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322 - GSW - GSWM solar diurnal & semidiurnal tides
Instrument Type: Instrument
Observatory: None
Observation Site: None
Operating Mode:

Instrument Page: GSW

The Global Scale Wave Model (GSWM) simulates solar diurnal and semidiurnal tides calculated in the Earth's atmosphere using realistic ozone and water vapor forcing. The calculations were done for 4 months (January, April, July, October), where the day assumed was the 15th of each month. The background winds are calculated assuming geostrophic balance between 20-80 km. Above 80 km, they are taken from the Portnyagin and Solov'eva model, and below 20 they are taken from the Groves/MSIS model. The background temperature and density are taken from the MSISE90 model using a solar flux of 120 and an Ap of 4. The results are only weakly dependent on solar cycle, so the year is arbitrary. The year 1995 was chosen because this was the year that the reference appeared. The diurnal and semidiurnal amplitudes and phases of the neutral temperature, the eastward neutral wind, the northward neutral wind, and the vertical neutral wind are given for 31 altitudes between 0 and 124 km in steps of approximately 4 km. There are 59 geographic latitudes that vary between 87 and -87 in steps of 3 degrees. The tidal results are zonal averages. The results from this set of calculations are now known as GSWM-95 tidal predictions. The vertical velocity is defined to be 0 at the surface, but other temperature and wind values may be zero with a non-zero phase due to round-off.