干旱区生态环境知识资源中心(Arid): Earth as an Exoplanet. I. Time Variable Thermal Emission Using Spatially Resolved Moderate Imaging Spectroradiometer Data

Arid

DOI	10.3847/1538-3881/abbc15
	Earth as an Exoplanet. I. Time Variable Thermal Emission Using Spatially Resolved Moderate Imaging Spectroradiometer Data
	Mettler, Jean-Noel; Quanz, Sascha P.; Helled, Ravit
通讯作者	Mettler, JN
来源期刊	ASTRONOMICAL JOURNAL
ISSN	0004-6256
EISSN	1538-3881
出版年	2020
卷号	160 期号:6
英文摘要	Among the more than 4000 exoplanets known today, some terrestrial planets have been detected in the so-called habitable zone of their host stars and their number is expected to increase in the near future, energizing a drive to understand and interpret the eagerly awaited wealth of data to identify signs of life beyond our solar system. So far, Earth remains the best and only example of a habitable (and inhabited) world. Although, it seems extremely unlikely that any other exoplanets will be true Earth twins, it is important to explore and understand the full range of spectral signatures and variability of Earth in order to inform the design of future instruments and missions, and understand their diagnostic power as well as potential limitations. In this work we use Earth observation data collected by the MODIS instrument aboard the Aqua satellite. The complete data set comprises 15 years of thermal emission observations in the 3.66-14.40 mu m range for five different locations on Earth (Amazon Rainforest, Antarctica, Arctic, Indian Ocean, and the Sahara Desert). We then determine flux levels and variations as a function of wavelength and surface type (i.e., climate zone and surface thermal properties) and investigate whether periodic signals indicating Earth's tilted rotation axis can be detected. Our findings suggest that (1) viewing geometry plays an important role when thermal emission data is analyzed as Earth's spectrum varies by a factor of three and more depending on the dominant surface type underneath; (2) typically strong absorption bands from CO2 (15 mu m) and O-3 (9.65 mu m) are significantly less pronounced and partially absent in data from the polar regions implying that estimating correct abundance levels for these molecules might be challenging in these cases; and (3) the time-resolved thermal emission spectrum encodes information about seasons/planetary obliquity, but the significance depends on the viewing geometry and spectral band considered.
英文关键词	Earth atmosphere Space vehicle instruments Exoplanet atmospheres Infrared sources
类型	Article
语种	英语
开放获取类型	Green Submitted
收录类别	SCI-E
WOS记录号	WOS:000586326700001
WOS关键词	TERRESTRIAL PLANETS ; SURFACE ; SPECTRUM ; BIOSIGNATURES ; HABITABILITY ; TEMPERATURE ; EVOLUTION ; LAND ; LIFE
WOS类目	Astronomy & Astrophysics
WOS研究方向	Astronomy & Astrophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/327340
作者单位	[Mettler, Jean-Noel; Quanz, Sascha P.] Swiss Fed Inst Technol, Inst Particle Phys & Astrophys, Wolfgang Pauli Str 27, CH-8093 Zurich, Switzerland; [Mettler, Jean-Noel; Helled, Ravit] Univ Zurich, Ctr Theoret Astrophys & Cosmol, Inst Computat Sci, Zurich, Switzerland
推荐引用方式 GB/T 7714	Mettler, Jean-Noel,Quanz, Sascha P.,Helled, Ravit. Earth as an Exoplanet. I. Time Variable Thermal Emission Using Spatially Resolved Moderate Imaging Spectroradiometer Data[J],2020,160(6).
APA	Mettler, Jean-Noel,Quanz, Sascha P.,&Helled, Ravit.(2020).Earth as an Exoplanet. I. Time Variable Thermal Emission Using Spatially Resolved Moderate Imaging Spectroradiometer Data.ASTRONOMICAL JOURNAL,160(6).
MLA	Mettler, Jean-Noel,et al."Earth as an Exoplanet. I. Time Variable Thermal Emission Using Spatially Resolved Moderate Imaging Spectroradiometer Data".ASTRONOMICAL JOURNAL 160.6(2020).