Fig 1 - available via license: Creative Commons Attribution 3.0 Unported
Content may be subject to copyright.
Field of view for the Syowa-East HF radar with a 16-beam coverage (beams numbered as B0, B1, B2, . . . , B15). Ground ranges from Syowa Station and the Syowa-South HF radar field of view are also indicated with curved dot-dashed lines and black dashed lines, respectively.
Source publication
A Rayleigh–Raman lidar system was installed in January 2011 at Syowa
Station, Antarctica (69.0° S, 39.6° E). Polar mesospheric
clouds (PMCs) were detected by lidar at around 22:30 UTC (LT −3 h) on 4
February 2011, which was the first day of observation. This was the first
detection of PMCs over Syowa Station by lidar. On the same day, a Super Dual...
Similar publications
Southern Hemispheric (SH) sudden stratospheric warmings (SSWs) are relatively rare compared to their Northern Hemisphere counterparts. No study has so far investigated the impacts of the SH minor SSWs on the tropical atmosphere and connection between the tropical and polar atmospheres. Here, we analyze the MERRA‐2 and ERA‐interim datasets, and Micr...
Citations
... Polar mesospheric summer echoes (PMSE) are an intriguing strong radar echo phenomenon measured in the very high frequency (VHF) band at high latitudes (>60°) and 80-to 90-km heights, first reported by Ecklund and Balsley (1981). The lower part of PMSE is overlapped with the layer of noctilucent clouds (NLC) (Kaifler et al., 2011;Klekociuk et al., 2008;Suzuki et al., 2013). PMSE and NLC are known to be commonly composed of charged ice particles but are distinguished by the size of ice particles and the method of measurement. ...
We report observations of dynamically unstable strong wind shear (Richardson number < 0.25) capable of inducing Kelvin‐Helmholtz instability in the polar mesospheric summer echoes (PMSE) layer (80–90 km) using very high frequency radar measurements in Kiruna (67.8°N, 20.4°E), Sweden, in 2006. The unstable strong wind shear can play an important role in producing PMSE by inducing turbulence and adiabatic cooling. We find that the strong shears take up 64% of the observed wind profiles and are frequently composed of systematically single‐shear/multishear (layer) structures, which gradually or abruptly vary in wind directions, so‐called wind shifts, through heights at intervals of 4–8 km. The strong shear rate normalized by PMSE counts has a good correlation (R = 0.7) in day‐to‐day variation with energetic electron (>30 keV) precipitations that were related to high‐speed solar wind streams. The observations of strong wind shear can be supported by satellite‐measured temperature modulations matching with the peaks of the first three high‐speed solar wind stream events. This study suggests that PMSE production is closely associated with the strong shear that is in turn linked to the effects of energetic electron precipitation.
... It is hardly possible to perform long-term synchronous observations of PMSEs by radar methods or of NLCs by optical methods, since the latter require a clear sky and a solar position of less than 5°-10° below the horizon. Research at Spitzbergen (Lubken et al., 2004) and in the Antarctic region (Suzuki et al., 2013) with lidars confirms the general link between the phenomena. However, Stebel et al. (2000) reported that PMSE are sometimes observed without NLCs; likewise, an anomalous echo may be absent in the presence of NLCs. ...
Variations in the amplitude of the ordinary wave from a received signal on a partial reflection radar at a short-wave range on the Kola Peninsula during the appearance of noctilucent clouds on August 12, 2016, are examined. Noctilucent clouds are registered by the all-sky camera located 100 km southward of the partial reflection radar. They extended over the entire celestial hemisphere observed by the all-sky camera; all of them moved in the southern direction, and the clouds had a tenuous structure and showed gravity waves with spatial periods of 15–100 km. During the presence of noctilucent clouds over the partial reflection radar, polar mesospheric summer echoes (PMSEs) were recorded at heights of 83–86 km. It was found that the presence of only noctilucent clouds in diagram of the antenna pattern of partial frequency radar is not sufficient for the appearance of PMSEs; noctilucent clouds must also have irregularities of several kilometers. The PMSE heights decreased with a velocity of 0.5 and 1.3 m/s. The issue of aerosols that cause the appearance of PMSEs and noctilucent clouds is discussed.
... During the past decades, radars have been used to investigate mesospheric phenomena, e.g., polar mesospheric echoes (Rapp et al., 2008, Suzuki et al., 2013, Chau et al., 2014 and atmospheric dynamics (e.g. Andrews et al., 1987, Fritts et al., 2012, Iimura et al., 2015. ...
The Andenes Meteor Radar (MR) and the Saura Medium Frequency (MF) Radar are located in northern Norway (69° N, 16° E) and operate continuously to provide wind measurements of the mesosphere and lower thermosphere (MLT) region. We compare the two systems to find potential biases between the radars and combine the data from both systems to enhance altitudinal coverage between 60 and 110 km. The systems have altitudinal overlap between 78 and 100 km at which we compare winds and tides on the basis of hourly winds with 2 km altitude bins. Our results indicate reasonable agreement for the zonal and meridional wind components between 78 and 92 km. An exception to this is the altitude range below 84 km during the summer, at which the correlation decreases. We also compare semidiurnal and diurnal tides according to their amplitudes and phases with good agreement below 90 km for the diurnal and below 96 km for the semidiurnal tides.
Based on these findings we have taken the MR data as a reference. By comparing the MF and MR winds within the overlapping region, we have empirically estimated correction factors to be applied to the MF winds. Existing gaps in that data set will be filled with weighted MF data. This weighting is done due to underestimated wind values of the MF compared to the MR, and the resulting correction factors fit to a polynomial function of second degree within the overlapping area. We are therefore able to construct a consistent and homogenous wind from approximately 60 to 110 km.
... Since FUJIN is always above the cloud layer, it can continuously observe targets as long as they are over the horizon, except for very special clouds called as polar stratospheric clouds and polar mesospheric clouds which sometimes appear in spring and summer, respectively, in the polar regions. 9,10) Recently utilization of a super-pressure balloon accelerates observations of celestial bodies by a long-duration balloon flight. NASA succeeded in a long duration test flight by a superpressure balloon for 32 days from March 26, 2015. ...
This paper reports the balloon borne telescope named FUJIN-2 which is being developed for the optical observation of planets with better quality and longer continuity than observations by existing observation methods. The project has already developed prototypes for the domestic flight test, and it proceeds the status to the development of the flight system for the long duration flight around the north pole. In this article the science mission overview and the advantages is addressed first. Then the new flight system for the long duration flight is introduced. In the latter of the article a result of the performance evaluation ground test which is the base of the design of the new flight system is reported.
We report the history and progress of the Japanese contribution to the Super Dual Auroral Radar Network (SuperDARN) project; especially focusing on the initial stage of SENSU (Syowa South and East HF Radars of NIPR for SUperDARN) project. The SENSU Syowa South HF radar operated by NIPR was one of the starting members of the initial SuperDARN radar operating at Syowa Station in Antarctica in 1995. It provided bi-directional common-volume observations with the Halley radar. In 1997 the SENSU Syowa East radar was installed. The King Salmon radar organized by NICT was installed in Alaska, USA in 2001. The Hokkaido East radar organized by Nagoya University was installed in Hokkaido, Japan in 2006, and the Hokkaido West radar began operation in 2014. The Japanese group has also contributed to SuperDARN by hosting three SuperDARN workshops in Japan namely: 1) in Tokyo in 1998 hosted by NIPR, 2) in Hokkaido in 2007 hosted by Nagoya University and 3) at Yamanashi in 2019 hosted by NICT.
