精准的风速预报是风电功率预测的基础,风场的预报评估是提升风电功率预测水平的有效途径之一。基于中尺度数值天气预报模式(weather research and forecast,WRF),采用风险评分、相关系数及均方根误差等定量分析指标,结合西北电网数值预...精准的风速预报是风电功率预测的基础,风场的预报评估是提升风电功率预测水平的有效途径之一。基于中尺度数值天气预报模式(weather research and forecast,WRF),采用风险评分、相关系数及均方根误差等定量分析指标,结合西北电网数值预报结果,开展6种大气边界层参数化方案的适用性研究。结果表明:YSU(Yonsei University)方案预报的地面纬向风平均相关系数最高为0.87、均方根误差最低仅1.0 m/s,且地面经向风、850 hPa和500 hPa高度场、以及500 hPa风速预报效果均最优,是提升西北电网风场预报的最优边界层方案。本研究为西北电网风场(以及其他气象要素)预报效果的提升指明了方向。展开更多
During mid-January 2011,a rarely seen twin-extratropical-cyclone event appeared over the western North Pacific Ocean.One of the twin cyclones developed into an extreme explosive extratropical cyclone(EEC),which was co...During mid-January 2011,a rarely seen twin-extratropical-cyclone event appeared over the western North Pacific Ocean.One of the twin cyclones developed into an extreme explosive extratropical cyclone(EEC),which was comparable to the intensity of a typhoon.Rotational and divergent wind kinetic energy(KE)analyses were applied to understand the low-level wind’s rapid enhancement associated with the cyclone.It was found that:(i)the total wind KE associated with the EEC showed a remarkable enhancement in the lower troposphere during the cyclone’s maximum development stage,with the maximum/minimum wind acceleration appearing in the southeastern/northwestern quadrant of the EEC;(ii)the rotational wind KE experienced an obvious increase,which corresponded to the total wind KE enhancement,whereas the divergent wind KE,which was much smaller than the rotational wind,mainly featured a decreasing trend;(iii)the rotational wind KE enhancement showed variational features consistent with the horizontal enlargement and upward stretching of the EEC;(iv)the nonorthogonal wind KE enhanced the total wind KE in regions with strong rotational wind,which resulted in the maximum lower-tropospheric maximum wind,whereas in regions with strong divergent wind it mainly reduced the total wind KE;(v)the northward transport of total wind KE and the rotational wind KE production due to the work done by pressure gradient force were dominant factors for the enhancement of winds associated with the EEC,particularly in its southeastern section.In contrast,an overall conversion from rotational wind KE to divergent wind KE decelerated the rotational wind enhancement.展开更多
文摘精准的风速预报是风电功率预测的基础,风场的预报评估是提升风电功率预测水平的有效途径之一。基于中尺度数值天气预报模式(weather research and forecast,WRF),采用风险评分、相关系数及均方根误差等定量分析指标,结合西北电网数值预报结果,开展6种大气边界层参数化方案的适用性研究。结果表明:YSU(Yonsei University)方案预报的地面纬向风平均相关系数最高为0.87、均方根误差最低仅1.0 m/s,且地面经向风、850 hPa和500 hPa高度场、以及500 hPa风速预报效果均最优,是提升西北电网风场预报的最优边界层方案。本研究为西北电网风场(以及其他气象要素)预报效果的提升指明了方向。
基金supported by the National Key R&D Program of China grant number 2018YFC0809400the National Natural Science Foundation of China grant numbers41775046 and 91637211the Youth Innovation Promotion Association,Chinese Academy of Sciences。
文摘During mid-January 2011,a rarely seen twin-extratropical-cyclone event appeared over the western North Pacific Ocean.One of the twin cyclones developed into an extreme explosive extratropical cyclone(EEC),which was comparable to the intensity of a typhoon.Rotational and divergent wind kinetic energy(KE)analyses were applied to understand the low-level wind’s rapid enhancement associated with the cyclone.It was found that:(i)the total wind KE associated with the EEC showed a remarkable enhancement in the lower troposphere during the cyclone’s maximum development stage,with the maximum/minimum wind acceleration appearing in the southeastern/northwestern quadrant of the EEC;(ii)the rotational wind KE experienced an obvious increase,which corresponded to the total wind KE enhancement,whereas the divergent wind KE,which was much smaller than the rotational wind,mainly featured a decreasing trend;(iii)the rotational wind KE enhancement showed variational features consistent with the horizontal enlargement and upward stretching of the EEC;(iv)the nonorthogonal wind KE enhanced the total wind KE in regions with strong rotational wind,which resulted in the maximum lower-tropospheric maximum wind,whereas in regions with strong divergent wind it mainly reduced the total wind KE;(v)the northward transport of total wind KE and the rotational wind KE production due to the work done by pressure gradient force were dominant factors for the enhancement of winds associated with the EEC,particularly in its southeastern section.In contrast,an overall conversion from rotational wind KE to divergent wind KE decelerated the rotational wind enhancement.
