Coronas and iridescence in mountain wave clouds.
Coronas and iridescence in mountain wave clouds.
复制标题
山波云中的日冕和虹彩。
DOI：
10.1364/ao.42.000476
复制
发表时间：
2003
期刊：
影响因子：
1.9
通讯作者：
P. Neiman
中科院分区：
文献类型：
--
作者：
J. Shaw;P. Neiman
我们使用Fraunhofer衍射理论和气象数据来确定云粒子分布的性质和解释山波云中的日冕和虹彩照片所需的平均粒子尺寸。传统上对日冕和彩虹色的描述通常将这些光学现象解释为液态水滴的衍射。我们的分析表明，所拍摄的显示器的平均粒径为7.6至24.3微米，超过一半的情况下，需要衍射的小（approximatley 20微米）准球形冰粒，而不是液态水滴。以前关于冰粒产生的日冕的文献仅限于对似乎由小冰晶组成的卷云的观测，而我们的观测表明，日冕和彩虹色通常可以由微小的准球形冰粒产生，这可能是山波云所特有的。此外，我们看到，在山波云日冕的主色是红色和蓝色，而不是传统上描述的红色和绿色。
We use Fraunhofer diffraction theory and meterological data to determine the nature of cloud-particle distributions and the mean particle sizes required for interpreting photographs of coronas and iridescence in mountain wave clouds. Traditional descriptions of coronas and iridescence usually explain these optical phenomena as diffraction by droplets of liquid water. Our analysis shows that the photographed displays have mean particle sizes from 7.6 to 24.3 microm, with over half the cases requiring diffraction by small (approximatley 20 microm) quasispherical ice particles rather than liquid water droplets. Previous documentation of coronas produced by ice particles are limited to observations in cirrus clouds that appear to be composed of small ice crystals, whereas our observations suggest that coronas and iridescence quite often can be created by tiny quasispherical ice particles that might be unique to mountain wave clouds. Furthermore, we see that the dominant colors in mountain wave-cloud coronas are red and blue, rather than the traditionally described red and green.