scholarly journals Alternate history: A synthetic ensemble of ocean chlorophyll concentrations

2021 ◽  
Author(s):  
Geneviève W. Elsworth ◽  
Nicole S. Lovenduski ◽  
Karen A. McKinnon
Keyword(s):  
Alternate History ◽  
Chlorophyll Concentrations

scholarly journals Alternate history: A synthetic ensemble of ocean chlorophyll concentrations

2021 ◽  
Author(s):  
Geneviève Elsworth ◽  
Nicole Lovenduski ◽  
Karen McKinnon
Keyword(s):  
Alternate History ◽  
Chlorophyll Concentrations

scholarly journals Alternate history: A synthetic ensemble of ocean chlorophyll concentrations

2021 ◽  
Author(s):  
Geneviève Wheeler Elsworth ◽  
Nicole Suzanne Lovenduski ◽  
Karen McKinnon
Keyword(s):  
Alternate History ◽  
Chlorophyll Concentrations

The Romantics in Alternate History from Hawthorne to Clarke: Generic Edges and the Counterfactual Turn

Romanticism ◽  
2018 ◽  
Vol 24 (2) ◽  
pp. 203-215
Author(s):  
Alex Broadhead
Keyword(s):  
Nineteenth Century ◽  
Alternate History ◽  
Recent Developments ◽  
The Relationship ◽  
Critical Interest

In 2009, Damian Walford Davies called for a counterfactual turn in Romantic studies, a move reflective of a wider growth of critical interest in the relationship between Romanticism and counterfactual historiography. In contrast to these more recent developments, the lives of the Romantics have provided a consistent source of speculation for authors of popular alternate history since the nineteenth century. Yet the aims of alternate history as a genre differ markedly from those of its more scholarly cousin, counterfactual historiography. How, then, might such works fit in to the proposed counterfactual turn? This article makes a case for the critical as well as the creative value of alternate histories featuring the Romantics. By exploring how these narratives differ from works of counterfactual historiography, it seeks to explain why the Romantics continue to inspire authors of alternate history and to illuminate the forking paths that Davies's counterfactual turn might take.

Balance between Phytoplankton Production and Plankton Respiration in Lakes

1993 ◽  
Vol 50 (2) ◽  
pp. 282-289 ◽  
Author(s):  
Paul A. del Giorgio ◽  
Robert H. Peters
Keyword(s):  
Community Respiration ◽  
Phytoplankton Production ◽  
External Energy ◽  
Eutrophic Lakes ◽  
Oligotrophic Lakes ◽  
Plankton Community Respiration ◽  
Algal Photosynthesis ◽  
Chlorophyll Concentrations ◽  
Trophic Range ◽  
Good Agreement

We analyzed published rates of algal photosynthesis and plankton community respiration to test the hypothesis that the ratio of planktonic primary production to community (P/R) varies systematically with lake trophy. Regression analyses show that algal production and plankton respiration are closely related to chlorophyll concentrations for lakes spanning a wide trophic range. More surprisingly, plankton respiration exceeds algal photosynthesis in oligotrophic lakes, and P/R rises above unity only when chlorophyll concentrations are above 17 mg∙m−3. A simple allometric model based on the predicted biomasses of the different planktonic component yield rates of community respiration that are in good agreement with measured values. Moreover, the model suggest that in oligotrophic lakes, microbial respiration may greatly exceed the current estimates based on bacterial production data and that heterotrophs contribute proportionately more to total plankton metabolism than they do in eutrophic lakes. Because such high respiration rates require external energy subsidies, these results; challenge the view that pelagial communities of most lakes are even approximately self-supporting.

Alternate History: Playing with Contingency and Necessity

Poetics Today ◽  
2015 ◽  
Vol 36 (1-2) ◽  
pp. 143-146
Author(s):  
E. Segal
Keyword(s):  
Alternate History

Influence of Reservoir Transit on Riverine Algal Transport and Abundance

1984 ◽  
Vol 41 (12) ◽  
pp. 1803-1813 ◽  
Author(s):  
D. M. Søballe ◽  
R. W. Bachmann
Keyword(s):  
Water Temperature ◽  
Retention Time ◽  
Standing Crop ◽  
Algal Biomass ◽  
Chlorophyll Concentration ◽  
Light Limitation ◽  
Des Moines ◽  
Flow Dependence ◽  
Major Loss ◽  
Chlorophyll Concentrations

The Des Moines River lost 65–75% of its algal standing crop (chlorophyll a) in passing through each of two impoundments (mean retention times 11 and 16 d), and chlorophyll concentrations within both impoundments were 50–90% below the predictions of empirical chlorophyll–nutrient models. Sedimentation of river-borne algae and light limitation within the impoundments were identified as major loss processes. A reduction in algal size from upstream to downstream in one reservoir paralleled the loss of algal biomass. Algal losses in each impoundment increased with both increasing retention time and water temperature so that chlorophyll concentration below the dams was uncoupled from the temperature and flow dependence seen in river reaches not influenced by impoundments. The reduction in riverine algal transport associated with reservoir transit was cumulative over the two-reservoir series; this reduction can be interpreted as a "reset" to river headwater conditions.

Importance of Human-Induced Nitrogen Flux Increases for Simulated Arctic Warming

2021 ◽  
Vol 34 (10) ◽  
pp. 3799-3819
Author(s):  
Hyung-Gyu Lim ◽  
Jong-Yeon Park ◽  
John P. Dunne ◽  
Charles A. Stock ◽  
Sung-Ho Kang ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
The Arctic ◽  
Biogeochemical Model ◽  
Biological Feedback ◽  
Arctic Warming ◽  
The Arctic Ocean ◽  
N Fluxes ◽  
The Impact ◽  
Chlorophyll Concentrations

AbstractHuman activities such as fossil fuel combustion, land-use change, nitrogen (N) fertilizer use, emission of livestock, and waste excretion accelerate the transformation of reactive N and its impact on the marine environment. This study elucidates that anthropogenic N fluxes (ANFs) from atmospheric and river deposition exacerbate Arctic warming and sea ice loss via physical–biological feedback. The impact of physical–biological feedback is quantified through a suite of experiments using a coupled climate–ocean–biogeochemical model (GFDL-CM2.1-TOPAZ) by prescribing the preindustrial and contemporary amounts of riverine and atmospheric N fluxes into the Arctic Ocean. The experiment forced by ANFs represents the increase in ocean N inventory and chlorophyll concentrations in present and projected future Arctic Ocean relative to the experiment forced by preindustrial N flux inputs. The enhanced chlorophyll concentrations by ANFs reinforce shortwave attenuation in the upper ocean, generating additional warming in the Arctic Ocean. The strongest responses are simulated in the Eurasian shelf seas (Kara, Barents, and Laptev Seas; 65°–90°N, 20°–160°E) due to increased N fluxes, where the annual mean surface temperature increase by 12% and the annual mean sea ice concentration decrease by 17% relative to the future projection, forced by preindustrial N inputs.

scholarly journals Spectral studies of ocean water using DOAS

2007 ◽  
Vol 4 (3) ◽  
pp. 459-489
Author(s):  
M. Vountas ◽  
T. Dinter ◽  
A. Bracher ◽  
J. P. Burrows ◽  
B. Sierk
Keyword(s):  
Spectral Studies ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Technique ◽  
Phytoplankton Absorption ◽  
Visible Wavelengths ◽  
Scanning Imaging ◽  
Atmospheric Trace Gas ◽  
First Time ◽  
Chlorophyll Concentrations

Abstract. Methods enabling the retrieval of oceanic parameter from the space borne instrumentation Scanning Imaging Absorption Spectrometer for Atmospheric ChartographY (SCIAMACHY) using Differential Optical Absorption Spectroscopy (DOAS) are presented. SCIAMACHY onboard ENVISAT measures back scattered solar radiation at a spectral resolution (0.2 to 1.5 nm). The DOAS method was used for the first time to fit modelled Vibrational Raman Scattering (VRS) in liquid water and in situ measured phytoplankton absorption reference spectra to optical depths measured by SCIAMACHY. Spectral structures of VRS and phytoplankton absorption were clearly found in these optical depths. Both fitting approaches lead to consistent results. DOAS fits correlate with estimates of chlorophyll concentrations: low fit factors for VRS retrievals correspond to large chlorophyll concentrations and vice versa; large fit factors for phytoplankton absorption correspond with high chlorophyll concentrations and vice versa. From these results a simple retrieval technique taking advantage of both measurements is shown. First maps of global chlorophyll concentrations were compared to the corresponding MODIS measurements with very promising results. In addition, results from this study will be used to improve atmospheric trace gas DOAS-retrievals from visible wavelengths by including these oceanographic signatures.

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