Search

Atmospheric motions in the retrograde diurnal ([S.sub.1]) band are of interest to a wide community of researchers in earth dynamics and geodesy, due to their potential contribution to the low-frequency motions of the rotation axis known as nutations. Previous studies of these effects have noted an order-of-magnitude discrepancy between estimates of atmosphere-induced nutation based on the torque and angular momentum approaches. In this note, angular momentum budgets computed from NCEP reanalysis data are examined in order to isolate the reasons for this discrepancy, and associated constraints on the atmospheric response to solar diurnal forcing are considered.

The IAU Commission 19 meeting during the XXVII IAU General Assembly in Rio de Janeiro was held on Wednesday 5 August 2009, sessions 3 (14:00–15:30) and 4 (16:00–17:30). It was attended by about 40 participants. The meeting was split into three sessions. [ABSTRACT FROM PUBLISHER]

The IAU Commission 19 meeting during the XXVII IAU General Assembly in Rio de Janeiro was held on Wednesday 5 August 2009, sessions 3 (14:00–15:30) and 4 (16:00–17:30). It was attended by about 40 participants. The meeting was split into three sessions. [ABSTRACT FROM PUBLISHER]

The Commission supports and coordinates scientific investigations in the Earth rotation and related reference frames. Several changes had been introduced to the structure of Commission 19 since the IAU XXVI General Assembly in Prague, 2006. The Organizing Committee of Commission 19 has been substantially reduced. It consists now of six ex-officio members, the Commission president, vice-president, past president and representatives from the International Association of Geodesy (IAG), International Earth Rotation and Reference Systems Service (IERS), International VLBI Service for Geodesy and Astrometry (IVS), and five members at-large who are nominated by the OC, selected by the Commission members and elected by the IAU GA for a maximum of two terms. The modified terms of reference of Commission 19, the list of members and other details can be found at the Commission website . [ABSTRACT FROM PUBLISHER]

Focuses on the dynamical processes within the Earth's deep interior that give rise to decadal fluctuations in the rate of rotation of the solid Earth and involve angular momentum transfer not only between the core and the overlying mantle but also between different parts of the core. Non-steady differential rotation characteristic of the buoyancy-driven flow within the Earth's liquid metallic outer core that generates the main geomagnetic field by magnetohydrodynamic dynamo action; Evidence of the propagation of core angular momentum anomalies from the equatorial to polar regions. [ABSTRACT FROM AUTHOR]