STRATOSPHERIC PROFILE OF HCN ON TITAN FROM MILLIMETER OBSERVATIONS

被引：56

作者：

TANGUY, L ^{[1
]}

BEZARD, B ^{[1
]}

MARTEN, A ^{[1
]}

GAUTIER, D ^{[1
]}

GERARD, E ^{[1
]}

PAUBERT, G ^{[1
]}

LECACHEUX, A ^{[1
]}

机构：

[1] INST RADIOASTRON MILLIMETR,GRANADA,SPAIN

来源：

ICARUS | 1990年 / 85卷 / 01期

关键词：

D O I：

10.1016/0019-1035(90)90102-F

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Measurements of the (1-0) line of hydrogen cyanide at 88.6 GHz in the Titan atmosphere are reported. Synthetic spectra were fitted to the observations to derive the vertical distribution of HCN in the stratosphere. The observed line is significantly narrower than that computed for constant stratospheric mixing ratios, implying an increase in the HCN concentration with altitude. From a least-squares analysis taking into account measurement noise and calibration uncertainties, a mean mixing ratio scale height of 47-11+36 km is derived for the 100- to 300-km region. The HCN abundance is found to be best constrained around the 170-km level where the inferred mixing ratio is 3.3-0.8+0.9 × 10-7. The results are consistent with recent analyses of Voyager infrared measurements. The inferred vertical concentration gradient is much steeper and the abundance in the lower stratosphere smaller than predicted by current photochemical models. Theoretical HCN profiles may, however, be brought into agreement with the present results by reducing the magnitude of the vertical eddy mixing assumed in the stratosphere. © 1990.

引用

页码：43 / 57

页数：15

共 21 条

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