edu.ucar.opensky::articles:6064 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T15:26:22.118690 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7vt1s8n Detection of migrating diurnal tide in the tropical upper troposphere and lower stratosphere using the Challenging Minisatellite Payload radio occultation data 2008-02-02T00:00:00Z publication https://n2t.org/ark:/85065/d7vt1s8n https://doi.org/10.1029/2007JD008725 Zeng, Zhen author Randel, William author Sokolovskiy, Sergey author Deser, Clara author Kuo, Ying-Hwa author Hagan, Maura author UCAR/NCAR - Library publisher The atmospheric limb sounding technique making use of radio signals transmitted by the Global Positioning System (GPS) has already proven to be a promising approach for global atmospheric measurements. In this study, we assess for the first time the potential of GPS radio occultation soundings for detecting the migrating diurnal tide. Retrieved temperatures between 10 and 30 km in the tropics from the Challenging Minisatellite Payload (CHAMP) occultation observations during May 2001 to August 2005 are analyzed using space-time spectrum analysis to isolate diurnal waves. Because of incomplete local time (LT) coverage of the monthly CHAMP occultation data in any given year, data from all available years are merged to obtain complete 24-h LT coverage. The effects of aliasing associated with uneven data sampling and measurement noise are estimated using synthetic data. The results show the feasibility of determining tidal structures from the composite CHAMP occultation data, and the vertical, seasonal, and latitudinal structures of the diurnal tide are presented. The estimated diurnal amplitude generally increases with altitude, exhibiting a maximum of order 1 K at 30 km. The estimated phase indicates an upward propagating mode above 14 km with a vertical wavelength about 20 km. The observed diurnal tide at 30 km exhibits a distinct seasonal-latitudinal variation. Comparison of the observed diurnal tide to the simulated tide in the extended Canadian Middle Atmosphere Model (CMAM) and Global-Scale Wave Model Version 2 (GSWM02) indicates that CMAM overestimates the amplitude but reproduces the seasonal-latitudinal variation of the diurnal tide while GSWM02 simulates well the annual mean amplitude but lacks the seasonal-latitudinal variation of the diurnal tide. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union. None eng geoscientificInformation