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CARINA alkalinity data in the Atlantic Ocean

CARINA alkalinity data in the Atlantic Ocean

The second part of CARINA are three merged quality controlled and adjusted data files; one each for the Atlantic Ocean, Arctic Mediterranean Seas and Southern Ocean re- gions. These files contain all the CARINA data and include: 1) interpolated values for nutrients, oxygen and salinity if those data are missing and if interpolation could be made ac- cording to criteria described in Key et al. (2009) (this spe- cial issue); calculated carbon parameters (e.g. if total dis- solved inorganic carbon (TCO 2 ) and Total Alkalinity (A T )

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Bacterioplankton community composition and activity in the Atlantic Ocean

Bacterioplankton community composition and activity in the Atlantic Ocean

Several studies have shown that certain parts of the Atlantic oligotrophic gyres along with the equatorial region are net heterotrophic. Hoppe et al. (2002) calculated a higher bacterial carbon demand (BCD) for production and respiration than the rate of carbon fixed by phytoplankton between 8 ºN and 20 ºS in the Atlantic Ocean at approximately 30 ºW. These calculated values do not include the respiratory carbon demand of larger organisms such as zooplankton and therefore underestimate the heterotrophic state of these waters. The rate of respiration (determined by dark community oxygen consumption rates) alone has also been shown to exceed that of primary production in oligotrophic waters (Del Giorgio et al., 1997; Duarte and Agusti, 1998). For net heterotrophy to exist, external inputs of carbon via upwelling, terrestrial sources or by slow-degrading
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CARINA: nutrient data in the Atlantic Ocean

CARINA: nutrient data in the Atlantic Ocean

Nutrient values in the deep water of the Atlantic Ocean are influenced by hydrographic variability. Variations in the contributions of water masses originating in the south or the north are of great importance, the southern end mem- ber particularly having higher concentrations of silicate. The Mediterranean outflow also has di ff erent nutrient concentra- tions compared to the Atlantic water in the same density range. Water samples in areas prone to variations in Antarc- tic Bottom Water and / or Mediterranean Water are therefore somewhat more di ffi cult to apply adjustments to. This was taken into consideration during the secondary QC process and larger o ff sets were generally tolerated before an ad- justment was applied in areas a ff ected by this variability (e.g. Tanhua et al., 2009a).
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CARINA TCO2 data in the Atlantic Ocean

CARINA TCO2 data in the Atlantic Ocean

The CARINA database includes data and metadata from 188 oceanographic cruises / campaigns, of which 5 entries consist of multiple cruises. The Atlantic Ocean subset of the CA- RINA data set (CARINA-ATL) consists of 98 cruises / entries, of which one is a time series, and two are collections of mul- tiple cruises over several years within the framework of a common project. Five of these cruises are in common with the Southern Ocean (SO) region, and five are in common with the Arctic Mediterranean Seas (AMS) region. These overlapping cruises ensure consistency between the three re- gions of the CARINA data set. Additionally, six reference cruises are included in the secondary QC for CARINA-ATL to ensure consistency between CARINA and historical data bases, i.e. the Global Ocean Data Project (GLODAP). The cruises included in the CARINA data products generally ex- clude those that were included in GLODAP. This was done primarily to facilitate later merging of these two data prod- ucts. There are, however, 3 exceptions: 06MT19941012, 06MT19941115 and 74DI19970807 (Cruise Numbers 12, 13 and 171 respectively). These cruises were added to CA- RINA because additional parameters critical to the CARINA goals became available after GLODAP was published.
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The impacts of deglacial meltwater forcing on the South Atlantic Ocean deep circulation since the Last Glacial Maximum

The impacts of deglacial meltwater forcing on the South Atlantic Ocean deep circulation since the Last Glacial Maximum

It is believed that freshwater inflow into the Atlantic Ocean played a significant role in past climate changes. Menviel et al. (2011), using an earth system model of intermediate com- plexity forced by continuously varying boundary conditions and a hypothetical profile of freshwater forcing, were able to simulate H1, the BA warm period, the Older Dryas, the Antarctic Cold Reversal (ACR) and the YD in close agree- ment with paleo-proxy data. The freshwater flux and fresh- water transport play an important role in inhibiting heat re- lease from the ocean and in determining dense water sink- ing regions. The influence of salinity became important since it is the key element that causes the nonlinear instability of the thermohaline system (Stommel, 1961). The freshwater inflow has a stabilizing effect on the water column which changes (weakens) fundamentally the formation of the dense water masses, the main drivers of the thermohaline circula- tion (e.g. Broeker, 1998, Ganopolski and Rahmstorf, 2001). The link between freshwater and climate, thus, is primarily given by the restructuring of the AMOC (e.g., Broeker, 1990; Mikolajewicz, 1998; Seidov et al., 2001).
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Teleconnections and Extreme Ocean States in the Northeast Atlantic Ocean

Teleconnections and Extreme Ocean States in the Northeast Atlantic Ocean

The Northeast Atlantic has an energetic, variable wind and wave climate with a significant potential for renewable en- ergy applications (Gallagher et al., 2013; Gallagher et al., 2016b; Atan et al., 2016). Global atmospheric circulation patterns and wave climate characteristics are inherently con- nected through the role of surface winds in the genera- tion of ocean waves. Several previous studies have shown strong correlations between the wave climate of the North Atlantic Ocean and atmospheric teleconnection patterns such as the North Atlantic Oscillation (NAO) and the East At- lantic teleconnection pattern (EA) (for example, Barnston
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Propagation of Atlantic Ocean swells in the north Indian Ocean: a case study

Propagation of Atlantic Ocean swells in the north Indian Ocean: a case study

A series of very high waves broke over La R´eunion is- land in the Indian Ocean on 12 May 2007, when there was an extreme weather event that occurred off southern tip of South Africa in the Atlantic Ocean. The waves did numer- ous damages on property and lives of R´eunion and neigh- bouring islands, and the maximum wave height was 11.3 m and significant wave height 6.4 m. During 14–15 May, the significant wave height was 8.0 m, as measured by wave gauges (http://www.aviso.oceanobs.com). The storm engen- dered swells, which propagated in the Indian Ocean at about 1000 km day −1 , arrived at R´eunion, where low winds do not disrupt the swell. Lasting long enough, and with a rather large extension, it was observed by multiple altimeter tracks. This event that took place in May 2007 affected the north Indian Ocean wave characteristics as the swell heights were very high of the order of 15.0 m near the generation area. The swells spread their energy as they travelled from the Atlantic Ocean towards the north Indian Ocean.
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CARINA oxygen data in the Atlantic Ocean

CARINA oxygen data in the Atlantic Ocean

Abstract. In the CARINA (Carbon dioxide in the Atlantic Ocean) project, a new dataset with many previously unpublished hydrographic data from the Atlantic, Arctic and Southern Ocean was assembled and subjected to careful quality control (QC) procedures. Here, we present the dissolved oxygen measurements in the Atlantic region of the dataset and describe in detail the secondary QC procedures that aim to ensure that the data are internally consistent. This is achieved by a cross-over analysis, i.e. the comparison of deep ocean data at places that were sampled by di ff erent cruises at di ff erent times. Initial adjustments to the individual cruises were then determined by an inverse procedure that computes a set of adjustments that requires the minimum amount of adjustment and at the same time reduces the o ff sets in an optimal manner. The initial adjustments were then reviewed by the CARINA members, and only those that passed the following two criteria were adopted: (i) the region is not subject to substantial temporal variability, and (ii) the adjustment must be based on at least three stations from each cruise. No adjustment was recommended for cruises that did not fit these criteria. The final CARINA-Oxygen dataset has 103414 oxygen samples from 9491 stations obtained during 98 cruises covering three decades. The sampling density of the oxygen data is particularly good in the North Atlantic north of about 40 ◦ N especially after 1987. In contrast, the sample density in the South Atlantic is much lower. Some cruises appear to have poor data quality, and were subsequently omitted from the adjusted dataset. Of the data included in the adjusted dataset, 20% were adjusted with a mean adjustment of 2%. Due to the achieved internal consistency, the resulting product is well suited to produce an improved climatology or to study long- term changes in the oxygen content of the ocean. However, the adjusted dataset is not necessarily better suited than the unadjusted data to address questions that require a high level of accuracy, such as the computation of the saturation state.
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Processes affecting the cycling of iron in the Atlantic Ocean

Processes affecting the cycling of iron in the Atlantic Ocean

Application of the preformed and regenerated framework to iron is challenging because of the various processes that affect iron distributions in the ocean. The cycling of phosphate is predominantly a circulation of nutrient from surface mixed layer to ocean interior and a subsequent return of the nutrient back to the surface. Though there is burial and external supply of phosphate, these processes have a small contribution to the balances compared to the physical transport and biological utilisation that occurs in the water column. Consequently phosphate has a long ocean residence time of 20 to 100 Kyr (Paytan and McLaughlin, 2007). In contrast, iron has numerous sources (Tagliabue et al., 2010; Duce and Tindale, 1991) that are important, and clearly evident in the oceanic distribution of iron (Laes et al., 2007; Moore and Braucher, 2008; Bennett et al., 2008), because of the rapid removal of the trace metal from the water column by a range of processes. Particle scavenging (Yuan-Hui, 1981; Honeyman et al., 1988); surface adsorption, brownian and turbulent aggregation and colloidal association (Wen et al., 1997) are the major processes acting to move iron from the dissolved phase into a sinking particulate phase. When taking into consideration the various sources of iron, it becomes clear that the method of determining N pre in observations, using
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The transport of Mediterranean water in the North Atlantic Ocean

The transport of Mediterranean water in the North Atlantic Ocean

This overturning circulation is attributed both to the exchange at the Strait of Gibraltar where surface waters enter the Mediterranean and the outflow occurs at intermediate depths, and[r]

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Soft-shelled benthic foraminifera from a hadal site (7800 m water depth) in the Atacama Trench

Soft-shelled benthic foraminifera from a hadal site (7800 m water depth) in the Atacama Trench

ABSTRACT – Soft-shelled foraminifera (organic-walled allogromiids and agglutinated saccamminids) are an important component of the deep-sea meiofauna. Although these largely monothalamous taxa are common at bathyal and abyssal sites in almost all oceans, there are only two records from hadal depths. Here we report the occurrence of numerous allogromiids and saccamminids in a sample collected at 7800 m water depth in the Atacama Trench. The >20 µm fraction of the core sample (0–6 cm layer) yielded a total of 546 soft-walled specimens, the vast majority of them Rose Bengal stained, belonging to 20 morphospecies. Most specimens were allogromiids (82.0%), followed by saccamminids (11.0%) and psammosphaerids (6.0%). Allogromiids, particularly Nodellum- and Resigella-like forms, were responsible for a distinct peak around 120–160 µm in the size distribution, while the spherical Allogromiid sp. 1 dominated the larger-size classes. This sample provides further evidence for the widespread occurrence of soft-walled monothalamous foraminifera in marine habitats. A form resembling Resigella is common in the Atacama Trench sample but has not been observed at abyssal sites in the Pacific Ocean or Atlantic Ocean. J. Micropalaeontol. 21(2): 131–135, December 2002.
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An introduction to Internet based climate science teaching

An introduction to Internet based climate science teaching

In this particular view of the GTC introduced to the scientific community during the 1980s (Broecker, 1991), the sinking process operates most vigorously and very localized in the North Atlantic (Figure 3). In the deep ocean water moves slowly as a deep ocean current into the Southern Hemisphere. It is obvious that the removal of surface water requires a process that replaces it. This is facilitated through a return flow of surface water which has its origin in the surface of the Indian and Pacific Ocean. This return flow closes a global circulation loop, which operates on very long time scales. If one thinks in terms of water parcels, then it takes many hundreds of years for a water parcel that left the surface ocean in the North Atlantic Ocean, to complete one circulation loop.
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Evaluation of Arctic Ocean surface salinities from the Soil Moisture and Ocean Salinity (SMOS) mission against a regional reanalysis and in situ data

Evaluation of Arctic Ocean surface salinities from the Soil Moisture and Ocean Salinity (SMOS) mission against a regional reanalysis and in situ data

Figures 4 and 5 show the deviations of the monthly mean SSS of the five products with reference to the TP4 SSS in Au- gust and September, respectively. In August, the two SMOS products (Fig. 4a, c) show coherently negative deviations ( ∼ 2 psu) in the marginal seas of the Beaufort Sea, the ESS, the Laptev Sea, and the Kara Sea. A positive deviation of CEC is noticeable in the Kara Sea, which indicates that the land–ocean interaction is stronger than in BEC. In the North Atlantic Ocean, away from the sea-ice edge, the deviation of the BEC from TP4 is lower (bias less than 0.5 psu). Focusing on the Arctic domain (> 60 ◦ N), the mean deviation of the BEC SSS is − 0.87 psu and its root mean square is 1.75 psu. The CEC SSS shows considerable negative deviations over 1 psu in the North Atlantic, from north of Denmark Strait to the west coast of Ireland. This is remarkably different from the BEC and does not discern the subpolar from the subtrop- ical waters there (Hátún et al., 2005). For the BEC and CEC products that use different ice masks, the deviations are av- eraged outside their respective ice mask, not their intersec- tion. Comparing the low-salinity lines of 33.6 psu in Fig. 3a and d, it clearly shows the polar water southward of Arctic has a misinterpretation in CEC owing to the ice mask used.
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The CARINA data synthesis project: introduction and overview

The CARINA data synthesis project: introduction and overview

The CARINA data products represent the work of hundreds of scientists. The project has now extended for a decade with the final e ff ort requiring half that time. The original goal, to assemble a collection of European data that would be useful to study the inorganic carbon system in the North Atlantic Ocean, was significantly expanded and, we believe, success- fully completed. Not only were the data assembled, but the most critical parameters were subjected to very careful anal- ysis to remove various data biases. An independent analy- sis of the CARINA data product would undoubtedly show that overall the data quality of CARINA is not as high as GLODAP. This was expected. The CARINA cruises cover a longer time interval and more importantly the cruises were primarily carried out by individual scientists operating in small groups rather than being the result of a globally orga- nized survey e ff ort. Regardless, the secondary quality control activities have resulted in a data product that is su ffi ciently accurate for modern analyses including climate change is- sues. Equally important is the fact that CARINA both sup- plements and extends the global coverage provided by GLO- DAP. Chemical oceanographers now have a very nice data set covering the northern North Atlantic and Nordic Seas, the beginning of coverage for the Arctic Ocean, and signifi- cantly more data for the Southern Ocean. Additionally, while the CARINA calibration techniques di ff ered somewhat from those of GLODAP, the two data sets are thought to be com- patible without alteration for large scale investigations.
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Copepod species abundance from the Southern Ocean and other regions (1980–2005) – a legacy

Copepod species abundance from the Southern Ocean and other regions (1980–2005) – a legacy

While samples of the Magellan region (November 1994), the Gulf of Aqaba and the northern Red Sea (February– March 1999), the Great Meteor Bank (September 1998), and the eastern Atlantic Ocean (November 2002) were restricted to 1 year and 1 season, the Southern Ocean was sampled mul- tiple times (Table 1). Samples in the Southern Ocean were taken from 1980 to 2005 (Table 1, Fig. 2a, b). The high- est number of zooplankton samples was taken in the 1980s (Fig. 2b). In the 1980s the sampling effort was concentrated to the Antarctic Peninsula, the Scotia Sea and the Weddell Sea (Fig. 2a). Samples were taken in multiple years. In the 1990s until 2005 most samples were taken in the Belling- shausen and Amundsen Sea, with fewer samples in the west- ern and eastern Weddell Sea. Two transects were sampled across the Weddell Sea in the 1990s in austral summer and autumn (Fig. 2b). In general, most stations were sampled dur- ing summer (December to February), followed by autumn (March to May) and spring (September to November), while winter samples are only available from 1986 in the eastern Weddell Sea (Fig. 2b, c). Summer and autumn samples are widely distributed from the Amundsen Sea to the eastern Weddell Sea (Fig. 2b), while spring and autumn samples are mostly present from the Scotia Sea and eastern Weddell Sea. Most samples were taken in January and February (Fig. 2d). Samples are scattered throughout the entire day (Fig. 3).
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High-latitude obliquity as a dominant forcing in the Agulhas current system

High-latitude obliquity as a dominant forcing in the Agulhas current system

in climate models (Gordon, 2003), for better understand- ing the evolution of global climate, and for credible long- term climate predictions. However, long-term sea surface salinity (SSS) records are scarce in the Agulhas system and, to date, most of the sea surface temperature (SST) records were reconstructed either in the Agulhas rings leakage re- gion (Peeters et al., 2004; Martinez Mendez et al., 2010) or outside of the Agulhas current trajectory (Bard and Rickaby, 2009) (Fig. 1). Studies in the Agulhas rings leakage region have shown conflicting results between SST reconstructions, which is perhaps not surprising given the complexity of the studied area with vigorous regional ocean currents, the de- velopment of SST contrasts during glacial periods in asso- ciation with seasonal changes in Agulhas water transport, or lateral shifts of the Agulhas retroflection (Martinez-Mendez et al., 2010). Knowledge of SST and SSS changes in the upstream (precursor) region of the Agulhas current system might provide new insights into this problem. Such knowl- edge is also important considering that the upstream waters end up in the Agulhas leakage system further downstream and partially flow into the Atlantic Ocean, thereby potentially altering the buoyancy balance of the Atlantic Ocean (Weijer et al., 2001, 2002). In addition, the role of orbital forcing on the dynamics of the Agulhas current system is not completely understood, in particular, the origin of the potential low lat- itude forcing (strengthen/weaken monsoon) in the Agulhas leakage (Peeters et al., 2004).
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Nordic Seas dissolved oxygen data in CARINA

Nordic Seas dissolved oxygen data in CARINA

The whole CARINA database is published at the CARINA home page at http: // cdiac.ornl.gov / oceans / CARINA / Carina inv.html. It contains 188 individual cruise files in comma- separated WHP exchange format. Condensed metadata are contained in the header of each data file, the data in these files have not been adjusted according to the recommenda- tions presented here. They have, however, been adjusted in the three merged, comma-separated data files with the data products, one for each of the CARINA regions, the Arctic Mediterranean Seas, the Atlantic Ocean, and the Southern Ocean.
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Relating Agulhas leakage to the Agulhas Current retroflection location

Relating Agulhas leakage to the Agulhas Current retroflection location

the line several times are only added to the Agulhas leakage flux time series once, at the moment of their last crossing if that is into the Atlantic Ocean. The flux from floats that cross the GoodHope line and end in the Indian Ocean is negligible. The estimates of the magnitude of Agulhas leakage in lit- erature have a large range, from 4 Sv (Schmitz Jr, 1995; Gar- zoli and Gordon, 1996) to 22 Sv (Donners and Drijfhout, 2004). However, most studies report an estimate of 11– 17 Sv. These estimates are based on different methods, such as water mass analysis (Gordon et al., 1992), altimetry (Gar- zoli and Goni, 2000), Eulerian model fluxes (Reason et al., 2003), numerical Lagrangian floats (Doglioli et al., 2006; Bi- astoch et al., 2008b), or drifting buoy trajectories (Richard- son, 2007). However, none of these studies provide an es- timate of the (interannual) variability of Agulhas leakage as the time series obtained in these measurement campaigns or model runs is generally too short to yield higher order statis- tics.
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MODELING AND PREDICTION OF RAINFALL DATA USING DATA MINING

MODELING AND PREDICTION OF RAINFALL DATA USING DATA MINING

Rainfall Prediction is an important crucial application of data mining techniques. The long term rainfall prediction is very useful in planning and decision making of agricultural crop pattern and water management strategy. In this study effort has been made to examine the relationship of Gujarat (India) rainfall with important global parameters such as Sea Surface Temperature (SST), Sea Level Pressure (SLP), U-wind, V-wind, U- windstress and V-windstress. Attention has been made to find out correlation of rainfall with these elements. This analysis shows that, Sea Surface Temperature of North Pacific Ocean, Sea Level Pressure of Atlantic Ocean, U-windstress and V-windstress of Atlantic Ocean affect Gujarat rainfall. Further a Stepwise method to perform multilinear regression on these predictors is used to develop a proposed model. One month lagged (June-July) correlation is considered throughout the study as the lagged relationship is more useful for predictive purposes than the simultaneous correlation. The forty years data (1960 – 1999) available from NOAA (National Oceanic and Atmospheric Administration) is used for modeling. Validation of generated monthly rainfall series was done by comparison of generated and measured series. The correlation coefficient between generated and measured rainfall series was found to be 0.8377.
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Redescription ofHeterokrohnia mirabilis Ritter-Záhony, 1911 (Chaetognatha)

Redescription ofHeterokrohnia mirabilis Ritter-Záhony, 1911 (Chaetognatha)

A new benthopelagic species of Heterokrohnia (Chaetognatha) from the North Atlantic Ocean.. The distribution of the Chaetognatha of the Southern Ocean.[r]

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