利用IAP AGCM4(Institute of Atmospheric Physics Atmospheric General Circulation Model 4)气候模式,首先采用基于标准化异常的积雪初始化方案,获取青藏高原区域相对“真实”的积雪初值。然后通过两组集合后报试验,考察青藏高原积雪...利用IAP AGCM4(Institute of Atmospheric Physics Atmospheric General Circulation Model 4)气候模式,首先采用基于标准化异常的积雪初始化方案,获取青藏高原区域相对“真实”的积雪初值。然后通过两组集合后报试验,考察青藏高原积雪初值对我国东部夏季降水可预报性的影响,以检验初始化方案的有效性。结果表明:考虑“真实”的青藏高原区域初始积雪异常作用后,春季高原雪深模拟能力相比于常规后报试验有明显改进,特别是高原中西部地区改进显著;对夏季环流场可预报性的分析表明,考虑较真实的青藏高原积雪初值后,欧亚中高纬度环流场的可预报性有明显提高,东亚夏季风环流的预报技巧也有所改善,这些都有利于我国夏季降水预报技巧的改进;考虑积雪初值作用能提高模式对我国东部夏季降水的预报技巧,尤其是积雪显著异常年份。就东部分区而言,江淮区域降水预报技巧的改进最明显,36年平均的空间相关评分由0.02提高到0.11;最后通过个例分析进一步检验积雪初始化方案的有效性,结果表明,引入积雪初始化方案后,青藏高原积雪预报技巧得以改进,改进后的高原积雪通过影响东亚季风环流场,最终使我国东部夏季降水预报技巧得以改善。以上结果表明基于标准化异常的积雪初始化方案对提高我国短期气候的预测水平是有效的,可应用于实时预测中。展开更多
降水作为地球水循环与能量循环的核心环节,对全球气候演变、水文过程及人类社会活动具有深远影响。热带地区贡献了全球约三分之二的降水量,而海南岛作为典型热带海岛,其独特的下垫面条件和复杂的海陆相互作用导致降水呈现多尺度、多形...降水作为地球水循环与能量循环的核心环节,对全球气候演变、水文过程及人类社会活动具有深远影响。热带地区贡献了全球约三分之二的降水量,而海南岛作为典型热带海岛,其独特的下垫面条件和复杂的海陆相互作用导致降水呈现多尺度、多形态特征,对数值模式中积云对流参数化方案的适应性提出了更高挑战。本研究基于WRF模式(V4.2),选取7种积云对流参数化方案(包括Kain-Fritsch、BMJ、Modified Tiedtke等),结合ERA5再分析资料、地面观测站数据、CMPAS融合降水产品及GSMaP卫星反演数据,对海南岛2017年雨季13类典型降水案例开展高分辨率(5 km)模拟,并通过相关系数(R)、平均绝对误差(MAE)和Kling-Gupta效率系数(KGE)等多指标评估方案性能。结果表明:(1) Modified Tiedtke(cu6)和New Tiedtke (cu16)方案在热带海岛环境表现最优,尤其是Modified Tiedtke (cu6)在台风活跃期(9~10月)相关系数高达0.913,全案例平均达0.41 ± 0.26;(2) “灰区”分辨率(4~10km)下综合季节性和降水类型差异,提出分时段优化策略:传统的Kain-Fritsch方案(cu1)和改进的Kain-Fritsch方案(cu10)适合模拟降水增长过程,但需要注意其在时间和降水量上的系统性偏差;Modified Tiedtke方案(cu6)和BMJ方案(cu2)适合模拟弱降水过程,并且Modified Tiedtke方案(cu6)在强降水情况下表现也较好;Multi-scale Kain-Fritsch方案(cu11)、KSAS方案(cu14)和新版Tiedtke方案(cu16)则展现出较好的综合性能。(3) Multi-scale Kain-Fritsch方案(cu11)在降水中心位置、降水空间分布和虚假降水控制上表现出优异性能。(4)综合季节性和降水类型差异,提出分时段优化策略:台风季节和季风转换前期选择Modified Tiedtke方案(cu6)或新版Tiedtke方案(cu16),雨季盛期采用Kain-Fritsch方案(cu1)和Modified Kain-Fritsch方案(cu10)的集合平均。研究结果为热带海岛地区降水模拟的参数化方案优化提供了关键科学依据。Precipitation plays a pivotal role in the global water and energy cycles, significantly impacting climate evolution, hydrological processes, and human activities. The tropics contribute approximately two-thirds of global precipitation, and as a representative tropical island, Hainan Island exhibits distinct precipitation characteristics due to its unique underlying surface conditions and complex land-sea interactions, posing significant challenges to the applicability of cumulus convection parameterization schemes in numerical models. This study employs the Weather Research and Forecasting (WRF) model (V4.2) to simulate 13 typical precipitation cases during the 2017 rainy season at a high resolution (5 km), using seven cumulus parameterization schemes, including Kain-Fritsch, BMJ, Modified Tiedtke, etc. The simulation results are evaluated against ERA5 reanalysis data, ground-based observations, CMPAS merged precipitation products, and GSMaP satellite-derived data using multiple metrics, including correlation coefficient (R), mean absolute error (MAE), and Kling-Gupta efficiency (KGE). The results indicate that (1) the Modified Tiedtke (cu6) and New Tiedtke (cu16) schemes perform best in the tropical island environment, with Modified Tiedtke (cu6) achieving a correlation coefficient of up to 0.913 during the typhoon-active period (September–October) and an overall case-average of 0.41 ± 0.26;(2) considering the “gray-zone” resolution (4~10 km), a time-dependent optimization strategy is proposed: the traditional Kain-Fritsch scheme (cu1) and its modified version (cu10) are suitable for simulating precipitation growth but exhibit systematic biases in timing and magnitude, while the Modified Tiedtke scheme (cu6) and BMJ scheme (cu2) excel in weak precipitation scenarios, with Modified Tiedtke (cu6) also performing well in heavy precipitation events;(3) the Multi-scale Kain-Fritsch scheme (cu11), KSAS scheme (cu14), and New Tiedtke scheme (cu16) demonstrate strong overall performance, with the Multi-scale Kain-Fritsch scheme (cu11) exhibiting superior accuracy in capturing precipitation center locations, spatial distribution, and reducing false precipitation;(4) based on seasonal variations and precipitation type differences, a phased optimization strategy is recommended: the Modified Tiedtke scheme (cu6) or New Tiedtke scheme (cu16) for the typhoon season and early monsoon transition, and an ensemble of the Kain-Fritsch (cu1) and Modified Kain-Fritsch (cu10) schemes for the peak rainy season. This study provides critical scientific insights for optimizing cumulus parameterization schemes in precipitation simulations over tropical island regions.展开更多
该文旨在改进风速订正模型,以提高第6代跨学科气候研究模式(Model for Interdisciplinary Research on Climate Version 6,MIROC6)历史时期10 m风速的模拟准确性。研究基于Informer模型,结合多层感知机,构造了非平稳Informer(Ns-Informe...该文旨在改进风速订正模型,以提高第6代跨学科气候研究模式(Model for Interdisciplinary Research on Climate Version 6,MIROC6)历史时期10 m风速的模拟准确性。研究基于Informer模型,结合多层感知机,构造了非平稳Informer(Ns-Informer)10 m风速订正模型。研究提出了一种新的加权趋势均方误差损失函数,以优化模型在高风速条件下的订正性能,选取北京站、拐子湖站、茫崖站、吉安站4个代表站进行验证。结果表明:Ns-Informer在月尺度和年代际尺度上均能还原风速时间分布特征,订正后10 m风速的均方根误差降低20%~50%,在风速超过5 m·s^(-1)时表现最佳。Ns-Informer订正后的月平均10 m风速演变趋势与观测吻合度提高。在夏季和秋季订正效果显著,月平均10 m风速均方根误差降低25%以上。年代际变化趋势的订正表明Ns-Informer能矫正MIROC6对风速长期变化趋势的偏差,订正后的风速序列捕获了不同站点风速长期的上升或下降趋势。未来情景检验进一步表明:Ns-Informer能在SSP1-2.6情景下对高风速阈值的订正稳定性优于MIROC6。Ns-Informer可以有效降低MIROC6的系统偏差,为未来气候变化情景下风速的精确预估提供参考。展开更多
文摘利用IAP AGCM4(Institute of Atmospheric Physics Atmospheric General Circulation Model 4)气候模式,首先采用基于标准化异常的积雪初始化方案,获取青藏高原区域相对“真实”的积雪初值。然后通过两组集合后报试验,考察青藏高原积雪初值对我国东部夏季降水可预报性的影响,以检验初始化方案的有效性。结果表明:考虑“真实”的青藏高原区域初始积雪异常作用后,春季高原雪深模拟能力相比于常规后报试验有明显改进,特别是高原中西部地区改进显著;对夏季环流场可预报性的分析表明,考虑较真实的青藏高原积雪初值后,欧亚中高纬度环流场的可预报性有明显提高,东亚夏季风环流的预报技巧也有所改善,这些都有利于我国夏季降水预报技巧的改进;考虑积雪初值作用能提高模式对我国东部夏季降水的预报技巧,尤其是积雪显著异常年份。就东部分区而言,江淮区域降水预报技巧的改进最明显,36年平均的空间相关评分由0.02提高到0.11;最后通过个例分析进一步检验积雪初始化方案的有效性,结果表明,引入积雪初始化方案后,青藏高原积雪预报技巧得以改进,改进后的高原积雪通过影响东亚季风环流场,最终使我国东部夏季降水预报技巧得以改善。以上结果表明基于标准化异常的积雪初始化方案对提高我国短期气候的预测水平是有效的,可应用于实时预测中。
文摘降水作为地球水循环与能量循环的核心环节,对全球气候演变、水文过程及人类社会活动具有深远影响。热带地区贡献了全球约三分之二的降水量,而海南岛作为典型热带海岛,其独特的下垫面条件和复杂的海陆相互作用导致降水呈现多尺度、多形态特征,对数值模式中积云对流参数化方案的适应性提出了更高挑战。本研究基于WRF模式(V4.2),选取7种积云对流参数化方案(包括Kain-Fritsch、BMJ、Modified Tiedtke等),结合ERA5再分析资料、地面观测站数据、CMPAS融合降水产品及GSMaP卫星反演数据,对海南岛2017年雨季13类典型降水案例开展高分辨率(5 km)模拟,并通过相关系数(R)、平均绝对误差(MAE)和Kling-Gupta效率系数(KGE)等多指标评估方案性能。结果表明:(1) Modified Tiedtke(cu6)和New Tiedtke (cu16)方案在热带海岛环境表现最优,尤其是Modified Tiedtke (cu6)在台风活跃期(9~10月)相关系数高达0.913,全案例平均达0.41 ± 0.26;(2) “灰区”分辨率(4~10km)下综合季节性和降水类型差异,提出分时段优化策略:传统的Kain-Fritsch方案(cu1)和改进的Kain-Fritsch方案(cu10)适合模拟降水增长过程,但需要注意其在时间和降水量上的系统性偏差;Modified Tiedtke方案(cu6)和BMJ方案(cu2)适合模拟弱降水过程,并且Modified Tiedtke方案(cu6)在强降水情况下表现也较好;Multi-scale Kain-Fritsch方案(cu11)、KSAS方案(cu14)和新版Tiedtke方案(cu16)则展现出较好的综合性能。(3) Multi-scale Kain-Fritsch方案(cu11)在降水中心位置、降水空间分布和虚假降水控制上表现出优异性能。(4)综合季节性和降水类型差异,提出分时段优化策略:台风季节和季风转换前期选择Modified Tiedtke方案(cu6)或新版Tiedtke方案(cu16),雨季盛期采用Kain-Fritsch方案(cu1)和Modified Kain-Fritsch方案(cu10)的集合平均。研究结果为热带海岛地区降水模拟的参数化方案优化提供了关键科学依据。Precipitation plays a pivotal role in the global water and energy cycles, significantly impacting climate evolution, hydrological processes, and human activities. The tropics contribute approximately two-thirds of global precipitation, and as a representative tropical island, Hainan Island exhibits distinct precipitation characteristics due to its unique underlying surface conditions and complex land-sea interactions, posing significant challenges to the applicability of cumulus convection parameterization schemes in numerical models. This study employs the Weather Research and Forecasting (WRF) model (V4.2) to simulate 13 typical precipitation cases during the 2017 rainy season at a high resolution (5 km), using seven cumulus parameterization schemes, including Kain-Fritsch, BMJ, Modified Tiedtke, etc. The simulation results are evaluated against ERA5 reanalysis data, ground-based observations, CMPAS merged precipitation products, and GSMaP satellite-derived data using multiple metrics, including correlation coefficient (R), mean absolute error (MAE), and Kling-Gupta efficiency (KGE). The results indicate that (1) the Modified Tiedtke (cu6) and New Tiedtke (cu16) schemes perform best in the tropical island environment, with Modified Tiedtke (cu6) achieving a correlation coefficient of up to 0.913 during the typhoon-active period (September–October) and an overall case-average of 0.41 ± 0.26;(2) considering the “gray-zone” resolution (4~10 km), a time-dependent optimization strategy is proposed: the traditional Kain-Fritsch scheme (cu1) and its modified version (cu10) are suitable for simulating precipitation growth but exhibit systematic biases in timing and magnitude, while the Modified Tiedtke scheme (cu6) and BMJ scheme (cu2) excel in weak precipitation scenarios, with Modified Tiedtke (cu6) also performing well in heavy precipitation events;(3) the Multi-scale Kain-Fritsch scheme (cu11), KSAS scheme (cu14), and New Tiedtke scheme (cu16) demonstrate strong overall performance, with the Multi-scale Kain-Fritsch scheme (cu11) exhibiting superior accuracy in capturing precipitation center locations, spatial distribution, and reducing false precipitation;(4) based on seasonal variations and precipitation type differences, a phased optimization strategy is recommended: the Modified Tiedtke scheme (cu6) or New Tiedtke scheme (cu16) for the typhoon season and early monsoon transition, and an ensemble of the Kain-Fritsch (cu1) and Modified Kain-Fritsch (cu10) schemes for the peak rainy season. This study provides critical scientific insights for optimizing cumulus parameterization schemes in precipitation simulations over tropical island regions.
文摘该文旨在改进风速订正模型,以提高第6代跨学科气候研究模式(Model for Interdisciplinary Research on Climate Version 6,MIROC6)历史时期10 m风速的模拟准确性。研究基于Informer模型,结合多层感知机,构造了非平稳Informer(Ns-Informer)10 m风速订正模型。研究提出了一种新的加权趋势均方误差损失函数,以优化模型在高风速条件下的订正性能,选取北京站、拐子湖站、茫崖站、吉安站4个代表站进行验证。结果表明:Ns-Informer在月尺度和年代际尺度上均能还原风速时间分布特征,订正后10 m风速的均方根误差降低20%~50%,在风速超过5 m·s^(-1)时表现最佳。Ns-Informer订正后的月平均10 m风速演变趋势与观测吻合度提高。在夏季和秋季订正效果显著,月平均10 m风速均方根误差降低25%以上。年代际变化趋势的订正表明Ns-Informer能矫正MIROC6对风速长期变化趋势的偏差,订正后的风速序列捕获了不同站点风速长期的上升或下降趋势。未来情景检验进一步表明:Ns-Informer能在SSP1-2.6情景下对高风速阈值的订正稳定性优于MIROC6。Ns-Informer可以有效降低MIROC6的系统偏差,为未来气候变化情景下风速的精确预估提供参考。
