• 検索結果がありません。

Study of gravity wave in middle atmosphere over Syowa using Rayleigh/Raman lidar from 2011 to 2015

N/A
N/A
Info
ダウンロード
Protected

Academic year: 2021

シェア "Study of gravity wave in middle atmosphere over Syowa using Rayleigh/Raman lidar from 2011 to 2015"

Copied!
1
0
0

読み込み中.... (全文を見る)

今ダウンロードする ( 1 ページ )

全文

(1)

Study of gravity wave in middle atmosphere over Syowa using Rayleigh/Raman lidar from 2011 to 2015

Masaru Kogure

１,2

, Takuji Nakamura

1,2

, Mitsumu K. Ejiri

1,2

,Takanori Nishiyama

1,2

, Yoshihiro Tomikawa

1,2

, and Masaki Tsutsumi

1,2

1

Department of Polar Science, The Graduate University for Advanced Studies,

2

National Institute of Polar Research

The gravity waves are generated in the lower atmosphere, propagate upward and transfer their momentum and energy to the middle atmosphere. It has been found that the gravity waves induce the large scale meridional circulation and drive the middle atmosphere away from radiative equilibrium [Lindzen, 1981; Holton, 1982; Matsuno, 1982]. However, we have not completely known the

quantification of gravity wave roles in the middle atmospheric circulation. A Rayleigh/Raman (RR) lidar was installed in January 2011 at Syowa Station, Antarctica (69°S,40°E). The lidar has measured

temperature profiles between 10 and 80 km since February 2011.

In this study, we investigated monthly mean gravity wave potential energy (Ep) in the height range of 15-70 km from May 2011 to October 2015 except for November, December and January. The number of nights used for this analysis is 360 nights in five years. Above 30km altitude, Ep was maximized during winter in each year. The seasonal dependence of Ep over Syowa was similar to Ep over Davis

(69°S,79°E) [Alexander et al., 2011; Kaifler et al., 2014] and McMurdo (78°S, 167°E) [Lu et al., 2015].

Almost all Ep profiles had a roughly constant exponential slope between 30 and 70 km altitude. Between 35 and 64 km, the mean scale height was ~11 km in the 4 years except for 2014. The scale heights of winter (May to August) and spring (September and October) were quite similar and lager than those of autumn (March and April) in each year.

We compared our results with previous studies [Alexander et al., 2011; Kaifler et al., 2014; Lu et al.

2015]. Alexander et al. [2011] and Kaifler et al. [2014] showed the scale heights of winter over Davis where is relatively close to Syowa, and the scale heights were smaller than that over Syowa. Moreover, the scale heights over Davis increased with altitude between 30 and 60 km altitude. Lu et al. [2015]

showed the scale heights of winter over McMurdo where is much further from Syowa than Davis, and the scale heights were roughly constant and quite similar to those over Syowa. It suggests that attenuation of gravity waves over Syowa is larger than that over Davis and close to that over McMurdo through the vertical propagation.

In this presentation, we will discuss the local variation and the annual variation of Ep.

参照

今ダウンロードする ( PDF - 1 ページ - 22.32 KB )

関連したドキュメント

1.Introduction A.M.Abd-Alla, S.M.Abo-Dahab, andF.S.Bayones RayleighWavesinGeneralizedMagneto-Thermo-ViscoelasticGranularMediumundertheInfluenceofRotation,GravityField,andInitialStress ResearchArticle

Figure 5 shows that the velocity of Rayleigh waves Re and attenuation coefficient Im under effect of gravity field, friction coefficient, relaxation time, and rotation with respect to

Later, it has been completed in works of the author

All (4 × 4) rank one solutions of the Yang equation with rational vacuum curve with ordinary double point are gauge equivalent to the Cherednik solution.. The Cherednik and the

It is assumed that the restoring force is asymptotically negligible as the solution becomes large, and that the per- turbation tends to zero as time becomes indefinitely large

We have formulated and discussed our main results for scalar equations where the solutions remain of a single sign. This restriction has enabled us to achieve sharp results on

Fragments of geometric topology from the sixties

The main problem upon which most of the geometric topology is based is that of classifying and comparing the various supplementary structures that can be imposed on a

(3.) In the statement of the criterion

Then it follows immediately from a suitable version of “Hensel’s Lemma” [cf., e.g., the argument of [4], Lemma 2.1] that S may be obtained, as the notation suggests, as the m A

Moreover, we study the use of the unsymmetric Lanczos process that, to the best of our knowledge, has just marginally been considered in this setting

discrete ill-posed problems, Krylov projection methods, Tikhonov regularization, Lanczos bidiago- nalization, nonsymmetric Lanczos process, Arnoldi algorithm, discrepancy

The study of a terminal value problem for ordinary differential equations using the method of lower and upper solutions can be found in [12]

This problem becomes more interesting in the case of a fractional differential equation where it closely resembles a boundary value problem, in the sense that the initial value

The Analysis of the Artifacts due to

While conducting an experiment regarding fetal move- ments as a result of Pulsed Wave Doppler (PWD) ultrasound, [8] we encountered the severe artifacts in the acquired image2.