A Case Modeling of Sea-Land Breeze in Macao and Its Neighborhood

PSU / NCAR MM5 was utilized to simulate the sea-land breeze circulation in Macao and the three-dimensional flow around the Pearl River estuary. Four two-way nested grids having resolution of 1, 3, 9, and 27 km were included in the simulation. It was initialized with conventional observational data, and a 30 h simulation and analysis of one sea-land breeze case were performed. It was shown, that the model with a finer resolution (1 km) captures the sea breeze and land breeze in Macao with reasonable skill. The sea breeze front and the thermal internal boundary layer (TIBL) were also obviously revealed. However, the coarser horizontal resolution (3 km) could capture the sea breeze but not the land breeze.

Cenozoic Sea-land Transition and its Petroleum Geological Significance in the Northern South China Sea

The process of Cenozoic sea-land changes in the northern South China Sea(SCS)controlled the sedimentary filling pattern and played an important role in the petroleum geological characteristics of the northern marginal sedimentary basins.Under the control of the opening process of the SCS,the northern SCS Cenozoic transgression generally showed the characteristics of early in the east and late in the west,and early in the south and late in the north.The initial transgression occurred in the Eocene in the Taixinan Basin(TXNB)of the eastern SCS,while the transgression occurred until the Pliocene in the Yinggehai Basin(YGHB)of the western SCS.International Ocean Discovery Program(IODP)expeditions(Expeditions 367/368)revealed that the initial transgression of the SCS basin occurred at approximately 34 Ma,which was the initial opening time of the SCS.The period of drastic changes in the sedimentary environment caused by large-scale transgression corresponded to the opening time of the southwestern subbasin(approximately 23 Ma),which also represented the peak of the spreading of the SCS.The sea-land transition process controls the distribution of alternating continent-marine facies,marine facies source rocks and reservoirs in the basins.The marine facies source rocks of the basins in the northern SCS have a trend of gradually becoming younger from east to west,which is consistent with the regional process of gradual transgression from east to west.Regional sea-level changes were comprehensively influenced by SCS opening and global sea-level changes.These processes led to the early development in the east and south and late development in the west and north for the carbonate platform in the SCS.Carbonate platforms form another type of"selfgenerating and self-accumulating"oil-gas reservoir in the northern SCS.The sea-land transition controlled the depositional filling patterns of different basins and laid the foundation of marine deposits for oil and gas resources.The source-reservoircap assemblage in the northern SCS was controlled horizontally by provenance supply and sedimentary environmental changes caused by sea-land transition and vertically by the tectonic evolution of the SCS and regional sea-level changes.

Analytic Study of Sea-Land Breezes

An analytic study of the structure of sea-land breezes is presented, with special attention paid to the dependence on the model parameters. In this linearized model, the wind speed of the sea-land breezes is directly proportional to the difference of sea and land heating rates. For the same differential heating, the sea-land breeze is more prominent if the stratification is weakly stable, or if the frictional force is small. The horizontal penetration from the coast is also investigated, and found to be asymmetric between the land and the sea. The above results are in agreement with observation.

Whether human-induced activities could change the gradient pattern of coastal land use along the sea-land direction:a case study in Manila Bay,Philippines

Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains unclear.Manila Bay was selected as the study area in this work.According to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in 1988.Three typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land direction.For example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to 2016.The increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the DFC.Therefore,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.

STATISTICAL CHARACTERISTICS AND NUMERICAL SIMULATION OF SEA-LAND BREEZES IN HAINAN ISLAND

The sea-land breeze circulation(SLBC) occurs regularly at coastal locations and influences the local weather and climate significantly. In this study, based on the observed surface wind in 9 conventional meteorological stations of Hainan Island, the frequency of sea-land breeze(SLB) is studied to depict the diurnal and seasonal variations. The statistics indicated that there is a monthly average of 12.2 SLB days and an occurrence frequency of about 40%, with the maximum frequency(49%) in summer and the minimum frequency(29%) in autumn. SLB frequencies(41%) are comparable in winter and spring. A higher frequency of SLB is present in the southern and central mountains due to the enhancement effect of the mountain-valley breeze. Due to the synoptic wind the number of SLB days in the northern hilly area is less than in other areas. Moreover, the WRF model, adopted to simulate the SLBC over the island for all seasons, performs reasonably well reproducing the phenomenon, evolution and mechanism of SLBC. Chiefly affected by the difference of temperature between sea and land, the SLBC varies in coverage and intensity with the seasons and reaches the greatest intensity in summer. The typical depth is about 2.5 km for sea breeze circulation and about 1.5 km for land breeze circulation. A strong convergence zone with severe ascending motion appears on the line parallel to the major axis of the island, penetrating 60 to 100 km inland. This type of weak sea breeze convergence zone in winter is north-south oriented. The features of SLBC in spring are similar both to that in summer with southerly wind and to that in winter with easterly wind. The coverage and intensity of SLBC in autumn is the weakest and confined to the southwest edge of the central mountainous area. The land breeze is inherently very weak and easily affected by the topography and weather. The coverage and intensity of the land breeze convergence line is significantly less than those of the sea breeze. The orographic forcing of the central mountain exhibits significant impacts on low-level airflow. A windward land breeze front usually occurs along the coastline between the wee hours and the morning in summer, with an arc-shaped convergence zone about 10 to 30 km off shore. In winter the arc-shaped convergence zone is weak and appears only in the southeast coastal area. Landing on the flat regions of northern to western parts of the island and going inland from there, the sea breeze front at the leeward side meets with that at the windward side in the centre of the island when sea breeze fully develops, causing an intense convergence zone throughout the whole island. Consistent with prevailing winds in direction, the windward sea breeze and leeward land breeze develop quickly but are not distinguishable from background winds.

Sea-Land Segmentation of Remote Sensing Images Based on SDW-UNet

Image segmentation of sea-land remote sensing images is of great importance for downstream applications including shoreline extraction,the monitoring of near-shore marine environment,and near-shore target recognition.To mitigate large number of parameters and improve the segmentation accuracy,we propose a new Squeeze-Depth-Wise UNet(SDW-UNet)deep learning model for sea-land remote sensing image segmentation.The proposed SDW-UNet model leverages the squeeze-excitation and depth-wise separable convolution to construct new convolution modules,which enhance the model capacity in combining multiple channels and reduces the model parameters.We further explore the effect of position-encoded information in NLP(Natural Language Processing)domain on sea-land segmentation task.We have conducted extensive experiments to compare the proposed network with the mainstream segmentation network in terms of accuracy,the number of parameters and the time cost for prediction.The test results on remote sensing data sets of Guam,Okinawa,Taiwan China,San Diego,and Diego Garcia demonstrate the effectiveness of SDW-UNet in recognizing different types of sea-land areas with a smaller number of parameters,reduces prediction time cost and improves performance over other mainstream segmentation models.We also show that the position encoding can further improve the accuracy of model segmentation.

The research of sea-land breeze (SLB) on the west coast of Bohai Bay based on field observation

Four automatic meteorological stations were set up in a line from beach to inland perpendicular to the west coast of Bohai Bay. Wind direction and velocity at altitudes of 2 m, 4 m and 12 m were surveyed with 10 minute intervals. On ＂Sea-Land Breeze＂ （SLB） days, the transition from sea breeze to land breeze was very evident in the study area. Direction of sea breeze was basically perpendicular to the coast and mainly from the ENE and E. Duration of sea breeze varied by the stations＇ distance to the coastline, and the near-coast wind velocity was larger than that of the inland and decreases as it reaches inland. There was increased development of SLB on sunny days than on overcast days. The term ＂Climatic Coastal Zone＂ can be defined for the area influenced by SLB, which reaches more than 74 km inland on a typical SLB day but less than 10 km on a non-typical SLB day.

Numerical Studies on Urban Heat Island Associated with Urbanization in Yangtze Delta Region

おhe impact of modifications of the surface characteristics on local climate is simulated with a numerical mesoscale model in the Yangtze delta region, east of China. The simulated reference case with the current surface properties shows that there is urban heat island in Shanghai city which is located in the center of this region. The modifications of surface characteristics due to the urbanization around Shanghai will lead to the change of local air circulation and redistribution of surface temperature. Simulation for this case shows that the urbanization around Shanghai has little effect on Shanghai, but will extend the area of heat island. Another case is assumed that the area of grassland is kept as 50% while the urban areas are extended. Compared with the case of pure urbanization, the maximum reduction of surface air temperature is 2.0oC in the daytime and 2.3oC at night.

城市热岛和海风环流相互作用的数值模拟研究进展

在沿海城市地区,城市热岛环流和海风环流往往同时存在;它们在空气污染物的传输和扩散中均起至关重要的作用,对强对流天气亦有重要的触发作用。随着城市化的发展,空气污染等环境问题变得越来越严峻,突然性强对流天气所造成的灾害也越来越严重。因此,沿海城市地区城市热岛和海风环流相互作用的研究受到日益广泛的关注。本文回顾了近30a来国内外关于城市热岛和海风环流相互作用数值模拟的研究历史,分析了目前的研究现状及存在的一些问题,概述了城市化、城市热岛对海风环流的影响,海风对城市热岛、城市热岛环流的影响,以及城市热岛环流和海风环流的耦合效应。最后,本文提出了一些有待于研究或需深入研究的问题;这些问题的研究将有助于进一步揭示沿海城市地区空气污染动力学机制、强对流天气触发机制。

Comparison of the Activity Differences in Two Terminal Oxidases between Upland Cotton and Sea-island Cotton

[Objective] This study was to reveal the differences in two terminal oxdiases,so as to provide theoretical basis for the selection of upland and sea-land hybrid materials. [Methods] Using 7 shares of upland cotton cultivars and 4 shares of sea-land cultivars as experimental materials,the change differences in AAO and PPO activities during whole growth period of the materials tested were studied. [Results] Two terminal oxdiases both in upland and sea-land cotton cultivars assumed similar change laws during whole growth period. AAO activity assumed a low-high trend,and there is a peak at the early stage. PPO activity presented two peaks,and that at the early stage was higher than at the late stage; the first peak is obviously higher than the second for sea-land cultivars,and two peaks are not remarkably different for upland cultivars. [Conclusion] The differences in AAO and PPO activities of sea-land and upland cotton cultivars observed on Jul.4th and Aug.6th,may provide guidance for the selection of upland and sea-land hybrids.

STUDY OF THE VERTICAL WIND FIELD STRUCTURE AND ITS RELATIONSHIP WITH PM2.5 AIR POLLUTION OVER THE PEARL RIVER DELTA IN AUTUMN

Meteorological conditions,particularly the vertical wind field structure,have a direct influence on the PM2.5 concentrations over the Pearl River Delta(PRD).In October 2012,an exceptional air pollution event occurred in the PRD,and a high concentration of PM2.5 was registered at some stations.During days with PM2.5 air pollution,the wind speed was less than 3 m s-1 at the surface,and the vertical wind field featured a weak wind layer(WWL)with a thickness of approximately 1000 m.The mean atmospheric boundary layer height was less than 500 m during pollution days,but it was greater than 1400 m during non-pollution days.A strong negative correlation was detected between the PM2.5 concentration and the ventilation index(VI).The VI was less than 2000 m2 s-1 during PM2.5 air pollution days.Because of the weak wind,sea-land breezes occurred frequently,the recirculation factor(RF)values were small at a height of 800 m during pollution days,and the zones with the lowest RF values always occurred between the heights of 300 and 600 m.The RF values during PM2.5 pollution days were approximately 0.4 to 0.6 below a height of 800 m,reducing the transportation capacity of the wind field to only 40%to 60%.The RF and wind profile characteristics indicated that sealand breezes were highly important in the accumulation of PM2.5 air pollution in the PRD.The sea breezes may transport pollutants back inland and may result in the peak PM2.5 concentrations at night.

辽西新石器时代的海陆互动--以出土海贝为中心

根据目前的考古资料,辽西地区自新石器时代中期的兴隆洼文化开始到春秋战国时期的夏家店上层文化中均有海贝出土,可见该区域有着浓厚的海洋文化色彩。但目前对于辽西地区海贝的研究,多集中于青铜时代出土遗物,尤以夏家店下层文化中出土宝贝科海贝的相关研究最为丰富。而新石器时代出土的海贝,除部分动物考古学的相关研究中对其种属进行了简单辨识,尚未有专文对海贝进行更深入的研究。尤其是这类遗物的来源与传播途径,以及由此反映出的海陆互动等问题的讨论至今仍旧是空白。因此,笔者拟以辽西出土海贝为中心,对上述问题进行进一步的研究和讨论。

From sea to land: assessment of the bio-transport of phosphorus by penguins in Antarctica

In Antarctica, the marine ecosystem is dynamically interrelated with the terrestrial ecosystem. An example of the link between these two ecosystems is the biogeochemical cycle of phosphorus. Bio- vectors, such as penguins, transport phosphorus from sea to land, play a key role in this cycle. In this paper, we selected three colonies of penguins, the most important seabirds in Antarctica, and computed the annual quantity of phosphorus transferred from sea to land by these birds. Our results show that adult penguins from colonies at Ardley Island, the Vestfold Hills, and Ross Island could transfer phosphorus in the form of guano at up to 12 349, 167 036, and 97 841 kg/a, respectively, over their breeding period. These quantities are equivalent to an annual input of 3.96× 10^9-1.63 × 10^10 kg of seawater to the land of Antarctica. Finally, we discuss the impact of phosphorus on the ice-flee areas of the Antarctica.

The Anatomy of the South Carolina U.S.A. Coastal Sea Breeze 2019-2020

The study presented herein is the analysis of Sodar based instrument measurements of air temperature, dew point, and vertical wind speed and direction, recorded at two South Carolina sites, Waties Island in North Myrtle Beach and in Sumter, and at three atmospheric ground stations. Two of the ground stations are National Weather Service stations near the Sodars and one is a Coastal Carolina University Sea-Econet, as a part of the National Oceanic & Atmospheric Administration, MESO program, weather-sensor site on the Coastal Carolina University campus in Conway South Carolina. Objectives of this study are to establish specific values of winds, land and sea temperatures, precipitation and dew points associated with the changes induced by passages of the Sea Breeze Front, and to examine differences in the station-to-station incarnation of the Sea Breeze circulation. Variability from station to station in the nature and timing of Sea Breeze Front passage is found to be a function of relative proximity to the coast with Sea Breeze Front passage occurring earliest at the North Myrtle Beach site (the station at the coast), then at Sumter (~100 km inland) and finally Aiken at >100 km inland. Satellite based estimates of the percentages of onshore penetration distances from the coast are depicted. Wind vectors and air temperatures associated with onsets and passages of the Sea Breeze display robust wind fields directed onshore perpendicular to the coastline. Kinematical descriptors of the Sea Breeze wind particle motions are presented and display coherent stable elliptical motions during the late summer to early fall but are absent during the winter.

Influence of sea-land breeze on the formation and dissipation of severe dense fog and its burst reinforcement in the Yellow Sea coastal area,China

Based on the global reanalysis data of the National Centers for Environmental Prediction(NCEP)/National Center for Atmospheric Research,the surface meteorological observation data,sounding data and satellite observation data,this paper comprehensively analyzes the evolution process and formation mechanism of a persistent severe dense fog process occurred on February 15–17,2015 in Yancheng,eastern China.Through the numerical simulation experiment of Weather Research and Forecast(WRF)model,we further analyze the impact of sea-land breeze on the formation and burst reinforcement of fog.Results show that the precipitation caused by the southwesterly airflow in front of the upper-level trough and the low-pressure inverted trough are conducive to the formation of early rain fog,while the nighttime clear radiance under the control of surface cold high and the infiltration of weak cold advection are conducive to the formation and development of later radiation-advection fog.The WRF model simulates the fog evolution process,which is basically consistent with the actual fog area,and the simulation results are credible to a certain extent.The simulation results show that the establishment of sea breeze has an advection cooling effect on the near surface layer,which is conducive to the formation and development of the inversion layer on the near surface,providing stable stratification conditions for the formation and burst reinforcement of fog.On one hand,the strengthening of sea breeze circulation can continuously transport water vapor to the study area.On the other,the occurrence of ultra-low level jet is favorable for the accumulation of low-level water vapor.At the same time,the inversion intensity further strengthens,which is in favor of the burst reinforcement and long-term maintenance of fog.

Age estimation of the mid-Pleistocene microtektite event in the South China Sea: A case showing the complexity of the sea-land correlation

The present study confirms the stratigraphical position of microtektite layer being clearly located below the Brunhes/Matuyama (B/M) boundary. Based on the sedimentation rate derived from the stable isotopic and magnetic data of ODP Site 772A, cores 17957 and 17959 in the South China Sea, the age of the mid-Pleistocene impact event was estimated at 10-12 ka earlier than the Brunhes-Matuyama polarity reversal. However, the microtektites were found above the measured B/M boundary in the loess profile due to the downward deviation of the measured B/M boundary from its true position. This demonstrates the complexity of paleo-magnetic records in the loess profiles which, in turn, causes the confusion in the sea-land stratigraphic correlation.

A Model of the Sea-Land Transition of the Mean Wind Profile in the Tropical Cyclone Boundary Layer Considering Climate Changes

The tropical cyclone boundary layer(TCBL)connecting the underlying terrain and the upper atmosphere plays a crucial role in the overall dynamics of a tropical cyclone system.When tropical cyclones approach the coastline,the wind field inside the TCBL makes a sea-land transition to impact both onshore and offshore structures.So better understanding of the wind field inside the TCBL in the sea-land transition zone is of great importance.To this end,a semiempirical model that integrates the sea-land transition model from the Engineering Sciences Data Unit(ESDU),Huang's refined TCBL wind field model,and the climate change scenarios from the Coupled Model Intercomparison Project Phase 6(CMIP6)is used to investigate the influence of climate changes on the sea-land transition of the TCBL wind flow in Hong Kong.More specifically,such a semiempirical method is employed in a series of Monte-Carlo simulations to predict the wind profiles inside the TCBL across the coastline of Hong Kong under the impact of future climate changes.The wind profiles calculated based on the Monte-Carlo simulation results reveal that,under the influences of the most severe climate change scenario,slightly higher and significantly lower wind speeds are found at altitudes above and below 400 m,respectively,compared to the wind speeds recommended in the Hong Kong Wind Code of Practice.Such findings imply that the wind profile model currently adopted by the Hong Kong authorities in assessing the safety of low-to high-rise buildings may be unnecessarily over-conservative under the influence of climate change.On the other hand,the coded wind loads on super-tall buildings slightly underestimate the typhoon impacts under the severe climate change conditions anticipated for coastal southern China.

The evolution of Paleozoic vascular land plant diversity of South China

Data of Paleozoic and some Early Triassic vascular land plant fossils from South China are synthetically analyzed,revealing evolutionary characteristics of Paleozoic vascular land plant diversity.Vascular land plant diversity keeps increasing in the Paleozoic as a whole.The Silurian witnessed the earliest evolution and initial diversification of land plants.From the Early Devonian to the Early Carboniferous(Mississippian),the great development,diversification,and differentiation really occurred in vascular land plants,with fluctuations of diversity,rapid replacement of the plant types,and an all-out takeover of terrestrial ecological niches.From the Early Permian,land plant diversity dramatically increased,and reached a climax in the Middle-Late Permian.Comparisons between late Paleozoic marine and terrestrial biodiversity reveal co-evolution of the late Paleozoic animals and plants as well as the individual evolutionary patterns of sea/land ecosystems.Vascular land plant diversity dramatically declined in the Frasnian as a result of the F/F event,and the end-Permian mass extinctions completely turned over the phytogroups.

MM5 Simulations of the China Regional Climate During the LGM.Ⅱ:Influence of Change of Land Area,Vegetation,and Large-scale Circulation Background

Using a regional climate model MM5 nested to an atmospheric global climate model CCM3, a series of simulations and sensitivity experiments have been performed to investigate the relative LGM climate response to changes of land-sea distribution, vegetation, and large-scale circulation background over China. Model results show that compared with the present climate, the fluctuations of sea-land distribution in eastern Asia during the LGM result in the temperature decrease in winter and increase in summer. It has significant impact on the temperature and precipitation in the east coastal region of China. The impact on precipitation in the east coastal region of China is the most significant one, with 25%-50% decrease in the total precipitation change during the LGM. On the other hand, the changes in sea-land distribution have less influence on the climate of inland and western part of China. During the LGM, significant changes in vegetation result in temperature alternating with winter increase and summer decrease, but differences in the annual mean temperature are minor. During the LGM, the global climate, i.e., the large-scale circulation background has changed significantly. These changes have significant influences on temperature and precipitation over China. They result in considerable temperature decreases in this area, and direct the primary patterns and characteristics of temperature changes. Results display that, northeastern China has the greatest temperature decrease, and the temperature decrease in the Tibetan Plateau is larger than in the eastern part of China located at the same latitude. Moreover, the change of large-scale circulation background also controls the pattern of precipitation change. Results also show that, most of the changes in precipitation over western and northeastern parts of China are the consequences of changing large-scale circulation background, of which 50%-75% of precipitation changes over northern and eastern China are the results of changes in large-scale circulation background. Over China, the LGM climate responses to different mechanisms in order of strength from strong to weak are, the large-scale circulation pattern, sea- land distribution, vegetation, CO2 concentration, and earth orbital parameters.

Analysis of the influence of Taihu Lake and the urban heat islands on the local circulation in the Yangtze Delta

A fine-mesh regional meteorological model that suits the Yangtze Delta region was developed. This model was used to simulate some micro weathers, such as the land and sea breezes, land and lake breezes and urban heat island effect, in the Yangtze Delta successfully. The model was also used to study the characteristics and the formation mechanism of surface shear line in the region. It is indicated that the interaction between the sea breeze and the lake breeze is the main factor for the formation and maintenance of the surface shear line.