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Author Kelly, T.B. ; Goericke, R. ; Kahru, M. ; Song, H. ; Stukel, M.R.
Title CCE II: Spatial and interannual variability in export efficiency and the biological pump in an eastern boundary current upwelling system with substantial lateral advection Type $loc['typeJournal Article']
Year 2018 Publication Deep Sea Research Part I: Oceanographic Research Papers Abbreviated Journal Deep Sea Research Part I: Oceanographic Research Papers
Volume 140
Issue Pages 14-25
Keywords california current ecosystem ; coastal waters ; flux ; frontal zone ; ocean carbon-cycle ; oceanography ; pacific ; sea ; sinking ; time-series ; Zooplankton
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0967-0637
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1022
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Author Morrow, R.M. ; Ohman, M.D. ; Goericke, R. ; Kelly, T.B. ; Stephens, B.M. ; Stukel, M.R.
Title CCE V: Primary production, mesozooplankton grazing, and the biological pump in the California Current Ecosystem: Variability and response to El Niño Type $loc['typeJournal Article']
Year 2018 Publication Deep Sea Research Part I: Oceanographic Research Papers Abbreviated Journal Deep Sea Research Part I: Oceanographic Research Papers
Volume 140
Issue Pages 52-62
Keywords Carbon export ; Fecal pellets ; Sinking particles ; Interannual variability ; Net primary productivity ; Eastern boundary upwelling system KeyWords Plus:ZOOPLANKTON FECAL PELLETS ; NORTH PACIFIC-OCEAN ; CURRENT SYSTEM ; SOUTHERN CALIFORNIA ; UNDERWATER GLIDERS ; CARBON EXPORT ; ZONE ; CHLOROPHYLL ; STABILITY ; EQUATIONS
Abstract Predicting marine carbon sequestration in a changing climate requires mechanistic understanding of the processes controlling sinking particle flux under different climatic conditions. The recent occurrence of a warm anomaly (2014-2015) followed by an El Nino (2015-2016) in the southern sector of the California Current System presented an opportunity to analyze changes in the biological carbon pump in response to altered climate forcing. We compare primary production, mesozooplankton grazing, and carbon export from the euphotic zone during quasi-Lagrangian experiments conducted in contrasting conditions: two cruises during warm years – one during the warm anomaly in 2014 and one toward the end of El Nino 2016 – and three cruises during El Ninoneutral years. Results showed no substantial differences in the relationships between vertical carbon export and its presumed drivers (primary production, mesozooplankton grazing) between warm and neutral years. Mesozooplankton fecal pellet enumeration and phaeopigment measurements both showed that fecal pellets were the dominant contributor to export in productive upwelling regions. In more oligotrophic regions, fluxes were dominated by amorphous marine snow with negligible pigment content. We found no evidence for a significant shift in the relationship between mesozooplankton grazing rate and chlorophyll concentration. However, massspecific grazing rates were lower at low-to-moderate chlorophyll concentrations during warm years relative to neutral years. We also detected a significant difference in the relationship between phytoplankton primary production and photosynthetically active radiation between years: at similar irradiance and nutrient concentrations, productivity decreased during the warm events. Whether these changes resulted from species composition changes remains to be determined. Overall, our results suggest that the processes driving export remain similar during different climate conditions, but that species compositional changes or other structural changes require further attention.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0967-0637
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ rl18 @
Serial 983
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Author Morrow, R.M. ; Ohman, M.D. ; Goericke, R. ; Kelly, T.B. ; Stephens, B.M. ; Stukel, M.R.
Title CCE V: Primary production, mesozooplankton grazing, and the biological pump in the California Current Ecosystem: Variability and response to El Niño Type $loc['typeJournal Article']
Year 2018 Publication Deep Sea Research Part I: Oceanographic Research Papers Abbreviated Journal Deep Sea Research Part I: Oceanographic Research Papers
Volume Issue Pages
Keywords Carbon export ; Fecal pellets ; Sinking particles ; Interannual variability ; Net primary productivity ; Eastern boundary upwelling system
Abstract Predicting marine carbon sequestration in a changing climate requires mechanistic understanding of the processes controlling sinking particle flux under different climatic conditions. The recent occurrence of a warm anomaly (2014�2015) followed by an El Niño (2015�2016) in the southern sector of the California Current System presented an opportunity to analyze changes in the biological carbon pump in response to altered climate forcing. We compare primary production, mesozooplankton grazing, and carbon export from the euphotic zone during quasi-Lagrangian experiments conducted in contrasting conditions: two cruises during warm years – one during the warm anomaly in 2014 and one toward the end of El Niño 2016 � and three cruises during El Niño-neutral years. Results showed no substantial differences in the relationships between vertical carbon export and its presumed drivers (primary production, mesozooplankton grazing) between warm and neutral years. Mesozooplankton fecal pellet enumeration and phaeopigment measurements both showed that fecal pellets were the dominant contributor to export in productive upwelling regions. In more oligotrophic regions, fluxes were dominated by amorphous marine snow with negligible pigment content. We found no evidence for a significant shift in the relationship between mesozooplankton grazing rate and chlorophyll concentration. However, mass-specific grazing rates were lower at low-to-moderate chlorophyll concentrations during warm years relative to neutral years. We also detected a significant difference in the relationship between phytoplankton primary production and photosynthetically active radiation between years: at similar irradiance and nutrient concentrations, productivity decreased during the warm events. Whether these changes resulted from species composition changes remains to be determined. Overall, our results suggest that the processes driving export remain similar during different climate conditions, but that species compositional changes or other structural changes require further attention
Address Deep-Sea Research Part I
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0967-0637
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 966
Permanent link to this record
Author Morrow, R.M. ; Ohman, M.D. ; Goericke, R. ; Kelly, T.B. ; Stephens, B.M. ; Stukel, M.R.
Title CCE V: Primary production, mesozooplankton grazing, and the biological pump in the California Current Ecosystem: Variability and response to El Niño Type $loc['typeJournal Article']
Year 2018 Publication Deep Sea Research Part I: Oceanographic Research Papers Abbreviated Journal Deep Sea Research Part I: Oceanographic Research Papers
Volume 140
Issue Pages 52-62
Keywords Carbon export ; Fecal pellets ; Sinking particles ; Interannual variability ; Net primary productivity ; Eastern boundary upwelling system
Abstract Predicting marine carbon sequestration in a changing climate requires mechanistic understanding of the processes controlling sinking particle flux under different climatic conditions. The recent occurrence of a warm anomaly (2014-2015) followed by an El Nino (2015-2016) in the southern sector of the California Current System presented an opportunity to analyze changes in the biological carbon pump in response to altered climate forcing. We compare primary production, mesozooplankton grazing, and carbon export from the euphotic zone during quasi-Lagrangian experiments conducted in contrasting conditions: two cruises during warm years – one during the warm anomaly in 2014 and one toward the end of El Nino 2016 – and three cruises during El Ninoneutral years. Results showed no substantial differences in the relationships between vertical carbon export and its presumed drivers (primary production, mesozooplankton grazing) between warm and neutral years. Mesozooplankton fecal pellet enumeration and phaeopigment measurements both showed that fecal pellets were the dominant contributor to export in productive upwelling regions. In more oligotrophic regions, fluxes were dominated by amorphous marine snow with negligible pigment content. We found no evidence for a significant shift in the relationship between mesozooplankton grazing rate and chlorophyll concentration. However, massspecific grazing rates were lower at low-to-moderate chlorophyll concentrations during warm years relative to neutral years. We also detected a significant difference in the relationship between phytoplankton primary production and photosynthetically active radiation between years: at similar irradiance and nutrient concentrations, productivity decreased during the warm events. Whether these changes resulted from species composition changes remains to be determined. Overall, our results suggest that the processes driving export remain similar during different climate conditions, but that species compositional changes or other structural changes require further attention.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0967-0637
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1021
Permanent link to this record
Author Stukel, M.R. ; Kelly, T.B.
Title The carbon: 234Thorium ratios of sinking particles in the California current ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model Type $loc['typeJournal Article']
Year Publication Marine Chemistry Abbreviated Journal Marine Chemistry
Volume Issue Pages
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-4203
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1037
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Author Deng, J. ; Wu, Z. ; Zhang, M. ; Huang, N.E. ; Wang, S. ; Qiao, F.
Title Using Holo-Hilbert spectral analysis to quantify the modulation of Dansgaard-Oeschger events by obliquity Type $loc['typeJournal Article']
Year 2018 Publication Quaternary Science Reviews Abbreviated Journal Quaternary Science Reviews
Volume 192
Issue Pages 282-299
Keywords Pleistocene ; Paleoclimatology ; Greenland ; Antarctica ; Data treatment ; Data analysis ; Dansgaard-oeschger (DO) events ; Obliquity forcing ; Phase preference ; Holo-hilbert spectral analysis ; Amplitude modulation ; EMPIRICAL MODE DECOMPOSITION ; GREENLAND ICE-CORE ; NONSTATIONARY TIME-SERIES ; ABRUPT CLIMATE-CHANGE ; LAST GLACIAL PERIOD ; NORTH-ATLANTIC ; MILLENNIAL-SCALE ; RECORDS ; VARIABILITY ; CYCLE
Abstract Astronomical forcing (obliquity and precession) has been thought to modulate Dansgaard-Oeschger (DO) events, yet the detailed quantification of such modulations has not been examined. In this study, we apply the novel Holo-Hilbert Spectral Analysis (HHSA) to five polar ice core records, quantifying astronomical forcing's time-varying amplitude modulation of DO events and identifying the preferred obliquity phases for large amplitude modulations. The unique advantages of HHSA over the widely used windowed Fourier spectral analysis for quantifying astronomical forcing's nonlinear modulations of DO events is first demonstrated with a synthetic data that closely resembles DO events recorded in Greenland ice cores (NGRIP, GRIP, and GISP2 cores on GICC05 modelext timescale). The analysis of paleoclimatic proxies show that statistically significantly more frequent DO events, with larger amplitude modulation in the Greenland region, tend to occur in the decreasing phase of obliquity, especially from its mean value to its minimum value. In the eastern Antarctic, although statistically significantly more DO events tend to occur in the decreasing obliquity phase in general, the preferred phase of obliquity for large amplitude modulation on DO events is a segment of the increasing phase near the maximum obliquity, implying that the physical mechanisms of DO events may be different for the two polar regions. Additionally, by using cross-spectrum and magnitude-squared analyses, Greenland DO mode at a timescale of about 1400 years leads the Antarctic DO mode at the same timescale by about 1000 years. (C) 2018 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0277-3791
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 971
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Author Misra, V ; Bhardwaj, A ; Mishra, A
Title Characterizing the rainy season of Peninsular Florida Type $loc['typeJournal Article']
Year 2018 Publication Climate Dynamics Abbreviated Journal
Volume 51
Issue 5-6
Pages 2157-2167
Keywords
Abstract Peninsular Florida (PF) has a very distinct wet season that can be objectively defined with onset and demise dates based on daily rainfall. The dramatic onset of rains and its retreat coincides with the seasonal cycle of the regional scale atmospheric and upper ocean circulations and upper ocean heat content of the immediate surrounding ocean. The gradual warming of the Intra-Americas Seas (IAS; includes Gulf of Mexico, Caribbean Sea and parts of northwestern subtropical Atlantic Ocean) with the seasonal evolution of the Loop Current and increased atmospheric heat flux in to the ocean eventually enhance the moisture flux into terrestrial PF around the time of the onset of the Rainy Season of PF (RSPF). Similarly, the RSPF retreats with the cooling of the IAS that coincides with the weakening of the Loop Current and reduction of the upper ocean heat content of the IAS. It is also shown that anomalous onset and demise dates of the RSPF have implications on its seasonal rainfall anomalies.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @
Serial 556
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Author Misra, V. ; Bhardwaj, A. ; Mishra, A.
Title Local onset and demise of the Indian summer monsoon Type $loc['typeJournal Article']
Year 2018 Publication Climate Dynamics Abbreviated Journal
Volume 51
Issue 5-6
Pages 1609-1622
Keywords Indian monsoon ; ENSO ; Onset of monsoon
Abstract This paper introduces an objective definition of local onset and demise of the Indian summer monsoon (ISM) at the native grid of the Indian Meteorological Department's rainfall analysis based on more than 100 years of rain gauge observations. The variability of the local onset/demise of the ISM is shown to be closely associated with the All India averaged rainfall onset/demise. This association is consistent with the corresponding evolution of the slow large-scale reversals of upper air and ocean variables that raise the hope of predictability of local onset and demise of the ISM. The local onset/demise of the ISM also show robust internannual variations associated with El Nino and the Southern Oscillation and Indian Ocean dipole mode. It is also shown that the early monsoon rains over northeast India has a predictive potential for the following seasonal anomalies of rainfall and seasonal length of the monsoon over rest of India.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @
Serial 360
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Author Bhowmick, S. A. ; Agarwal, N. ; Ali, M. M. ; Kishtawal, C. M. ; Sharma, R.
Title Role of ocean heat content in boosting post-monsoon tropical storms over Bay of Bengal during La-Nina events Type $loc['typeJournal Article']
Year 2019 Publication Climate Dynamics Abbreviated Journal
Volume 52
Issue 12
Pages 7225-7234
Keywords La-Niña ; Bay of Bengal ; Tropical cyclones ; Ocean heat content
Abstract This study aims to analyze the role of ocean heat content in boosting the post-monsoon cyclonic activities over Bay of Bengal during La-Niña events. In strong La-Niña years, accumulated cyclone energy in Bay of Bengal is much more as compared to any other year. It is observed that during late June to October of moderate to strong La-Nina years, western Pacific is warmer. Sea surface temperature anomaly of western Pacific Ocean clearly indicates the presence of relatively warmer water mass in the channel connecting the Indian Ocean and Pacific Ocean, situated above Australia. Ocean currents transport the heat zonally from Pacific to South eastern Indian Ocean. Excess heat of the southern Indian Ocean is eventually transported to eastern equatorial Indian Ocean through strong geostrophic component of ocean current. By September the northward transport of this excess heat from eastern equatorial Indian Ocean to Bay of Bengal takes place during La-Nina years boosting the cyclonic activities thereafter.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @
Serial 71
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Author Laurencin, C. ; Misra, V.
Title Characterizing the Variations of the motion of the North Atlantic tropical cyclones Type $loc['typeJournal Article']
Year 2018 Publication Meteorology and Atmospheric Physics Abbreviated Journal Meteorol Atmos Phys
Volume 130
Issue 303
Pages 1-12
Keywords climatology ; interannual scales ; environment
Abstract In this study, we examine the seasonal and interannual variability of the North Atlantic (NATL) tropical cyclone (TC) motion from the historical Hurricane Database (HURDAT2) over the period 1988-2014. We characterize these motions based on their position, lifecycle, and seasonal cycle. The main findings of this study include: (1) of the 11,469 NATL TC fixes examined between 1988 and 2014, 81% of them had a translation speed of < 20 mph; (2) TCs in the deep tropics of the NATL are invariably slow-moving in comparison with TCs in higher latitudes. Although fast-moving TCs (> 40 mph) are exclusively found north of 30 N, the slow-moving TCs have a wide range of latitude. This is largely a consequence of the background steering flow being weaker (stronger) in the tropical (higher) latitudes with a minimum around the subtropical latitudes of NATL; (3) there is an overall decrease in the frequency of all categories of translation speed of TCs in warm relative to cold El Niño Southern Oscillation (ENSO) years. However, in terms of the percentage change, TCs with a translation speed in the range of 10-20 mph display the most change (42%) in warm relative to cold ENSO years; and (4) there is an overall decrease in frequency across all categories of TC translation speed in small relative to large Atlantic Warm Pool years, but in terms of percentage change in the frequency of TCs, there is a significant and comparable change in the frequency over a wider range of translation speeds than the ENSO composites. This last finding suggests that Atlantic Warm Pool variations have a more profound impact on the translation speed of Atlantic TCs than ENSO.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ rl18 @
Serial 991
Permanent link to this record
