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A diagnostic study of waves on the tropopause
The spatial structure and phase velocity of tropopause disturbances localized around the subpolar jet in the Southern Hemisphere are investigated using 6-hourly European Centre for Medium-Range Weather Forecasts reanalysis data covering 15 yr (1979–93). The phase velocity and phase structure of the tropopause disturbances are in good agreement with those of an edge wave vertically trapped at the tropopause. However, the vertical distribution of the ratio of potential to kinetic energy exhibits maxima above and below the tropopause and a minimum around the tropopause, in contradiction to edge wave theory for which the ratio is unity throughout the troposphere and stratosphere. This difference in vertical structure between the observed tropopause disturbances and edge wave theory is attributed to the effects of a finite-depth tropopause together with the next-order corrections in Rossby number to quasigeostrophic dynamic
A new method to estimate total momentum fluxes
第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月14日(月) 国立極地研究所 2階大会議
Comparison of gravity wave propagation directions observed by mesospheric airglow imaging at three different latitudes using the M-transform
We developed user-friendly software based on Matsuda et al.'s (2014) 3D-FFT
method (Matsuda-transform, M-transform) for airglow imaging data analysis as
a function of Interactive Data Language (IDL). Users can customize the range
of wave parameters to process when executing the program. The input for this
function is a 3-D array of a time series of a 2-D airglow image in
geographical coordinates. We applied this new function to mesospheric airglow
imaging data with slightly different observation parameters obtained for the
period of April–May at three different latitudes: Syowa Station, the
Antarctic (69∘ S, 40∘ E); Shigaraki, Japan (35∘ N,
136∘ E); and Tomohon, Indonesia (1∘ N, 122∘ E).
The day-to-day variation of the phase velocity spectrum at the Syowa Station
is smaller and the propagation direction is mainly westward. In Shigaraki,
the day-to-day variation of the horizontal propagation direction is larger
than that at the Syowa Station; the variation in Tomohon is even larger. In
Tomohon, the variation of the nightly power spectrum magnitude is remarkable,
which indicates the intermittency of atmospheric gravity waves (AGWs). The
average nightly spectrum obtained from April–May shows that the dominant
propagation is westward with a phase speed <50 m s−1 at the Syowa Station and
east-southeastward with a phase speed of up to ∼80 m s−1 in
Shigaraki. The day-to-day variation in Tomohon is too strong to discuss
average characteristics; however, a phase speed of up to ∼100 m s−1 and faster is observed. The corresponding background wind
profiles derived from MERRA-2 indicate that wind filtering plays a
significant role in filtering out waves that propagate eastward at the Syowa
Station. On the other hand, the background wind is not strong enough to
filter out relatively high-speed AGWs in Shigaraki and Tomohon and the
dominant propagation direction is likely related to the
distribution and characteristics of the source region, at least in April and May.</p
Roles of energetic precipitating protons and electrons in the mesosphere: Multiple event studies based on the PANSY radar and MF radar
観光資源の評価におけるガイド付き観光の有効性
ガイド付き観光は、観光資源によって魅力を高める効果がある。このような観光資源が特定できれば、地域の多様な観光資源を選択的にガイド付きにすることで観光振興に繋げることが期待できる。これまでガイドの役割を論じた研究は、観光形態や職種を限定したものに限られる。本研究は、ガイド付き観光によって商品価値が高まる観光資源を明らかにすることを目的とした。調査は、京都府福知山市で開催されたモニターツアーを対象とした。その結果、社寺、および自然と人文の複合資源に対して有効であることが明らかになった
Extended Hemi-Hepatectomy with Portal Vein Reconstruction in a Patient with Situs Ambiguous
We report a case of far-advanced hepatocellular carcinoma (HCC) with situs ambiguous, complex visceral and vascular anomalies, who was successfully managed by extended hemi-hepatectomy. A 67-year-old man was referred to our hospital with a large liver mass. Abdominal ultrasonography, computed tomography and angiography revealed HCC with a diameter of 10 cm, with tumor thrombus in the main and first branch of the portal vein. Multiple complex anomalies in the abdomen were determined preoperatively. He had right-sided spleens-stomach-duodenum, liver at midline, inferior vena cava interruption with azygous continuation, and hepatic arterial anomaly. Extended left lobectomy of the liver with reconstruction of the portal vein was performed. Postoperatively, the patient recovered without major complications, and he was discharged on postoperative day 21. We report the first successful extended hepatectomy with portal vein reconstruction for HCC in a patient with rare situs anomalies
Successful Treatment for Hepatic Encephalopathy Aggravated by Portal Vein Thrombosis with Balloon-Occluded Retrograde Transvenous Obliteration
This report presents the case of a 78-year-old female with hepatic encephalopathy due to an inferior mesenteric venous-inferior vena cava shunt. She developed hepatocellular carcinoma affected by hepatitis C virus-related cirrhosis and underwent posterior sectionectomy. Portal vein thrombosis developed and the portal trunk was narrowed after hepatectomy. Portal vein thrombosis resulted in high portal pressure and increased blood flow in an inferior mesenteric venous-inferior vena cava shunt, and hepatic encephalopathy with hyperammonemia was aggravated. The hepatic encephalopathy aggravated by portal vein thrombosis was successfully treated by balloon-occluded retrograde transvenous obliteration via a right transjugular venous approach without the development of other collateral vessels
Role Of the Sun and the Middle atmosphere/thermosphere/ionosphere In Climate (ROSMIC): a retrospective and prospective view
While knowledge of the energy inputs from the Sun (as it is the primary energy source) is important for understanding the solar-terrestrial system, of equal importance is the manner in which the terrestrial part of the system organizes itself in a quasi-equilibrium state to accommodate and re-emit this energy. The ROSMIC project (2014–2018 inclusive) was the component of SCOSTEP’s Variability of the Sun and Its Terrestrial Impact (VarSITI) program which supported research into the terrestrial component of this system. The four themes supported under ROSMIC are solar influence on climate, coupling by dynamics, trends in the mesosphere lower thermosphere, and trends and solar influence in the thermosphere. Over the course of the VarSITI program, scientific advances were made in all four themes. This included improvements in understanding (1) the transport of photochemically produced species from the thermosphere into the lower atmosphere; (2) the manner in which waves produced in the lower atmosphere propagate upward and influence the winds, dynamical variability, and transport of constituents in the mesosphere, ionosphere, and thermosphere; (3) the character of the long-term trends in the mesosphere and lower thermosphere; and (4) the trends and structural changes taking place in the thermosphere. This paper reviews the progress made in these four areas over the past 5 years and summarizes the anticipated research directions in these areas in the future. It also provides a physical context of the elements which maintain the structure of the terrestrial component of this system. The effects that changes to the atmosphere (such as those currently occurring as a result of anthropogenic influences) as well as plausible variations in solar activity may have on the solar terrestrial system need to be understood to support and guide future human activities on Earth
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