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

2019 ◽  
Vol 12 (7) ◽  
pp. 3595-3627 ◽  
Author(s):  
Andrew M. Sayer ◽  
N. Christina Hsu ◽  
Jaehwa Lee ◽  
Woogyung V. Kim ◽  
Sharon Burton ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Optical Depth ◽  
Data Sets ◽  
The South ◽  
Validation Data ◽  
Field Campaign ◽  
Airborne Measurements ◽  
South Eastern ◽  
Eastern Atlantic Ocean ◽  
Uncertainty Estimates

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.

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

2019 ◽  
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.

scholarly journals Increasing the Resolution of Ocean pCO2 Maps in the South Eastern Atlantic Ocean Merging Multifractal Satellite-Derived Ocean Variables

2018 ◽  
Vol 56 (11) ◽  
pp. 6596-6610 ◽  
Author(s):  
Ismael Hernandez-Carrasco ◽  
Veronique Garcon ◽  
Joel Sudre ◽  
Christoph Garbe ◽  
Hussein Yahia
Keyword(s):  
Atlantic Ocean ◽  
The South ◽  
South Eastern ◽  
Eastern Atlantic Ocean

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

2011 ◽  
Vol 89 (1-4) ◽  
pp. 31-37 ◽  
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

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

Zootaxa ◽  
2006 ◽  
Vol 1276 (1) ◽  
pp. 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.

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

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.

scholarly journals Copepod species abundance from the Southern Ocean and other regions (1980–2005) – a legacy

2018 ◽  
Vol 10 (3) ◽  
pp. 1457-1471 ◽  
Author(s):  
Astrid Cornils ◽  
Rainer Sieger ◽  
Elke Mizdalski ◽  
Stefanie Schumacher ◽  
Hannes Grobe ◽  
...  
Keyword(s):  
Life Cycle ◽  
Atlantic Ocean ◽  
Southern Ocean ◽  
Calanoid Copepod ◽  
Weddell Sea ◽  
Copepod Species ◽  
Data Sets ◽  
Abundance Distribution ◽  
Sampling Depth ◽  
Eastern Atlantic Ocean

Abstract. This data collection originates from the efforts of Sigrid Schnack-Schiel (1946–2016), a zooplankton ecologist with great expertise in life cycle strategies of Antarctic calanoid copepods, who also investigated zooplankton communities in tropical and subtropical marine environments. Here, we present 33 data sets with abundances of planktonic copepods from 20 expeditions to the Southern Ocean (Weddell Sea, Scotia Sea, Amundsen Sea, Bellingshausen Sea, Antarctic Peninsula), one expedition to the Magellan region, one latitudinal transect in the eastern Atlantic Ocean, one expedition to the Great Meteor Bank, and one expedition to the northern Red Sea and Gulf of Aqaba as part of her scientific legacy. A total of 349 stations from 1980 to 2005 were archived. During most expeditions depth-stratified samples were taken with a Hydrobios multinet with five or nine nets, thus allowing inter-comparability between the different expeditions. A Nansen or a Bongo net was deployed only during four cruises. Maximum sampling depth varied greatly among stations due to different bottom depths. However, during 11 cruises to the Southern Ocean the maximum sampling depth was restricted to 1000 m, even at locations with greater bottom depths. In the eastern Atlantic Ocean (PS63) sampling depth was restricted to the upper 300 m. All data are now freely available at PANGAEA via the persistent identifier https://doi.org/10.1594/PANGAEA.884619.Abundance and distribution data for 284 calanoid copepod species and 28 taxa of other copepod orders are provided. For selected species the abundance distribution at all stations was explored, revealing for example that species within a genus may have contrasting distribution patterns (Ctenocalanus, Stephos). In combination with the corresponding metadata (sampling data and time, latitude, longitude, bottom depth, sampling depth interval) the analysis of the data sets may add to a better understanding how the environment (currents, temperature, depths, season) interacts with copepod abundance, distribution and diversity. For each calanoid copepod species, females, males and copepodites were counted separately, providing a unique resource for biodiversity and modelling studies. For selected species the five copepodite stages were also counted separately, thus also allowing the data to be used to study life cycle strategies of abundant or key species.

scholarly journals A review and framework for the evaluation of pixel-level uncertainty estimates in satellite aerosol remote sensing

2020 ◽  
Vol 13 (2) ◽  
pp. 373-404 ◽  
Author(s):  
Andrew M. Sayer ◽  
Yves Govaerts ◽  
Pekka Kolmonen ◽  
Antti Lipponen ◽  
Marta Luffarelli ◽  
...  
Keyword(s):  
Uncertainty Propagation ◽  
Optimal Estimation ◽  
Sensitivity Analyses ◽  
Data Sets ◽  
Validation Data ◽  
Data Set ◽  
Formal Error ◽  
Uncertainty Estimates ◽  
Diagnostic Approaches

Abstract. Recent years have seen the increasing inclusion of per-retrieval prognostic (predictive) uncertainty estimates within satellite aerosol optical depth (AOD) data sets, providing users with quantitative tools to assist in the optimal use of these data. Prognostic estimates contrast with diagnostic (i.e. relative to some external truth) ones, which are typically obtained using sensitivity and/or validation analyses. Up to now, however, the quality of these uncertainty estimates has not been routinely assessed. This study presents a review of existing prognostic and diagnostic approaches for quantifying uncertainty in satellite AOD retrievals, and it presents a general framework to evaluate them based on the expected statistical properties of ensembles of estimated uncertainties and actual retrieval errors. It is hoped that this framework will be adopted as a complement to existing AOD validation exercises; it is not restricted to AOD and can in principle be applied to other quantities for which a reference validation data set is available. This framework is then applied to assess the uncertainties provided by several satellite data sets (seven over land, five over water), which draw on methods from the empirical to sensitivity analyses to formal error propagation, at 12 Aerosol Robotic Network (AERONET) sites. The AERONET sites are divided into those for which it is expected that the techniques will perform well and those for which some complexity about the site may provide a more severe test. Overall, all techniques show some skill in that larger estimated uncertainties are generally associated with larger observed errors, although they are sometimes poorly calibrated (i.e. too small or too large in magnitude). No technique uniformly performs best. For powerful formal uncertainty propagation approaches such as optimal estimation, the results illustrate some of the difficulties in appropriate population of the covariance matrices required by the technique. When the data sets are confronted by a situation strongly counter to the retrieval forward model (e.g. potentially mixed land–water surfaces or aerosol optical properties outside the family of assumptions), some algorithms fail to provide a retrieval, while others do but with a quantitatively unreliable uncertainty estimate. The discussion suggests paths forward for the refinement of these techniques.

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