scholarly journals Air-sea CO<sub>2</sub> flux in the Pacific Ocean for the period 1990–2009

2013 ◽  
Vol 10 (7) ◽  
pp. 12155-12216 ◽  
Author(s):  
M. Ishii ◽  
R. A. Feely ◽  
K. B. Rodgers ◽  
G.-H. Park ◽  
R. Wanninkhof ◽  
...  
Keyword(s):  
North Pacific ◽  
Co2 Flux ◽  
South Pacific ◽  
Tropical Pacific ◽  
The South ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The North Pacific ◽  
The Tropical Pacific

Abstract. Air-sea CO2 fluxes over the Pacific Ocean are known to be characterized by coherent large-scale structures that reflect not only ocean subduction and upwelling patterns, but also the combined effects of wind-driven gas exchange and biology. On the largest scales, a large net CO2 influx into the extra-tropics is associated with a robust seasonal cycle, and a large net CO2 efflux from the tropics is associated with substantial inter-annual variability. In this work, we have synthesized estimates of the net air-sea CO2 flux from a variety of products drawing upon a variety of approaches in three sub-basins of the Pacific Ocean, i.e., the North Pacific extra-tropics (18° N–66° N), the tropical Pacific (18° S–18° N), and the South Pacific extra-tropics (44.5° S–18° S). These approaches include those based on the measurements of CO2 partial pressure in surface seawater (pCO2sw), inversions of ocean interior CO2 data, forward ocean biogeochemistry models embedded in the ocean general circulation models (OBGCMs), a model with assimilation of pCO2sw data, and inversions of atmospheric CO2 measurements. Long-term means, inter-annual variations and mean seasonal variations of the regionally-integrated fluxes were compared in each of the sub-basins over the last two decades, spanning the period from 1990 through 2009. A simple average of the long-term mean fluxes obtained with surface water pCO2 diagnostics and those obtained with ocean interior CO2 inversions are –0.47 ± 0.13 Pg C yr–1 in the North Pacific extra-tropics, +0.44 ± 0.14 Pg C yr–1 in the tropical Pacific, and –0.37 ± 0.08 Pg C yr–1 in the South Pacific extra-tropics, where positive fluxes are into the atmosphere. This suggests that approximately half of the CO2 taken up over the North and South Pacific extra-tropics is released back to the atmosphere from the tropical Pacific. These estimates of the regional fluxes are also supported by the estimates from OBGCMs after adding the riverine CO2 flux, i.e., –0.49 ± 0.02 Pg C yr–1 in the North Pacific extra-tropics, +0.41 ± 0.05 Pg C yr–1 in the tropical Pacific, and –0.39 ± 0.11 Pg C yr–1 in the South Pacific extra-tropics. The estimates from the atmospheric CO2 inversions show large variations amongst different inversion systems, but their median fluxes are consistent with the estimates from climatological pCO2sw data and pCO2sw diagnostics. In the South Pacific extra-tropics, where CO2 variations in the surface and ocean interior are severely under-sampled, the difference in the air-sea CO2 flux estimates between the diagnostic models and ocean interior CO2 inversions is larger (0.18 Pg C yr–1). The range of estimates from forward OBGCMs is also large (−0.19 to −0.72 Pg C yr–1). Regarding inter-annual variability of air-sea CO2 fluxes, positive and negative anomalies are evident in the tropical Pacific during the cold and warm events of the El Niño Southern Oscillation in the estimates from pCO2sw diagnostic models and from OBGCMs. They are consistent in phase with the Southern Oscillation Index, but the peak-to-peak amplitudes tend to be higher in OBGCMs (0.40 ± 0.09 Pg C yr–1) than in the diagnostic models (0.27 ± 0.07 Pg C yr–1).

scholarly journals Air–sea CO<sub>2</sub> flux in the Pacific Ocean for the period 1990–2009

2014 ◽  
Vol 11 (3) ◽  
pp. 709-734 ◽  
Author(s):  
M. Ishii ◽  
R. A. Feely ◽  
K. B. Rodgers ◽  
G.-H. Park ◽  
R. Wanninkhof ◽  
...  
Keyword(s):  
Co2 Flux ◽  
South Pacific ◽  
Tropical Pacific ◽  
The South ◽  
The North ◽  
The Pacific ◽  
Diagnostic Models ◽  
The Pacific Ocean ◽  
The North Pacific ◽  
The Tropical Pacific

Abstract. Air–sea CO2 fluxes over the Pacific Ocean are known to be characterized by coherent large-scale structures that reflect not only ocean subduction and upwelling patterns, but also the combined effects of wind-driven gas exchange and biology. On the largest scales, a large net CO2 influx into the extratropics is associated with a robust seasonal cycle, and a large net CO2 efflux from the tropics is associated with substantial interannual variability. In this work, we have synthesized estimates of the net air–sea CO2 flux from a variety of products, drawing upon a variety of approaches in three sub-basins of the Pacific Ocean, i.e., the North Pacific extratropics (18–66° N), the tropical Pacific (18° S–18° N), and the South Pacific extratropics (44.5–18° S). These approaches include those based on the measurements of CO2 partial pressure in surface seawater (pCO2sw), inversions of ocean-interior CO2 data, forward ocean biogeochemistry models embedded in the ocean general circulation models (OBGCMs), a model with assimilation of pCO2sw data, and inversions of atmospheric CO2 measurements. Long-term means, interannual variations and mean seasonal variations of the regionally integrated fluxes were compared in each of the sub-basins over the last two decades, spanning the period from 1990 through 2009. A simple average of the long-term mean fluxes obtained with surface water pCO2 diagnostics and those obtained with ocean-interior CO2 inversions are −0.47 ± 0.13 Pg C yr−1 in the North Pacific extratropics, +0.44 ± 0.14 Pg C yr−1 in the tropical Pacific, and −0.37 ± 0.08 Pg C yr−1 in the South Pacific extratropics, where positive fluxes are into the atmosphere. This suggests that approximately half of the CO2 taken up over the North and South Pacific extratropics is released back to the atmosphere from the tropical Pacific. These estimates of the regional fluxes are also supported by the estimates from OBGCMs after adding the riverine CO2 flux, i.e., −0.49 ± 0.02 Pg C yr−1 in the North Pacific extratropics, +0.41 ± 0.05 Pg C yr−1 in the tropical Pacific, and −0.39 ± 0.11 Pg C yr−1 in the South Pacific extratropics. The estimates from the atmospheric CO2 inversions show large variations amongst different inversion systems, but their median fluxes are consistent with the estimates from climatological pCO2sw data and pCO2sw diagnostics. In the South Pacific extratropics, where CO2 variations in the surface and ocean interior are severely undersampled, the difference in the air–sea CO2 flux estimates between the diagnostic models and ocean-interior CO2 inversions is larger (0.18 Pg C yr−1). The range of estimates from forward OBGCMs is also large (−0.19 to −0.72 Pg C yr−1). Regarding interannual variability of air–sea CO2 fluxes, positive and negative anomalies are evident in the tropical Pacific during the cold and warm events of the El Niño–Southern Oscillation in the estimates from pCO2sw diagnostic models and from OBGCMs. They are consistent in phase with the Southern Oscillation Index, but the peak-to-peak amplitudes tend to be higher in OBGCMs (0.40 ± 0.09 Pg C yr−1) than in the diagnostic models (0.27 ± 0.07 Pg C yr−1).

scholarly journals The influence of decadal oscillations on the oxygen and nutrient trends in the Pacific Ocean

2019 ◽  
Author(s):  
Lothar Stramma ◽  
Sunke Schmidtko ◽  
Steven J. Bograd ◽  
Tsuneo Ono ◽  
Tetjana Ross ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Tropical Pacific ◽  
Ocean Warming ◽  
The North ◽  
The Pacific ◽  
Major Mode ◽  
The Pacific Ocean ◽  
The North Pacific ◽  
The Tropical Pacific

Abstract. A strong oxygen deficient layer is located in the upper layer of the tropical Pacific Ocean and at deeper depths in the North Pacific. Processes related to climate change (upper ocean warming, reduced ventilation) are expected to change ocean oxygen and nutrient inventories. In most ocean basins, a decrease in oxygen (‘deoxygenation’) and an increase of nutrients has been observed in subsurface layers. Deoxygenation trends are not linear and there could be other influences on oxygen and nutrient trends and variability. Here oxygen and nutrient time series since 1950 in the Pacific Ocean were investigated at 50 to 300 m depth, as this layer provides critical pelagic habitat for biological communities. In addition to trends related to ocean warming the oxygen and nutrient trends show a strong influence of the Pacific Decadal Oscillation (PDO) in the tropical and the eastern Pacific, and the North Pacific Gyre Oscillation (NPGO) especially in the North Pacific. In the Oyashio Region the PDO, the NPGO, the North Pacific Index (NPI) and a 18.6 year nodal tidal cycle overlay the long-term trend. In most regions oxygen increases and nutrients decrease in the 50 to 300 m layer during the negative PDO phase, with opposite trends during the positive PDO phase. The PDO index encapsulates the major mode of surface temperature variability in the Pacific and oxygen and nutrients trends throughout the basin can be described in the context of the PDO phases. An influence of the subtropical-tropical cell in the tropical Pacific cannot be proven with the available data. El Niño and La Niña years often influence the oxygen and nutrient distribution during the event in the eastern tropical Pacific, but do not have a multi-year influence on the trends.

Origins of Tropical Pacific Decadal Variability: Role of Stochastic Atmospheric Forcing from the South Pacific*

2013 ◽  
Vol 26 (24) ◽  
pp. 9791-9796 ◽  
Author(s):  
Yuko M. Okumura
Keyword(s):  
North Pacific ◽  
Decadal Variability ◽  
South Pacific ◽  
Atmospheric Model ◽  
Tropical Pacific ◽  
Ocean Dynamics ◽  
Atmospheric Forcing ◽  
The South ◽  
The North ◽  
The North Pacific

Abstract Based on the analysis of multicentury–millennium integrations of an atmospheric model coupled to the ocean with varying degrees, it is argued that ENSO-like decadal variability is primarily driven by stochastic atmospheric forcing. In particular, the leading mode of internal atmospheric variability over the South Pacific, which projects onto the Pacific–South American (PSA) pattern, plays an important role in modulating the trade winds and sea surface temperature (SST) in the southeast tropical Pacific. Subsequent ocean–atmosphere interactions organize a basinwide SST anomaly pattern in the tropics, which in turn forces atmospheric Rossby waves into the extratropics, reinforcing the PSA pattern and inducing coherent decadal changes in the North Pacific. In the absence of ocean dynamics, equatorial SST variability is reduced and the North Pacific exhibits decadal variability independent of the tropical–South Pacific. The strong tropical–South Pacific linkage may be attributed to the equatorially asymmetric nature of tropical Pacific climate.

Evaluating the effect of tropical and extratropical Pacific initial errors on two types of El Niño prediction using particle filter approach

2020 ◽  
Author(s):  
Meiyi Hou ◽  
Xiefei Zhi
Keyword(s):  
North Pacific ◽  
South Pacific ◽  
Tropical Pacific ◽  
Ocean Temperature ◽  
The North ◽  
Initial Errors ◽  
Southeast Pacific ◽  
The North Pacific ◽  
The Tropical Pacific

&lt;p&gt;Different types of El Ni&amp;#241;o-Southern Oscillation (ENSO) predictions are sensitive to the initial errors in different key areas in the Pacific Ocean. And it is known that the prediction can be improved by removing the initial errors by using assimilation methods. However yet, few studies have quantified to what extent can different types of ENSO predictions be improved by assimilating variable in different key areas. In Hou et.al (2019), 4 types of ocean temperature initial error patterns were classified for two types of El Ni&amp;#241;o prediction. It was indicated that initial errors in the north Pacific, covering the Victoria Mode region, along with south Pacific, covering the South Pacific Meridional Mode region, and subsurface layer of western equatorial Pacific have strong influence on the ENSO prediction. Following the data analysis method and the initial error patterns they proposed, we assimilate ocean temperature in these three key areas of Pacific Ocean by using CMIP5 pi-control dataset and particle filter method. Most EP- and CP-El Ni&amp;#241;o predictions in December are improved after assimilating the ocean temperature in southeast Pacific, north Pacific and western equatorial Pacific from January to March. Specially, for the prediction ensemble which contains EP(CP)-type-1 initial errors, the EP(CP)-El Ni&amp;#241;o prediction skill raises the most after assimilating the Tropical Pacific temperature, comparing with the result of assimilating the south Pacific and north Pacific. As for the prediction ensemble which contains EP-type-2 initial errors, which present similar pattern to EP-type-1 but with opposite sign, the EP-El Ni&amp;#241;o prediction skill increases the most by assimilating the north Pacific temperature. The results verify that the initial errors in the north Pacific exert contrary influences on the ENSO prediction with that in the southeast Pacific and western tropical Pacific. In addition, the initial errors in the north Pacific is more of concern for the SST prediction in the central tropical Pacific in December, while those in the southeast Pacific and tropical western Pacific is more related to the SST prediction in the central-eastern tropical Pacific. In conclusion, to better predict the types of El Ni&amp;#241;o, attentions should be paid to the initial ocean temperature accuracy not only in the tropical Pacific but also in the north and south Pacific.&amp;#160;&lt;/p&gt;&lt;div&gt; &lt;div&gt; &lt;div&gt;&amp;#160;&lt;/div&gt; &lt;/div&gt; &lt;div&gt;&amp;#160;&lt;/div&gt; &lt;/div&gt;

scholarly journals South Pacific Decadal Climate Variability and Potential Predictability

2019 ◽  
Vol 32 (18) ◽  
pp. 6051-6069 ◽  
Author(s):  
Jiale Lou ◽  
Neil J. Holbrook ◽  
Terence J. O’Kane
Keyword(s):  
Pacific Decadal Oscillation ◽  
North Pacific ◽  
Decadal Variability ◽  
South Pacific ◽  
The South ◽  
Potential Predictability ◽  
The North ◽  
The Pacific ◽  
The Relationship ◽  
The North Pacific

Abstract The South Pacific decadal oscillation (SPDO) characterizes the Southern Hemisphere contribution to the Pacific-wide interdecadal Pacific oscillation (IPO) and is analogous to the Pacific decadal oscillation (PDO) centered in the North Pacific. In this study, upper ocean variability and potential predictability of the SPDO is examined in HadISST data and an atmosphere-forced ocean general circulation model. The potential predictability of the IPO-related variability is investigated in terms of both the fractional contribution made by the decadal component in the South, tropical and North Pacific Oceans and in terms of a doubly integrated first-order autoregressive (AR1) model. Despite explaining a smaller fraction of the total variance, we find larger potential predictability of the SPDO relative to the PDO. We identify distinct local drivers in the western subtropical South Pacific, where nonlinear baroclinic Rossby wave–topographic interactions act to low-pass filter decadal variability. In particular, we show that the Kermadec Ridge in the southwest Pacific enhances the decadal signature more prominently than anywhere else in the Pacific basin. Applying the doubly integrated AR1 model, we demonstrate that variability associated with the Pacific–South American pattern is a critically important atmospheric driver of the SPDO via a reddening process analogous to the relationship between the Aleutian low and PDO in the North Pacific—albeit that the relationship in the South Pacific appears to be even stronger. Our results point to the largely unrecognized importance of South Pacific processes as a key source of decadal variability and predictability.

scholarly journals The Pacific Decadal Precession and its Relationship to Tropical Pacific Decadal Variability in CMIP6 Models

2021 ◽  
Author(s):  
Matthew H. Rogers ◽  
Jason Furtado ◽  
Bruce Anderson
Keyword(s):  
North Pacific ◽  
Tropical Pacific ◽  
S Phase ◽  
Atmospheric Circulations ◽  
Enso Events ◽  
The North ◽  
Sst Variability ◽  
The Pacific ◽  
The North Pacific ◽  
The Tropical Pacific

Abstract Persistent, multi-year shifts in atmospheric circulations and their associated influence on regional climates have profound impacts on physical, biological, and socioeconomic systems. The Pacific Decadal Precession (PDP), an atmospheric mode of variability consisting of a lower tropospheric height dipole which rotates counterclockwise over several years in the North Pacific, describes a series of such shifts in atmospheric circulations. One phase of the PDP, the north-south (N-S) phase, is hypothesized to be partially driven by central tropical Pacific (CP) sea surface temperature (SST) variability, but robust assessment of this dynamical connection in climate models remains to be done. In this study, we investigate this hypothesis with analyses in both reanalysis and selected models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) archive. We show that the emergence of the N-S phase is both related to and influenced by tropical Pacific decadal SST variability, specifically variability associated with CP El Niño-Southern Oscillation (ENSO) events. When examining the CMIP6 model output, we find that most models cannot recover the characteristic cyclonic precession of the dipoles of the PDP, instead featuring only amplitude and sign changes of the N-S phase, Moreover, the models do not replicate the dynamical connections between the tropical Pacific and this North Pacific mode. Our results suggest that primary reasons for this inconsistency are that models inaccurately simulate both the SST pattern associated with the PDP, shared low-frequency power associated with CP ENSO events, and incorrect Rossby wavetrains emanating from the tropical Pacific into the North Pacific on quasi-decadal timescales. Taken together, our analyses offer another benchmark by which to test the fidelity of the climate model simulations in capturing Pacific decadal climate variability in order to improve decadal-to-centennial climate projections.

Pacific Decadal Variability: The Tropical Pacific Mode and the North Pacific Mode*

2003 ◽  
Vol 16 (8) ◽  
pp. 1101-1120 ◽  
Author(s):  
L. Wu ◽  
Z. Liu ◽  
R. Gallimore ◽  
R. Jacob ◽  
D. Lee ◽  
...  
Keyword(s):  
North Pacific ◽  
Decadal Variability ◽  
Tropical Pacific ◽  
The North ◽  
Pacific Decadal Variability ◽  
The North Pacific ◽  
The Tropical Pacific

scholarly journals The Development of a Statistical Forecast Model for Changma

2013 ◽  
Vol 28 (6) ◽  
pp. 1304-1321 ◽  
Author(s):  
Seung-Eon Lee ◽  
Kyong-Hwan Seo
Keyword(s):  
Wave Propagation ◽  
North Atlantic ◽  
North Pacific ◽  
Forecast Model ◽  
Tropical Pacific ◽  
The North ◽  
Sst Anomaly ◽  
The North Atlantic ◽  
The North Pacific ◽  
The Tropical Pacific

Abstract Forecasting year-to-year variations in East Asian summer monsoon (EASM) precipitation is one of the most challenging tasks in climate prediction because the predictors are not sufficiently well known and the forecast skill of the numerical models is poor. In this paper, a statistical forecast model for changma (the Korean portion of the EASM system) precipitation is proposed that was constructed with three physically based predictors. A forward-stepwise regression was used to select the predictors that included sea surface temperature (SST) anomalies over the North Pacific, the North Atlantic, and the tropical Pacific Ocean. Seasonal predictions with this model showed high forecasting capabilities that had a Gerrity skill score of ~0.82. The dynamical processes associated with the predictors were examined prior to their use in the prediction scheme. All predictors tended to induce an anticyclonic anomaly to the east or southeast of Japan, which was responsible for transporting a large amount of moisture to the southern Korean Peninsula. The predictor in the North Pacific formed an SST front to the east of Japan during the summertime, which maintained a lower-tropospheric baroclinicity. The North Atlantic SST anomaly induced downstream wave propagation in the upper troposphere, developing anticyclonic activity east of Japan. Forcing from the tropical Pacific SST anomaly triggered a cyclonic anomaly over the South China Sea, which was maintained by atmosphere–ocean interactions and induced an anticyclonic anomaly via northward Rossby wave propagation. Overall, the model used for forecasting changma precipitation performed well (R = 0.85) and correctly predicted information for 16 out of 19 yr of observational data.

Sign in / Sign up

Export Citation Format

Share Document