Vertical wind distribution in the polar thermosphere during HEX campaign

Vertical winds in the thermosphere were measured with two Fabry-Perot Interferometers at the Poker Flat Research Range (PFRR) and Eagle observatory, Alaska during HEX campaign (Feburary-March, 2003). Since these two observatories have almost same geomagnetic latitude, we could deduce vertical wind distribution along the same auroral arc. OI557.7nm and OI630.0nm were measured using dichroic mirror, which enables us to estimate temporal variation of vertical winds in E- and F-region simultaneously. For measuring optical auroral distribution we used allsky imager at PFRR. We could have 13 clear nights in total 23 nights. The following results were obtained in this campaign. (1) The temporal variation of vertical wind observed with OI557.7nm at the two observatory have high correlation with each other, in spite of ∼300km apart. The correlation coefficient exceed 0.6 in six in 13 nights. (2) In OI630.0nm observation the correlation is relatively low. (3) Some of low-correlation cases in both wavelengths show the location of auroral arc against the observatory is different in the two sites, namely, whether the auroral arc exists poleward or equatorward of observational area. These results show that it is not rare to keep vertical wind structure 300 km along one auroral arc. This wind distribution is consistent with some previous works. However, it should be noted that some cases cannot be explained with this simple models.