中文摘要：

大旋涡的模拟被进行调查像西洋象棋盘的异构的表面在对流边界层(CBL ) 在第二等的发行量(SC ) 上加热和背景风的规模的影响。当风沿着西洋象棋盘模式的对角线刮时，有不同异质长度规模的案例(= 1.2 ， 2.4 ，和 4.8 km )并且弱背景风( U = 2.5 m s ¹)建议那在那里存在为像转动的 SC 的阀值，当异质长度规模是乘边界层高度的 1.6 时，它满足(= 1.6z _i )。在 CBL 发展期间，在这阀值被遇见以前， SC 紧张增加，而它此后减少。有不同背景的案例弯屈速度( U = 2.5 ， 5.0 ，并且 10.0 m s 1 )并且相对大的异质长度规模(= 4.8 km )当异质长度规模那么大阀值不能在 CBL 发展期间被遇见时， SC 被更大的风加强的表演加速。有沿着既不对角线也不像转动的 SC 能仍然被触发，但是转动削减的西洋象棋盘模式表演的方面的风方向的另一个盒子沿着西洋象棋盘模式的对角线而非沿着风方向被面向。

英文摘要：

Large-eddy simulations are conducted to investigate the impacts of the scale of chessboard-like heteroge- neous surface heating and the background wind on secondary circulations （SCs） in the convective boundary layer （CBL）. When the wind blows along the diagonal of the chessboard pattern, the cases with different heterogeneity length scales （λ = 1.2, 2.4, and 4.8 km） and weak background wind （U = 2.5 m s-1） suggest that there exists a threshold for the roll-like SCs, which is satisfied when the heterogeneity length scale is 1.6 times the boundary layer height （λ = 1.6zi）. During the CBL development, the SC intensity increases before this threshold is met, whereas it decreases thereafter. The cases with different background wind speeds （U = 2.5, 5.0, and 10.0 m s-1） and relatively large heterogeneity length scale （λ = 4.8 km） show that the SCs are strengthened by larger wind speeds when the heterogeneity length scale is so large that the threshold cannot be met during the CBL development. Another case with wind direction along neither the diagonal nor the side of the chessboard pattern shows that the roll-like SCs can still be triggered, but the roll axes are orientated along the diagonal of the chessboard pattern rather than along the wind direction.