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1.
基于延伸期过程性天气气候事件预报评估的特点,结合实际科研和业务工作的需求,提出了一种适用于延伸期过程预报的检验方法 (简称PPS方法)。该方法参考了常用的预报评分方法准则,借鉴了命中率、假警报率、欧式距离和动态时间弯曲距离等评估检验方法。利用命中率、假警报率和该方法对实际预报中可能出现的有漏报没有空报和既有漏报也有空报这两类情况的多个实例进行对比分析,表明该方法既能考虑大气随着时间的延长预报效果急剧降低的特性,也考虑了相似时间序列度量不精确匹配和形变的问题。利用该方法对1999—2010年冬季冷空气过程业务预报进行检验,结果表明:该方法能清晰表征延伸期预报时段内冷空气过程预报的准确程度,真实反映了目前延伸期预报准确率较低的现状,有较好的适用性。同时,该方法也适用于其他延伸期过程事件预报的评分,具有较好的应用前景。 相似文献
2.
2003年淮河流域大水期间体积降水量的研究 总被引：5，自引：2，他引：5
针对 2 0 0 3年梅雨期淮河流域大水提出了体积降水量的概念及其计算方法 ,在计算出淮河流域和其各子流域逐日和总体积降水量的基础上 ,将体积降水量与水文站的水位和流量进行了对比分析。结果表明 :水位对累计体积降水量有较好的即时响应 ,流量对体积降水量有较好的延迟响应。另外 ,讨论了流域体积降水量的预报问题 ,用国内外数值天气预报产品和中央气象台指导预报产品 ,进行了流域体积降水量预报试验 ,并对预报结果进行了检验分析。结果表明 :在目前天气预报水平条件下 ,利用数值天气预报和中央气象台业务预报产品制作体积降水量是可行的 ,能够延长洪水预报的预见期 ;而且 ,数值天气预报产品在预报体积降水量方面有明显的优势 ,因此可以直接利用数值天气预报产品进行体积降水量的客观预报 ,为防汛工作提供重要的依据。 相似文献
3.
A review on aspects of climate simulation assessment 总被引：2，自引：0，他引：2
This paper reviews some aspects of evaluation of climate simulation, including the ITCZ,
the surface air temperature (SAT), and the monsoon. A brief introduction of some recently proposed
approaches in weather forecast verification is followed by a discussion on their possible application
to evaluation of climate simulation. The authors suggest five strategies to extend the forecast
verification methods to climate simulation evaluation regardless significant differences between the
forecasts and climate simulations. It is argued that resolution, convection scheme, stratocumulus cloud
cover, among other processes in the atmospheric general circulation model (AGCM) and the ocean-atmosphere
feedback are the potential causes for the double ITCZ problem in coupled models and AGCM simulations,
based on the system- and component-level evaluations as well as the downscaling strategies in some recent
research. Evaluations of simulated SAT and monsoons suggest that both coupled models and AGCMs show good
performance in representing the SAT evolution and its variability over the past century in terms of
correlation and wavelet analysis but poor at reproducing rainfall, and in addition, the AGCM alone is not
suitable for monsoon regions due to the lack of air-sea interactions. 相似文献
4.
Forecast skill as a function of time lead and time averaging is examined in two 6-member ensembles of seasonal hindcasts.
One ensemble is produced with the second generation general circulation model of the Canadian Centre for Climate Modelling
and Analysis (GCM2) and the other with a reduced resolution version of the numerical weather prediction model of the Canadian
Meteorological Centre (SEF). The integrations are initiated from the NCEP/NCAR reanalyzed data. Monthly sea surface temperature
anomalies observed prior to the forecast period are maintained throughout the forecast season. A statistical forecast improvement
technique, based on the singular value decomposition of forecast and reanalyzed fields, is discussed and evaluated. A simple
analogue of the hindcast integrations is used to examine the behavior of two common skill scores, the correlation skill score
and the explained variance skill score. The maximal skill score and the corresponding optimal forecast in this analogue are
identified. The total skill of the optimal forecast is a sum of two terms, one associated with the initial conditions and
the other with the lower boundary forcing. The two sources of skill operate on different time scales, with initial conditions
being more important in the first one-two weeks and the atmospheric response to the boundary forcing becoming more dominant
for longer time leads and time averages. This suggests that these sources of skill should be considered separately in forecast
optimization. The statistical technique is moderately successful in improving the skill of monthly to seasonal forecasts of
500 hPa height (Z
500) and 700 hPa temperature (T
700) in the Northern Hemisphere and in the North Pacific/North America sector. The improvement is better when the forecasts for
the first week and for the rest of the season are optimized separately. The SEF model produces better Z
500 and T
700 forecasts than GCM2 in the first one-two weeks whereas GCM2 performs slightly better at longer time leads. The skill of zero
time lead forecast decays rapidly with averaging interval for time averages up to about 30–45 days and stabilizes, or even
rises, for longer time averages. Excluding the first week from seasonal forecasts results in substantial degradation of predictive
skill.
Received: 1 November 1999 / Accepted: 24 May 2000 相似文献
5.
The ability of Māori to understand, record and forecast weather and climate has been an important factor in successfully responding
to past weather and climatic change in New Zealand. Through interacting with local environments over the centuries Māori have
developed a wealth of environmental knowledge, with the lessons learnt having been incorporated into traditional and modern
practices of agriculture, fishing, medicine, education and conservation. In partnership with the tribal group Te Whānau-ā-Apanui,
NIWA’s Māori Research and Development Unit (Te Kuwaha o Taihoro Nukurangi) have initiated a pilot project to identify and
document Māori environmental knowledge (MEK) of weather and climate in New Zealand. Using a Kaupapa Māori based research approach
and semi-directive interviewing, an intimate understanding of local weather and climate was demonstrated by elders from Te
Whānau-ā-Apanui. This knowledge includes the use of a vast indigenous nomenclature for local weather and climate phenomenon,
the oral recording of weather and climate based events and trends, and the identification of environmental indicators to forecast
weather and climate. Learning from this knowledge provides an opportunity to understand what has helped Māori adapt to weather
and climate variability in the past. It also provides clues on how to enhance present day Māori and western scientific understanding
of local weather and climate in New Zealand.
An erratum to this article can be found at 相似文献
6.
Summary Estimates of spring precipitation for the inner Alpine dry valley of the upper Inn (Tyrol, Austria) are made back to A.D.
1724 using a ring width chronology of Scots pine (Pinus sylvestris L.) as predictor. A highly significant agreement in year-to-year ring width changes exists between several chronologies along
the dry valley. The dendroclimatic model used for climate reconstruction is a simple linear transfer function that estimates
April–June precipitation from current tree-ring width. All verification statistics commonly used in dendroclimatological research
are significant ( p < 0.01) and indicate that the reconstructed time series provides valuable information on past spring precipitation variability.
Reconstructed spring rainfall deficiencies and surpluses ≥ 20% compared to the long-term mean in 1819, 1832, 1834, 1865, 1885,
and in 1780, 1782, 1821, 1853, 1910, respectively, are also documented by local historical records. Furthermore, a comparison
is made with an independent climate reconstruction based on historical weather indices valid for the northern side of the
Swiss Alps. A fairly good agreement is found between both spring rainfall reconstructions at low frequency intervals during
1755–1862 and 1919–1981. This preliminary study shows that tree-rings can be used to reconstruct spring rainfall variability
for inner Alpine dry valleys.
Received December 18, 2000 Revised May 28, 2001 相似文献
7.
The propagation of optical and electromagnetic waves is affected by small-scale atmospheric turbulence, quantified by the
structure parameter of the refractive index. In the atmospheric surface layer, the mean structure parameter Cn2{C_{n}^{2}} , as averaged over the large-scale turbulence, relates to meteorological forcings through well-documented relationships.
Present-day numerical weather forecast models routinely produce these forcings at the global scale. This study introduces
a method where the products of such a model are used to calculate the mean optical turbulence near the surface. The method
is evaluated against scintillometry measurements over climatologically distinct sites in Western Europe. The diurnal cycle
modulation, and regional and seasonal contrasts, are all reproduced by our predictions. Hence, the present method explains
and predicts some essential aspects of the meteorological variability of Cn2{C_{n}^{2}} near the surface. The noted discrepancies combine instrumental limitations, site peculiarities, differences related to distinct
averaging procedures, and model errors, notably from weather forecasts. The minute-scale fluctuations of the measured scintillation
rate are also analysed in the light of the forecast weather conditions. Fair-weather daytime periods consistently show a small
short-term variability compared to the nighttime and perturbed weather periods. Thus, this short-term variability appears
to have a predictable component. 相似文献
8.
Decreasing teleconnections with inter-site distance in monthly climatic data and tree-ring width networks in a mountainous Alpine area 总被引：3，自引：0，他引：3
C. Rolland 《Theoretical and Applied Climatology》2002,71(1-2):63-75
Summary The similarities in time series recorded at sites which are distant from each other are called teleconnections. In this paper,
the loss of such correlations with inter-site distance was investigated for both climatic and dendrochronological data sets,
with 70 tree-ring chronologies. A dense network of weather stations was studied in the southeastern French Alps, covering
complex climatic gradients over three departments. 78 sites with precipitation data (with a total of 48 756 monthly values),
and 48 stations that recorded temperature (with 20 722 monthly mean values) were analysed. In the same area, four coniferous
species (mountain pine and stone pine, European larch and Norway spruce) provided 37 ring-width chronologies for high elevation
sites near the timberline. Both silver fir and Norway spruce provided a second tree-ring chronology network for 33 different
sites at lower elevations.
The teleconnections between precipitation series were found to be higher than those observed for temperature over short distances,
but the maximum threshold distance was lower (193 km) compared to a positive correlation distance that exceeds 500 km for
temperature. The maximum temperatures had stronger teleconnections than minimum values (522 km versus 476 km), since the latter
are linked more with other site factors, such as slope, exposure and local topography.
As expected, the tree-ring chronologies showed weaker teleconnections than the climatic series, with a threshold distance
of 374 km obtained for all high elevation forests. The coniferous species with high intra-specific teleconnections over large
distances were, in decreasing importance, Pinus uncinata (> 500 km), Picea abies (477 km), Pinus cembra (over 254 km) and Larix decidua (over 189 km only). The two former species showed the highest intra-specific correlations (with mean correlation R=0.625 and 0.666). The dendrochronological teleconnections were found to have a extent lesser for trees species that depend
on rainfall (such as larch, and stone pine). They are enhanced, however, for temperature sensitive species such as spruce
and mountain pine (a drought resistant tree). Therefore, these two latter conifers appear to be especially suitable for climatic
reconstruction over large distances in mountainous areas. However, teleconnections within silver fir (Abies alba) and spruce chronologies were sharply reduced (over 131 km and 135 km) in lower elevation forests, underlining the interest
of timberline forests for dendroclimatology.
A better knowledge of the spatial correlations in climatic series and ring-width data may enable the optimisation of weather
station networks. It may also permit a better choice of weather stations used for dendroclimatology, either for tree-ring
and climate relationship calibration or for climate reconstructions. In dendrochronology, wood dating also requires the knowledge
of to what extent remote ring-width chronologies can be used.
Received September 11, 2000 Revised March 26, 2001 相似文献
9.
目前高分辨率数值预报模式已具有一定的对流系统结构和演变特征预报能力,但对其预报能力的客观评估仍存在较多不足。选取2017年7—9月华北地区在不同天气系统背景下、具有不同组织模态的7次对流天气个例,使用模糊检验方法中的分数技巧评分（fraction skill score,简称FSS）指标评估不同高分辨率模式（包括快速更新同化GRAPES_Meso,GRAPES_3 km及华东区域中尺度模式）对中小尺度对流过程的预报能力。结果表明:分数技巧评分能够实现当模式预报存在位移和强度偏差时仍然给出有价值的评分结果,其优势还在于可以给出表征模式空间位移偏差尺度的预报技巧尺度信息;所用3个模式的雷达回波强度预报均偏弱,当回波强度小于44 dBZ时,华东区域中尺度模式预报最接近实况,而对于44 dBZ以上的较强回波,GRAPES_3 km模式预报偏差最小;采用百分位阈值（通过升序排列求出预报和实况数列的相同百分位数作为其相应的阈值）进行检验发现,对于预报难度更大的高阈值、小尺度的对流事件,GRAPES_3 km模式预报能力更强。 相似文献
10.
对21世纪以来定量降水预报技术流程中的数值模式预报、统计后处理、检验评估和预报员作用4个方面的研究工作进行了归纳,主要进展包括:业务全球模式对于降水的预报能力持续提升,而发展高分辨率模式 (尤其是对流尺度模式) 和集合预报是提高定量降水预报精准化水平的主要途径,且将两者相结合以促进短期降水预报是发展趋势;统计后处理技术已发展到应用数据挖掘方法对海量预报数据中有效信息进行提取和集成,而再预报资料的出现将进一步促进统计后处理技术的发展;为解决评估精细化定量降水预报面临的新问题,多种新的检验技术得到发展和应用,如极端降水检验评分、空间检验技术及概率检验方法等;预报员在模式和后处理方法上能够提供的附加值越来越有限,但在预报流程中仍将处于核心地位,其角色将逐渐向帮助用户进行决策方向转变。文章指出,定量降水预报技术的发展所面临的挑战包括大气水汽观测及同化技术改进、暖区和复杂地形下暴雨预报等科学问题的解决。 相似文献
11.
John D. Reid 《大气与海洋》2013,51(2):177-186
Abstract A terminal forecast verification scheme employing the ranked probability score (rps) has been developed. The forecast is interpreted in terms of probabilities of six operationally significant ceiling and visibility classes using probability interpretations of the terms vrbl, ocnl, RSK, etc. Comparison with the rps of climatological and persistence forecasts permits the assessment of forecast skill. To illustrate the technique, five months of forecasts for Winnipeg International Airport have been examined. The subjective forecast shows skill over climatology for the first five hours of the forecast period. A persistence forecast shows skill over climatology for three hours into the period and is a little superior to the subjective forecast in the first hour. 相似文献
12.
Traditional precipitation skill scores are affected by the well-known“double penalty”problem caused by the slight spatial or temporal mismatches between forecasts and observations. The fuzzy (neighborhood) method has been proposed for deterministic simulations and shown some ability to solve this problem. The increasing resolution of ensemble forecasts of precipitation means that they now have similar problems as deterministic forecasts. We developed an ensemble precipitation verification skill score, i.e., the Spatial Continuous Ranked Probability Score (SCRPS), and used it to extend spatial verification from deterministic into ensemble forecasts. The SCRPS is a spatial technique based on the Continuous Ranked Probability Score (CRPS) and the fuzzy method. A fast binomial random variation generator was used to obtain random indexes based on the climatological mean observed frequency, which were then used in the reference score to calculate the skill score of the SCRPS. The verification results obtained using daily forecast products from the ECMWF ensemble forecasts and quantitative precipitation estimation products from the OPERA datasets during June-August 2018 shows that the spatial score is not affected by the number of ensemble forecast members and that a consistent assessment can be obtained. The score can reflect the performance of ensemble forecasts in modeling precipitation and thus can be widely used. 相似文献
13.
一种基于可预报性的暴雨预报评分新方法Ⅱ:暴雨检验评分模型及评估试验 总被引：1，自引：0，他引：1
针对当前暴雨预报检验采用二分类事件检验方法存在较严重的“空报”“漏报”双重惩罚,没有考虑暴雨时空分布不均和预报评分可比性不够等问题,在分析预报员对暴雨预报评分期望值基础上,设计了一种基于可预报性的暴雨预报检验评分新方法和计算模型,分析了理想评分,并对2015-2016年4-10月中国中央气象台5 km×5 km定量降水格点预报和降水落区等级暴雨预报进行评分试验,获得了以下结果和结论:（1）预报员对暴雨预报评分期望值呈现梯级下降特征,与传统的TS评分存在显著差异;（2）设计了一种基于可预报性的暴雨预报检验新方法,通过引入e指数函数构建暴雨预报评分基函数,进而构建暴雨评分模型,该模型可以较好地拟合预报员对暴雨预报评分的期望值,同时改善了评分在不同量级阈值处的断崖式突变情况;（3）提出了预报与观测的邻域匹配方法,即一个预报点与所定义邻域中的一组观测相匹配,并利用距离加权最大值法确定暴雨评分值权重系数,预报与观测距离越近,距离权重系数越大,评分值权重越大,提高了评分的合理性,避免了距离较远的匹配站点得高分不利于鼓励预报员提高预报精度的问题;（4）对中国中央气象台逐日5 km×5 km水平分辨率的定量降水格点预报产品和中央气象台定量降水落区等级预报产品进行了评分试验,暴雨预报准确率全国平均值大于60分。基于可预报性的暴雨预报检验新评分与传统暴雨预报TS评分逐日演变特征相似,但可以较好地解析TS为0的预报评分,解析后的新评分与预报员和公众的心理预期更为接近。 相似文献
14.
R. S. Ross A. Chakraborty A. Chen L. Stefanova S. Sirdas T. N. Krishnamurti 《Meteorology and Atmospheric Physics》2007,98(3-4):137-174
Summary Climate variations in the Caribbean, largely manifest in rainfall activity, have important consequences for the large-scale
water budget, natural vegetation, and land use in the region. The wet and dry seasons will be defined, and the important roles
played by the El Ni?o-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO) in modulating the rainfall during
these seasons will be discussed.
The seasonal climate forecasts in this paper are made by 13 state of the art coupled atmosphere-ocean general circulation
models (CGCMs) and by the Florida State University Synthetic Superensemble (FSUSSE), whose forecasts are obtained by a weighted
combination of the individual CGCM forecasts based on a training period. The success of the models in simulating the observed
1989–2001 climatology of the various forecast parameters will be examined and linked to the models’ success in predicting
the seasonal climate for individual years. Seasonal forecasts will be examined for precipitation, sea-surface temperature (SST), 2-meter air temperature, and
850 hPa u- and v-wind components during the period 1989–2001. Evaluation metrics include root mean square (RMS) error and Brier skill score.
It will be shown that the FSUSSE is superior to the individual CGCMs and their ensemble mean both in simulating the 1989–2001
climatology for the various parameters and in predicting the seasonal climate of the various parameters for individual years.
The seasonal climate forecasts of the FSUSSE and of the ensemble mean of the 13 state of the art CGCMs will be evaluated for
years (during the period 1989–2001) that have particular ENSO and NAO signals that are known to influence Caribbean weather,
particularly the rainfall. It will be shown that the FSUSSE provides superior forecasts of rainfall, SST, 2-meter air temperature,
and 850 hPa u- and v-wind components during dry summers that are modulated by negative SOI and/or positive NAO indices. Such summers have become
a feature of a twenty-year pattern of drought in the Caribbean region. The results presented in this paper will show that
the FSUSSE is a valuable tool for forecasting rainfall and other atmospheric and oceanic variables during such periods of
drought. 相似文献
15.
Until now, most paleoclimate model-data comparisons have been limited to simple statistical evaluation and simple map comparisons.
We have applied a new method, based on fuzzy logic, to the comparison of 17 model simulations of the mid-Holocene (6 ka BP)
climate with reconstruction of three bioclimatic parameters (mean temperature of the coldest month, MTCO, growing degree-days
above 5 °C, GDD5, precipitation minus evapotranspiration, P−E) from pollen and lake-status data over Europe. With this method, no assumption is made about the distribution of the signal
and on its error, and both the error bars related to data and to model simulations are taken into account. Data are taken
at the drilling sites (not using a gridded interpolation of proxy data) and a varying domain size of comparison enables us
to make the best common resolution between observed and simulated maps. For each parameter and each model, we compute a Hagaman
distance which gives an objective measure of the goodness of fit between model and data. The results show that there is no
systematic order for the three climatic parameters between models. None of the models is able to satisfactorily reproduce
the three pollen-derived data. There is larger dispersion in the results for MTCO and P−E than for GDD5. There is also no systematic relationship between model resolution and the Hagaman distance, except for P−E. The more local character of P−E has little chance to be reproduced by a low resolution model, which can explain the inverse relationship between model resolution
and Hagaman distance. The results also reveal that most of the models are better at predicting 6 ka climate than the modern
climate.
Received: 27 May 1998 / Accepted: 8 January 1999 相似文献
16.
Summary The University of New South Wales (UNSW) High Resolution numerical weather prediction model (HIRES) is run routinely, on
a daily basis, at a horizontal resolution of 25 km. The output is made available to the New South Wales (NSW) regional office
of the Australian Bureau of Meteorology in Sydney. HIRES has been used to forecast mean wind direction and speed at a height
of 12 metres for a number of events in the past. The opportunity was used in December 1997 to run the model for the annual
Sydney to Hobart yacht race area.
For the 1997 Sydney to Hobart yacht race the model was run at 25 km horizontal resolution and the output was made available
to all competitors on the morning of the race, namely December 26th. It was also decided by the authors to expand the verification
to include all observations available both from land and sea within the model domain an well as those available from a moving
single point at sea, namely a yacht.
After the event, the model was run once at the increased resolution of 10 km, out to 5 days ahead. Both model runs were subjected
to detailed verification by one of the authors (KLB) who participated in the race aboard the maxi-yacht Nicorette and who carried out a pre-arranged observational program during the race. Surface synoptic weather maps prepared in the NSW
office of the Bureau of Meteorology were also consulted in order to extend the verification scheme. The model predicted winds
were verified on a six-hourly basis utilising instrumentation on the yacht as well as surface observations plotted in standard
World Meterological Organisation (WMO) format on surface synoptic weather maps. The yacht carried wind sensors situated on
top of the mast at a height of 30 metres above the water. The authors were most interested in the accuracy of the wind velocity
forecast by the model.
It is important to note that forecasting for points over the ocean at widely separated time intervals represents a very difficult
challenge. The verifications reveal that the model gave overall forecast guidance of very good to excellent quality and was
particularly accurate early in the race, when a Southerly Buster event occurred during the evening of the first day. However,
a caveat should be added that this forecast, despite its remarkable accuracy, is not a claim that accurate very high resolution
regional prediction is a solved problem. Rather, it is a demonstration that in particular instances current models are now
capable of achieving high levels of skill a number of days ahead.
Received September 28, 1999 Revised November 25, 1999 相似文献
17.
M. J. Best 《Theoretical and Applied Climatology》2006,84(1-3):47-55
Summary The current resolution of operational weather forecast model is not sufficient in general to explicitly resolve even the major
cities of the World. As a consequence, urban areas have traditionally been neglected in such models. The introduction of tiled
land surface models has enabled sub-gridscale landuse to be modelled, and hence has provided the opportunity to model cities
within weather forecast models. However, to date there has been little effort made within the operational weather forecast
community.
At present there is only one operational centre that explicitly resolves urban areas. This centre includes a simple urban
scheme within its mesoscale and global models, which has been shown to have a positive impact on the forecast. However, with
the recent developments within urban meteorology there are now a variety of urban schemes, which vary in their complexity
and parameter requirements, that would be suitable for operational weather forecast models. So it is likely that more operational
models, and in particular mesoscale models, will include urban areas in the near future.
With the majority of the World‘s population living in cities, the resilience of these cities to the impacts of climate change
is also becoming of increasing interest. This means that urban areas will have to be included within climate change simulations,
as well as weather forecast simulations, in the future. At present, only one climate change model has included a parametrisation
for urban areas. However, this is likely to increase if work in this area grows rapidly. 相似文献
18.
为了将格点观测融合产品用于模式预报产品的滚动订正中,获得精准的预报效果,使用国家气象信息中心HRCLDAS（High Resolution China Meteorological Administration Land Data Assimilation System）业务系统产生的高频次格点风场融合产品作为实况资料,采用两种风场模型和8种格点误差订正方案,对模式风预报产品进行订正预报试验,试验选择欧洲中期天气预报中心10 m风预报产品的2017年1月1日—2月28日以及2017年6月1日—7月31日两个时间段,进行了预报模拟试验,对8种格点误差订正方案的订正结果进行检验,同时将订正场插值到站点,使用国家级2400个地面气象站风场资料进行站点检验,结果表明:无论从格点还是站点检验的平均绝对偏差、准确率、绝对偏差分布频率结果看,采用基于模式和实况因子的全格点滑动建模订正方案具有最佳的订正效果。 相似文献
19.
S. Hofinger G. J. Mayr E. Dreiseitl M. Kuhn 《Meteorology and Atmospheric Physics》2000,72(2-4):175-184
Summary ?Intra-mountain summertime precipitation was studied in the Alps in a 40×20 km2 area centered around Innsbruck, Austria, from June through September 1997. An observational network with a mean separation
distance of 9 km and forecasts from the ECMWF model were used to examine the role the strong forcing from the lower boundary
plays in creating “hot spots” for the formation of thunderstorms and the location of heavy precipitation as well as systematic
precipitation patterns for different weather situations, which can be used to downscale forecasts from global scale routine
numerical weather prediction models.
Received March 16, 1999/Revised August 20, 1999 相似文献
20.
Climate change,weather variability and corn yield at a higher latitude locale: Southwestern Quebec 总被引：5，自引：0，他引：5
Juan Jose Almaraz Fazli Mabood Xiaomin Zhou Edward G. Gregorich Donald L. Smith 《Climatic change》2008,88(2):187-197
Climate change has led to increased temperatures, and simulation models suggest that this should affect crop production in
important agricultural regions of the world. Nations at higher latitudes, such as Canada, will be most affected. We studied
the relationship between climate variability (temperature and precipitation) and corn yield trends over a period of 33 years
for the Monteregie region of south-western Quebec using historical yield and climate records and statistical models. Growing
season mean temperature has increased in Monterregie, mainly due to increased September temperature. Precipitation did not
show any clear trend over the 33 year period. Yield increased about 118 kg ha−1 year−1 from 1973 to 2005 (under normal weather conditions) due mainly to changes in technology (genetics and management). Two climate
variables were strongly associated with corn yield variability: July temperature and May precipitation. These two variables
explain more than a half of yield variability associated with climate. In conclusion, July temperatures below normal and May
precipitation above normal have negative effects on corn yield, and the growing seasons have warmed, largely due to increases
in the September temperature. 相似文献