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830 results on '"Lühr, H."'

252. The CHAMP mission and its role in observing temporal variations of the geopotential fields (Abstract)

Author

Reigber, C., Lühr, H., Kang, Z., Schwintzer, P., 1.2 Global Geomonitoring and Gravity Field, 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum, 1.1 GPS/GALILEO Earth Observation, 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum, and Gravity Field and Gravimetry -2009, Geoengineering Centres, GFZ Publication Database, Deutsches GeoForschungsZentrum

Subjects
550 - Earth sciences
Published
1997

254. Zonal winds in the equatorial upper thermosphere: Decomposing the solar flux, geomagnetic activity, and seasonal dependencies

Author

Liu, H. (author), Lühr, H. (author), Watanabe, S. (author), Köhler, W. (author), Henize, V. (author), Visser, P.N.A.M. (author), Liu, H. (author), Lühr, H. (author), Watanabe, S. (author), Köhler, W. (author), Henize, V. (author), and Visser, P.N.A.M. (author)

Abstract

Using 3 years (2002–2004), over 16,400 orbits of measurements from the accelerometer on board the CHAMP satellite, we have studied the climatology of the equatorial zonal wind in the upper thermosphere. Several main features are noticed. The most prominent one is that the solar flux significantly influences both the daytime and nighttime winds. It overrides the geomagnetic activity effect, which is found to be rather limited to the nightside. An elevation of the solar flux level from F10.7 ? 100 × 10?22 W m?2 Hz?1 to F10.7 ? 190 × 10?22 W m?2 Hz?1 produces an eastward disturbance wind up to ?110 m s?1. This consequently enhances the nighttime eastward wind but suppresses the daytime westward wind. A seasonal variation with weaker wind (by over 50 m s?1 at night) around June solstice than in other seasons has been observed regardless of solar flux and geomagnetic activity levels. The zonal wind is eastward throughout the night except around June solstice, where it ebbs to almost zero or turns even westward in the postmidnight sector at low solar flux level. The daytime wind is found to be generally more stable than the nighttime wind, particularly unresponsive to geomagnetic activities. Predictions from the Horizontal Wind Model find good agreement with the CHAMP?observed wind at high solar flux levels during nighttime. At low solar flux levels, however, the model strongly underestimates the westward wind during morning hours by 50–120 m s?1 depending on season. The major difference between the HWM?predicted and the CHAMP?observed wind is seen in the phase of its diurnal variation. The CHAMP?observed wind turns eastward around 1200–1300 MLT instead of 1600–1700 MLT predicted by the model. Comparisons with ground FPI observations and the NCAR Thermosphere?Ionosphere?Electrodynamics General Circulation Model (TIEGCM) predictions show that the solar flux effect obtained from CHAMP is consistent with that modeled by TIEGCM. The solar flux dependence of zonal wind found h, Space Engineering, Aerospace Engineering

Published
2006
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255. CHAMP PhaseB - Executive Summary

Author

Reigber, Ch., Bock, R., Förste, Ch., Grunwaldt, L., Jakowski, N., Lühr, H., Schwintzer, P., and Tilgner, C.

Subjects
CHAMP, Phase B
Published
1996

272. The 9th generation international geomagnetic reference field

Author

Macmillan, S., Maus, S., Bondar, T., Chambodut, A., Golovkov, V., Holme, R., Langlais, B., Lesur, V., Lowes, F., Lühr, H., Mai, W., Mandea, M., Olsen, Nils, Rother, M., Sabaka, T., Thomson, A., Wardinski, I., Macmillan, S., Maus, S., Bondar, T., Chambodut, A., Golovkov, V., Holme, R., Langlais, B., Lesur, V., Lowes, F., Lühr, H., Mai, W., Mandea, M., Olsen, Nils, Rother, M., Sabaka, T., Thomson, A., and Wardinski, I.

Published
2003

274. CO2: A CHAMP magnetic field model

Author

Reigber, Chr., Lühr, H., Schwintzer, P., Holme, R., Olsen, Nils, Rother, M., Reigber, Chr., Lühr, H., Schwintzer, P., Holme, R., Olsen, Nils, and Rother, M.

Published
2003

294. EMAG2: A 2-arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements

Author

Maus, S., primary, Barckhausen, U., additional, Berkenbosch, H., additional, Bournas, N., additional, Brozena, J., additional, Childers, V., additional, Dostaler, F., additional, Fairhead, J. D., additional, Finn, C., additional, von Frese, R. R. B., additional, Gaina, C., additional, Golynsky, S., additional, Kucks, R., additional, Lühr, H., additional, Milligan, P., additional, Mogren, S., additional, Müller, R. D., additional, Olesen, O., additional, Pilkington, M., additional, Saltus, R., additional, Schreckenberger, B., additional, Thébault, E., additional, and Caratori Tontini, F., additional

Published
2009
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