中国近地面风速下降原因的分析和模拟

Long-term change of surface wind speed (SWS) over land was the combined effect of natural and anthropogenic climate changes, in which the pressure gradient force (PGF) was the driving force and the surface was the source of resistence. The change of PGF and resistence were related to the change of circulation and land use and cover change (LUCC) respectively. In current, there was few research about the characteristics of wind speed changes in different heights, and the quantitative influence from large scale circulation and LUCC to SWS remains unknown. In addition, the dynamical and therodynamical effects of LUCC to SWS cannot distinguish correctly in published papers. We plan to develop three research works in this project: 1) analyze the wind speed changes over different heights and get their mutual links and differences; 2) find the main signal source of large scale circulation change affecting SWS over China and assess its influence to SWS quantitatively; 3) separate the dynamical and therodynamical effects of LUCC to SWS using the frictional wind model and proper diagnostic analysis. This project can reveal the whole characteristics and reasons of SWS change over China quantitatively.

陆域近地面风速演变是气候自然变化和人类活动影响气候的联合结果，气压梯度力是风速的驱动力源，地面是风速的阻力源。驱动力的演变与环流变化有关，阻力的变化与土地利用/覆盖变化（LUCC）有关。已有研究还未能揭示不同高度风速变化特征及其异同，对环流场演变影响风速的研究也未能明确环流场信号的来源及其导致风速变化的程度，对LUCC影响风速变化多数基于定性分析，且未实现LUCC动力和热力效应影响风速变化作用的分离和评估。本项目分析我国不同高度风速演变特征及其异同，获取影响风速变化的环流场信号来源，利用动力学模型量化评估环流变化导致的气压梯度力演变引起的风速变化，通过诊断分析和数值模拟定量评估LUCC效应对我国近地面风速减弱的影响，并使用动力学模型通过对比阴晴天的模型风和实际风，实现LUCC动力和热力效应影响风速变化的分离与量化评估。实现对我国陆域风速变化现象的全面揭示和可能原因及其贡献的定量分析。

陆域近地面风速演变是气候自然改变和人类活动影响气候的联合结果，气压梯度力是风速的驱动力源，地面是风速的阻力源。驱动力的演变与环流变化有关，阻力的变化与土地利用/覆盖变化（LUCC）有关。已有研究还未能揭示不同高度风速变化特征及其异同，对环流场演变影响风速的研究也未能明确环流场信号的来源及其导致风速变化的程度，对LUCC影响风速变化多数基于定性分析，且未实现LUCC动力和热力效应影响风速变化作用的分离和评估。本项目分析我国不同高度风速演变特征及其异同，获取影响风速变化的环流场信号来源，利用动力学模型量化评估环流变化导致的气压梯度力演变引起的风速变化，通过诊断分析和数值模拟定量评估LUCC效应对我国近地面风速减弱的影响，并使用动力学模型通过对比阴晴天的模型风是实际风，实现LUCC动力和热力效应影响风速变化的分离与量化评估。实现对我国陆域风速变化现象的全面揭示和可能原因及其贡献的定量分析。