narrower in the scenario run than the reference one. The number of frost
days decreases markedly and the number of hot days increases. The regional distribution of heavy precipitation (over 80 mm/day)
changes considerably, indicating changes in flood vulnerable regions. The climate change signal shows pronounced fine scale
signal over Korea, indicating the need of high-resolution climate simulations 相似文献
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