Interannual variations in seasonal march of rainfall in the Philippines

Ikumi Akasaka

doi:10.1002/joc.1975

Seasonal march patterns of the summer rainy season in the Philippines and their long-term variability since the late twentieth century

Progress in Earth and Planetary Science ◽

10.1186/s40645-018-0178-5 ◽

2018 ◽

Vol 5 (1) ◽

Cited By ~ 3

Author(s):

Ikumi Akasaka ◽

Hisayuki Kubota ◽

Jun Matsumoto ◽

Esperanza O. Cayanan ◽

Rosalina G. de Guzman ◽

...

Keyword(s):

Twentieth Century ◽

Rainy Season ◽

The Philippines ◽

Late Twentieth ◽

Late Twentieth Century ◽

Seasonal March

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Considerable differences of the interannual variations for the tropical cyclone landfall over north and south East Asia in summer

10.5194/egusphere-egu2020-3982 ◽

2020 ◽

Author(s):

Jufen Lai ◽

Chaofan Li ◽

Riyu Lu

Keyword(s):

Tropical Cyclone ◽

East Asia ◽

The Philippines ◽

Boreal Summer ◽

South East Asia ◽

Interannual Variations ◽

Seasonal Forecasts ◽

The South ◽

North East ◽

North And South

<p>Interannual variation of tropical cyclone (TC) landfall frequency is not consistent along the coast of East Asia, with large contrast of north and south East Asia coast regions in boreal summer. This study examines interannual variations of TC landfall frequency over north and south East Asia and identifies roles of the western North Pacific subtropical high (WNPSH) and TC genesis frequency associated with these variations. Although the total number of landing TC of north and south East Asia is similar, interannual variations of TC landfall frequency are relatively independent to each other, with the corresponding correlation coefficient north and south of 25&#176;N is only &#8211;0.024 from 1979 to 2017. TC landfall over north East Asia is largely modulated by the circulation related to the WNPSH, while TC landfall in the south has no significant relationship with the WNPSH or other remote large-scale circulations. The WNPSH effectively regulates TC landfall in the north by modulating TC genesis east of the Philippines and steering flows. Nonetheless, the two factors have weak contradictory effects on TC landing in the south region. The frequency of TC genesis around the South China Sea directly connects to the TC landfall over south East Asia, which is modulated by the surrounding genesis environment, including relative humidity and relative vorticity. This work favors for a better understanding of the seasonal forecasts of TC landfall frequency and the subsequent climate service over East Asia.</p>

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Interannual Variations of the Seasonal March in the Southern Hemisphere Stratosphere for 1979–2002 and Characterization of the Unprecedented Year 2002

Journal of the Atmospheric Sciences ◽

10.1175/jas-3333.1 ◽

2005 ◽

Vol 62 (3) ◽

pp. 567-580 ◽

Cited By ~ 24

Author(s):

Yasuko Hio ◽

Shigeo Yoden

Keyword(s):

Southern Hemisphere ◽

Zonal Wind ◽

Lower Stratosphere ◽

Large Deviation ◽

Function Analysis ◽

Lower Troposphere ◽

The Other ◽

Interannual Variations ◽

Reanalysis Dataset ◽

Seasonal March

Abstract Dynamical features of the interannual variations of the seasonal march in the Southern Hemisphere stratosphere are investigated with the NCEP–NCAR reanalysis dataset from 1979 to 2002, and the unprecedented year 2002, in which a major stratosphere sudden warming occurred, is characterized by comparing it with the other 23 yr. A multiple empirical orthogonal function analysis of the stratospheric mean zonal wind and a composite analysis based on the principal component of the leading mode show that the interannual variations are characterized by early or late deceleration of the polar-night jet, which is well correlated with the variation of a time-averaged upward Eliassen–Palm (EP) flux in the lower stratosphere. The stronger wave activity in the lower stratosphere is associated with the earlier “shift down” of the jet. The composite difference of the stratospheric mean zonal wind can be traced down to the lower troposphere in September and October. These features are consistent with the variations of the Southern Hemisphere annular mode, although the main disturbance to maintain the variations is different between the stratosphere and troposphere. Some scatter diagrams show the extreme situation of the year 2002. It is far from the cluster of the other 23 yr, but the large deviation in 2002 is consistent with the tendency of the fluctuations in the other years except for its extreme nature.

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