scholarly journals Phytoplankton and Bacterial Response to Desert Dust Deposition in the Coastal Waters of the Southeastern Mediterranean Sea: A Four-Year In Situ Survey

Atmosphere ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 305 ◽  
Author(s):  
Eyal Rahav ◽  
Natalia Belkin ◽  
Adina Paytan ◽  
Barak Herut
Keyword(s):  
Mediterranean Sea ◽  
Coastal Waters ◽  
Standing Stock ◽  
Dust Emission ◽  
Deep Ocean ◽  
Biomass Accumulation ◽  
Storm Events ◽  
Atmospheric Conditions ◽  
Dust Deposition

Atmospheric dust/aerosol deposition is an important source of external nutrients for the surface of the ocean. This study shows high-resolution observational data gathered in situ over a period of four years on bacterial and phytoplankton abundance and activity during typical background atmospheric conditions and during intense dust storm events in the low-nutrient, low-chlorophyll (LNLC) coastal waters of the southeastern Mediterranean Sea (SEMS). Chlorophyll a (an estimate for phytoplankton biomass) and bacterial abundance show moderate changes in response to dust deposition/events (−10% and +20%, respectively), while primary production, bacterial production, and N2 fixation rates were all significantly and positively affected by deposition (+25 to +40%; p < 0.05). The rapid changes in bacterial and/or phytoplankton rate parameters suggest that the released micro-/macronutrients from atmospheric deposition are tunneled directly in metabolic processes and, to a lesser extent, for biomass accumulation. The predicted expansion of LNLC areas in oceans in the future, and the projected increase in dust emission due to desertification, may affect the production of marine microbial communities in the surface of the ocean, yet only moderately affect their biomass or standing stock. Such alterations may impact carbon sequestration to the deep ocean.

scholarly journals Impact of Argo Observation on the Regional Ocean Reanalysis of China Coastal Waters and Adjacent Seas: A Twin-Experiment Study

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Caixia Shao ◽  
Lili Xuan ◽  
Yingzhi Cao ◽  
Xiaojian Cui ◽  
Siyu Gao
Keyword(s):  
Coastal Waters ◽  
Unique Feature ◽  
Information Service ◽  
Deep Ocean ◽  
Ocean Reanalysis ◽  
Rms Error ◽  
Regional Reanalysis ◽  
Argo Profiles ◽  
The Impact

A regional ocean reanalysis system of China coastal waters and adjacent seas, called CORA (China ocean reanalysis), has been recently developed at the National Marine Data and Information Service (NMDIS). In this study, based on CORA, the impact of Argo profiles on the regional reanalysis is evaluated using a twin-experiment approach. It is found that, by assimilating Argo observations, the reanalysis quality is much improved: the root mean square (RMS) error of temperature and salinity can be further reduced by about 10% and the RMS error of current can be further reduced by 18%, compared to the case only assimilating conventional in situ temperature and salinity observations. Consistent with the unique feature of Argo observations, the temperature is improved in all levels and the largest improvement of salinity happens in the deep ocean. Argo profile data have a significant impact on the regional ocean reanalysis through improvements of both hydrographic and dynamic fields.

Impacts of aeolian dust deposition on phytoplankton dynamics in Queensland coastal waters

2008 ◽  
Vol 59 (11) ◽  
pp. 951 ◽  
Author(s):  
Emily C. Shaw ◽  
Albert J. Gabric ◽  
Grant H. McTainsh
Keyword(s):  
Coastal Waters ◽  
Standing Stock ◽  
Nutrient Budget ◽  
Dust Storms ◽  
Dust Deposition ◽  
Transport Modelling ◽  
Dust Transport ◽  
Aeolian Dust ◽  
Modelling Analysis

Aeolian dust deposition has been shown to stimulate phytoplankton growth in various oligotrophic oceanic regions of the northern hemisphere. The present study investigated the relationship between the change in phytoplankton biomass in Queensland coastal waters and aeolian dust deposition during the severe October 2002 dust storm, using satellite-derived chlorophyll concentrations. A response in phytoplankton standing stock immediately following dust deposition from this event was found in the area of maximal dust deposition, as defined by a previous dust transport modelling analysis. Standing stock levels increased to 1.5–2 times the long-term mean. This is the first documented episode of a dust fertilisation event in Australian coastal waters and, given the high frequency of dust storms in northern Australia, demonstrates that aeolian delivery of nutrients may be an important factor in future regional nutrient budget analyses.

scholarly journals Introduction: Process studies at the air–sea interface after atmospheric deposition in the Mediterranean Sea – objectives and strategy of the PEACETIME oceanographic campaign (May–June 2017)

2020 ◽  
Vol 17 (22) ◽  
pp. 5563-5585
Author(s):  
Cécile Guieu ◽  
Fabrizio D'Ortenzio ◽  
François Dulac ◽  
Vincent Taillandier ◽  
Andrea Doglioli ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Mediterranean Sea ◽  
Anthropogenic Sources ◽  
Dust Deposition ◽  
Action Strategy ◽  
Process Studies ◽  
In Situ Observations ◽  
The Mediterranean ◽  
First Time

Abstract. In spring, the Mediterranean Sea, a well-stratified low-nutrient–low-chlorophyll region, receives atmospheric deposition by both desert dust from the Sahara and airborne particles from anthropogenic sources. Such deposition translates into a supply of new nutrients and trace metals for the surface waters that likely impact biogeochemical cycles. However, the relative impacts of the processes involved are still far from being assessed in situ. After summarizing the knowledge on dust deposition and its impact on the Mediterranean Sea biogeochemistry, we present in this context the objectives and strategy of the PEACETIME project and cruise. Atmospheric and marine in situ observations and process studies have been conducted in contrasted areas encountering different atmospheric deposition context, including a dust deposition event that our dedicated “fast-action” strategy allowed us to catch. Process studies also include artificial dust seeding experiments conducted on board in large tanks in three ecoregions of the open waters of the Mediterranean Sea for the first time. This paper summarizes the work performed at sea and the type of data acquired in the atmosphere, at the air–sea interface and in the water column. An overview of the results presented in papers of this special issue (and in some others published elsewhere) is presented.

scholarly journals Process studies at the air-sea interface after atmospheric deposition in the Mediterranean Sea: objectives and strategy of the PEACETIME oceanographic campaign (May–June 2017)

2020 ◽  
Author(s):  
Cécile Guieu ◽  
Fabrizio D'Ortenzio ◽  
François Dulac ◽  
Vincent Taillandier ◽  
Andrea Doglioli ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Mediterranean Sea ◽  
Saharan Dust ◽  
Anthropogenic Sources ◽  
Dust Deposition ◽  
Process Studies ◽  
In Situ Observations ◽  
The Mediterranean ◽  
First Time

Abstract. In spring, the Mediterranean Sea, a well-stratified low nutrient low chlorophyll region, receives atmospheric deposition both desert dust from the Sahara and airborne particles from anthropogenic sources. Such deposition translates into a supply of new nutrients and trace metals for the surface waters that likely impact biogeochemical cycles. However, the quantification of the impacts and the processes involved are still far from being assessed in situ. In this paper, we provide a state of the art regarding dust deposition and its impact on the Mediterranean Sea biogeochemistry and we describe in this context the objectives and strategy of the PEACETIME project and cruise, entirely dedicated to filling this knowledge gap. Our strategy to go a step forward than in previous approaches in understanding these impacts by catching a real deposition event at sea is detailed. The PEACETIME oceanographic campaign took place in May–June 2017 and we describe how we were able to successfully adapt the planned transect in order to sample a Saharan dust deposition event, thanks to a dedicated strategy, so-called Fast Action. That was successful, providing, for the first time in our knowledge, a coupled atmospheric and oceanographic sampling before, during and after an atmospheric deposition event. Atmospheric and marine in situ observations and process studies have been conducted in contrasted area and we summarize the work performed at sea, the type of data acquired and their valorization in the papers published in the special issue.

Standing stock, community structure, species composition, distribution, and primary production of natural populations of phytoplankton in the southern Beaufort Sea

1977 ◽  
Vol 55 (6) ◽  
pp. 685-694 ◽  
Author(s):  
Stephen I. C. Hsiao ◽  
Malcolm G. Foy ◽  
Douglas W. Kittle
Keyword(s):  
Primary Production ◽  
Coastal Waters ◽  
Phytoplankton Community ◽  
Standing Stock ◽  
Natural Populations ◽  
Beaufort Sea ◽  
Composition Distribution ◽  
Blue Green Algae ◽  
River Mouths

Standing stock and in situ primary production of the southern Beaufort Sea phytoplankton were determined during the summers of 1973, 1974, and 1975. They decreased with increasing distance from shore and the Mackenzie river mouths. The phytoplankton community was composed largely of diatoms and flagellates with diatoms dominating in the coastal waters and flagellates being more abundant in the waters farther off shore. Dinoflagellates and chrysophytes occurred in relatively low numbers except in a few cases when blooms were observed. Blue-green algae were found occasionally in very low numbers. Seventy-two species of phytoplankton were identified, most of these being diatoms.

scholarly journals Strong stimulation of N<sub>2</sub> fixation in oligotrophic Mediterranean Sea: results from dust addition in large in situ mesocosms

2013 ◽  
Vol 10 (6) ◽  
pp. 10581-10613 ◽  
Author(s):  
C. Ridame ◽  
C. Guieu ◽  
S. L'Helguen
Keyword(s):  
Mediterranean Sea ◽  
N2 Fixation ◽  
Saharan Dust ◽  
Dust Deposition ◽  
Strong Stimulation ◽  
Stimulation Of

Abstract. The response of N2 fixation to contrasted (wet and dry) Saharan dust deposition was studied in the framework of the DUNE project "a DUst experiment in a low-Nutrient, low-chlorophyll Ecosystem" during which realistic simulations of dust deposition (10 g m

Post-Hurricane Michael damage assessment using ADCIRC storm surge hindcast, image classification, and LiDAR

Shore & Beach ◽  
2019 ◽  
pp. 3-14 ◽  
Author(s):  
Joshua Davis ◽  
Diana Mitsova ◽  
Tynon Briggs ◽  
Tiffany Briggs
Keyword(s):  
Wave Energy ◽  
Field Studies ◽  
Feedback Mechanism ◽  
Water Velocity ◽  
Airborne Lidar ◽  
Storm Events ◽  
Magnetic Current ◽  
Coastal Mapping ◽  
Electro Magnetic

Wave forcing from hurricanes, nor’easters, and energetic storms can cause erosion of the berm and beach face resulting in increased vulnerability of dunes and coastal infrastructure. LIDAR or other surveying techniques have quantified post-event morphology, but there is a lack of in situ hydrodynamic and morphodynamic measurements during extreme storm events. Two field studies were conducted in March 2018 and April 2019 at Bethany Beach, Delaware, where in situ hydrodynamic and morphodynamic measurements were made during a nor’easter (Nor’easter Riley) and an energetic storm (Easter Eve Storm). An array of sensors to measure water velocity, water depth, water elevation and bed elevation were mounted to scaffold pipes and deployed in a single cross-shore transect. Water velocity was measured using an electro-magnetic current meter while water and bed elevations were measured using an acoustic distance meter along with an algorithm to differentiate between the water and bed during swash processes. GPS profiles of the beach face were measured during every day-time low tide throughout the storm events. Both accretion and erosion were measured at different cross-shore positions and at different times during the storm events. Morphodynamic change along the back-beach was found to be related to berm erosion, suggesting an important morphologic feedback mechanism. Accumulated wave energy and wave energy flux per unit area between Nor’easter Riley and a recent mid-Atlantic hurricane (Hurricane Dorian) were calculated and compared. Coastal Observations: JALBTCX/NCMP emergency-response airborne Lidar coastal mapping & quick response data products for 2016/2017/2018 hurricane impact assessments

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