首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 359 毫秒
1.
基于分位数映射法的黑河上游气候模式降水误差订正   总被引:1,自引:0,他引:1  
区域气候模式降水弥补了高寒山区气象站点稀少的缺陷,是水文模拟的重要驱动变量。然而,高寒山区模式输出降水的总量和频率都存在较大不确定性。因此,改进了用于降水频率纠正的分位数映射法(Quantile Mapping,QM),对中尺度数值预报模式(Weather Research and Forecasting model,WRF)模拟的黑河上游日降水输出数据进行误差订正。选取第95分位和第98分位降水量为阈值,选择2004-2009年为建模时段,2010-2013年为验证时段,使用分段拟合的方法建立传递函数,侧重于对极端降水进行单独订正。研究结果表明:该方法不仅对降水空间分布有明显的改善,对极端降水也有很好的订正效果。订正前模式模拟日降水与台站之间的均方根误差为3.41 mm·d^-1,绝对偏差为115.67 mm·y^-1,订正后均方根误差减少为3.11 mm·d^-1,绝对偏差有明显改善,为60.3 mm·y^-1。订正后流域内年降水空间分布更加合理,年降水量也更接近于观测降水插值结果,其空间相关系数由0.74改善为0.94。春、夏季订正效果优于秋、冬季,其中夏季订正效果较为明显,订正前降水偏差百分比在-0.1~0.1以内的区域面积仅占流域总面积的28%,而订正后占比增加至66%。同时,该方法对极端降水有较好的订正效果,减小了日降水强度(SDII)和极强降水量(R99p)的模拟偏差,订正后的第95分位模拟降水与观测降水插值的相关系数由0.15提高到0.48。本研究为站点稀少的黑河上游提供了一种更有效的误差订正方案,有利于为寒区水文研究获取更精确的降水数据。  相似文献   

2.
分位数映射法在RegCM4中国气温模拟订正中的应用   总被引:1,自引:0,他引:1  
将一种分位数映射法RQUANT,应用到一个区域气候模式(RegCM4)所模拟中国气温的误差订正中。从气候平均态、年际变率、极端气候及农业气候等多方面,评估了该方法对日平均气温、日最高气温和日最低气温模拟的订正效果。结果表明,该订正方法对模式模拟的日平均、日最高和最低气温气候平均态的订正效果都非常明显,中国大部分地区的订正结果与观测的偏差在±0.5℃之间。在降低极端气温指数和农业气候相关指数的模拟误差方面也有显著的效果,但对气温年际变率的订正效果有限。结合以往对降水订正的评估分析,该方法对模式模拟结果有较好的订正效果,可以应用于区域气候模式的气候变化模拟预估中,为气候变化及相关影响评估研究提供更适用和可靠的数据。  相似文献   

3.
采用分位数映射(Quantile Mapping, QM)和delta分位数映射(Quantile Delta Mapping, QDM)两种误差订正方法对区域气候模式RegCM4在中国区域内模拟的逐日气温和降水数据进行订正。模式数据是5种不同全球气候模式驱动下的区域模式气候变化模拟结果。计算订正前后的极端气候指数进行对比分析,包括日最高气温极大值(TXx)、日最低气温极小值(TNn)、连续干旱日数(CDD)和最大日降水量(RX1day)。结果表明,5组模拟结果和其集合平均(ensR)都显示气温指数的模拟效果高于降水指数,其中对TXx模拟最好,对CDD的模拟最差;经过订正后,针对不同模式的两种订正结果都能够有效地减小模式与观测的偏差并提高了空间相关系数,且两种方法的订正效果无明显差别。对RCP4.5情景下未来变化的分析中,QM在一定程度上改变了模式模拟的未来变化幅度和空间分布特征,QDM则能够有效地保留所有极端指数的气候变化信号。从全国平均来看,除CDD外,所有指数未来都呈现增加趋势,且QDM订正结果与订正前模式模拟的变化趋势更为接近。建议在气候变化模拟的误差订正中采用QDM方法。  相似文献   

4.
对区域气候模式系统PRECIS在SRES A1B情景下模拟的上海日降水输出按季节进行了统计误差订正。该方法首先对降水日数进行比率订正,以消除模式产生的微小值降水。然后利用Γ分布拟合日降水量的累计概率分布,采用整体和分段拟合两种方法构建传递函数TF(Transfer Function)进行订正。选取1962年12月—1992年11月作为控制时段,构建TF并将其应用于验证时段(1992年12月—2002年11月)。该订正方案消除了模式产生的微小值降水,解决了模拟的小降水值偏多的问题,频率误差保持在1%以下,分段拟合订正相比整体拟合订正具有更强的对极端降水的订正能力;对冬、春季的订正效果比夏、秋季更显著。该方案不仅有效消除了平均值的漂移,而且显著订正了变率,同时提高了极端降水事件的再现能力,是一种相对完善的订正方案。   相似文献   

5.
基于最新一代CMIP6全球气候模式模拟的历史和未来SSPs排放情景下的逐日降水数据和高分辨率逐日格点观测数据,采用泰勒图和分位数映射法评估订正模式性能,计算并分析SSP2—4.5和SSP5—8.5情景下福建省21世纪近期(2021—2040年)、中期(2051—2070年)和末期(2081—2100年)8个极端降水指数的变化。结果表明:在参照期(1991—2010年)经过分位数映射法偏差订正后,各极端降水指数模式模拟与观测更加接近,其空间相关系数、均方根误差和标准差的模拟性能都大幅提升。21世纪各个阶段,福建省年累积降水量(Prcptot)、极端暴雨日数(R50mm)均多于参照期,且越到后期、高排放情景下增幅越大。大于10 mm的降水日数(R10mm)和极端大雨日数(R20mm)则是增减各异,R10mm表现为福建东北部减少、其他大部分地区增加,R20mm表现为SSP2—4.5情景下21世纪近期福建西北部减少、而其他情景和时段均增加。表征降水强度的最大1 d降水量(Rx1day)、最大连续5 d降水量(Rx5day)和日降水强度指数(SDⅡ)在未来全部增加,且沿海地区增幅高于内陆地区。持...  相似文献   

6.
基于1980—2015年6—8月CWRF模式(Climate-Weather Research and Forecasting model)14种方案的模拟结果和全国逐日降水观测资料,对比了Q-lin,Q-tri,RQ-lin,RQ-tri,SSP-lin和CDFt 6种误差订正方法对CWRF模式控制化方案(C1)模拟中国东部夏季日极端降水的订正效果,以CWRF模式14种方案日极端降水的模拟效果排名为基础,对比了模拟效果较好的4种方案集合、模拟较差的4种方案集合以及14种方案集合的订正效果,选出相对较好的订正方案进一步评估其成员集合后订正和成员分别订正后再集合的订正效果,结果表明:采用6种误差订正方法均可明显减少日极端降水模拟误差,其中RQ-lin方法订正效果最佳。CWRF模式对中国东部的极端降水指数均表现出较好的模拟能力,不同参数化集合方案得到14种方案成员先订正再集合与观测日极端降水平均值最为接近,研究结果对于改进模拟结果、提高其预测能力有重要应用价值。  相似文献   

7.
文章利用通辽国家基本气象站1951—2015年逐日最高气温、最低温度和日平均气温,计算了3个要素序列的算数平均值、中位数、众数及样本标准差等基本统计量,分析了每个气温等级出现的频次和不同气温段的气温日较差出现日数、日最高气温〉30℃日数和日最低气温≤-20℃日数等。结果表明:(1)该地极端最高气温达39.4℃,极端最低气温为-33.9℃,最高气温出现在7月12日,最低气温出现在1月17日。(2)全年26.1~28.0℃的最高气温出现频次和16.1~18.0℃的日最低气温出现频次最高。(3)一年中,日最高气温在0℃以上的天数占全年总日数的75%;日最低气温在0℃以下的日数占全年总日数的46%;日较差〉10℃的日数占全年总日数的69%。(4)1981—2015年平均气温比1951—1981年明显升高,表现为低温日数明显减少,而近10a不仅冬季低温日数减少而且夏季高温日数明显增多。  相似文献   

8.
可靠的降水资料对理解青藏高原水量平衡和水循环过程尤为重要。IMERG(Integrated Multi-satellitE Retrievals for Global Precipitation Measurement)是新一代卫星降水产品,具有更广的覆盖范围与更高的时空分辨率,但在高原复杂地形条件下仍然存在较大的不确定性。鉴于此,本研究应用Delta分位数映射法(Quantile Delta Mapping, QDM),对IMERG日降水数据进行偏差订正,使用2001-2010年的中国区域地面气象要素数据集(China Meteorological Forcing Dataset, CMFD)降水数据和IMERG日降水产品分季节建立传递函数,对2011-2014年的IMERG逐日降水进行订正。研究结果表明:(1)Delta分位数映射法能够有效订正IMERG的降水频率、数值和空间分布,对极端降水和负偏差较大区域的订正效果更为明显。订正后的IMERG降水概率分布更加接近观测概率分布,降水偏差也更符合正态分布,改进了对全年和季节降水空间分布的刻画,提高了月降水的精度。(2)订正后日降水量均...  相似文献   

9.
极端高温、极端低温、极端降水事件日数对全球平均气温变化都有较强响应。本文利用全国1960-2005年549个站点逐日均一化温度资料以及559个站点逐日降水数据,定量分析了中国夏季极端气温与降水事件日数随气温变化的特征。结果表明:全球平均气温升高1℃,全国平均的极端高温、低温和降水日数的变化量分别为5.69,-5.3和0.69天;区域尺度上,全球平均气温升高1℃,东南沿岸和四川地区极端高温日数可增加8~10天,东北地区极端低温日数减少10天左右,西北地区极端降水日数可增加4~6天。基于以上结果,利用模式对未来全球平均气温的预估表明:2006-2099年我国平均的极端高温、低温、降水日数变化量在RCP8.5情景下最大,分别增加23天、减少22天和增加3天;区域尺度上,RCP8.5情景下2006-2099年我国东南以及西南地区极端高温日数可增加42天左右,我国北方大部分地区极端低温日数减少33天左右,而西北地区极端降水日数可增加16天左右。该研究结果表明一系列应对气候变化的措施势在必行。  相似文献   

10.
不同升温阈值下中国地区极端气候事件变化预估   总被引:5,自引:1,他引:5  
陈晓晨  徐影  姚遥 《大气科学》2015,39(6):1123-1135
本文基于耦合模式比较计划第五阶段(CMIP5)的18个全球气候模式的模拟结果,预估了全球平均气温在不同典型浓度路径(RCPs)下达到2℃、3℃和4℃阈值时,中国地区气温和降水的变化,并采用了具有稳定统计意义的27个极端气候指标定量评估了全球平均气温达到不同阈值时,中国地区极端气候事件的可能变化。结果表明,未来我国平均气温增幅将高于全球平均增暖,极端暖事件(如暖夜、暖昼、热带夜)明显增多,达到4℃阈值时,暖夜指数相比参考时段增加约49.9%。极端冷事件(如冷夜、冷昼、霜冻)减少。随全球气温升高,中国北方平均降水增多。在不同升温阈值下,中国地区降水的极端性都体现出增强的趋势,强降水事件发生频率(如中雨日数、大雨日数)和强度(如五日最大降水量、极端强降水量)都明显增加。随升温阈值的升高,这些变化幅度更大,在 RCP8.5 情景下全球升温 3℃和4℃时,中国平均五日最大降水分别增加 12.5mm和17.0mm。我国西南地区极端降水强度的增幅高于其他地区。  相似文献   

11.
Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.  相似文献   

12.
<正>The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth’s climate and environment.  相似文献   

13.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.  相似文献   

14.
Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.  相似文献   

15.
The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.  相似文献   

16.
基于最新的GTAP8 (Global Trade Analysis Project)数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。  相似文献   

17.
正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any  相似文献   

18.
19.
Index to Vol.31     
正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang;  相似文献   

20.
正Journal of Meteorological Research is an international academic journal in atmospheric sciences edited and published by Acta Meteorologica Sinica Press,sponsored by the Chinese Meteorological Society.It has been acting as a bridge of academic exchange between Chinese and foreign meteorologists and aiming at introduction of the current advancements in atmospheric sciences in China.The journal columns include Articles.Note and Correspondence,and research letters.Contributions from all over the world are welcome.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号