scholarly journals Strengthened Relationship between Tropical West Pacific and Midsummer Precipitation over Northeast China after the Mid-1990s

2020 ◽  
Vol 33 (16) ◽  
pp. 6833-6848
Author(s):  
Tingting Han ◽  
Minghua Zhang ◽  
Botao Zhou ◽  
Xin Hao ◽  
Shangfeng Li
Keyword(s):  
North Pacific ◽  
Northeast China ◽  
Aleutian Islands ◽  
Northwest Pacific ◽  
West Pacific ◽  
The North ◽  
Circulation Anomalies ◽  
The Relationship ◽  
The North Pacific ◽  
Central North Pacific

AbstractThe relationship between the tropical west Pacific (TWP) and East Asian summer monsoon/precipitation has been documented in previous studies. However, the stability for the signals of midsummer precipitation in the TWP sea surface temperature (SST_TWP), which is important for climate variation, has drawn little attention. This study identifies a strengthened relationship between the leading empirical orthogonal function mode (EOF1) of midsummer precipitation over Northeast China (NEC) and the SST_TWP after the mid-1990s. The EOF1 mode shows a significant positive correlation with the SST_TWP for 1996–2016, whereas the relationship is statistically insignificant for 1961–90. Further results indicate that the North Pacific multidecadal oscillation (NPMO) shifts to a positive phase after the 1990s. In the positive NPMO phase, the anomalous circulation over the northeast Pacific expands westward over the central North Pacific–Aleutian Islands region. Concurrently, the SST_TWP-associated wavelike pattern propagates northeastward from the west Pacific to the northwest Pacific and farther to the North Pacific, facilitating the poleward expansion and intensification of the SST_TWP-related circulation anomalies over the North Pacific. Therefore, the SST_TWP has an enhanced influence on NEC precipitation through the modulation of the circulation anomalies over the central North Pacific–Aleutian Islands region after the mid-1990s. Additionally, the tropical anticyclone/cyclone associated with the SST_TWP expands westward to South China, exerting an intensified impact on meridional wind anomalies along eastern China and on moisture transport over NEC. These conditions jointly contribute to the strengthened relationship between the SST_TWP and the EOF1 mode of NEC midsummer precipitation after the mid-1990s.

Winter-to-Winter Recurrence of Sea Surface Temperature Anomalies in the Northern Hemisphere

2010 ◽  
Vol 23 (14) ◽  
pp. 3835-3854 ◽  
Author(s):  
Xia Zhao ◽  
Jianping Li
Keyword(s):  
Atmospheric Circulation ◽  
North Atlantic ◽  
North Pacific ◽  
Sea Surface ◽  
The North ◽  
Sea Surface Temperature Anomalies ◽  
Circulation Anomalies ◽  
Atmospheric Circulation Anomalies ◽  
The North Pacific ◽  
Central North Pacific

Abstract The spatiotemporal characteristics of the winter-to-winter recurrence (WWR) of sea surface temperature anomalies (SSTA) in the Northern Hemisphere (NH) are comprehensively studied through lag correlation analysis. On this basis the relationships between the SSTA WWR and the WWR of the atmospheric circulation anomalies, El Niño–Southern Oscillation (ENSO), and SSTA interdecadal variability are also investigated. Results show that the SSTA WWR occurs over most parts of the North Pacific and Atlantic Oceans, but the spatiotemporal distributions of the SSTA WWR are distinctly different in these two oceans. Analyses indicate that the spatiotemporal distribution of the SSTA WWR in the North Atlantic Ocean is consistent with the spatial distribution of the seasonal cycle of its mixed layer depth (MLD), whereas that in the North Pacific Ocean, particularly the recurrence timing, cannot be fully explained by the change in the MLD between winter and summer in some regions. In addition, the atmospheric circulation anomalies also exhibit the WWR at the mid–high latitude of the NH, which is mainly located in eastern Asia, the central North Pacific, and the North Atlantic. The sea level pressure anomalies (SLPA) in the central North Pacific are essential for the occurrence of the SSTA WWR in this region. Moreover, the strongest positive correlation occurs when the SLPA lead SSTA in the central North Pacific by 1 month, which suggests that the atmospheric forcing on the ocean may play a dominant role in this region. Therefore, the “reemergence mechanism” is not the only process influencing the SSTA WWR, and the WWR of the atmospheric circulation anomalies may be one of the causes of the SSTA WWR in the central North Pacific. Finally, the occurrence of the SSTA WWR in the NH is closely related to SSTA interdecadal variability in the NH, but it is linearly independent of ENSO.

scholarly journals Interferential Impact of ENSO and PDO on Dry and Wet Conditions in the U.S. Great Plains

2009 ◽  
Vol 22 (22) ◽  
pp. 6047-6065 ◽  
Author(s):  
Zeng-Zhen Hu ◽  
Bohua Huang
Keyword(s):  
Great Plains ◽  
North Pacific ◽  
Teleconnection Pattern ◽  
Climate Anomalies ◽  
The North ◽  
Dry And Wet Conditions ◽  
The Relationship ◽  
The North Pacific ◽  
Sst Anomalies ◽  
Central North Pacific

Abstract The influence of the El Niño–Southern Oscillation (ENSO) and Pacific decadal oscillation (PDO) interference on the dry and wet conditions in the Great Plains of the United States has been examined using monthly observational datasets. It is shown that both ENSO and PDO can generate a similar pattern of atmospheric and oceanic anomalies over the eastern part of the North Pacific and western North America that has significant impact on the climate over the Great Plains. Furthermore, the relationship between ENSO–PDO and climate anomalies in the Great Plains is intensified when ENSO and PDO are in phase (El Niño and warm PDO or La Niña and cold PDO). On average, anomalies over the Great Plains favor wet (dry) conditions when both ENSO and PDO are in the positive (negative) phase. However, when ENSO and PDO are out of phase, the relationship is weakened and the anomalies over the Great Plains tend toward neutral. Without ENSO, PDO alone does not affect the North American climate significantly. The relationship is quite robust for different seasons, with the strongest effects for the months of spring and the weakest effects for the months of autumn, whereas the months of winter and summer fall in between. The seasonality of the relationship may be associated with the seasonal dependence of the anomalies of general circulation and the pattern of mean seasonal cycle in the North Pacific. The contrasting impact of the interference of ENSO and PDO on the climate anomalies in the Great Plains is associated with differences in the ocean–atmosphere anomalies. When ENSO and PDO are in phase, the sea surface temperature (SST) anomalies extend from the equatorial Pacific to the higher latitudes of the North Pacific via the eastern ocean. The distribution of the corresponding anomalies of sea level pressure (SLP) and the wind at 1000 hPa form an ellipse with a southeast–northwest orientation of the long axis because the SST anomalies promote coherent changes in SLP in the central North Pacific. In the upper troposphere, a similar teleconnection pattern with the same sign generated by ENSO and PDO is overlapped and enhanced, which favors anomaly (dry and wet) conditions in the Great Plains. However, when ENSO and PDO are out of phase, the SST anomalies have the same sign in the tropical and central North Pacific, which is opposite to the anomalies near the west coast of North America. The anomalously cyclonic circulation over the North Pacific is weaker in the out-of-phase situation than in the in-phase situation. The distribution of the anomalies of SLP and the wind at 1000 hPa resembles a circle. Meanwhile, in the upper troposphere, ENSO and PDO generate a similar teleconnection pattern with opposite sign, causing cancellation of the anomalous circulation and favoring neutral climate in the Great Plains.

Palmaria hecatensis sp. nov. (Rhodophyta, Palmariales) from British Columbia and Alaska with a survey of other Palmaria species

1985 ◽  
Vol 63 (3) ◽  
pp. 474-482 ◽  
Author(s):  
Michael W. Hawkes
Keyword(s):  
British Columbia ◽  
Pacific Ocean ◽  
Geographical Distribution ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Aleutian Islands ◽  
Rocky Shores ◽  
Intertidal Zones ◽  
The North ◽  
The North Pacific

Palmaria hecatensis sp. nov. is described based on material from northern British Columbia. Male gametophytes and tetrasporophytes are thick, coriaceous, flattened blades, linear to lobed in habit and arise from an extensive encrusting basal holdfast. Putative female gametophytes are microscopic multicellular discs. Palmaria hecatensis grows on rocky shores in the midintertidal to lower intertidal zones and has a known geographical distribution from Nootka Island, Vancouver Island, B.C., to Shemya Island in the Aleutian Islands, Alaska. Palmaria hecatensis is compared with other species in the genus and, in addition, another distinctive (and possibly undescribed) Palmaria species from British Columbia and Alaska is discussed, bringing the total number of Palmaria species reported in the North Pacific Ocean to six.

scholarly journals Study on the Association of Casualties and Classification of Heat Wave Weather Patterns in South Korea Using K-Means Clustering Analysis

2020 ◽  
Vol 20 (3) ◽  
pp. 11-18
Author(s):  
Hyeon-Cheol Lee ◽  
Young-Jun Cho ◽  
Byunghwan Lim ◽  
Seung-Bum Kim
Keyword(s):  
South Korea ◽  
Heat Wave ◽  
North Pacific ◽  
Korean Peninsula ◽  
Clustering Analysis ◽  
Weather Patterns ◽  
The North ◽  
The Relationship ◽  
The North Pacific

In this study, weather patterns (WPs) associated with the heat wave in South Korea are objectively classified by applying <i>K</i>-means clustering analysis. The representative weather patterns that caused the heat wave were divided into three WPs, namely WP 1, WP 2, and WP 3. The heat wave over the Korean Peninsula was mainly related to the expansion of the North Pacific High (NPH). Moreover, we analyzed the relationship between casualties and WPs of the heat wave. In WP 1, the isobar of NPH was located in the southern part of South Korea. Most casualties (18 people) occurred in this region. In WP 2, NPH was distributed throughout South Korea, with nationwide casualties of 44 people. Moreover, the duration of the heat wave for WP 2 was the longest, at 4.5 days. WP 3 occurred mainly in June, when the NPH was not yet developed, presenting the smallest number of casualties.

scholarly journals Eddy Trains and Striations in Quasigeostrophic Simulations and the Ocean

2016 ◽  
Vol 46 (9) ◽  
pp. 2807-2825 ◽  
Author(s):  
Changheng Chen ◽  
Igor Kamenkovich ◽  
Pavel Berloff
Keyword(s):  
North Pacific ◽  
Empirical Orthogonal Functions ◽  
Eof Analysis ◽  
Sea Level Anomaly ◽  
Orthogonal Functions ◽  
The North ◽  
Temporal Averaging ◽  
Low Pass ◽  
The Relationship ◽  
The North Pacific

AbstractThis study explores the relationship between coherent eddies and zonally elongated striations. The investigation involves an analysis of two baroclinic quasigeostrophic models of a zonal and double-gyre flow and a set of altimetry sea level anomaly data in the North Pacific. Striations are defined by either spatiotemporal filtering or empirical orthogonal functions (EOFs), with both approaches leading to consistent results. Coherent eddies, identified here by the modified Okubo–Weiss parameter, tend to propagate along well-defined paths, thus forming “eddy trains” that coincide with striations. The striations and eddy trains tend to drift away from the intergyre boundary at the same speed in both the model and observations. The EOF analysis further confirms that these striations in model simulations and altimetry are not an artifact of temporal averaging of random, spatially uncorrelated vortices. This study suggests instead that eddies organize into eddy trains, which manifest themselves as striations in low-pass filtered data and EOF modes.

scholarly journals Significant Atmospheric Circulation Anomalies over the North Pacific Associated with the Enhanced Pacific ITCZ during the Summer–Fall of 2014

SOLA ◽  
2016 ◽  
Vol 12 (0) ◽  
pp. 282-286
Author(s):  
Shuhei Maeda ◽  
Yusuke Urabe ◽  
Kazuto Takemura ◽  
Tamaki Yasuda ◽  
Youichi Tanimoto
Keyword(s):  
Atmospheric Circulation ◽  
North Pacific ◽  
The North ◽  
Circulation Anomalies ◽  
Atmospheric Circulation Anomalies ◽  
The North Pacific

New species of Poecilosclerida (Demospongiae, Porifera) from the Aleutian Islands, Alaska, USA

Zootaxa ◽  
2006 ◽  
Vol 1155 (1) ◽  
pp. 1 ◽  
Author(s):  
HELMUT LEHNERT ◽  
ROBERT STONE ◽  
WOLFGANG HEIMLER
Keyword(s):  
New Species ◽  
North Pacific ◽  
Aleutian Islands ◽  
The North ◽  
The North Pacific

Five new species of poecilosclerid sponges, Artemisina amlia sp. nov., Coelosphaera oglalai sp. nov., Melonanchora globogilva sp. nov., Tedania kagalaskai sp. nov., and Mycale carlilei sp. nov, are described from the Aleutian Islands, Alaska, from depths ranging between 100–190m and are compared with congeners of the North Pacific Ocean.Keywords: Taxonomy, Porifera, Demospongiae, Poecilosclerida, new species, N-Pacific, Aleutian Islands, Alaska

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