Monthly mean climatology of the prevailing winds and tides in the Arctic mesosphere/lower thermosphere

Portnyagin, Yu. I.; Solovjova, T.V.; Makarov, N. M.; Merzlyakov, E. G.; Manson, A. H.; Meek, C. E.; Hocking, W. K.; Mitchell, N. J.; Pancheva, D.; Hoffmann, Peter; Singer, W.; Murayama, Yasuhiro; Igarashi, K.; Forbes, Jeffrey M.; Palo, S. E.; Hall, Chris M.; Nozawa, Satonori

doi:10.5194/angeo-22-3395-2004

Cited by 58 publications

(58 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies of mean winds in the Arctic MLT include those of Portnyagin et al (1992Portnyagin et al ( , 1993Portnyagin et al ( , 2004Portnyagin et al ( , 2006, Hocking (2001), Dowdy et al (2001Dowdy et al ( , 2007a, Hall et al (2003), Kishore et al (2003). Again, we will not consider further the studies of Portnyagin et al (1992) because they used meteor radar without height finding capability.…”

Section: Discussionmentioning

confidence: 99%

“…Nevertheless, in the Arctic MF and Meteor radars have been used to establish a limited number of simple climatologies of the zonal and meridional mean winds. These include the MF radar studies of Portnyagin et al (1992Portnyagin et al ( , 1993Portnyagin et al ( , 2004; Dowdy et al (2001Dowdy et al ( , 2007a; Hall et al (2003); Kishore et al (2003) and the meteor radar studies of Hocking (2001); Mitchell et al (2002); Hall et al (2003).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamics of the Antarctic and Arctic mesosphere and lower thermosphere – Part 1: Mean winds

et al. 2010

View full text Add to dashboard Cite

Abstract. Zonal and meridional winds have been measured in the upper mesosphere and lower thermosphere at polar latitudes using two ground-based meteor radars. One radar is located at Rothera (68 • S, 68 • W) in the Antarctic and has been operational since February 2005. The second radar is located at Esrange (68 • N, 21 • E) in the Arctic and has been operational since October 1999. Both radars have produced relatively continuous measurements. Here we consider measurements made up to the end of 2009. Both radars are of similar design and at conjugate geographical latitudes, making the results directly comparable and thus allowing investigation of the differences in the mean winds of the Antarctic and Arctic regions. The data from each radar have been used to construct climatologies of monthly-mean zonal and meridional winds at heights between 80 and 100 km. Both Antarctic and Arctic data sets reveal seasonally varying zonal and meridional winds in which the broad pattern repeats from year to year. In particular, the zonal winds display a strong shear in summer associated with the upper part of the westward summertime zonal jet. The winds generally reverse to eastward flow at heights of ∼90 km. The zonal winds are eastward throughout the rest of the year. The meridional winds are generally equatorward over both sites, although brief episodes of poleward flow are often evident near the equinoxes and during winter. The strongest equatorward flows occur at heights of ∼90 km during summer.There are significant differences between the mean winds observed in the Antarctic and Arctic. In particular, the westward winds in summer are stronger and occur earlier in the season in the Antarctic compared with the Arctic. The eastward winds evident above the summertime zonal wind reversal are significantly stronger in the Arctic. The summertime equatorward flow in the Antarctic is slightly weaker, but occurs over a greater depth than is the case in the Arctic.Correspondence to: D. J. Sandford (d.j.sandford@bath.ac.uk) Comparisons of these observations with those of the URAP and HWM-07 empirical models reveal a number of significant differences. In particular, the zonal winds observed in the Antarctic during wintertime are significantly weaker than those of URAP. However, the URAP zonal winds are a good match to the observations of the Arctic. Significant differences are evident between the observations and HWM-07. In particular, the strong wintertime zonal winds of the Arctic in HWM-07 are not evident in the observations and the summertime zonal winds in HWM-07 are systematically stronger than observed. The agreement with meridional winds is generally poor.There is a significant amount of inter-annual variability in the observed zonal and meridional winds. Particularly high variability is observed in the Arctic zonal winds in spring and is probably associated with stratospheric warmings.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dynamics of the Antarctic and Arctic mesosphere and lower thermosphere – Part 1: Mean winds

et al. 2010

View full text Add to dashboard Cite

show abstract

“…at the winter pole (Gardner et al, 2005;Portnyagin et al, 2004), which has two effects: the temperature increases because of adiabatic heating, and Na is transported downwards from the peak of the layer. Figure 2 illustrates the latitudinal distribution of the correlation coefficient between the retrieved Na density and temperature (taken from the MSIS model, Picone et al, 2002), as a function of height.…”

Section: Global Latitudinal and Seasonal Variationsmentioning

confidence: 99%

Satellite measurements of the global mesospheric sodium layer

et al. 2007

View full text Add to dashboard Cite

Abstract. Optimal estimation theory is used to retrieve the absolute Na density profiles in the mesosphere/lower thermosphere from limb-scanning measurements of the Na radiance at 589 nm in the dayglow. Two years of observations (2003 and 2004), recorded by the OSIRIS spectrometer on the Odin satellite, have been analysed to yield the seasonal and latitudinal variation of the Na layer column abundance, peak height, and peak width. The layer shows little seasonal variation at low latitudes, but the winter/summer ratio increases from a factor of ∼3 at mid-latitudes to ∼10 in the polar regions. Comparison of the measurements made at about 06:00 and 18:00 LT shows little diurnal variation in the layer, apart from the equatorial region where, during the equinoxes, there is a two-fold increase in Na density below 94 km between morning and evening. This is most likely caused by the strong downward wind produced by the diurnal tide between ∼02:00 and 10:00 LT. The dramatic removal of Na below 85 km at latitudes above 50 • during summer is explained by the uptake of sodium species on the ice surfaces of polar mesospheric clouds, which were simultaneously observed by the Odin satellite.

show abstract

“…Somewhat randomly placed radars now extend from equator to Arctic latitudes, including the two recently installed radars that are the focus of this paper. The irregularly shaped Arctic Ocean precludes longitudinal networks north of 65-70 • N, although some studies exist using six or so of such temporally contemporaneous systems near those latitudes (Portnyagin et al, 2004). However, the absence of coverage in north-eastern Russia and the longitudinal extent of the northern Pacific Ocean (a 140 • data gap) have made identification of NMT difficult.…”

mentioning

confidence: 99%

“…However, the absence of coverage in north-eastern Russia and the longitudinal extent of the northern Pacific Ocean (a 140 • data gap) have made identification of NMT difficult. Portnyagin et al (2004) concluded that the migrating tides (diurnal D and semi-diurnal SD) are dominant in the southern • N), but with some indications of NMT. These latter were based on the modest departures from slopes of 1 and 2, respectively (corresponding to the MT, s=+1 and +2) for the plots of D and SD phases (time of maximum in UT) versus longitudes.…”

mentioning

confidence: 99%

Arctic tidal characteristics at Eureka (80° N, 86° W) and Svalbard (78° N, 16° E) for 2006/07: seasonal and longitudinal variations, migrating and non-migrating tides

et al. 2009

Self Cite

View full text Add to dashboard Cite

NMT with s=0, +2 (westward) dominate in non-summer months, while for the semi-diurnal tide NMT with s=+1, +3 occur most often during equinoctial or early summer months. These wave numbers are consistent with stationary planetary wave (SPW)-tidal interactions.Assessment of the global topographic forcing and atmospheric propagation of the SPW (S=1, 2) suggests these winter waves of the Northern Hemisphere are associated with the 78-80 • N diurnal NMT, but that the SPW of the Southern Hemisphere winter have little influence on the summer Arctic tidal fields. In contrast the large SPW and NMT of the Arctic winter may be associated, consistent with Antarctic observations, with the observed occurrence of the semidiurnal NMT in the Antarctic summer.

show abstract

Monthly mean climatology of the prevailing winds and tides in the Arctic mesosphere/lower thermosphere

Cited by 58 publications

References 43 publications

Dynamics of the Antarctic and Arctic mesosphere and lower thermosphere – Part 1: Mean winds

Dynamics of the Antarctic and Arctic mesosphere and lower thermosphere – Part 1: Mean winds

Satellite measurements of the global mesospheric sodium layer

Arctic tidal characteristics at Eureka (80° N, 86° W) and Svalbard (78° N, 16° E) for 2006/07: seasonal and longitudinal variations, migrating and non-migrating tides

Contact Info

Product

Resources

About