Morphology and dynamics of Venus's middle clouds with Akatsuki/IR1

التفاصيل البيبلوغرافية
العنوان: Morphology and dynamics of Venus's middle clouds with Akatsuki/IR1
المؤلفون: Peralta, J., Iwagami, N., Sánchez-Lavega, Lee, Y. J., Hueso, R., Narita, M., Imamura, T., Miles, P., Wesley, A., Kardasis, E., Takagi, S.
المصدر: Geophysical Research Letters, 46, (2019)
سنة النشر: 2019
المجموعة: Astrophysics
Physics (Other)
مصطلحات موضوعية: Astrophysics - Earth and Planetary Astrophysics, Physics - Atmospheric and Oceanic Physics
الوصف: The Venusian atmosphere is covered by clouds with super-rotating winds whose accelerating mechanism is still not well understood. The fastest winds, occurring at the cloud tops ($\sim$70 km height), have been studied for decades thanks to their visual contrast in dayside ultraviolet images. The middle clouds ($\sim$50-55 km) can be observed at near-infrared wavelengths (800-950 nm), although with very low contrast. Here we present the first extensive analysis of their morphology and motions at lower latitudes along 2016 with 900-nm images from the IR1 camera onboard Akatsuki. The middle clouds exhibit hemispherical asymmetries every 4-5 days, sharp discontinuities in elongated "hook-like" stripes, and large contrasts (3-21%) probably associated with large changes in the optical thickness. Zonal winds obtained with IR1 images and with ground-based observations reveal mean zonal winds peaking at the equator, while their combination with Venus Express unveils long-term variations of 20 m s$^{-1}$ along 10 years.
Comment: 18 pages, 4 figures
نوع الوثيقة: Working Paper
DOI: 10.1029/2018GL081670
URL الوصول: http://arxiv.org/abs/1903.02883
رقم الأكسشن: edsarx.1903.02883
قاعدة البيانات: arXiv