Specific Relationship between the Surface Air Temperature and the Area of the Terra Nova Bay Polynya,Antarctica

Antarctic polynyas play an important role in regional atmosphere?ice?ocean interactions and are considered to help generate the global deep ocean conveyer belt.Polynyas therefore have a potential impact on the Earth’s climate in terms of the production of sea ice and high-salinity shelf water.In this study,we investigated the relationship between the area of the Terra Nova Bay polynya and the air temperature as well as the eastward and northward wind based on the ERA5 and ERAInterim reanalysis datasets and observations from automatic weather stations during the polar night.We examined the correlation between each factor and the polynya area under different temperature conditions.Previous studies have focused more on the effect of winds on the polynya,but the relationship between air temperature and the polynya area has not been fully investigated.Our study shows,eliminating the influence of winds,lower air temperature has a stronger positive correlation with the polynya area.The results show that the relationship between the polynya area and air temperature is more likely to be interactively influenced.As temperature drops,the relationship of the polynya area with air temperature becomes closer with increasing correlation coefficients.In the low temperature conditions,the correlation coefficients of the polynya area with air temperature are above 0.5,larger than that with the wind speed.

Effect of Meteorological Factors on PM₁₀Concentration in Hanoi, Vietnam

According to the Ministry of Natural Resources and Environment, Hanoi city is currently facing the increased air pollution, especially particulate matter. This study examines the influence of meteorological factors including temperature, humidity and wind speed on PM10 concentration in Hanoi. The data used in this study include 24-h PM10 concentration data, hourly temperature, humidity and wind speed data in 2018 at three automatic air monitoring stations under Vietnam Environment Administration and Hanoi Natural Resources and Environment Department. The SPSS statistical analysis tools are utilized to analyze the correlation between PM10 concentration and meteorological factors through the Spearman (r) correlation coefficient. Additionally, the Independent-Sample T-Test is also employed to assess the difference in PM10 concentration in the period between dry season (from October to March) and wet season (from May to September). The results show that there is a trend of seasonal variation of PM10 concentration. Specifically, PM10 concentration recorded a higher value in winter and lower in summer. Different correlations between air pollutants and meteorological factors were also observed. PM10 concentration was inversely correlated (r 10 concentration during dry and wetseason. This outcome has confirmed the important role of meteorological factors in the formation of air pollution with large variations in different seasons and geological areas.

An Observational Study on the Local Climate Effect of the Shangyi Wind Farm in Hebei Province

Zhangjiakou is an important wind power base in Hebei Province,China.The impact of its wind farms on the local climate is controversial.Based on long-term meteorological data from 1981 to 2018,we investigated the effects of the Shangyi Wind Farm(SWF)in Zhangjiakou on air temperature,wind speed,relative humidity,and precipitation using the anomaly or ratio method between the impacted weather station and the non-impacted background weather station.The influence of the SWF on land surface temperature(LST)and evapotranspiration(ET)using MODIS satellite data from 2003 to 2018 was also explored.The results showed that the SWF had an atmospheric warming effect at night especially in summer and autumn(up to 0.95℃).The daytime air temperature changes were marginal,and their signs were varying depending on the season.The annual mean wind speed decreased by 6%,mainly noted in spring and winter(up to 14%).The precipitation and relative humidity were not affected by the SWF.There was no increase in LST in the SWF perhaps due to the increased vegetation coverage unrelated to the wind farms,which canceled out the wind farm-induced land surface warming and also resulted in an increase in ET.The results showed that the impact of wind farms on the local climate was significant,while their impact on the regional climate was slight.

An Assessment of the Quality of Surface Sensible Heat Flux Derived from Reanalysis Data through Comparison with Station Observations in Northwest China

The present study compares seasonal and interdecadal variations in surface sensible heat flux over Northwest China between station observations and ERA-40 and NCEP-NCAR reanalysis data for the period 1960-2000. While the seasonal variation in sensible heat flux is found to be consistent between station observations and the two reanalysis datasets, both land-air temperatures difference and surface wind speed show remarkable systematic differences. The sensible heat flux displays obvious interdecadal variability that is season-dependent. In the ERA-40 data, the sensible heat flux in spring, fall, and winter shows interdecadal variations that are similar to observations. In the NCEP-NCAR reanalysis data, sensible heat flux variations are inconsistent with and sometimes even opposite to observations. While surface wind speeds from the NCEP-NCAR reanalysis data show interdecadal changes consistent with station observations, variations in land-air temperature difference differ greatly from the observed dataset. In terms of land-air temperature difference and surface wind speed, almost no consistency with observations can be identified in the ERA-40 data, apart from the land-air temperature difference in fall and winter. These inconsistencies pose a major obstacle to the application in climate studies of surface sensible heat flux derived from reanalysis data.

Analysis on Temporal Pattern of Fine Particulate Matter (PM_2.5) in Hanoi, Vietnam and the Impact of Meteorological Conditions

Air quality is one of key issues to be addressed in the Vietnam environmental security strategy. As part of the strategy, this study investigates the temporal patterns of PM2.5 variations in Hanoi using data measured from January 2017 to December 2018. The loglinear regression is used to analyze how the meteorological factors affect the PM2.5 variations. The analysis indicates the seasonal, monthly and diurnal variations of PM2.5 concentrations. The lowest concentration level is found in the summer due to hot climatic conditions with strong winds and high solar radiation. The highest PM2.5 concentration is observed in winter as a result of stagnation. The concentration levels from 2:00 AM to 8:00 AM tend to be higher than other hours of the day while the downtrend is recorded from 11:00 AM to 7:00 PM and reaches the lowest levels of the day at 2:00 PM to 3:00 PM. The study results provide important information for government authorities, international and civil society organizations on when and why the PM2.5 concentration levels increase. This predictive analysis would be useful to develop early warning systems and to minimize the negative impacts of air pollution on public health.

Evolution of Surface Sensible Heat over the Tibetan Plateau Under the Recent Global Warming Hiatus

Based on regular surface meteorological observations and NCEP/DOE reanalysis data, this study investigates the evolution of surface sensible heat（SH） over the central and eastern Tibetan Plateau（CE-TP） under the recent global warming hiatus. The results reveal that the SH over the CE-TP presents a recovery since the slowdown of the global warming. The restored surface wind speed together with increased difference in ground-air temperature contribute to the recovery in SH.During the global warming hiatus, the persistent weakening wind speed is alleviated due to the variation of the meridional temperature gradient. Meanwhile, the ground surface temperature and the difference in ground-air temperature show a significant increasing trend in that period caused by the increased total cloud amount, especially at night. At nighttime, the increased total cloud cover reduces the surface effective radiation via a strengthening of atmospheric counter radiation and subsequently brings about a clear upward trend in ground surface temperature and the difference in ground-air temperature.Cloud–radiation feedback plays a significant role in the evolution of the surface temperature and even SH during the global warming hiatus. Consequently, besides the surface wind speed, the difference in ground-air temperature becomes another significant factor for the variation in SH since the slowdown of global warming, particularly at night.

Vertical structure of low-level atmosphere over the southeast Indian Ocean fronts

During the 25th Chinese National Antarctic Research Expedition, GPS radiosondes were launched to detect the atmos- pheric vertical structure over the southeast Indian Ocean frontal region. Some low-level characteristics along the cruise are studied based on in-situ observation. The observations reveal that vertical distributions of the low-level wind field and air temperature field on both sides of the Subantarctic Front are very different. A stronger （weaker） vertical gradient is on the cold （warm） side, which demonstrates that the mid-latitude ocean-atmosphere interaction is active in the southeast Indian Ocean frontal region. A low-level jet is observed over the Subantarctic Front, with speed up to 14 m＇s-1. For the Antarctic polar front, low-level wind speed near the sea surface is greater than that aloft, in contrast with the situation of the Subantarctic Front. Comparing satellite remote sensing data and widely-used reanalysis datasets with our in-situ observations, differences of varying magnitudes are found. Air temperature from Atmospheric Infrared Sounder （AIRS） data has a limited difference. The European Center for Medium Range Weather Forecasts Interim Re-Analysis （ERA Interim） dataset is much more consistent with the observations than the National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） Reanalysis 1 in the southeast Indian Ocean frontal region.

唐钢2号高炉风温提升研究

对唐钢2号高炉进行热风炉制约条件的束缚及高炉操作制度的持续优化,并进行理论系统分析,采取调整烧炉参数、严格执行标准化操作等一系列提高风温的措施,使唐钢2号高炉风温水平得到显著提高,降低了生产成本。

湿热地区建筑能耗模拟气象年开发及参数影响

气象年数据是建筑能耗模拟的基础参数。基于10年期城市气象站逐时实测数据制作了湿热地区代表城市广州和西沙的测试参考年(TRY),并通过模拟验证了具有较好的长期代表性。在TRY基础上通过气象参数偏移形成对比模型组,评估各气象要素对建筑能耗的影响权重,结果表明空气温度和太阳辐射对建筑能耗有主导影响,对广州相对影响权重全年均值(IFw.mean)分别为44.81%和40.62%,对西沙相应值为28.70%和57.11%;相对湿度影响具有季节性,对广州和西沙IFw.mean分别为11.30%和8.98%;风速影响对广州不明显,对西沙则有一定幅度提高,IFw.mean分别为3.28%和5.21%。为湿热地区的建筑能耗模拟提供了气象数据支持,为建筑节能设计提供参考。

高低温试验箱温度均匀性调节技术研究

温度均匀性是保证高低温试验箱实验结果有效性和可信性的重要指标。现有关于高低温试验箱出风口气流组织形式对温度均匀性影响的研究主要通过仿真模拟技术,并且都忽略了试验箱风道在宽度方向的不均对试验箱整体温度均匀性的影响。通过对设备温度均匀性、调节复杂度、能耗情况等进行比较,在内箱容积均为1000 L的高低温试验箱中,实验了3种不同的温度均匀性调节技术,即可调百叶、热气除霜、双边进蒸发器等。结果发现双边进蒸发器技术更加有益于设备风道内部换热,可有效排除因试验箱风道温度不均对实验结果的影响,并且在同一试验箱中分别实验了3种出风口形状(正方形、圆形、菱形)及不同风速下试验箱的温度均匀性。结果表明:风速对环境试验箱的影响很大,风速越高,试验箱温度均匀性越好。当风速相同时,在高温工况下,出风口形状对试验箱温度均匀性的影响很大,方形出风口温度均匀性最好;在常温及低温工况下,出风口形状对试验箱温度均匀性的影响很小。

岱海水面蒸发与气象要素关系分析

该文以岱海为研究对象,以乌兰察布市凉城县岱海镇三苏木水文站为依托,以水面蒸发物理成因为基础,根据蒸发实测资料,建立了20 cm口径蒸发器与E601型蒸发器与气温、相对湿度、水汽压、降水量、风速、地温、日照等气象要素的相关性分析,通过SPSS双侧相关性检验以及散点图趋势线分析,20 cm口径蒸发器监测蒸发量时更灵敏,与气象要素相关性更好,对于气象要素的变化反应更敏感;气象要素对蒸发量的影响中,对蒸发量影响最大的是最高地面温度,其次是日照时数、平均相对湿度和最高气温,最高地面温度、最高气温越高、日照时数越长、风速越高,蒸发量越大;平均相对湿度越大,环境中水汽含量越高,蒸发量越小。

利用气象因子估算天然河道水温的新公式

结合某流域水温原型观测资料,通过分析水温与气温、太阳辐射、湿度和风速之间的相关关系,采用最小二乘法建立了水温与气温、湿度和风速三者之间的多变量函数方程式,提出了一种利用气象因子估算天然河道水温的新公式。研究成果可用于缺乏水温监测资料河流的水温估算,为流域开发的环境影响评价提供科学依据。

环境影响下的直接空冷系统运行特性研究

环境变化会显著影响直接空冷机组的凝汽器压力,因此,研究直接空冷系统在环境影响下的运行特性,对保证直接空冷机组安全经济运行具有重要意义。通过理论分析,建立了空冷凝汽器温度和压力随汽轮机排汽热负荷、凝汽器迎风面风速以及进口空气温度变化的理论模型。以山西平朔煤矸石发电有限公司50MW机组直接空冷系统为例,通过数值计算,得到了环境气温、环境风速风向以及汽轮机排汽热负荷对凝汽器温度和压力的影响规律。结果表明:在凝汽器热负荷不变的情况下,环境气温越高,空冷凝汽器进口空气温度就越高,凝汽器压力就越高。环境风速越大,空冷器进口空气温度就越高,迎面风速就越小,从而凝汽器内冷凝温度和压力就越高。反之,凝汽器压力就越低。

全球气候变化下的半干旱区相对湿度变化研究

为揭示全球气候变化下半干旱区空气相对湿度的变化规律,利用线性回归分析、多元线性相关分析以及M-K检验法对吉林省西部5个站点的1953年以来的相对湿度、气温、降水和风速资料进行了研究.结果表明:相对湿度的年变化曲线呈双峰型,相对湿度的最大值出现在8月,次大值出现在1月,最小值出现在4月,次小值出现在10月.夏、秋季的相对湿度较大,而春、冬季的相对湿度较小.近50年,年平均相对湿度及春、夏、秋、冬四季的相对湿度在波动中下降,下降趋势不显著;但是9月和10月的平均相对湿度下降显著.影响相对湿度变化的主要因子是温度和降水,风速也起一定的作用.相对湿度的变化与温度和风速变化呈负相关关系,与降水变化呈正相关关系.

青藏高原唐古拉垭口地区小气候特征

利用中国科学院青藏高原冰冻圈观测试验研究站唐古拉站点2005年的气象资料,分析了该地区的小气候特征.结果表明:各辐射量呈现明显的季节特征,反照率冬春季节较强,夏季较弱,年平均反照率为0.31;气温、比湿、气压及地温等变化均呈现夏季高,冬春季低,而风速冬季高于夏季.无论干季(且活动层冻结)还是湿季(且活动层融化),夜晚或清晨由于长波辐射冷却,近地表出现冷中心,形成逆温,大气趋于稳定,湍能活动受到抑制,风速变小,水汽输送也相应变弱,形成高比湿中心;白天加热地表形成热中心,近地表温度较高,湍能增强,风速增强,水汽输送也相应变强烈,形成比湿的低值中心.

新疆维吾尔自治区策勒县绿洲一沙漠过渡带小气候特征

利用HOBO小气候观测仪,在2010年7月23日至8月24日对新疆策勒绿洲—沙漠过渡带的柽柳群落、柽柳—骆驼刺—花花柴群落、骆驼刺群落3个典型天然植物群落的风速、气温、空气相对湿度、光合有效辐射进行了同步观测,分析了它们的小气候特征的差异,初步探讨了产生这些差异的原因。结果表明,策勒绿洲—沙漠过渡带的植被具有独特的小气候作用,植被覆盖度越大,风速越小,气温越低,相对湿度越高。相比植被覆盖度仅3%的柽柳群落,柽柳—骆驼刺—花花柴群落(覆盖度27%)和骆驼刺群落(覆盖度67%)在观测期内0.5,1,2,4,8和10m处风速平均减小了32%,47%,近地表0.5m风速减少的最多,分别为57%,87%;2m处气温的平均值分别减少了0.32,1.02℃;2m处空气相对湿度的平均值分别增加2.33%,7.67%;策勒绿洲—沙漠过渡带柽柳群落、柽柳—骆驼刺—花花柴群落和骆驼刺群落的光合有效辐射差异不明显;阴天和沙尘暴天气光合有效辐射比晴天分别减少40%,60%。

风速记录差异对评估风电变流器可靠性的影响

风速的随机变化使得风电变流器中器件的结温产生波动，影响变流器的可靠运行。现有文献依据每小时的风速记录来评估风电变流器的可靠性，忽略了每小时内风速的频繁变化对变流器可靠性的影响，这会高估风电变流器的可靠性。根据实际的风速及气温数据，分析了不同风速记录时间刻度对风电变流器中器件结温及其波动计算结果的影响；利用Coffin-Manson器件可靠性评估模型评估了在不同时间刻度下的可靠性。评估结果表明，在不同风速记录间隔下，风电变流器的可靠性并不一致。研究结果表明，当风速及气温数据的记录时间间隔在2～3min之间，风电变流器可靠性的评估结果较为准确；若记录时间间隔较长f如大于10min），将会高估变流器的可靠性。

北京城区城市热岛的多时空尺度变化

利用气象台站数据分析北京城郊气温和城市热岛(UHI)强度的年变化及风速对北京UHI的影响;同时分析北京5个城市站点UHI在不同季节的日变化特征。结果表明,近44 a来北京市区与郊区的多年平均气温和UHI强度均呈增加的趋势。风速的降低促进北京城区的UHI出现增加趋势。风速对UHI的季节变化影响也很显著。2005年北京UHI日变化呈现了明显的夜间强,午间弱的特征,尤以天安门和公主坟站点的UHI日变化明显;冬季UHI强度比其他季节相应时次的UHI都强,且冬季UHI日变化幅度最大,夏季日变化幅度最小。

城市区域屋顶上与地上的风速和温度特征分析

以低纬高原城市昆明市为研究对象，利用城内外屋顶上和地上的风速和温度实测资料，分析了研究较少的，做为城市第二热力面的屋顶面附近的风速和温度特征、变化规律及其与地上的差异，得到了一些有益的结果。

直接空冷机组空冷系统运行问题分析及对策

直接空冷技术代表了未来空冷系统的发展方向,分析直接空冷系统运行中的主要问题并提出相应防治对策,对直接空冷机组安全高效运行具有重要意义。以山西平朔煤矸石发电有限公司50MW机组直接空冷系统为例,针对直接空冷系统运行中的真空泄漏,管束积灰,严寒环境下的冻裂问题,尤其是环境气温、风速、风向对空冷岛运行的影响进行了分析,重点研究了空冷岛回流率与电厂平面布局、环境风速风向的关系。结合直接空冷系统运行中出现的各种问题,提出了初步防治对策。指出通过合理的空冷散热器结构设计,优化的直接空冷电站平面布局,运行过程中针对不同环境条件的科学风量调节等措施,可有效克服直接空冷系统运行中出现的问题,从而提高机组安全经济运行水平。