scholarly journals Comparing CAM5 and Superparameterized CAM5 Simulations of Summer Precipitation Characteristics over Continental East Asia: Mean State, Frequency–Intensity Relationship, Diurnal Cycle, and Influencing Factors

2016 ◽  
Vol 29 (3) ◽  
pp. 1067-1089 ◽  
Author(s):  
Yi Zhang ◽  
Haoming Chen
Keyword(s):  
East Asia ◽  
Southern China ◽  
Deep Convection ◽  
Summer Precipitation ◽  
Western China ◽  
Peak Time ◽  
Modeling Framework ◽  
Precipitation Frequency ◽  
Diurnal Variability ◽  
Hourly Precipitation

Abstract Numerical experiments are conducted to investigate the differences between summer precipitation over continental East Asia simulated by the Community Atmosphere Model, version 5 (CAM5), and superparameterized CAM5 (SPCAM5, a multiscale modeling framework). The results show that SPCAM5 effectively alleviates several original biases. Overestimates of precipitation on the eastern periphery of the Tibetan Plateau are reduced from CAM5 to SPCAM5 as a result of decreases in both the average hourly precipitation frequency and mean hourly intensity. Underestimates along the coastal regions in southern China are improved following a corresponding increase in mean hourly intensity and a decrease in average hourly precipitation frequency. The frequency–intesnsity relationship is also more realistic in SPCAM5. For western China, overestimated frequency values (in CAM5) of both weak-to-moderate (0–20 mm day−1) and heavy (20–50 mm day−1) intensity ranges are reduced in SPCAM5. For southern China, overestimates of frequency values (in CAM5) in the weak-to-moderate range are also reduced, whereas underestimates in the intense ranges are enhanced. In terms of diurnal variability, SPCAM5 generally exhibits a delay in the afternoon peak time and greater diurnal amplitude. The possible physical reasons for the variations in the precipitation between the models are further investigated. It is found that the change in deep convection intensity is a primary factor governing the shift in the precipitation simulations. SPCAM5 better simulates an intermediate transition stage from shallow to deep convection, which helps the deep convection to grow more fully to a greater magnitude, thus delaying the peak time and increasing the precipitation maxima.

scholarly journals Source apportionment of atmospheric water over East Asia – a source tracer study in CAM5.1

2017 ◽  
Vol 10 (2) ◽  
pp. 673-688 ◽  
Author(s):  
Chen Pan ◽  
Bin Zhu ◽  
Jinhui Gao ◽  
Hanqing Kang
Keyword(s):  
East Asia ◽  
Source Apportionment ◽  
Water Vapour ◽  
Southern China ◽  
Source Region ◽  
Summer Precipitation ◽  
Small Contribution ◽  
Atmospheric Water ◽  
Transport Pathway ◽  
Moisture Source

Abstract. The atmospheric water tracer (AWT) method is implemented in the Community Atmosphere Model version 5.1 (CAM5.1) to quantitatively identify the contributions of various source regions to precipitation and water vapour over East Asia. Compared to other source apportionment methods, the AWT method was developed based on detailed physical parameterisations, and can therefore trace the behaviour of atmospheric water substances directly and exactly. According to the simulation, the northern Indian Ocean (NIO) is the dominant oceanic moisture source region for precipitation over the Yangtze River valley (YRV) and southern China (SCN) in summer, while the north-western Pacific (NWP) dominates during other seasons. Evaporation over the South China Sea (SCS) is responsible for only 2.7–3.7 % of summer precipitation over the YRV and SCN. In addition, the Indo-China Peninsula is an important terrestrial moisture source region (annual contribution of  ∼  10 %). The overall relative contribution of each source region to the water vapour amount is similar to the corresponding contribution to precipitation over the YRV and SCN. A case study for the SCS shows that only a small part ( ≤  5.5 %) of water vapour originates from local evaporation, whereas much more water vapour is supplied by the NWP and NIO. In addition, because evaporation from the SCS represents only a small contribution to the water vapour over the YRV and SCN in summer, the SCS mainly acts as a water vapour transport pathway where moisture from the NIO and NWP meet.

Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China

2020 ◽  
Author(s):  
Chao Wang
Keyword(s):  
East Asia ◽  
Extreme Precipitation ◽  
Southern China ◽  
Summer Precipitation ◽  
Western Pacific Subtropical High ◽  
Asia Pacific ◽  
Combined Effects ◽  
Teleconnection Patterns ◽  
South Asia High ◽  
Westerly Jet

<p>Using ERA-Interim daily reanalysis and precipitation data, the combined effects of East Asia-Pacific (EAP) and Silk Road (SR) teleconnection patterns on summer precipitation in southern China were investigated on synoptic to sub-monthly timescales. Combined EAP and SR patterns lead to more persistent and extreme precipitation in the Yangtze River Valley (YRV) and exhibit an obvious zonal advance between the South Asia High (SAH) and Western Pacific Subtropical High (WPSH) prior to its onset. During typical combined events, an overlap between the SAH and WPSH remains in a favorable position for Persistent Extreme Precipitation (PEP). Furthermore, SR-induced acceleration of the westerly jet stream and extra positive vorticity advection provide persistent upper-level divergence for YRV precipitation. An anomalous EAP-related cyclone/anticyclone pair over East Asia induces enhanced low-level southwesterlies to the northern anticyclone flank and northerlies from the mid-latitudes, advecting anomalously abundant moisture toward the YRV, resulting in clear moisture convergence. Moreover, the strong ascent of warmer/moister air along a quasi-stationary front may be crucial for PEP. During decay, the SAH and WPSH diverge from each other and retreat to their normal positions, and the strong ascent of warmer/moister air rapidly weakens to dissipation, terminating PEP in the YRV.</p>

scholarly journals Atmospheric Thermal and Dynamic Vertical Structures of Summer Hourly Precipitation in Jiulong of the Tibetan Plateau

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 505
Author(s):  
Yonglan Tang ◽  
Guirong Xu ◽  
Rong Wan ◽  
Xiaofang Wang ◽  
Junchao Wang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Tibetan Plateau ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
The Tibetan Plateau ◽  
Hourly Precipitation ◽  
Air Convection ◽  
Precipitation Variation ◽  
Long Term Observation

It is an important to study atmospheric thermal and dynamic vertical structures over the Tibetan Plateau (TP) and their impact on precipitation by using long-term observation at representative stations. This study exhibits the observational facts of summer precipitation variation on subdiurnal scale and its atmospheric thermal and dynamic vertical structures over the TP with hourly precipitation and intensive soundings in Jiulong during 2013–2020. It is found that precipitation amount and frequency are low in the daytime and high in the nighttime, and hourly precipitation greater than 1 mm mostly occurs at nighttime. Weak precipitation during the daytime may be caused by air advection, and strong precipitation at nighttime may be closely related with air convection. Both humidity and wind speed profiles show obvious fluctuation when precipitation occurs, and the greater the precipitation intensity, the larger the fluctuation. Moreover, the fluctuation of wind speed is small in the morning, large at noon and largest at night, presenting a similar diurnal cycle to that of convective activity over the TP, which is conductive to nighttime precipitation. Additionally, the inverse layer is accompanied by the inverse humidity layer, and wind speed presents multi-peaks distribution in its vertical structure. Both of these are closely related with the underlying surface and topography of Jiulong. More studies on physical mechanism and numerical simulation are necessary for better understanding the atmospheric phenomenon over the TP.

Names of Large Exotic Animals and the Urheimat of Japonic

2021 ◽  
Vol 3 (1) ◽  
pp. 105-120
Author(s):  
Alexander Vovin
Keyword(s):  
East Asia ◽  
Southern China ◽  
South East Asia ◽  
Language Family ◽  
Exotic Animals ◽  
Saltwater Crocodile ◽  
Disyllabic Words ◽  
Considerable Support

Abstract This article argues that three words designating large tropical animals not endemic for Japan: kisa ‘elephant’, tora ‘tiger’, and wani ‘saltwater crocodile’ were borrowed into Japonic from Austroasiatic or Kradai languages. If so, this becomes another important piece of evidence for locating the Urheimat of the Japonic Language family in Southern China and/or Northern South-East Asia driving yet another nail into the coffin of the ‘Altaic’ theory. Since all these words are disyllabic, they also contribute to the reconstruction of the disyllabic words in Austroasiatic and Kradai. This is especially important in the case of Kradai, where in spite of the rather recent fall of the monosyllabic curtain, the idea about the ‘primordial’ nature of the monosyllabic structure is still enjoying considerable support.

Observed and Projected Frontal Activities in East Asia

2021 ◽  
pp. 1-46
Author(s):  
Chia-Chi Wang ◽  
Huang-Hsiung Hsu ◽  
Ying-Ting Chen
Keyword(s):  
East Asia ◽  
Climate Model ◽  
Southern China ◽  
Model Performance ◽  
Moisture Flux ◽  
Central China ◽  
Cmip5 Models ◽  
The South ◽  
Front Detection ◽  
Local Moisture

AbstractAn objective front detection method is applied to ERA5, CMIP5 historical, and RCP8.5 simulations to evaluate climate model performance in simulating front frequency and understand future projections of seasonal front activities. The study area is East Asia for two natural seasons, defined as winter (December 2nd –February 14th) and spring (February 15th –May 15th), in accordance with regional circulation and precipitation patterns. Seasonal means of atmospheric circulation and thermal structures are analyzed to understand possible factors responsible for future front changes.The front location and frequency in CMIP5 historical simulations are captured reasonably. Frontal precipitation accounts for more than 30% of total precipitation over subtropical regions. Projections suggest that winter fronts will decrease over East Asia, especially over southern China. Frontal precipitation is projected to decrease for 10-30%. Front frequency increases in the South China Sea and tropical western Pacific because of more tropical moisture supply, which enhances local moisture contrasts. During spring, southern China and Taiwan will experience fewer fronts and less frontal precipitation while central China, Korea, and Japan may experience more fronts and more frontal precipitation due to moisture flux from the south that enhances 𝜽𝒘 gradients.Consensus among CMIP5 models in front frequency tendency is evaluated. The models exhibit relatively high consensus in the decreasing trend over polar and subtropical frontal zone in winter and over southern China and Taiwan in spring that may prolong the dry season. Spring front activities are crucial for water resource and risk management in the southern China and Taiwan.

scholarly journals Application and Evaluation of the China Meteorological Assimilation Driving Datasets for the SWAT Model (CMADS) in Poorly Gauged Regions in Western China

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2171 ◽  
Author(s):  
Xianyong Meng ◽  
Xuesong Zhang ◽  
Mingxiang Yang ◽  
Hao Wang ◽  
Ji Chen ◽  
...  
Keyword(s):  
East Asia ◽  
Assessment Tool ◽  
Swat Model ◽  
Spatial Differentiation ◽  
The Other ◽  
Western China ◽  
Surface Processes ◽  
Human Cognition ◽  
Heihe River ◽  
Observation Data

The temporal and spatial differentiation of the underlying surface in East Asia is complex. Due to a lack of meteorological observation data, human cognition and understanding of the surface processes (runoff, snowmelt, soil moisture, water production, etc.) in the area have been greatly limited. With the Heihe River Basin, a poorly gauged region in the cold region of Western China, selected as the study area, three meteorological datasets are evaluated for their suitability to drive the Soil and Water Assessment Tool (SWAT): China Meteorological Assimilation Driving Datasets for the SWAT model (CMADS), Climate Forecast System Reanalysis (CFSR), and Traditional Weather Station (TWS). Resultingly, (1) the runoff output of CMADS + SWAT mode is generally better than that of the other two modes (CFSR + SWAT and TWS + SWAT) and the monthly and daily Nash–Sutcliffe efficiency ranges of the CMADS + SWAT mode are 0.75–0.95 and 0.58–0.77, respectively; (2) the CMADS + SWAT and TWS + SWAT results were fairly similar to the actual data (especially for precipitation and evaporation), with the results produced by CMADS + SWAT lower than those produced by TWS + SWAT; (3) the CMADS + SWAT mode has a greater ability to reproduce water balance than the other two modes. Overestimation of CFSR precipitation results in greater error impact on the uncertainty output of the model, whereas the performances of CMADS and TWS are more similar. This study addresses the gap in the study of surface processes by CMADS users in Western China and provides an important scientific basis for analyzing poorly gauged regions in East Asia.

scholarly journals Relative impact of insolation and Warm Pool surface temperature on the East Asia Summer Monsoon during the MIS-13 interglacial

2014 ◽  
Vol 10 (2) ◽  
pp. 1025-1051 ◽  
Author(s):  
Q. Z. Yin ◽  
U. K. Singh ◽  
A. Berger ◽  
Z. T. Guo ◽  
M. Crucifix
Keyword(s):  
Surface Temperature ◽  
Summer Monsoon ◽  
Climate Modeling ◽  
Southern China ◽  
Asian Summer Monsoon ◽  
Summer Precipitation ◽  
Northern China ◽  
Warm Pool ◽  
Pool Surface ◽  
The Impact

Abstract. During Marine Isotope Stage (MIS) 13, an interglacial about 500 000 years ago, the East Asian summer monsoon (EASM) was suggested exceptionally strong by different proxies in China. However, MIS-13 is a weak interglacial in marine oxygen isotope records and has relatively low CO2 and CH4 concentrations compared to other interglacials of the last 800 000 years. In the mean time, the sea surface temperature (SST) reconstructions show that the Western Pacific Warm Pool was relatively warm during MIS-13. Based on climate modeling experiments, this study aims at investigating whether this Warm Pool warming could explain the exceptionally strong EASM occurring during the relatively cool interglacial MIS-13. The individual contributions of insolation and of the Warm Pool SST as well as their synergism are quantified through experiments with the Hadley Centre atmosphere model, HadAM3 and using the factor separation technique. The SST over the Warm Pool region has been increased based on geological reconstructions. Our results show that the pure impact of a strong summer insolation contributes to strengthen significantly the summer precipitation in northern China but only little in southern China. The pure impact of enhanced Warm Pool SST reduces, slightly, the summer precipitation in both northern and southern China. However, the synergism between insolation and enhanced Warm Pool SST contributes to a large increase of summer precipitation in southern China but to a decrease in northern China. Therefore, the ultimate role of enhanced Warm Pool SST reinforces the impact of insolation in southern China but reduces its impact in northern China. We conclude that enhanced SST over the Warm Pool region does help to explain the strong MIS-13 EASM precipitation in southern China as recorded in proxy data, but other explanation is needed for explaining the exceptionally strong EASM in northern China.

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