Identification

Title

Detection of migrating diurnal tide in the tropical upper troposphere and lower stratosphere using the Challenging Minisatellite Payload radio occultation data

Abstract

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.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7vt1s8n

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2008-02-02T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact