Regime Shifts Found in the Northern Hemisphere SST Field
スポンサーリンク
概要
- 論文の詳細を見る
A `regime shift' is characterized by an abrupt transition from one quasi-steady climatic state to another, and its transition period is much shorter than the lengths of the individual epochs of each climatic state. In the present study, we investigate when regime shifts occurred and what was the difference in climatic states before and after the shifts, using the wintertime sea surface temperature (SST) field in the Northern Hemisphere. The relationship between changes in the SST field, and those in the atmospheric circulation, is also investigated. In order to detect organized patterns of the SST variations, we apply an empirical orthogonal function (EOF) analysis. As the results, the first mode is identical to El Nino/Southern Oscillation (ENSO) and so-called Pacific Decadal Oscillation (PDO), and corresponds to the Pacific/North American (PNA) pattern. The second mode, which relates to the Arctic Oscillation (AO), has a zonally elongated signal in both the North Atlantic, and North Pacific. EOF analyses to each oceanic basin are made separately, and the robustness of these modes is confirmed. In the present study, we define the regime shifts as the`significant'and`systematic'changes between the two quasi-steady states, continuing more than 5 years. Then, in order to identify the years when regime shifts occurred in the SST field, we carefully inspect the time series of original gridded SST data and those of the EOF modes. As a result, six regime shifts are detected in the study period from the 1910s to the 1990s: 1925/26, 1945/46, 1957/58, 1970/71, 1976/77 and 1988/89. It is ascertained that the shifts at almost all grids are completed within one year. All regime shifts having similar SST and atmospheric circulation pattern, including the changes in an intensity of the Aleutian Low (AL), and the corresponding SST changes in the central North Pacific. All regime shifts can be well described by the combination of the first and the second EOF modes. The duration between each regime shift is about 10 years, which are identical to the PDO. The simultaneous shifts in the first, and the second EOF modes, imply that the change in the AL activity associated with the PNA pattern, might have some connection with that of the AO.
- 社団法人日本気象学会の論文
- 2002-02-25
著者
-
HANAWA Kimio
Department of Geophysics, Graduate School of Science, Tohoku University
-
YASUNAKA Sayaka
Department of Geophysics, Graduate School of Science, Tohoku University
-
Yasunaka Sayaka
Department Of Geophysics Graduate School Of Science Tohoku University
-
Hanawa Kimio
Department Of Astronomy And Geophysics Faculty Of Science Tohoku University
-
Yasunaga Sayaka
Department of Geophysics, Graduate School of Science, Tohoku University
関連論文
- Trajectory of Mesoscale Eddies in the Kuroshio Recirculation Region
- Influence of Mesoscale Eddies on Variations of the Kuroshio Path South of Japan
- Mesoscale Eddies Observed by TOLEX-ADCP and TOPEX/POSEIDON Altimter in the Kuroshio Recirculation Region South of Japan
- Zonally Asymmetric Response of the Japan Sea to Synoptic Pressure Forcing
- Numerical Study of Formation of Dichothermal Water in the Bering Sea
- Further Evidence for Non-Reemergence of Winter SST Anomalies in the North Pacific Eastern Subtropical Mode Water Area
- Upper Ocean Heat Content and Atmospheric Anomaly Fields in the Off-Equatorial North Pacific Related to ENSO
- Impact of Quasi-decadal Variability in the Tropical Pacific on ENSO Modulations
- New Type of Pycnostad in the Western Subtropical-Subarctic Transition Region of the North Pacific : Transition Region Mode Water
- Possible Source of the Antarctic Bottom Water in the Prydz Bay Region
- Subtropical Mode Water South of Honshu, Japan in the Spring of 1988 and 1989
- Subsurface Water Masses in the Central North Pacific Transition Region : The Repeat Section along the 180^゜ Meridian
- Variability of Upper Ocean Heat Balance in the Shikoku Basin during the Ocean Mixed Layer Experiment (OMLET)
- Regime Shifts Found in the Northern Hemisphere SST Field
- Regime Shifts in the Northern Hemisphere SST Field : Revisited in Relation to Tropical Variations
- A New Fall-Rate Equation for T-5 Expendable Bathythermograph (XBT) by TSK
- Interannual Summer Temperature Variations over Japan and Their Relation to Large-Scale Atmospheric Circulation Field
- Decadal and Interdecadal Variations of the Aleutian Low Activity and Their Relation to Upper Oceanic Variations over the North Pacific
- North Pacific Subtropical Mode Waters Observed in Long XBT Cross Sections along 32.5°N Line
- Anticyclonic Eddy Revealing Low Sea Surface Temperature in the Sea South of Japan : Case Study of the Eddy Observed in 1999-2000
- Comparison of Sea Surface Heights Observed by TOPEX Altimeter with Sea Level Data at Chichijima
- Temporal Variations of the Net Kuroshio Transport and Its Relation to Atmospheric Variations
- Winter Mixed Layer and Formation of Dichothermal Water in the Bering Sea
- Biogeochemical evidence of large diapycnal diffusivity associated with the subtropical mode water of the North Pacific
- Quasi-decadal modulations of North Pacific Intermediate Water area in the cross section along the 137°E meridian : impact of the Aleutian Low activity
- Influence of Asymmetric Wind Stress Curl on the General Ocean Circulation Using an Eddy-Resolving Quasi-Geostrophic Model
- Recorder-Dependent Temperature Error of Expendable Bathythermograph
- Composite Analysis of North Pacific Subtropical Mode Water Properties with Respect to the Strength of the Wintertime East Asian Monsoon
- Hydrographic Features off the Southeast Coast of Kyushu during the Kuroshio Small Meanders : A Case Study for Small Meanders that Occurred in 1994 and 1995 Spring
- Comparison of Surface Current Variations Observed by TOPEX Altimeter with TOLEX-ADCP Data