scholarly journals Recycled selenium in hot spot–influenced lavas records ocean-atmosphere oxygenation

2020 ◽  
Vol 6 (39) ◽  
pp. eabb6179
Author(s):  
Aierken Yierpan ◽  
Stephan König ◽  
Jabrane Labidi ◽  
Ronny Schoenberg
Keyword(s):  
Hot Spot ◽  
Atmospheric Oxygen ◽  
Sediment Record ◽  
Atmosphere System ◽  
Ocean Atmosphere ◽  
Selenium Isotope ◽  
Mass Dependent ◽  
Global Surface ◽  
Significant Mass

Oxygenation of Earth’s oceans and atmosphere through time has consequences for subducted surface signatures that are now stored in the mantle. Here, we report significant mass-dependent selenium isotope variations in modern hot spot–influenced oceanic lavas. These variations are correlated with tracers of mantle source enrichment, which can only be explained by incorporation of abyssal pelagic sediments subducted from a redox-stratified mid-Proterozoic ocean. Selenium geochemical signatures of these sediments have mostly been preserved during long-term recycling and may therefore complement the global surface sediment record as ancient oxygen archives. Combined deep mantle and surface perspectives, together with emerging models for atmospheric oxygen based on selenium systematics, further imply a significantly oxygenated ocean-atmosphere system throughout the mid-Proterozoic.

scholarly journals Biogeochemical Controls on the Redox Evolution of Earth’s Oceans and Atmosphere

Elements ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Christopher T. Reinhard ◽  
Noah J. Planavsky
Keyword(s):  
Redox State ◽  
Modeling Tools ◽  
Evolutionary Trajectory ◽  
Geochemical Tracers ◽  
Atmosphere System ◽  
Ocean Atmosphere ◽  
Dramatic Shift ◽  
Redox Evolution

The redox state of Earth’s atmosphere has undergone a dramatic shift over geologic time from reducing to strongly oxidizing, and this shift has been coupled with changes in ocean redox structure and the size and activity of Earth’s biosphere. Delineating this evolutionary trajectory remains a major problem in Earth system science. Significant insights have emerged through the application of redox-sensitive geochemical systems. Existing and emerging biogeochemical modeling tools are pushing the limits of the quantitative constraints on ocean–atmosphere redox that can be extracted from geochemical tracers. This work is honing our understanding of the central role of Earth’s biosphere in shaping the long-term redox evolution of the ocean–atmosphere system.

Albedo of the ocean–atmosphere system: influence of sea foam

1977 ◽  
Vol 16 (8) ◽  
pp. 2257 ◽  
Author(s):  
Howard R. Gordon ◽  
Michael M. Jacobs
Keyword(s):  
Atmosphere System ◽  
Ocean Atmosphere

Using a lake sediment record to infer the long-term history of cyanobacteria and the recent rise of an anatoxin producing Dolichospermum sp.

Harmful Algae ◽  
2021 ◽  
Vol 101 ◽  
pp. 101971
Author(s):  
William O. Hobbs ◽  
Theo W. Dreher ◽  
Edward W. Davis ◽  
Rolf D. Vinebrooke ◽  
Siana Wong ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Sediment Record ◽  
History Of

INFLUENCE OF REGULARITY OF SATELLITE MICROWAVE RADIOMETER MEASUREMENTS ON THE ACCURACY OF BRIGHTNESS TEMPERATURE REPRODUCTION IN AREAS OF THE TROPICAL CYCLONES

2021 ◽  
pp. 78-85
Author(s):  
А. G. Grankov ◽  
◽  
А. А. Milshin ◽  
Keyword(s):  
Brightness Temperature ◽  
Tropical Cyclones ◽  
Microwave Radiometer ◽  
Measurement Data ◽  
Hurricane Wilma ◽  
Brightness Temperatures ◽  
Atmosphere System ◽  
Ocean Atmosphere ◽  
The Caribbean ◽  
Satellite Microwave

An accuracy of reproduction of daily variations in the ocean–atmosphere system brightness temperature in the areas of development and movement of tropical hurricanes in the Caribbean Sea and Gulf of Mexico is analyzed. The analysis is based on the data of single and group satellite microwave radiometer measurements. The results are obtained using archival measurement data of SSM/I radiometers from the F11, F13, F14, and F15 DMSP satellites during the period of existence of tropical hurricanes Bret and Wilma. An example is given to demonstrate the use of daily brightness temperatures obtained from DMSP satellites for monitoring the development and propagation of hurricane Wilma.

scholarly journals A 250-year periodicity in Southern Hemisphere westerly winds over the last 2600 years

2016 ◽  
Vol 12 (2) ◽  
pp. 189-200 ◽  
Author(s):  
C. S. M. Turney ◽  
R. T. Jones ◽  
C. Fogwill ◽  
J. Hatton ◽  
A. N. Williams ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Global Climate Change ◽  
Late Holocene ◽  
Global Climate ◽  
Falkland Islands ◽  
The Core ◽  
Atmosphere System ◽  
Westerly Winds ◽  
Ocean Atmosphere ◽  
Southern Hemisphere Westerly Winds

Abstract. Southern Hemisphere westerly airflow has a significant influence on the ocean–atmosphere system of the mid- to high latitudes with potentially global climate implications. Unfortunately, historic observations only extend back to the late 19th century, limiting our understanding of multi-decadal to centennial change. Here we present a highly resolved (30-year) record of past westerly wind strength from a Falkland Islands peat sequence spanning the last 2600 years. Situated within the core latitude of Southern Hemisphere westerly airflow (the so-called furious fifties), we identify highly variable changes in exotic pollen and charcoal derived from South America which can be used to inform on past westerly air strength. We find a period of high charcoal content between 2000 and 1000 cal. years BP, associated with increased burning in Patagonia, most probably as a result of higher temperatures and stronger westerly airflow. Spectral analysis of the charcoal record identifies a pervasive ca. 250-year periodicity that is coherent with radiocarbon production rates, suggesting that solar variability has a modulating influence on Southern Hemisphere westerly airflow. Our results have important implications for understanding global climate change through the late Holocene.

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