摘要：As the utilization of low-Earth orbit increases, so does the need for improved ephemeris predictions and thus more accurate density models. In this paper we quantify the density variability of the thermosphere attributable to the lunar gravitational tide, a potentially predictable component of variability not included in any operational density prediction models to date. Using accelerometer measurements from the GOCE satellite near 260 km altitude, the level of lunar tidal density variability is shown to be about half that associated with the low level of geomagnetic variability that occurs about 75% of the time (Kp ≤ 3), thus constituting an element of “space weather.” Our conclusion is that the lunar tide ought to be considered for inclusion in contemporary density models of the thermosphere for operational ephemeris predictions. Some suggested first steps are included in the conclusions of this paper.
