Bubble clouds and temperature anomalies in the upper ocean

Nature ◽  
1987 ◽  
Vol 328 (6125) ◽  
pp. 48-51 ◽  
Author(s):  
S. A. Thorpe ◽  
A. J. Hall
Keyword(s):  
Upper Ocean ◽  
Temperature Anomalies ◽  
Bubble Clouds

scholarly journals Decadal Variability of Upper-Ocean Heat Content Associated with Meridional Shifts of Western Boundary Current Extensions in the North Pacific

2017 ◽  
Vol 30 (16) ◽  
pp. 6247-6264 ◽  
Author(s):  
Bunmei Taguchi ◽  
Niklas Schneider ◽  
Masami Nonaka ◽  
Hideharu Sasaki
Keyword(s):  
North Pacific ◽  
Frontal Zone ◽  
Heat Content ◽  
Ocean Heat Content ◽  
Upper Ocean ◽  
Upper Ocean Heat Content ◽  
Temperature Anomalies ◽  
The North ◽  
Subarctic Frontal Zone ◽  
The North Pacific

Generation and propagation processes of upper-ocean heat content (OHC) in the North Pacific are investigated using oceanic subsurface observations and an eddy-resolving ocean general circulation model hindcast simulation. OHC anomalies are decomposed into physically distinct dynamical components (OHC ρ) due to temperature anomalies that are associated with density anomalies and spiciness components (OHC χ) due to temperature anomalies that are density compensating with salinity. Analysis of the observational and model data consistently shows that both dynamical and spiciness components contribute to interannual–decadal OHC variability, with the former (latter) component dominating in the subtropical (subpolar) North Pacific. OHC ρ variability represents heaving of thermocline, propagates westward, and intensifies along the Kuroshio Extension, consistent with jet-trapped Rossby waves, while OHC χ variability propagates eastward along the subarctic frontal zone, suggesting advection by mean eastward currents. OHC χ variability tightly corresponds in space to horizontal mean spiciness gradients. Meanwhile, area-averaged OHC χ anomalies in the western subarctic frontal zone closely correspond in time to meridional shifts of the subarctic frontal zone. Regression coefficient of the OHC χ time series on the frontal displacement anomalies quantitatively agree with the area-averaged mean spiciness gradient in the region, and suggest that OHC χ is generated via frontal variability in the subarctic frontal zone.

scholarly journals The Effect of the 2013–2016 High Temperature Anomaly in the Subarctic Northeast Pacific (The “Blob”) on Net Community Production

2018 ◽  
Author(s):  
Bo Yang ◽  
Steven R. Emerson ◽  
M. Angelica Peña
Keyword(s):  
Gas Exchange ◽  
Mass Balance ◽  
Mean Value ◽  
Warm Water ◽  
Upper Ocean ◽  
Mass Balances ◽  
Net Community Production ◽  
Pigment Analysis ◽  
Temperature Anomalies ◽  
Community Production

Abstract. A large anomalously warm water patch (the “Blob”) appeared in the NE Pacific Ocean in the winter of 2013–14 and persisted through 2016 causing strong positive upper ocean temperature anomalies at Ocean Station Papa (OSP, 50° N, 145° W). The effect of the temperature anomalies on annual net community production (ANCP) was determined by upper ocean chemical mass balances of O2 and DIC using data from a profiling float and a surface mooring. Year-round oxygen mass balance in the upper ocean (surface to 91–111 m) indicates that ANCP decreased after the first year when warmer water invaded this area and then returned to the “pre-blob” value (2.4, 0.8, 2.1, and 1.6 mol C m−2 yr−1 with a mean value of 1.7 ± 0.7 mol C m−2 yr−1). ANCP determined from DIC mass balance has a mean value that is similar within the errors as that from the O2 mass balance but without significant trend (2.0, 2.1, 2.6, and 3.0 mol C m−2 yr−1 with a mean value of 2.4 ± 0.6 mol C m−2 yr−1). This is likely due to differences in the air-sea gas exchange, which is a major term for both mass balances. Oxygen has a residence time with respect to gas exchange of about one month while the CO2 gas exchange response time is more like a year. Therefore the biologically induced oxygen saturation anomaly responds fast enough to record annual changes whereas that for CO2 does not. Phytoplankton pigment analysis from the upper ocean show lower chlorophyll-a concentrations and greater relative abundance of picoplankton in the year after the warm water patch entered the area than in previous and subsequent years. Our analysis of multiple physical and biological processes that may have caused the ANCP decrease after warm water entered the area suggests that it was most likely due to changes in plankton community composition.

scholarly journals Physical Response of the Tropical–Subtropical North Atlantic Ocean to Decadal–Multidecadal Forcing by African Dust

2012 ◽  
Vol 25 (17) ◽  
pp. 5817-5829 ◽  
Author(s):  
Amato T. Evan ◽  
Gregory R. Foltz ◽  
Dongxiao Zhang
Keyword(s):  
Surface Temperature ◽  
Time Scales ◽  
Ocean Circulation ◽  
North Atlantic ◽  
General Circulation ◽  
Dust Storms ◽  
Upper Ocean ◽  
Temperature Anomalies ◽  
Tropical North Atlantic ◽  
Wide Range

Abstract Dust storms are a persistent feature of the tropical North Atlantic and vary over a wide range of temporal scales. While it is well known that mineral aerosols alter the local radiative fluxes, far less is understood about the oceanic response to such forced changes to the radiative budget, particularly on long time scales. This study uses an observation-based climatology of dust surface forcing and an ocean general circulation model to examine the influence of anomalous atmospheric dust cover over the tropical North Atlantic on upper ocean temperature and circulation during 1955–2008. It is found that surface temperature anomalies from the model experiments are forced primarily by local radiation-induced changes to the surface heat budget. The subsurface temperature anomalies are additionally influenced by upper ocean circulation anomalies, which are the response to dust-forced steric changes in dynamic height. The results herein suggest that on decadal time scales dust-forced variability of ocean surface and subsurface temperatures are of a magnitude comparable to observed variability. On longer time scales dust-forced sea surface temperature anomalies vary in phase with the Atlantic multidecadal oscillation, implying that tropical North Atlantic multidecadal variability is related to changes in dust emissions from West Africa.

scholarly journals The effect of the 2013–2016 high temperature anomaly in the subarctic Northeast Pacific (the “Blob”) on net community production

2018 ◽  
Vol 15 (21) ◽  
pp. 6747-6759 ◽  
Author(s):  
Bo Yang ◽  
Steven R. Emerson ◽  
M. Angelica Peña
Keyword(s):  
Gas Exchange ◽  
Mass Balance ◽  
Mean Value ◽  
Warm Water ◽  
Upper Ocean ◽  
Biological Processes ◽  
Mass Balances ◽  
Net Community Production ◽  
Temperature Anomalies ◽  
Community Production

Abstract. A large anomalously warm water patch (the “Blob”) appeared in the NE Pacific Ocean in the winter of 2013–2014 and persisted through 2016 causing strong positive upper ocean temperature anomalies at Ocean Station Papa (OSP, 50∘ N, 145∘ W). The effect of the temperature anomalies on annual net community production (ANCP) was determined by upper ocean chemical mass balances of O2 and dissolved inorganic carbon (DIC) using data from a profiling float and a surface mooring. Year-round oxygen mass balance in the upper ocean (0 to 91–111 m) indicates that ANCP decreased after the first year when warmer water invaded this area and then returned to the “pre-Blob” value (2.4, 0.8, 2.1, and 1.6 mol C m−2 yr−1 from 2012 to 2016, with a mean value of 1.7±0.7 mol C m−2 yr−1). ANCP determined from the DIC mass balance has a mean value that is similar within the errors as that from the O2 mass balance but without a significant trend (2.0, 2.1, 2.6, and 3.0 mol C m−2 yr−1 with a mean value of 2.4±0.6 mol C m−2 yr−1). This is likely due to differences in the air–sea gas exchange, which is a major term for both mass balances. Oxygen has a residence time with respect to gas exchange of about 1 month while the CO2 gas exchange response time is more like a year. Therefore the biologically induced oxygen saturation anomaly responds fast enough to record annual changes, whereas that for CO2 does not. Phytoplankton pigment analysis from the upper ocean shows lower chlorophyll a concentrations and changes in plankton community composition (greater relative abundance of picoplankton) in the year after the warm water patch entered the area than in previous and subsequent years. Our analysis of multiple physical and biological processes that may have caused the ANCP decrease after warm water entered the area suggests that it was most likely due to the temperature-induced changes in biological processes.

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