Dynamic and Thermodynamic Factors Associated with Different Precipitation Regimes over South China during Pre-Monsoon Season

The temporal and spatial distributions of tropospheric ozone and its precursors (NO2, CO, HCHO) are analyzed over Guangxi (GX) in South China. We used tropospheric column ozone (TCO) from the Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) onboard the Aura satellite (OMI/MLS), NO2 and HCHO from OMI and CO from the Measurements of Pollution in the Troposphere (MOPITT) instrument in the period 2005–2016. The TCO shows strong seasonality, with the highest value in spring and the lowest value observed in the monsoon season. The seasonal variation of HCHO is similar to that of TCO, while NO2 and CO show slightly different patterns with higher values in spring and winter compared to lower values in autumn and summer. The surface ozone, NO2 and CO observed by national air quality monitoring network sites are also compared with satellite-observed TCO, NO2 and CO, showing good agreement for NO2 and CO but a different seasonal pattern for ozone. Unlike TCO, surface ozone has the highest value in autumn and the lowest value in winter. To reveal the difference, the vertical profiles of ozone and CO from the measurement of ozone and water vapor by airbus in-service aircraft (MOZAIC) observations over South China are also examined. The seasonal averaged vertical profiles of ozone and CO show obvious enhancements at 2–6 km altitudes in spring. Furthermore, we investigate the dependence of TCO and surface ozone on meteorology and transport in detail along with the ECMWF reanalysis data, Tropical Rainfall Measuring Mission (TRMM) 3BV42 dataset, OMI ultraviolet index (UV index) dataset, MODIS Fire Radiative Power (FRP) and back trajectory. Our results show that the wind pattern at 800 hPa plays a significant role in determining the seasonality of TCO over GX, especially for the highest value in spring. Trajectory analysis, combined with MODIS FRP suggests that the air masses that passed through the biomass burning (BB) region of Southeast Asia (SEA) induced the enhancement of TCO and CO in the upper-middle troposphere in spring. However, the seasonal cycle of surface ozone is associated with wind patterns at 950 hPa, and the contribution of the photochemical effect is offset by the strong summer monsoon, which results in the maximum surface ozone concentration in post-monsoon September. The variations in the meteorological conditions at different levels and the influence of transport from SEA can account for the vertical distribution of ozone and CO. We conclude that the seasonal distribution of TCO results from the combined impact of meteorology and long-term transport.

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Prevalence and risk factors associated with headache amongst medical staff in South China

The Journal of Headache and Pain ◽

10.1186/s10194-020-1075-z ◽

2020 ◽

Vol 21 (1) ◽

Cited By ~ 1

Author(s):

Wei Xie ◽

Ruibing Li ◽

Mianwang He ◽

Fang Cui ◽

Tingting Sun ◽

...

Keyword(s):

Risk Factors ◽

South China ◽

Medical Staff ◽

Factors Associated

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Seasonality of the hydrological cycle in major South and Southeast Asian River Basins as simulated by PCMDI/CMIP3 experiments

Earth System Dynamics Discussions ◽

10.5194/esdd-4-627-2013 ◽

2013 ◽

Vol 4 (2) ◽

pp. 627-675 ◽

Cited By ~ 1

Author(s):

S. Hasson ◽

V. Lucarini ◽

S. Pascale ◽

J. Böhner

Keyword(s):

General Circulation ◽

Hydrological Cycle ◽

Monsoon Season ◽

General Circulation Models ◽

River Basins ◽

Southeast Asian ◽

Indus Basin ◽

Precipitation Regime ◽

Precipitation Regimes ◽

Projected Changes

Abstract. In this study, we investigate how PCMDI/CMIP3 general circulation models (GCMs) represent the seasonal properties of the hydrological cycle in four major South and Southeast Asian river basins (Indus, Ganges, and Brahmaputra and Mekong). First, we examine the skill of GCMs by analysing their simulations for the XX century climate (1961–2000) under present-day forcing, and then we analyse the projected changes for the corresponding XXI and XXII century climates under SRESA1B scenario. CMIP3 GCMs show a varying degree of skill in simulating the basic characteristics of the monsoonal precipitation regimes of the Ganges, Brahmaputra and Mekong basins, while the representation of the hydrological cycle over the Indus basin is poor in most cases, with few GCMs not capturing the monsoon signal at all. Although the models' outputs feature a remarkable spread for the monsoonal precipitations, a satisfactory representation of the western mid-latitude precipitation regime is instead observed. Similarly, most of the models exhibit a satisfactory agreement for the basin-integrated runoff in winter and spring, while the spread is large for the runoff during the monsoon season. For future climate scenarios, winter (spring) P − E decreases over all four (Indus and Ganges) basins due to decrease in precipitation associated with the western mid-latitude disturbances. Consequently, the spring (winter) runoff drops (rises) for the Indus and Ganges basins. Such changes indicate a shift from rather glacial and nival to more pluvial runoff regimes, particularly for the Indus basin. Furthermore, the rise in the projected runoff along with the increase in precipitations during summer and autumn indicates an intensification of the summer monsoon regime for all study basins.

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Statistical Characteristics of Raindrop Size Distribution in Southwest Monsoon Season

Journal of Applied Meteorology and Climatology ◽

10.1175/2007jamc1610.1 ◽

2008 ◽

Vol 47 (2) ◽

pp. 576-590 ◽

Cited By ~ 33

Author(s):

N. V. P. Kirankumar ◽

T. Narayana Rao ◽

B. Radhakrishna ◽

D. Narayana Rao

Keyword(s):

Size Distribution ◽

Case Studies ◽

Monsoon Season ◽

Parameter Distribution ◽

Convective Rain ◽

Raindrop Size Distribution ◽

Precipitation Regimes ◽

Raindrop Size ◽

Microphysical Processes ◽

Vertical Variability

Abstract Raindrop size distribution (DSD) parameters are retrieved from dual-frequency (UHF and VHF) wind profiler measurements made at Gadanki, India, in a summer monsoon season. The convoluted UHF spectra are first corrected for vertical air motion and spectral broadening (using VHF measurements) and later are used for deriving DSD parameters. Two distinctly different case studies, a mesoscale convective system and a pure stratiform precipitation system, have been considered for a detailed study. DSD parameters obtained in these case studies reveal systematic variations of DSD from case to case and also from one rain regime to another within the same precipitating system. A statistical study has been carried out using the profiler data collected during the passage of 16 rain events. The retrieved DSD profiles are divided into separate rain regimes (stratiform and convection), based on reflectivity, to examine salient microphysical characteristics and the vertical variability of DSD in different precipitation regimes. The distribution of DSD parameters is, in general, wider in the convective rain regime than in the stratiform regime, particularly below 2.4 km. The vertical variation of the gamma parameter distribution in the stratiform rain regime is minimal, indicating that the microphysical processes (growth and decay), which alter the rain DSD, may be in equilibrium. On the other hand, the distribution in the convective rain regime appears to be more complex, with the mean profile of the shape parameter varying significantly with height. The observed vertical variability of the gamma parameters and the median volume diameter in the convective rain regime is attributed to two major microphysical processes: evaporation and breakup. The role of other processes, like drop sorting and collision–coalescence, in altering the DSD parameters is also discussed. The present statistics, representing continental monsoon rainfall, are compared with the existing statistics at Darwin, Australia, and the results are discussed in light of DSD differences in oceanic and continental monsoon precipitation.

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Synoptic characteristics of heavy rainfall events in pre-monsoon season in South China

Advances in Atmospheric Sciences ◽

10.1007/s00376-009-8219-z ◽

2010 ◽

Vol 27 (2) ◽

pp. 315-327 ◽

Cited By ~ 8

Author(s):

Liji Wu ◽

Ronghui Huang ◽

Haiyan He ◽

Yaping Shao ◽

Zhiping Wen

Keyword(s):

South China ◽

Heavy Rainfall ◽

Monsoon Season ◽

Rainfall Events ◽

Heavy Rainfall Events

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Statistical Characteristics of Raindrop Size Distribution in Monsoon Season over South China Sea

Remote Sensing ◽

10.3390/rs13152878 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2878

Author(s):

Chaoying Huang ◽

Sheng Chen ◽

Asi Zhang ◽

Ying Pang

Keyword(s):

South China Sea ◽

Size Distribution ◽

Summer Monsoon ◽

South China ◽

Southern China ◽

Monsoon Season ◽

Statistical Characteristics ◽

China Sea ◽

Raindrop Size Distribution ◽

Raindrop Size

The South China Sea (SCS) is the largest and southernmost sea in China. Water vapor from the SCS is the primary source of precipitation over coastal areas during the summer monsoon season and may cause the uneven distribution of rainfall in southern China. Deep insight into the spatial variability of raindrop size distribution (DSD) is essential for understanding precipitation microphysics, since DSD contains abundant information about rainfall microphysics processes. However, compared to the studies of DSDs over mainland China, very little is known about DSDs over Chinese ocean areas, especially over the South China Sea (SCS). This study investigated the statistical characteristics of the DSD in summer monsoon seasons using the second-generation Particle Size and Velocity (Parsivel2) installed on the scientific research vessel that measured the size and velocity of raindrops over the SCS. In this study, the characteristics of precipitation over the SCS for daytime and nighttime rains were analyzed for different precipitation systems and upon different rain rates. It was found that: 1) rain events were more frequent during the late evening to early morning; 2) more than 78.2% of the raindrops’ diameters were less than 2 mm, and the average value of mass-weighted mean diameter (1.46 mm) of the SCS is similar to that over land in the southern China; 3) the stratiform precipitation features a relatively high concentration of medium to large-sized rain drops compared to other regions; 4) the DSD in the SCS agreed with a three-parameter gamma distribution for the small raindrop diameter. Furthermore, a possible factor for significant DSD variability in the ocean compared with the coast and large islands is also discussed.

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Awareness, knowledge and attitudes towards cardiopulmonary resuscitation among people with and without heart disease relatives in South China: a cross-sectional survey

BMJ Open ◽

10.1136/bmjopen-2020-041245 ◽

2020 ◽

Vol 10 (12) ◽

pp. e041245

Author(s):

Yun Teng ◽

Yunxuan Li ◽

Liya Xu ◽

Fanyu Chen ◽

Hailiu Chen ◽

...

Keyword(s):

Heart Disease ◽

Cardiopulmonary Resuscitation ◽

South China ◽

Training Experience ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Factors Associated ◽

Knowledge And Attitudes ◽

Cpr Training ◽

And Training

ObjectivesTo assess the awareness, knowledge and attitudes towards cardiopulmonary resuscitation (CPR) among relatives of people with and without heart disease and their influence in South China.DesignThis is a cross-sectional survey. Logistic regression was used to evaluate the demographic factors associated with CPR training, learning and knowledge.SettingThe study was conducted in two hospitals, the largest cardiovascular institute and the largest eye care centre in South China.ParticipantsHealthy individuals who accompanied their relatives with heart disease to the outpatient department of cardiovascular disease and systemically healthy patients who came for regular ophthalmic examination and had no relatives with heart disease were consecutively recruited for the study. A total of 1644 respondents with heart disease relatives and 813 respondents without heart disease relatives completed the survey.ResultsThirty three per cent of respondents never heard of CPR and only 11% had received CPR training. Factors associated with a higher rate of CPR training were higher level of education and income (p<0.001). Most respondents stated that CPR training was necessary and would like to learn CPR. However, only one-third considered it beneficial to perform CPR as a layperson. In addition, healthcare respondents (p<0.001), younger (p<0.05) and more educated respondents (p<0.001) earned higher scores on the knowledge of CPR skills. Only 5.3% had perfect scores on a CPR skills test. Notably, respondents with relatives suffering from heart disease had significantly less training experience and CPR knowledge than those without (p<0.001).ConclusionsAlthough the attitudes towards learning CPR are very positive, there was a lack of knowledge on this topic among the general public. This study demonstrates an urgent need to boost awareness and training in CPR in South China, especially among people whose relatives have heart disease.

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Primary productivity and its variability in the equatorial South China Sea during the northeast monsoon

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-21573-2013 ◽

2013 ◽

Vol 13 (8) ◽

pp. 21573-21608 ◽

Cited By ~ 4

Author(s):

S. H. Ooi ◽

A. A. Samah ◽

P. Braesicke

Keyword(s):

South China Sea ◽

Chlorophyll A ◽

South China ◽

Primary Productivity ◽

Monsoon Season ◽

Winter Monsoon ◽

Phytoplankton Growth ◽

Northeast Monsoon ◽

Cold Surge ◽

China Sea

Abstract. Near coastal areas of the equatorial South China Sea (SCS) are one of the world's regions with highest primary productivity (phytoplankton growth). Concentrations of phytoplankton in the SCS depend significantly on atmospheric forcings and the oceanic state, in particular during the northeast (winter) monsoon season from November to March. Aided by new ocean-observing satellite data, we present a climatological overview of recent surface atmospheric and oceanic features in the equatorial SCS during the northeast monsoon to identify the dominant air-sea processes influencing and modulating the primary productivity of the region. Measured chlorophyll a concentrations are used as a proxy for phytoplankton amounts and the spatial and temporal variations are characterized according to meteorological conditions. Converging northeasterly surface winds support high chlorophyll a concentrations along East Malaysia's coastline in conjunction with a continual nutrient supply from the bottom of the continental shelf by vertical mixing. The mixing can be enhanced due to increased turbulence by wind-generated high waves when they approach shallow water from the deep basin during strong cold surges and monsoon disturbances. Intraseasonal variability during the winter monsoon is characterized by a coastal increase of chlorophyll a starting in November and peaking in January. A general decrease is observed in March. Interannual variability of chlorophyll a concentrations is influenced by ENSO (due to the known modulation of cold surge occurrences), with decreases during El Niño and increases during La Niña in early winter along the shore of East Malaysia. As an example, we discuss an enhanced phytoplankton growth event that occurred due to a typical cold surge-induced Borneo vortex event in January 2010.

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