17 Result(s)

Article

Characteristics of gravity waves observed with intensive radiosonde campaign during November–December 2005 over western Sumatera

Characteristics of gravity waves are studied using radiosonde campaign conducted during November–December 2005 at Koto Tabang (KT, 0.2°S, 100.32°E). Intensive sounding with hourly launches was also conducted o...

M. Venkat Ratnam, Simon P. Alexander, T. Kozu, T. Tsuda in Earth, Planets and Space (2009)

Article

Radar observations of the diurnal tide in the tropical mesosphere-lower thermosphere region: Longitudinal variabilities

Significant attention is being paid in recent times by several observational and modeling studies to quantify the spatial and temporal variabilities of diurnal tide in the mesosphere and lower thermosphere (ML...

S. Gurubaran, R. Rajaram, T. Nakamura, T. Tsuda, D. Riggin… in Earth, Planets and Space (2009)

Article

EISCAT observational results during the DELTA campaign

This paper aims at describing the ionospheric conditions during the DELTA (Dynamics and Energetics of the Lower Thermosphere in Aurora) campaign period based on EISCAT radar observations conducted at Tromsø (6...

S. Nozawa, Y. Ogawa, A. Brekke, T. Tsuda, C. M. Hall… in Earth, Planets and Space (2006)

Article

A global distribution of sporadic E events revealed by means of CHAMP-GPS occultations

With the advent of the GPS/MET mission, the atmospheric sciences were given a new tool to enhance studies related to global and seasonal variations of different atmospheric parameters. In particular, it has pr...

M. Garcia-Fernandez, T. Tsuda in Earth, Planets and Space (2006)

Article

Atmospheric density and pressure inferred from the meteor diffusion coefficient and airglow O₂b temperature in the MLT region

Atmospheric density and pressure in the upper mesosphere-lower thermosphere (MLT) region, around 90 km, are inferred from the meteor trail ambipolar diffusion coefficients, D, and simultaneously observed airglow ...

H. Takahashi, T. Nakamura, K. Shiokawa, T. Tsuda, L. M. Lima… in Earth, Planets and Space (2004)

Article

A study of spatial water vapor distributions by using one-way residuals of GPS phase measurements

We investigated water vapor distribution in the troposphere, concentrating especially on meso-scale phenomena, such as a cumulus cloud, with dimension less than about 10 km in the horizontal direction by using...

T. Yoshihara, T. Tsuda, K. Hirahara in Earth, Planets and Space (2001)

Article

High time resolution measurements of precipitable water vapor from propagation delay of GPS satellite signals

We estimated precipitable water vapor (PWV) with a high time resolution using Global Positioning System (GPS) measurements taken at Shigaraki, Japan, in 1995, and Yamagawa, Japan, in 1996. We have compared PWV...

T. Yoshihara, T. Tsuda, K. Hirahara in Earth, Planets and Space (2000)

Article

Development of Optical Mesosphere Thermosphere Imagers (OMTI)

The Optical Mesosphere Thermosphere Imagers (OMTI) have been developed to investigate the dynamics of the upper atmosphere through nocturnal airglow emissions. The OMTI consist of an imaging Fabry-Perot interf...

K. Shiokawa, Y. Katoh, M. Satoh, M. K. Ejiri, T. Ogawa… in Earth, Planets and Space (1999)

Article

Seasonal variations of 3.0∼3.8-day ultra-fast Kelvin waves observed with a meteor wind radar and radiosonde in Indonesia

This paper is concerned with observations of the long-term behavior of Kelvin waves with the wave period ranging from 3 to 4 days, which are generally called an ultra-fast Kelvin (UFK) wave. Horizontal wind ve...

S. Yoshida, T. Tsuda, A. Shimizu, T. Nakamura in Earth, Planets and Space (1999)

Article

Simultaneous measurements of dynamical structure in the mesopause region with lidars and MU radar

In order to clarify the horizontal structure of the wavelike oscillation frequently observed in the night time sodium density profile with a small Gaussian half-width in the middle of the night and a broad dis...

K. Kobayashi, T. Kitahara, T. D. Kawahara, Y. Saito, A. Nomura… in Earth, Planets and Space (1999)

Article

Response of the airglow OH emission, temperature and mesopause wind to the atmospheric wave propagation over Shigaraki, Japan

Simultaneous observations of the night airglow OH (6, 2) band emission intensity and rotational temperature, by a sky scanning airglow spectrophotometer, and meteor winds, by a middle and upper atmosphere rada...

H. Takahashi, P. P. Batista, R. A. Buriti, D. Gobbi… in Earth, Planets and Space (1999)

Article

Longitudinal variations in planetary wave activity in the equatorial mesosphere

Zonal and meridional winds in the equatorial mesosphere and lower thermosphere (65–98 km) measured at two sites separated by 94° in longitude are used to study the zonal structure of planetary-scale waves. The...

S. Kovalam, R. A. Vincent, I. M. Reid, T. Tsuda, T. Nakamura… in Earth, Planets and Space (1999)

Article

Cooperative wind observation in the upper mesosphere and lower thermosphere with foil chaff technique, the MU radar, and Yamagawa MF radar

An in-situ rocket technique using foil chaff is used to observe wind fields in the mesosphere and lower thermosphere (80–98 km in altitude). We launched two micro-rockets at 1200 and 1315 UT on 14 January 1997 fr...

Y. Murayama, K. Igarashi, I. Nishimuta, R. Yamazaki… in Earth, Planets and Space (1999)

Article

Seasonal variations of gravity wave structures in OH airglow with a CCD imager at Shigaraki

A wideview CCD imager for OH airglow observations was operated at the MU radar site in Shigaraki, Japan (35°N, 136°E). From the 18 months’ observation, dominant gravity wave components in the OH images are ext...

T. Nakamura, A. Higashikawa, T. Tsuda, Y. Matsushita in Earth, Planets and Space (1999)

Article

GPS meteorology project of Japan —Exploring frontiers of geodesy—

T. Tsuda, K. Heki, S. Miyazaki, K. Aonashi, K. Hirahara… in Earth, Planets and Space (1998)

Article

MU radar observations of tropopause variations by using clear air echo characteristics

We present in this paper the characteristics of clear air echoes revealed by the MU radar experiments in Shigaraki, Japan (34° 51′ N, 136° 06′ E). In particular, we study a relation between atmospheric stabili...

E. Hermawan, T. Tsuda, T. Adachi in Earth, Planets and Space (1998)