Pedro M.S. Monteiro

Pedro M.S. Monteiro
Council for Scientific and Industrial Research, South Africa | CSIR · Natural Resources and the Environment Research Area

PhD Oceanography

About

96
Publications
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Publications

Publications (96)
Article
Full-text available
The Southern Ocean is a complex system yet is sparsely sampled in both space and time. These factors raise questions about the confidence in present sampling strategies and associated machine learning (ML) reconstructions. Previous studies have not yielded a clear understanding of the origin of uncertainties and biases for the reconstructions of th...
Article
Full-text available
Water mass transformation in the Southern Ocean is vital for driving the large‐scale overturning circulation, which transports heat from the surface to the ocean interior. Using profiling gliders, this study investigates the role of summertime buoyancy forcing and wind‐driven processes on the intraseasonal (1–10 days) mixed layer thermohaline varia...
Article
Full-text available
The subpolar Southern Ocean is a critical region where CO 2 outgassing influences the global mean air-sea CO 2 flux (F CO2 ). However, the processes controlling the outgassing remain elusive. We show, using a multi-glider dataset combining F CO2 and ocean turbulence, that the air-sea gradient of CO 2 (∆pCO 2 ) is modulated by synoptic storm-driven...
Preprint
Full-text available
The Southern Ocean is a complex system yet is sparsely sampled in both space and time. These factors raise questions about the confidence in present sampling strategies and associated machine learning (ML) reconstructions. Previous studies have not yielded a clear understanding of the origin of uncertainties and biases for the reconstructions of th...
Chapter
Full-text available
The Working Group I (WGI) contribution to the Intergovernmental Panel on Climate Change Sixth Assessment Report (AR6) assess the physical science basis of climate change. As part of that contribution, this Technical Summary (TS) is designed to bridge between the comprehensive assessment of the WGI Chapters and its Summary for Policymakers (SPM). I...
Technical Report
Full-text available
Full report available from https://unesdoc.unesco.org/ark:/48223/pf0000376708.locale=en doi:10.25607/h0gj-pq41
Conference Paper
The Working Group I (WGI) contribution to the Intergovernmental Panel on Climate Change Sixth Assessment Report (AR6) assess the physical science basis of climate change. As part of that contribution, this Technical Summary (TS) is designed to bridge between the comprehensive assessment of the WGI Chapters and its Summary for Policymakers (SPM). It...
Data
An update to the original CSIR-ML6 method. The following changes have been made: SOCATv2020 is used; ERA5 wind data and MSLP are used (instead of ERA interim); SODA salinity is used instead of EN4 salinity. Please cite the dataset as well as the original publication (https://doi.org/10.5194/gmd-12-5113-2019).
Article
Full-text available
Dissolved iron (DFe) plays an immeasurable role in shaping the biogeochemical processes of the open‐ocean Southern Ocean. However, due to observational constraints iron supply pathways remain poorly understood. Using an idealized eddy‐resolving physical‐biogeochemical model representing a turbulent sector of the Southern Ocean with seasonal buoyanc...
Article
Full-text available
Over the last decade, advanced statistical inference and machine learning have been used to fill the gaps in sparse surface ocean CO2 measurements (Rödenbeck et al., 2015). The estimates from these methods have been used to constrain seasonal, interannual and decadal variability in sea–air CO2 fluxes and the drivers of these changes (Landschützer e...
Article
Full-text available
Natural variability and change of the Earth’s climate have significant global societal impacts. With its large heat and carbon capacity and relatively slow dynamics, the ocean plays an integral role in climate, and provides an important source of predictability at seasonal and longer timescales. In addition, the ocean provides the slowly evolving l...
Article
Full-text available
Plain Language Summary Trace metal iron is one of the limiting nutrients for primary productivity in the Southern Ocean; however, the relative importance of seasonal iron supply and sinks remains poorly understood, due to sparse data coverage across the seasonal cycle and lack of high‐resolution dissolved iron (DFe) measurements. Here we present fo...
Preprint
Full-text available
Over the last decade, advanced statistical inference and machine learning have been used to fill the gaps in sparse surface ocean CO 2 measurements (Rödenbeck et al. 2015). The estimates from these methods have been used to constrain seasonal, interannual and decadal variability in sea­air CO 2 fluxes and the drivers of these changes (Landschützer...
Article
Full-text available
The Southern Ocean forms an important component of the Earth system as a major sink of CO2 and heat. Recent studies based on the Coupled Model Intercomparison Project version 5 (CMIP5) Earth system models (ESMs) show that CMIP5 models disagree on the phasing of the seasonal cycle of the CO2 flux (FCO2) and compare poorly with available observation...
Article
Full-text available
Resolving and understanding the drivers of variability of CO2 in the Southern Ocean and its potential climate feedback is one of the major scientific challenges of the ocean-climate community. Here we use a regional approach on empirical estimates of pCO2 to understand the role that seasonal variability has in long-term CO2 changes in the Southern...
Article
Full-text available
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and m...
Article
Full-text available
The Southern Ocean accounts for 40 % of oceanic CO2 uptake, but the estimates are bound by large uncertainties due to a paucity in observations. Gap-filling empirical methods have been used to good effect to approximate pCO2 from satellite observable variables in other parts of the ocean, but many of these methods are not in agreement in the Southe...
Preprint
Full-text available
The Southern Ocean forms a key component of the global carbon cycle. Recent studies, however, show that CMIP5 Earth System Models (ESM) disagree on the representation of the seasonal cycle of the CO2 flux (FCO2) and compare poorly to observations in the Southern Ocean. This model-observations bias has important implications on the ability of ESMs t...
Preprint
Full-text available
Machine learning methods (support vector regression and random forest regression) were used to map gridded estimates of ΔpCO2 in the Southern Ocean from SOCAT v3 data. A low (1° × monthly) and high (0.25° × 16-day) resolution implementation of each of these methods as well as the SOM-FFN method of Landschützer et al. (2014) were added to a five mem...
Preprint
Full-text available
The Southern Ocean accounts for 40 % of oceanic CO2 uptake, but the estimates are bound by large uncertainties due to a paucity in observations. Gap filling empirical methods have been used to good effect to approximate pCO2 from satellite observable variables in other parts of the ocean, but many of these methods are not in agreement in the Southe...
Article
South Africa’s small-pelagic fishery is a socio-economically important component of the country’s commercial fisheries sector, second in value only to the demersal trawl fishery. Management of this sector relies on infrequent hydro-acoustic surveys, which provide measures of anchovy Engraulis encrasicolus and sardine Sardinops sagax biomass used in...
Article
Full-text available
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and m...
Article
Full-text available
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and m...
Article
The Southern Ocean forms a key component of the global carbon budget, taking up about 1.0 Pg C yr⁻¹ of anthropogenic CO2 emitted annually (∼10.7 ± 0.5 Pg C yr⁻¹ for 2012). However, despite its importance, it still remains undersampled with respect to surface ocean carbon flux variability, resulting in weak constraints for ocean carbon and carbon –...
Article
Full-text available
The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values rela...
Article
Full-text available
In the Sub-Antarctic Ocean elevated phytoplankton biomass persists through summer at a time when productivity is expected to be low due to iron limitation. Biological iron recycling has been shown to support summer biomass. In addition, we investigate an iron supply mechanism previously unaccounted for in iron budget studies. Using a 1-D biogeochem...
Working Paper
Full-text available
The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.5 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.4 million fCO2 values rela...
Article
Full-text available
The Southern Ocean (SO) contributes most of the uncertainty in contemporary estimates of the mean annual flux of carbon dioxide CO2 between the ocean and the atmosphere. Attempts to reduce this uncertainty have aimed at resolving the seasonal cycle of the fugacity of CO2 (fCO2). We use hourly CO2 flux and driver observations collected by the combin...
Article
Full-text available
In the Southern Ocean, there is increasing evidence that seasonal to subseasonal temporal scales, and meso- to submesoscales play an important role in understanding the sensitivity of ocean primary productivity to climate change. This drives the need for a high-resolution approach to resolving biogeochemical processes. In this study, 5.5 months of...
Article
Full-text available
Increasing anthropogenic CO2 is decreasing surface water aragonite saturation state (ΩA), a growing concern for calcifying Euthecosome pteropods and its wider impact on Antarctic ecosystems. However, our understanding of the seasonal cycle and interannual variability of this vulnerable ecosystem remains limited. This study examines surface water ΩA...
Article
Full-text available
The objective in this paper is to investigate the use of a non-parametric approach to model the relationship between oceanic carbon dioxide \((pCO_2)\) and a range of ocean physics and biogeochemical in situ variables in the Southern Ocean, which influence its in situ variability. The need for this stems from the need to obtain reliable estimates o...
Article
Full-text available
The seasonal cycle of primary productivity is impacted by seasonal and intra-seasonal dynamics of the mixed layer through the changing balance between mixing and buoyancy forcing, which regulates nutrient supply and light availability. Of particular recent interest is the role of synoptic scale events in supplying nutrients, particularly iron, to t...
Article
In this study we use the southern Benguela upwelling system to investigate the role of nutrient and carbon stoichiometry on carbonate dynamics in eastern boundary upwelling systems. Six months in 2010 were sampled along a cross-shelf transect. Data were classified into summer, autumn, and winter. Nitrate, phosphate, dissolved inorganic carbon, and...
Article
Three scales of LOW variability were found to be amenable to forecasting as well as being suitable to provide information that would be of use to management response plans.u⊙ Short time scale: 7 day lead events linked to local wind variability and "HABs"⊙ Medium Time Scale: 2 month lead events linked to "ETSA" easterly equatorial winds⊙ Decadal Tim...
Article
Full-text available
The Southern Ocean (44–75° S) plays a critical role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Different approaches have been used to estimate sea–air CO2 fluxes in this region: synthesis of surface ocean observations, ocean biogeochemical models, and atmospheric and ocean inversions. As part of the RECCAP...
Article
Full-text available
The Southern Ocean (44° S–75° S) plays a critical role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Different approaches have been used to estimate sea-air CO2 fluxes in this region: synthesis of surface ocean observations, ocean biogeochemical models, and atmospheric and ocean inversions. As part of the REC...
Article
Full-text available
This study was undertaken to characterise the seasonal cycle of air-sea fluxes of carbon dioxide (CO2) in the southern Benguela upwelling system off the South African west coast. Samples were collected from six monthly cross-shelf cruises in the St. Helena Bay region during 2010. CO2 fluxes were calculated from pCO2 derived from total alkalinity an...
Article
Full-text available
Two sets of high-resolution subsurface hydrographic and underway surface chlorophyll a (Chl a) measurements are used, in conjunction with satellite remotely sensed data, to investigate the upper layer oceanography (mesoscale features and mixed layer depth variability) and phytoplankton biomass at the GoodHope line south of Africa, during the 2010–2...
Article
Full-text available
1] We examine the sensitivity of surface chlorophyll‐a concentrations (as a proxy for phytoplankton biomass) to short‐term, transient Mixed‐Layer variability in the High Nutrient‐Low Chlorophyll Southern Ocean during the austral summer. To investigate this sensitivity, we use satellite remote sensing data, Ocean reanalyses, and the biogeo-chemical...
Article
Full-text available
In early May 2012, South Africa will take delivery of a new polar research ship, the SA Agulhas II, representing a significant investment of R1.6 billion in polar infrastructure to further strengthen South Africa's presence in the polar region, particularly in support of its stewardship of the Southern Ocean and Antarctic Treaty obligations. This i...
Article
Full-text available
In the Ocean, the seasonal cycle is the mode that couples climate forcing to ecosystem response in production, diversity and carbon export. A better characterisation of the ecosystem's seasonal cycle therefore addresses an important gap in our ability to estimate the sensitivity of the biological pump to climate change. In this study, the regional...
Article
Workshop on the Seasonal Cycle of the Carbon-Climate System in the Southern Ocean; Cape Town, South Africa, 23-25 August 2010; There is increasing evidence in the Southern Ocean that mesoscales and seasonal scales play an important role in the coupling of ocean carbon cycling and climate. The seasonal cycle is one of the strongest modes of variabil...
Article
Full-text available
The seasonal cycle is the mode that couples climate forcing to ecosystem production. A better understanding of the regional characteristics of the seasonal cycle addresses an important gap in our understanding of the sensitivity of the biological pump to climate change. The regional characteristics of the seasonal cycle of phytoplankton biomass in...
Article
Full-text available
In this study we investigate the possible reasons for the widespread differences between the seasonal cycles of carbon production and export compared to those of hypoxia in eastern boundary upwelling systems. An idealized model is proposed that qualitatively characterizes the relative roles of physics and biogeochemical fluxes. The model is tested...
Article
Full-text available
This paper reviews the current state of observation, parameterization and evaluation of surface air-sea energy and gas fluxes, and sea ice, for the purposes of monitoring and predicting the state of the global ocean. The last 10 years have been marked by the development of more accurate parameterizations of turbulent fluxes, in particular COARE-3....
Article
Full-text available
We review here the available information on methane (CH<sub>4</sub>) and nitrous oxide (N<sub>2</sub>O) from major marine, mostly coastal, oxygen (O<sub>2</sub>)-deficient zones formed both naturally and as a result of human activities (mainly eutrophication). Concentrations of both gases in subsurface waters are affected by ambient O<sub>2</sub> l...
Article
Full-text available
Hypoxia has become a world-wide phenomenon in the global coastal ocean and causes a deterioration of the structure and function of ecosystems. Based on the collective contributions of members of SCOR Working Group #128, the present study provides an overview of the major aspects of coastal hypoxia in different biogeochemical provinces, including es...
Article
With data obtained in the course of a pollution monitoring programme in Saldanha Bay between 1974 and 1979, it is shown how chlorophyll is affected by interannual variability in the characteristics of coastal water. Inflow of warm, oligotrophic oceanic water into the inshore zone in December 1974 and 1976 caused a marked depression in the nitrate c...
Article
Full-text available
This study uses stable isotope ratios of nitrogen (δ15N) to test the hypothesis that a bloom of the green seaweed Ulva lactuca, which occurred in Saldanha Bay, South Africa, in summer 1993/94 was linked to an adjacent discharge of nitrogen from pelagic fish processing waste. It is suggested that only two significant sources of new nitrogen were ava...
Article
In 1975, major harbour works modified the physiography of Saldanha Bay, dividing it into two bodies of water, Big Bay and Small Bay. This study uses historical drogue data to investigate the relative importance of physical forcing mechanisms (wind and tides) in Saldanha Bay after 1975. It is concluded that wind-forcing is the dominant factor in det...