一枚Chaff火箭观测到的湍流谱

在一个异常强水平风速和极端大风切变层内, 垂直速度扰动谱表明几个相当重要特征:(1)垂直速度扰动谱有二个区域, 一个在低频区, 有谱斜率一1.65, 这个谱斜率接近于惯性子区内-5/3谱斜率, 另一个在高频区, 有谱斜率-7.11, 它接近于粘性子区内-7谱斜率.(2)垂直速度扰动谱有一个崩溃点, 约位于70m, 这与计算的内尺度有好的一致.(3)由垂直速度扰动谱计算的湍流能量耗散率是0.087m²·s^-3, 这比MAP/WINE试验中得到的值约大一个数量级.

TURBULENCE SPECTRUM OBSERVED FROM A CHAFF ROCKET

Spectrum of the venical velocity fluctuations for the height interval in which anenormously strong horizontal wind velocity and an extremely large wind shear areobserved indicates some qulte important fetas. (1) The spectrum shows two regions,one at lower frequencies has spectral slope of -1.65, which is close to -5/3 expectedin an inenial subrange, the other at higher frequencies has spectral slope of-7. 11,which is close to -7 expected in a viscous subrange. (2) The spectrum has abreakpoint which occurs at about 70m. This observation is in good agreement withthe inner scale calculated. (3) Tuthulence energy dissipahon rate obtained from thespectrum is about 0.087 W/kg, which is about an order of magnitud higher thanthose measured during the MAP/ WINE campaign.