Vertical temperature profile and mesospheric winds retrieval on Mars from CO millimeter observations Comparison with general circulation model predictions
Vertical temperature profile and mesospheric winds retrieval on Mars from CO millimeter observations Comparison with general circulation model predictions
复制标题
通过 CO 毫米观测反演火星垂直温度廓线和中层风 与大气环流模型预测的比较
DOI：
10.1051/0004-6361:200809815
复制
发表时间：
2008
影响因子：
6.5
通讯作者：
E. Lellouch
中科院分区：
文献类型：
--
作者：
T. Cavalié;F. Billebaud;T. Encrenaz;M. Dobrijevic;J. Brillet;F. Forget;E. Lellouch
目标。我们记录了高光谱分辨率的光谱，并得出了精确的大气温度分布和火星大气中的风速。我们已经比较了观测行星平均热剖面和中层风速的磁盘上，获得与我们的毫米观测CO旋转线，从气象动力学（LMD）火星环流模型的预测，通过火星气候数据库（MCD）的数值工具。方法. 2001年6月和2005年11月，我们使用IRAM 30 m天线在CO（1 - 0）和CO（2 - 1）波长处观察了火星大气。我们从高、低光谱分辨率数据中反演了这颗行星的平均热剖面，详细介绍了反演方法。高光谱分辨率光谱被用来推导行星盘上的中层风速。我们还报告了使用13个CO（2−1）线芯位移测量40 km处的风速。结果无论是火星24年（MY 24），也不是沙尘暴的情况下，从火星气候数据库（MCD）提供令人满意的适合2001年和2005年的数据时，检索的热剖面。温暖的情况下，只提供了良好的拟合低于30公里的高度。大气层比预测的要温暖，直到60公里，然后变得更冷。灰尘负载可能是这种不匹配的原因。MCD MY 24情景预测逆温层在40至60公里之间，这不是从高光谱分辨率数据中检索出来的。我们的结果一般与10 - 40 km高度的其他观测结果一致，但我们从高光谱分辨率光谱获得的结果在40 - 70 km层不同，那里的仪器是最灵敏的。我们从我们的12 CO观测检索的风速证实MCD预测2001年和2005年。从13 CO观测得到的速度与MCD在2001年的预测是一致的，但低于2005年的预测。
Aims. We have recorded high spectral resolution spectra and derived precise atmospheric temperature profiles and wind velocities in the atmosphere of Mars. We have compared observations of the planetary mean thermal profile and mesospheric wind velocities on the disk, obtained with our millimetric observations of CO rotational lines, to predictions from the Laboratoire de Meteorologie Dynamique (LMD) Mars General Circulation Model, as provided through the Mars Climate Database (MCD) numerical tool. Methods. We observed the atmosphere of Mars at CO(1−0) and CO(2−1) wavelengths with the IRAM 30-m antenna in June 2001 and November 2005. We retrieved the mean thermal profile of the planet from high and low spectral resolution data with an inversion method detailed here. High spectral resolution spectra were used to derive mesospheric wind velocities on the planetary disk. We also report here the use of 13 CO(2−1) line core shifts to measure wind velocities at 40 km. Results. Neither the Mars Year 24 (MY24) nor the Dust Storm scenario from the Mars Climate Database (MCD) provides satisfactory fits to the 2001 and 2005 data when retrieving the thermal profiles. The Warm scenario only provides good fits for altitudes lower than 30 km. The atmosphere is warmer than predicted up to 60 km and then becomes colder. Dust loading could be the reason for this mismatch. The MCD MY24 scenario predicts a thermal inversion layer between 40 and 60 km, which is not retrieved from the high spectral resolution data. Our results are generally in agreement with other observations from 10 to 40 km in altitude, but our results obtained from the high spectral resolution spectra differ in the 40−70 km layer, where the instruments are the most sensitive. The wind velocities we retrieve from our 12 CO observations confirm MCD predictions for 2001 and 2005. Velocities obtained from 13 CO observations are consistent with MCD predictions in 2001, but are lower than predicted in 2005.