Drift in Salinity Data from Argo Profiling Floats in the Sea of Japan*

2012 ◽  
Vol 29 (1) ◽  
pp. 129-138 ◽  
Author(s):  
Pankajakshan Thadathil ◽  
C. C. Bajish ◽  
Swadhin Behera ◽  
V. V. Gopalakrishna

Abstract In drift analysis of salinity sensors, one major problem is the difficulty in delineating sensor drift from water mass changes. In the present study, a new method is proposed for finding sensor drift that is free from water mass changes. The efficiency of this new method in finding out possible drift in the Argo salinity is demonstrated in the Sea of Japan (SOJ) by using the “near-linear” subsurface salinity structure of the SOJ. The new method is based on the time–space decorrelation scale. The salinity difference between two neighboring observations within the time–space decorrelation scale (SALD) is used to find out possible drift. Neighboring observations within the time–space decorrelation scale are referred to as matchups. The SALD derived from matchups between Argo floats and shipboard CTD observations from the SOJ shows linear drift. Although all four selected floats (5 yr completed) from the SOJ show linear drift (<0.001 PSS yr−1), the drift alone is not so significant to affect the objective of the Argo program in understanding climate variability. In the SOJ, SALD identified salinity error other than drift in good quality data that are flagged by the Argo delayed-mode quality control (ADMQC) method. Therefore, SALD could be used as an effective additional tool in the Argo data quality control. To examine the applicability of SALD in open ocean regions, in addition to confined basins such as SOJ, SALD was applied successfully to detect salinity error in Argo data from the subtropical North Pacific (SNP).

2017 ◽  
Vol 2 (1) ◽  
pp. 43-55
Author(s):  
V. V. Kasyan

In Russia the Far East Marine Reserve (FEMR) is the Federal Nature Reserve with the richest but insufficiently studied biodiversity. Spatiotemporal variations in the zooplankton dwelling in the area were sporadically observed over 20 years ago. The recent investigation focused on the species composition, population density and distribution of copepods – the basic member of zooplankton in FEMR. Samples of plankton were taken from 10 stations above the 50-m isobath monthly during June – September 2012, the months when temperature in the seawater area varies widest. The Calanoida and Cyclopoida copepods were represented by 17 and by 4 species, respectively; 21 species altogether. Genera Acartia and Oithona had larger diversity – by 4 species each. Marine species dominated in the samples (80 % of the total species number), neritic – in the biotope (58 %). The copepods were boreal (55 %) and tropical + subtropical (45 %). Species number increased to 16 in June and dropped to 5 in September. Oithona similis and Pseudocalanus newmani dominated during June – July, Paracalanus parvus, Oithona brevicornis and O. similis – in August, and P. parvus and O. brevicornis – in September. The abundance and diversity decreased in all areas of the reserve from June to September. In June, when the cold-water O. similis, P. newmani, Acartia hudsonica и Eurytemora pacifica prevailed, the average population density (20959±3007 ind.·m-3) maximally increased and in September it was minimal. Concentrations of copepods were largest (to 36 thousand ind.·m-3) above the 10-m depth in the Gulf of Posyet (western FEMR) in June. Cluster analysis applied to the total seawater area of the reserve evaluated Bray – Curtis coefficient as 60 %; three plankton copepod complexes were determined, species composition in each formed under the influence of the water mass. The complexes from the west and the east of FEMR had larger species richness and population density. In the shallow-water western complex high densities of brackish-water copepods (genera Acartia, Eurytemora, Centropages, Tortanus and Pseudodiaptomus) suggested presence of estuarine and coastal waters whereas tropical and subtropical O. nana, Mesocalanus tenuicornis, Pseudodiatomus inopinus – warm-water intrusion from the East Korea current. The concurrent presence of cold- and warm-water copepods in the deep-water eastern complex in summer evidenced the water stratification effect when cold water from the Sea of Japan dominated in the depth and its warmer modification – in the upper seawater layer. The diversity and density were poorest in the southern complex, largely of Panthalassa and neritic copepods. In summer, large presence of cold-water copepods O. similis and P. newmani indicated the cold-water mass penetration to near-bottom layer; numbers estimates of these copepods can represent the degree of the cold-water effect in the south of the reserve. The copepod distribution, stable abundance and diversity in the seawater area south of FEMR suggested desalination by the river influx and, possibly, harmful impact of pollutants. Species composition and quantitative characteristics of copepods can be used for environmental quality determination in different areas of FEMR. 


2020 ◽  
Vol 48 (3) ◽  
pp. 148-163
Author(s):  
V.V. Navrotsky ◽  
V.B. Lobanov ◽  
A.F. Sergeev ◽  
A.A. Voronin ◽  
I.I. Gorin ◽  
...  

Analysis of cascading dynamic structure is carried out using measurements at three bottom autonomous stations installed on the continental slope of the Peter the Great Bay in the Sea of Japan. It is shown that in the course of immersion of surface waters disturbances of current velocity are generated. Interaction of temperature and current velocity fluctuations leads to fluxes of heat and momentum whose time-space and spectral structures is defined by duration and value of the immersed waters density anomalies. In the time of considerable anomalies, the immersion process has turbulent-vortical character.


2012 ◽  
Vol 132 (6) ◽  
pp. 560-567 ◽  
Author(s):  
Megumu Miki ◽  
Toru Miki ◽  
Akira Asakawa ◽  
Takatoshi Shindo ◽  
Shigeru Yokoyama

2011 ◽  
Vol 131 (12) ◽  
pp. 973-978 ◽  
Author(s):  
Fumiyuki Fujii ◽  
Masaru Ishii ◽  
Mikihisa Saito ◽  
Michihiro Matsui ◽  
Daisuke Natsuno

Author(s):  
G.G. Tkachenko

Морское побережье является одной из самых выраженных естественных географических границ, которая одновременно разделяет и связывает географические структуры суши морей или океанов. В основе формирования типов природопользования в прибрежных зонах, как и на других типах географического пространства, лежит природноресурсный потенциал. Природноресурсный потенциал и типы природопользования как явления пространственнодифференцированные должны быть рассмотрены, прежде всего, в рамках классических географических подходов и оценок, таких как районирование территории и акватории. При этом пространственные сочетания наземных и морских природных, природноресурсных компонентов рассматриваются как важнейшие предпосылки инфраструктурного и хозяйственного развития прибрежных регионов. Необходимым этапом природноресурсного районирования является выявление границ, при пересечении которых существенно меняются природные ресурсы и условия. Данная работа выполнена на примере рассмотрения минеральных ресурсов прибрежных муниципальных образований и является частью исследования природноресурсных сочетаний зоны сушаокеан Дальнего Востока России в рамках изучения пространственной дифференциации факторов, условий и ограничений формирования и развития структур природопользования в прибрежной зоне Тихоокеанской России с учетом воздействия экстремальных природных процессов и явлений. Дана сравнительная характеристика месторождений минерального сырья российской части побережья Японского моря. Определена их видовая и географическая структура. На основе того, что месторождения минерального сырья сгруппированы в 8 основных ресурсных групп ввыполнено районирование российской части побережья Японского моря по сочетанию основных видов минеральных ресурсов. Выделены типы муниципальных образований по сочетанию минеральных ресурсов и показаны особенности каждого из них. Выделены шесть районов по сочетанию минеральных ресурсов. В связи с необходимостью учета географической особенности в сочетании со спецификой минеральных ресурсов, северной и южной частям территории одного типа районов присвоены свои собственные названия. По результатам исследования была построена карта. The seacoast is one of the most pronounced natural geographical boundaries, which divides and connects simultaneously the geographical structures of the land, seas or oceans. The formation of the types of nature management in coastal zones, as well as on other types of geographical space, is based on the natural resource potential. Being spatially differentiated phenomena, the natural resource potential and the types of environmental management should be considered, first of all, within the framework of classical geographical approaches and assessments, such as zoning of the territory and water areas. In this case, spatial combinations of the land and sea natural, naturalresource components are considered as the most important prerequisites for the infrastructure and economic development of coastal regions. Identification of borders, at the intersection of which the natural resources and conditions change significantly, is a necessary stage of natural resource zoning. This work is carried out by example of consideration of mineral resources of coastal municipal unions and appears to be a part of studies of naturalresource combinations of the landocean zone of the Russian Far East in the framework of studies of spatial differentiation of factors, conditions and restrictions of formation and development of structures of nature management in the coastal zone of Pacific Russia, taking into account the influence of extreme natural processes and phenomena. The comparative characteristic of mineral deposits of the Russian part of the coast of the Sea of Japan is given. Their species and a geographical structure are determined. Based on the fact that the mineral deposits are grouped into eight main resource groups, zoning of the Russian part of the coast of the Sea of Japan by a combination of the main types of mineral resources is performed. The types of municipalities are allocated by a combination of mineral resources and their features are shown. Six areas are singled out by a combination of mineral resources. Due to the need to take into account the geographical features in combination with the specifics of mineral resources, the northern and southern parts of the territory of one type of areas have obtained their own names. According to the results of the studies, the map has been compiled.


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