Supplementary material to "The significant role of biomass burning aerosols in clouds and radiation in the South-eastern Atlantic Ocean"

Abstract. This study presents and evaluates an updated algorithm for quantification of absorbing aerosols above clouds (AACs) from passive satellite measurements. The focus is biomass burning in the south-eastern Atlantic Ocean during the 2016 and 2017 ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field campaign deployments. The algorithm retrieves the above-cloud aerosol optical depth (AOD) and underlying liquid cloud optical depth and is applied to measurements from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometer (MODIS), and Visible Infrared Imaging Radiometer Suite (VIIRS) from 1997 to 2017. Airborne NASA Ames Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) and NASA Langley High Spectral Resolution Lidar 2 (HSRL2) data collected during ORACLES provide important validation for spectral AOD for MODIS and VIIRS; as the SeaWiFS mission ended in 2010, it cannot be evaluated directly. The 4STAR and HSRL2 comparisons are complementary and reveal performance generally in line with uncertainty estimates provided by the optimal estimation retrieval framework used. At present the two MODIS-based data records seem the most reliable, although there are differences between the deployments, which may indicate that the available data are not yet sufficient to provide a robust regional validation. Spatiotemporal patterns in the data sets are similar, and the time series are very strongly correlated with each other (correlation coefficients from 0.95 to 0.99). Offsets between the satellite data sets are thought to be chiefly due to differences in absolute calibration between the sensors. The available validation data for this type of algorithm are limited to a small number of field campaigns, and it is strongly recommended that such airborne measurements continue to be made, both over the southern Atlantic Ocean and elsewhere.

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The significant role of biomass burning aerosols in clouds and radiation in the South-eastern Atlantic Ocean

10.5194/acp-2020-532 ◽

2020 ◽

Author(s):

Haochi Che ◽

Philip Stier ◽

Hamish Gordon ◽

Duncan Watson-Parris ◽

Lucia Deaconu

Keyword(s):

Significant Role ◽

Biomass Burning ◽

Fire Season ◽

Radiation Balance ◽

Radiative Effect ◽

Radiative Effects ◽

Liquid Water Path ◽

Absorption Effect ◽

Eastern Atlantic Ocean

Abstract. The South-eastern Atlantic Ocean (SEA) is semi-permanently covered by one of the most extensive stratocumulus cloud decks on the planet and experiences about one-third of the global biomass burning emissions from the southern Africa savannah region during the fire season. To get a better understanding of the impact of these biomass burning aerosols on clouds and radiation balance over the SEA, the latest generation of the UK Earth System Model (UKESM1) is employed. Measurements from the CLARIFY and ORACLES flight campaigns are used to evaluate the model, demonstrating that the model has good skill in reproducing the biomass burning plume. To investigate the underlying mechanisms in detail, the effects of biomass burning aerosols on the clouds are decomposed into radiative effects (via absorption and scattering) and microphysical effects (via perturbation of cloud condensation nuclei (CCN) and cloud microphysical processes). The July–August means are used to characterise aerosols, clouds and the radiation balance during the fire season. Results show around 68 % of CCN at 0.2 % supersaturation in the SEA domain can be attributed to biomass burning. The absorption effect of biomass burning aerosols is the most significant in affecting clouds and radiation. Near the continent it increases the maximum supersaturation diagnosed by the activation scheme, while further from the continent it reduces the altitude of the maximum supersaturation. As a result, the cloud droplet number concentration shows a similar pattern. The microphysical effect of biomass burning aerosols decreases the maximum supersaturation and increases the cloud droplets concentration over the ocean; however, this change is relatively small. The liquid water path is also significantly increased over the SEA (mainly caused by the absorption effect of biomass burning aerosols) when biomass burning aerosols are above the stratocumulus cloud deck. The microphysical pathways lead to a slight increase in the liquid water path over the ocean. These changes in cloud properties indicate the significant role of biomass burning aerosols on clouds in this region. Among the effects of biomass burning aerosols on radiation balance, the semi-direct radiative effects (rapid adjustments induced by biomass burning aerosols radiative effects) have a dominant cooling impact over the SEA, which offset the warming direct radiative effect (radiative forcing from biomass burning aerosol–radiation interactions). However, the magnitude and the sign of the semi-direct effects are dependent on the relative location of biomass burning aerosols and clouds. The net biomass burning aerosols radiative effect shows a negative cooling effect in the SEA, indicating the significant role of biomass burning aerosols in affecting the regional radiation balance and climate.

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Transport of North Pacific 137Cs labeled waters to the south-eastern Atlantic Ocean

Progress In Oceanography ◽

10.1016/j.pocean.2010.12.005 ◽

2011 ◽

Vol 89 (1-4) ◽

pp. 31-37 ◽

Cited By ~ 19

Author(s):

J.A. Sanchez-Cabeza ◽

I. Levy ◽

J. Gastaud ◽

M. Eriksson ◽

I. Osvath ◽

...

Keyword(s):

Atlantic Ocean ◽

North Pacific ◽

The South ◽

South Eastern ◽

Eastern Atlantic Ocean

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Two decades observing smoke above clouds in the south-eastern Atlantic Ocean: Deep Blue algorithm updates and validation with ORACLES field campaign data

10.5194/amt-2019-58 ◽

2019 ◽

Cited By ~ 1

Author(s):

Andrew M. Sayer ◽

N. Christina Hsu ◽

Jaehwa Lee ◽

Woogyung V. Kim ◽

Sharon Burton ◽

...

Keyword(s):

Time Series ◽

Atlantic Ocean ◽

Optical Depth ◽

High Spectral Resolution ◽

Absolute Calibration ◽

Strongly Correlated ◽

The South ◽

Field Campaign ◽

South Eastern ◽

Eastern Atlantic Ocean

Abstract. This study presents and evaluates an updated algorithm for quantification of absorbing aerosols above clouds (AACs) from passive satellite measurements. The focus is biomass burning in the south-eastern Atlantic Ocean during the 2016 and 2017 ObserRvations of Aerosols above CLouds and their interactionS (ORACLES) field campaign deployments. The algorithm retrieves the above-cloud aerosol optical depth (AOD) and underlying liquid cloud optical depth, and is intended to be applied to measurements from sensors including the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometers (MODIS), and Visible Infrared Imaging Radiometer Suite (VIIRS). Together, these sensors provide around twenty years of observations to date. Airborne NASA Ames Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) and NASA Langley High Spectral Resolution Lidar 2 (HSRL2) data collected during ORACLES provide important validation for spectral AOD for MODIS and VIIRS; as the SeaWiFS mission ended in 2010, it cannot be evaluated directly. These 4STAR and HSRL2 comparisons are complimentary and reveal performance generally in line with theoretical expectations. At present the two MODIS-based data records seem the most reliable, although there are differences between the deployments. Data collected in the region from other sources are also used to evaluate some assumptions made in the AAC retrieval. Spatiotemporal patterns in the data sets are very similar, and the time series themselves are very strongly correlated with each other (correlation coefficients from 0.95–0.99). Offsets between the time series are thought to be linked to differences in absolute calibration between the sensors, which can also explain some of the differences in validation results. The time series are also strongly correlated (correlations 0.78-0.94) with quantities such as ultraviolet aerosol index, total column AOD from standard MODIS aerosol products, and active fire detections. This suggests that these quantities may also act as proxies for the above-cloud aerosol load in this region, when AAC retrievals are unavailable.

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Crinoidea and Holothuroidea (Echinodermata) of the abyssal Angola Basin—Results of the DIVA-1 expedition of FS "Meteor" (Cruise M48/1)

Zootaxa ◽

10.11646/zootaxa.1276.1.1 ◽

2006 ◽

Vol 1276 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

JENS MICHAEL BOHN

Keyword(s):

Atlantic Ocean ◽

Rich Variety ◽

South Eastern ◽

Epibenthic Sledge ◽

Eastern Atlantic Ocean ◽

Agassiz Trawl

Agassiz trawl and epibenthic sledge samples taken at abyssal depths in the Angola Basin (south-eastern Atlantic Ocean) during the expedition DIVA-1 with FS "Meteor" in July 2000 yielded a rich variety of Echinodermata: inter alia one stalked crinoid (Bathycrinus cf. aldrichianus Wyville Thomson, 1876) and altogether nine holothurian species, two of which are subspecies. One of these, Achlyonice longicornis spec. nov., is new to science, while all others have been described earlier: Deima validum validum Théel, 1879, Psychropotes semperiana Théel, 1882, Peniagone purpurea (Théel, 1882), Molpadiodemas atlanticus (R. Perrier, 1898), Molpadia liska Pawson, 1977, Protankyra brychia (Verrill, 1885), Siniotrochus myriodontus Gage & Billett, 1986 and Neolepidotrochus parvidiscus angolensis Bohn, 2005. All species collected are described and their known distributions are given. Finally, two crinoids and 21 holothurian species, so far known from the abyssal Angola Basin, are listed and their zoogeographical relationships are discussed.

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Dual role of DOM in a scenario of global change on photosynthesis and structure of coastal phytoplankton from the South Atlantic Ocean

The Science of The Total Environment ◽

10.1016/j.scitotenv.2018.04.121 ◽

2018 ◽

Vol 634 ◽

pp. 1352-1361 ◽

Cited By ~ 6

Author(s):

Virginia E. Villafañe ◽

Joanna Paczkowska ◽

Agneta Andersson ◽

Cristina Durán Romero ◽

Macarena S. Valiñas ◽

...

Keyword(s):

Global Change ◽

Atlantic Ocean ◽

South Atlantic ◽

Dual Role ◽

South Atlantic Ocean ◽

The South ◽

Coastal Phytoplankton

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Southern right whales in the South-western Atlantic Ocean: proposed criteria to identify suitable areas of use in poorly known reproductive grounds

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315418001042 ◽

2019 ◽

Vol 99 (5) ◽

pp. 1231-1236

Author(s):

Giovanna Corrêa e Figueiredo ◽

Samara Cazzoli y Goya ◽

Marcos César de Oliveira Santos

Keyword(s):

Atlantic Ocean ◽

Eastern Coast ◽

The South ◽

Sandy Bottom ◽

Western Atlantic ◽

South Eastern ◽

Western Atlantic Ocean ◽

Right Whale ◽

Ranking Criteria ◽

Right Whales

AbstractUrbanization and intense vessel traffic in coastal areas are obstacles for right whales when selecting breeding and calving grounds. Human activities might be the main cause for the recently observed drop in right whale sightings along the south-eastern coast of Brazil. Information concerning the biology and the activities that can potentially affect the presence of individuals along the coast are essential for management purposes, as well as for the recovery of the species stocks after a period of whaling pressure. This study correlated the occurrence of right whales in the northern limit of the breeding ground in the South-western Atlantic Ocean with local geomorphology, degree of urbanization and oceanographic features to better identify suitable areas for use by these whales. The study area was divided into 14 sub-areas based on local coastal geomorphology and discharge of large rivers. The following five ranking criteria were applied to each sub-area: presence of whaling stations and whaling activity in the past; presence and activity of ports; protection from swell, coastal slope and composition of the bottom substrate. The sub-areas that offered conditions conducive to the presence of right whales received higher scores. The proposed criteria were validated by overlapping the ranking scores with the records of right whales sighted in each sub-area. In south-eastern Brazil, protected areas with sandy bottom and gentle slope were associated with more sightings of female-calf pairs. The criteria can be used as a primary diagnostic indicating suitable sub-areas for right whales in poorly known breeding grounds.

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