CMIP5多模式资料中气温的BMA预测方法研究   总被引：6，自引：1，他引：5  

智协飞  王晶  林春泽  彭婷  王佳 《气象科学》2015,35(4):405-412

利用CMIP5的8个全球气候系统模式对气温的回报结果进行贝叶斯模式平均(简称BMA)试验,并采用均方根误差、距平相关系数、连续等级概率评分等对多模式集合平均(简称EMN)和BMA的回报结果进行检验、评估。结果表明,EMN的回报效果优于8个单模式的回报效果,而BMA的回报效果最好,其区域平均的均方根误差比EMN小0.5℃左右。在此基础上,利用中等排放情景RCP4.5下CMIP5模式中的年际年代际预估资料对2011—2035年的气温进行预估。研究发现东亚地区在2011—2035年气温将普遍升高,海洋上的增暖幅度较小,陆地上的增暖幅度较大,且增暖幅度随纬度升高而增大。青藏高原及中国北方大部分地区气温将明显升高,升温幅度在1℃左右,而南方的升温幅度较小,约为0.3~0.6℃。  相似文献   

雷暴云宏观特性对其电过程影响的数值模拟研究     

赵鹏国  银燕  周筠珺  肖辉 《气象科学》2015,35(2):126-132

利用一维雷暴云起电放电模式,初步模拟了STEPS(夏季雷暴降水与闪电研究计划)一次雷暴个例的一些基本电学特性。模拟的电荷结构为:雷暴云上部为正电荷,下部为负电荷,即符合典型雷暴云的偶极性电场分布特征,放电层电场随时间变化规律呈锯齿状分布。在此基础上,对云底高度和温度垂直递减率进行了敏感性试验,研究这两种因子对雷暴电过程的影响。结果表明:当云底高度降低时,放电高度升高,闪电频数增加,首次放电时间随之提前,即放电过程变强。温度垂直递减率增大,闪电频数降低,首次放电时间随之延后,正负电荷的分布范围减小。  相似文献   

Climate change,social vulnerability and child nutrition in South Asia     

《Global Environmental Change》2021

Despite recent advancements in global population well-being and food security, climate change threatens to undermine child nutritional health, particularly for marginalized populations in tropical low- and middle-income countries. South Asia is at particular risk for climate-driven undernutrition due to a combination of historical weather exposures, existing nutritional deficits, and a lack of sanitation access. Previous studies have established that precipitation extremes increase rates of undernutrition in this region, but the existing literature lacks adequate consideration of temperature anomalies, mediating social factors, and the developmentally-relevant timing of exposure. We combine high-resolution temperature and precipitation data with large-sample survey data on household demographics and child anthropometry, using an approach that incorporates three key developmental periods and a rigorous fixed effects design. We find that precipitation extremes in the first year of life significantly decrease children’s height-for-age (HAZ) in South Asia. The detrimental effects of extreme precipitation are especially concentrated in under-resourced households, such as those lacking access to proper sanitation and education for women, while anomalous heat is particularly harmful for children in Pakistan, though it tends to benefit children in some demographic groups. These results indicate that nutritional status in South Asia is highly responsive to climate exposures, and that addressing sanitation infrastructure and other development priorities is a pathway towards reducing this vulnerability.  相似文献   

黄河流域蒸散发与气温和降水以及风速的相关性分析     

谷同辉  管晓丹  高照逵  黄小倩  郭书扬 《气象与环境学报》2022,38(1):48-56

黄河流经我国干旱半干旱地区,其流域蒸散发变化对当地的生态安全和经济发展尤其重要。本文利用欧洲中期天气预报中心第五代再分析产品（ERA5）定量分析了1979-2020年黄河流域蒸散发的时空变化特征,并结合气温、降水和风速数据,对黄河流域蒸散发与3种气候因子进行了相关性分析。结果表明：黄河流域蒸散发在1979-2020年呈波动下降趋势,空间分布差异明显,源区附近蒸散发上升,上游的干旱区附近蒸散发基本不变,而中游和下游地区主要呈现下降趋势。1979-2020年黄河流域气温持续上升,降水呈波动下降趋势,风速呈上升趋势。对黄河流域蒸散发与气候因子的相关性分析表明,蒸散发与气候因子的相关性空间差异较为明显,蒸散发与气温、风速呈负相关,与降水呈正相关的区域占流域的较大部分;而在复相关性方面,黄河流域大部分地区蒸散发与气候因子的相关性较强,其中以流域上游的干旱区附近复相关性最强。研究黄河流域不同地区蒸散发与气候因子的相关性可为黄河流域水资源的开发管理和区域气候调节提供科学参考。  相似文献   

An application of artificial intelligence for investigating the effect of COVID-19 lockdown on three-dimensional temperature variation in equatorial Africa     

《地学前缘(英文版)》2022,13(2):101318

We present interesting application of artificial intelligence for investigating effect of the COVID-19 lockdown on 3-dimensional temperature variation across Nigeria (2°–15° E, 4°–14° N), in equatorial Africa. Artificial neural networks were trained to learn time-series temperature variation patterns using radio occultation measurements of atmospheric temperature from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC). Data used for training, validation and testing of the neural networks covered period prior to the lockdown. There was also an investigation into the viability of solar activity indicator (represented by the sunspot number) as an input for the process. The results indicated that including the sunspot number as an input for the training did not improve the network prediction accuracy. The trained network was then used to predict values for the lockdown period. Since the network was trained using pre-lockdown dataset, predictions from the network are regarded as expected temperatures, should there have been no lockdown. By comparing with the actual COSMIC measurements during the lockdown period, effects of the lockdown on atmospheric temperatures were deduced. In overall, the mean altitudinal temperatures rose by about 1.1 °C above expected values during the lockdown. An altitudinal breakdown, at 1 km resolution, reveals that the values were typically below 0.5 °C at most of the altitudes, but exceeded 1 °C at 28 and 29 km altitudes. The temperatures were also observed to drop below expected values at altitudes of 0–2 km, and 17–20 km.  相似文献   

Temperature and emissivity separation and mineral mapping based on airborne TASI hyperspectral thermal infrared data     

《International Journal of Applied Earth Observation and Geoinformation》2015

Thermal infrared remote sensing (8–12 μm) (TIR) has great potential for geologic remote sensing studies. TIR has been successfully used for terrestrial and planetary geologic studies to map surface materials. However, the complexity of the physics and the lack of hyperspectral data make the studies under-investigated. A new generation of commercial hyperspectral infrared sensors, known as Thermal Airborne Spectrographic Imager (TASI), was used for image analysis and mineral mapping in this study. In this paper, a combined method integrating normalized emissivity method (NEM), ratio algorithm (RATIO) and maximum–minimum apparent emissivity difference (MMD), being applied in multispectral data, has been modified and used to determine whether this method is suitable for retrieving emissivity from TASI hyperspectral data. MODTRAN 4 has been used for the atmospheric correction. The retrieved emissivity spectra matched well with the field measured spectra except for bands 1, 2, and 32. Quartz, calcite, diopside/hedenbergite, hornblende and microcline have been mapped by the emissivity image. Mineral mapping results agree with the dominant minerals identified by laboratory X-ray powder diffraction and spectroscopic analyses of field samples. Both of the results indicated that the atmospheric correction method and the combined temperature–emissivitiy method are suitable for TASI image. Carbonate skarnization was first found in the study area by the spatial extent of diopside. Chemical analyses of the skarn samples determined that the Au content was 0.32–1.74 g/t, with an average Au content of 0.73 g/t. This information provides an important resource for prospecting for skarn type gold deposits. It is also suggested that TASI is suitable for prospect and deposit scale exploration.  相似文献   

The Würmian Late-glacial in Iowland Switzerland     

B. Ammann  A. F. Lotter  U. Eicher  M.-J. Gaillard  B. Wohlfarth  W. Haeberli  G. Lister  M. Maisch  F. Niessen  Ch. Schlüchter 《第四纪科学杂志》1994,9(2):119-125

A synthesis is provided of Late-glacial (14-9 ka BP) environmental changes in lowland Switzerland (the ‘Swiss Plateau’). The chronology of deglaciation and subsequent developments in vegetation cover in the area are summarised. The sequence of climatic variations experienced in the region during the Late-glacial is then described and a curve representing the main palaeotemperature variations is presented.  相似文献   

青藏高原近600年的温度变化   总被引：28，自引：20，他引：28  

冯松  姚檀栋  江灏  康兴成  汤懋苍 《高原气象》2001,20(1):105-108

利用1983年7月－1990年12月ISCCP卫星反演的地表温度资料，将高原的温度变化分为三个区。在每一区找1－2个温度变化的代用资料（冰芯、树轮），将近600a的资料进行标准化处理，然后按面积加权，得到了大体可代表整个高原的平均温度变化序列，发现600a来高原上曾出现过三次冷期和暖期，最冷在17世纪中叶。  相似文献   

伊春市气候变化规律及预测     

白鸣祺  王芳 《黑龙江气象》2001,(1):29-31

通过统计分析，论述了本地各气候因子的变化情况，并对今后10年内的气候变化进行了初步预测。  相似文献   

Coherent eddies and temperature structure functions for three contrasting surfaces. Part II: Renewal model for sensible heat flux     

Wenjun Chen  Michael D. Novak  T. Andrew Black  Xuhui Lee 《Boundary-Layer Meteorology》1997,84(1):125-147

Sensible heat, latent heat, and other scalar fluxes cannot be measuredwithin short dense canopies, e.g., straw mulches, with standard approachessuch as eddy correlation, Bowen ratio-energy balance, aerodynamic, andvariance methods. However, recently developed surface renewal models, thatare based on the fact that most of the turbulent transfer within and abovecanopies is associated with large-scale coherent eddies, which are evidentas ramp patterns in scalar time series, offer a feasible solution. Wepresent a new air renewal model that calculates sensible heat flux atdifferent heights within and above a canopy from the average cubictemperature structure function, sampled at a moderate rate, and measuredaverage friction velocity. The model is calibrated and tested with datameasured above and within a Douglas-fir forest and above a straw mulch andbare soil. We show that the model describes half-hour variations ofsensible heat flux very well, both within the canopy and roughnesssublayers and in the inertial sublayer, for stable and unstable atmosphericconditions. The combined empirical coefficient that appears in the modelhas an apparently universal value of about 0.4 for all surfaces andheights, which makes application of the model particularly simple. Themodel is used to predict daytime and nighttime sensible heat flux profileswithin the straw mulch and within a small bare opening in the mulch.  相似文献