著者

和田 雄治

出版者

METEOROLOGICAL SOCIETY OF JAPAN

雑誌

氣象集誌. 第1輯 (ISSN:00261165)

巻号頁・発行日

vol.29, no.3, pp.81-87, 1910

著者

鹿角 義助

出版者

METEOROLOGICAL SOCIETY OF JAPAN

雑誌

氣象集誌. 第1輯 (ISSN:00261165)

巻号頁・発行日

vol.17, no.5, pp.215-220, 1898

著者

馬塲 信倫

出版者

METEOROLOGICAL SOCIETY OF JAPAN

雑誌

氣象集誌. 第1輯 (ISSN:00261165)

巻号頁・発行日

vol.10, no.9, pp.465-474, 1891

著者

Takahiro ITO Hirotada KANEHISA

出版者

Meteorological Society of Japan

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

vol.91, no.6, pp.775-788, 2013

被引用文献数

4

---

The initial value problem of vortex Rossby waves (VRWs) is analytically solved in a linearized barotropic system on an <i>f</i> plane. The basic axisymmetric vorticity <span style="text-decoration: overline;"><i>q</i></span> is assumed to be piecewise uniform in the radial direction so that the radial gradient <i>d<span style="text-decoration: overline;"><i>q</i></span>/dr</i> and the disturbance vorticity <i>q</i> are expressed in terms of Dirac delta functions. After Fourier transformation in the azimuthal direction with the wavenumber <i>m</i>, the linearized vorticity equation becomes a system of ordinary differential equations with respect to time; these can be analytically solved to give a closed-form solution with a prescribed initial value.<br> For a monopolar <span style="text-decoration: overline;"><i>q</i></span>, the solution of <i>q</i> starting from the innermost radius exhibits the outward propagation of VRWs. As the outer disturbances are generated, the inner disturbance is diminished. On the other hand, in the case of a solution forced at the innermost radius, the inner disturbance is not diminished, and the outward propagation of VRWs forms a distribution of spiral-shaped disturbance vorticity.<br> For a basic vorticity <span style="text-decoration: overline;"><i>q</i></span> with a moat, and if the radial distribution of <span style="text-decoration: overline;"><i>q</i></span> satisfies a certain additional condition, the solution of <i>q</i> with |<i>m</i>| ≠ 1 grows exponentially or linearly in time as a result of the interaction of counterpropagating VRWs near the moat. Although the solution of <i>q</i> with |<i>m</i>| = 1 cannot grow exponentially for any <span style="text-decoration: overline;"><i>q</i></span>, it can grow as a linear function of time. This linear growth may be regarded as a result of resonance between two internal modes of the system.

著者

Ryo Mizuta Osamu Arakawa Tomoaki Ose Shoji Kusunoki Hirokazu Endo Akio Kitoh

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.10, pp.167-171, 2014 (Released:2014-10-23)

参考文献数

14

被引用文献数

83 139

---

Climate changes for the end of the 21st century projected by Coupled Model Intercomparison Project phase 5 (CMIP5) models are classified into three clusters by a cluster analysis of annual-mean tropical sea surface temperature (SST) change patterns. The classified SST change patterns are featured by the zonal gradient of the change in the equatorial Pacific and inter-hemispheric contrast of the warming. Precipitation and atmospheric circulation responses are composited for the clusters, and their relationships to the SST changes are examined. Precipitation increase is larger where SST warming is larger than surroundings and vice versa. Common precipitation and atmospheric circulation responses for each cluster are found also over tropical lands and the extratropics as well as in the tropical oceans, suggesting that some remote effects of the tropical SST change patterns could be one reason for less agreement among CMIP5 models in climate changes.

著者

H. Takagi T. Saeki T. Oda M. Saito V. Valsala D. Belikov R. Saito Y. Yoshida I. Morino O. Uchino R. J. Andres T. Yokota S. Maksyutov

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.7, pp.161-164, 2011 (Released:2011-10-29)

参考文献数

32

被引用文献数

43 54

---

We assessed the utility of global CO2 distributions brought by the Greenhouse gases Observing SATellite (GOSAT) in the estimation of regional CO2 fluxes. We did so by estimating monthly fluxes and their uncertainty over a one-year period between June 2009 and May 2010 from 1) observational data collected in existing networks of surface CO2 measurement sites (GLOBALVIEW-CO2 2010; extrapolated to the year 2010) and 2) both the surface observations and column-averaged dry air mole fractions of CO2 (XCO2) retrieved from GOSAT soundings. Monthly means of the surface observations and GOSAT XCO2 retrievals gridded to 5° × 5° cells were used here. The estimation was performed for 64 subcontinental-scale regions. We compared these two sets of results in terms of change in uncertainty associated with the flux estimates. The rate of reduction in the flux uncertainty, which represents the degree to which the GOSAT XCO2 retrievals contribute to constraining the fluxes, was evaluated. We found that the GOSAT XCO2 retrievals could lower the flux uncertainty by as much as 48% (annual mean). Pronounced uncertainty reduction was found in the fluxes estimated for regions in Africa, South America, and Asia, where the sparsity of the surface monitoring sites is most evident.

著者

Chiaki KOBAYASHI Kiyotaka SHIBATA

出版者

Meteorological Society of Japan

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

vol.89, no.4, pp.363-376, 2011-08-25 (Released:2011-08-31)

参考文献数

35

被引用文献数

1 4

---

Dynamical contributions to past long-term changes in the lower stratospheric ozone over the northern mid-latitudes are evaluated using a chemical transport model (CTM) forced by the horizontal wind of the Japanese 25-year Reanalysis (JRA-25). Two simulations (i.e., one is a simulation that prescribes the time-dependent vertical profile of halogens and the other is a simulation which uses the fixed vertical profile of halogens at 1979.) were conducted to estimate chemical and dynamical contributions to the long-term changes in stratospheric ozone during the last three decades. Different from previous similar studies using meteorological data of ECMWF (European Centre for Medium Weather Forecast) 40-year re-analysis (ERA-40), our current simulation does not show a large positive anomaly of simulated total ozone over northern mid-latitudes in the late 1980s, which is consistent with the observation. Because the trend of the fixed halogen simulation amounts to about two-third of that of the time-dependent halogen simulation during 1980–1993 in the northern mid-latitudes, it is evaluated that about two-thirds of the negative trend in total ozone comes from dynamics in the northern mid-latitudes. Since the increasing ozone from 1994 to 1998 is also represented in the fixed halogen simulation, it is considered that the increase of ozone was mainly due to dynamics as pointed out in previous studies. However the dynamical contribution to the trend after 1994 could not be evaluated in our simulation because of simulated ozone gap in 1998. In the same manner, it is evaluated that about two-thirds of the negative ozone trend in the lower stratosphere comes from dynamics in the northern mid-latitudes from 1980 to the mid-1990s. The simulation results indicate that the effect of transport (dynamical influence) is predominant for the negative ozone trend in the lower stratosphere from 1980 to mid-1990s, while the upper stratospheric ozone trend is strongly influenced by long-term changes in halogens (chemical influence).

著者

Yohei Takano Yoshihiro Tachibana Katsushi Iwamoto

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.4, pp.113-116, 2008 (Released:2008-10-08)

参考文献数

16

被引用文献数

20 24

---

The characteristics of the anomalous winter climate around Japan in December 2005, including abnormally heavy snowfall, were analyzed from the viewpoint of interannual variation using reanalysis data for 50 years. The anomalous snowfall near the Sea of Japan in 2005 is attributed to an anomalous air-mass modification over the Sea of Japan, the large changes of thermodynamic characteristics due to the warmth of the Sea of Japan. Thermodynamic budget analyses showed that the air-mass modification in December 2005 over the Sea of Japan was the strongest in more than 40 years. Air-mass modification over the Sea of Japan was strongly related with a large-scale atmospheric north-south dipole pattern consisting of a northern high covering Siberia and a southern low covering a wide area of Japan in the 500 hPa height field in the positive phase (SJ pattern). In addition, the local SST variability during late autumn was significantly related to air-mass modification. However, the Arctic Oscillation was not significantly correlated with the air-mass modification over the Sea of Japan on an interannual timescale.

著者

Naoki Hirose Ken-ichi Fukudome

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.2, pp.61-63, 2006 (Released:2006-04-15)

参考文献数

8

被引用文献数

30 34

---

Seasonal predictions of rain or snowfall are usually too uncertain at regional scales. We suggest utilizing subsurface ocean measurements to improve long-term weather forecasts. The example we give is that regional snowfall in Japan can be predicted by a simple regression from an acoustic Doppler current profiler attached to a regular ferryboat to observe the transport of the Tsushima Warm Current. The lag correlation is shown to exceed 0.75 attributed to the simple underling marine meteorology and regional oceanography. The relationship certainly improves seasonal precipitation estimates led by the winter monsoon absorbing the latent heat from the Japan Sea. We predict there will be less snowfall this winter of 2005/2006 than in 2004/2005 despite the heavy snowfall event in the last December.