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.

Comment on 'Impacts of aeolian dust deposition on phytoplankton dynamics in Queensland coastal waters' by Shaw et al. (2008)

2010 ◽  
Vol 61 (4) ◽  
pp. 502 ◽  
Author(s):  
Doug Mackie
Keyword(s):  
Causative Agent ◽  
Coastal Waters ◽  
Dust Storm ◽  
Phytoplankton Dynamics ◽  
Dust Deposition ◽  
Aeolian Dust

The central premise of the paper by Shaw et al. (2008) (hereafter SGM) is that phytoplankton in coastal waters of Queensland, Australia, were nutrient-limited and that biomass increased immediately following a large dust storm in October 2002. I will show that (i) the timing of the phytoplankton response precludes the dust storm as a causative agent for chlorophyll increases and (ii) it is not clear that there was actually any change in chlorophyll in response to the dust storm.

scholarly journals Particle size traces modern Saharan dust transport and deposition across the equatorial North Atlantic

2016 ◽  
Author(s):  
Michèlle van der Does ◽  
Laura F. Korte ◽  
Chris I. Munday ◽  
Geert-Jan A. Brummer ◽  
Jan-Berend W. Stuut
Keyword(s):  
Particle Size ◽  
Atlantic Ocean ◽  
Seasonal Changes ◽  
Climate Models ◽  
Dust Cloud ◽  
Sediment Traps ◽  
Dust Storms ◽  
Saharan Dust ◽  
Dust Deposition ◽  
Dust Transport

Abstract. Mineral dust has a large impact on regional and global climate, depending on its particle size. Especially in the Atlantic Ocean downwind of the Sahara, the largest dust source on earth, the effects can be substantial but are poorly understood. This study focuses on seasonal and spatial variations in particle size of Saharan dust deposition across the Atlantic Ocean, using an array of submarine sediment traps moored along a transect at 12˚ N. We show that the particle size decreases downwind with increased distance from the Saharan source, due to higher gravitational settling velocities of coarse particles in the atmosphere. Modal grain sizes vary between 4 and 33 μm throughout the different seasons and at five locations along the transect. This is much coarser than previously suggested and incorporated into climate models. In addition, seasonal changes are prominent, with coarser dust in summer, and finer dust in winter and spring. Such seasonal changes are caused by transport at higher altitudes and at greater wind velocities during summer than in winter. Also the latitudinal migration of the dust cloud, associated with the Intertropical Convergence Zone, causes seasonal differences in deposition as the summer dust cloud is located more to the north, and more directly above the sampled transect. Furthermore, increased precipitation and more frequent dust storms in summer coincide with coarser dust deposition. Our findings contribute to understanding Saharan dust transport and deposition relevant for the interpretation of sedimentary records for climate reconstructions, as well as for global and regional models for improved prediction of future climate.

scholarly journals Tasman Sea biological response to dust storm events during the austral spring of 2009

2016 ◽  
Vol 67 (8) ◽  
pp. 1090 ◽  
Author(s):  
A. J. Gabric ◽  
R. Cropp ◽  
G. McTainsh ◽  
H. Butler ◽  
B. M. Johnston ◽  
...  
Keyword(s):  
Dust Storm ◽  
Biological Response ◽  
Heavy Precipitation ◽  
Iron Bioavailability ◽  
Dust Storms ◽  
Storm Events ◽  
Dust Deposition ◽  
Austral Spring ◽  
Tasman Sea

During the austral spring of 2009 several significant dust storms occurred in south-east Australia including the so-called ‘Red Dawn’ event in late September. Estimates of 2.5 Mt total suspended particulate sediment lost off the Australian coast in the 3000km long dust plume make it the largest off-continent loss of soil ever reported. Much of this material was transported over the coastline of New South Wales and into the adjacent Tasman Sea. Long-term model simulations of dust deposition over the south-west Tasman Sea suggest the amount deposited during the spring of 2009 was approximately three times the long-term monthly average. Previous satellite-based analyses of the biological response of Tasman Sea waters to dust-derived nutrients are equivocal or have observed no response. Satellite-derived surface chlorophyll concentrations in the southern Tasman during the spring of 2009 are well above the climatological mean, with positive anomalies as high as 0.5mgm–3. Dust transport simulations indicate strong deposition to the ocean surface, which during both the ‘Red Dawn’ event and mid-October 2009 dust storm events was enhanced by heavy precipitation. Cloud processing of the dust aerosol may have enhanced iron bioavailability for phytoplankton uptake.

scholarly journals Response to comment on 'Impacts of aeolian dust deposition on phytoplankton dynamics in Queensland coastal waters'

2010 ◽  
Vol 61 (4) ◽  
pp. 504 ◽  
Author(s):  
Emily C. Shaw ◽  
Albert J. Gabric ◽  
Grant H. McTainsh
Keyword(s):  
Coastal Waters ◽  
Phytoplankton Dynamics ◽  
Dust Deposition ◽  
Aeolian Dust

scholarly journals Particle size traces modern Saharan dust transport and deposition across the equatorial North Atlantic

2016 ◽  
Vol 16 (21) ◽  
pp. 13697-13710 ◽  
Author(s):  
Michèlle van der Does ◽  
Laura F. Korte ◽  
Chris I. Munday ◽  
Geert-Jan A. Brummer ◽  
Jan-Berend W. Stuut
Keyword(s):  
Particle Size ◽  
Atlantic Ocean ◽  
Seasonal Changes ◽  
Climate Models ◽  
Dust Cloud ◽  
Sediment Traps ◽  
Dust Storms ◽  
Saharan Dust ◽  
Dust Deposition ◽  
Dust Transport

Abstract. Mineral dust has a large impact on regional and global climate, depending on its particle size. Especially in the Atlantic Ocean downwind of the Sahara, the largest dust source on earth, the effects can be substantial but are poorly understood. This study focuses on seasonal and spatial variations in particle size of Saharan dust deposition across the Atlantic Ocean, using an array of submarine sediment traps moored along a transect at 12° N. We show that the particle size decreases downwind with increased distance from the Saharan source, due to higher gravitational settling velocities of coarse particles in the atmosphere. Modal grain sizes vary between 4 and 32 µm throughout the different seasons and at five locations along the transect. This is much coarser than previously suggested and incorporated into climate models. In addition, seasonal changes are prominent, with coarser dust in summer and finer dust in winter and spring. Such seasonal changes are caused by transport at higher altitudes and at greater wind velocities during summer than in winter. Also, the latitudinal migration of the dust cloud, associated with the Intertropical Convergence Zone, causes seasonal differences in deposition as the summer dust cloud is located more to the north and more directly above the sampled transect. Furthermore, increased precipitation and more frequent dust storms in summer coincide with coarser dust deposition. Our findings contribute to understanding Saharan dust transport and deposition relevant for the interpretation of sedimentary records for climate reconstructions, as well as for global and regional models for improved prediction of future climate.

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 Chemical Characterization of Aeolian Dust Deposition in Southern and Western Iran

2019 ◽  
pp. 1-22 ◽  
Author(s):  
Mansour A. Foroushani ◽  
Christian Opp ◽  
Michael Groll
Keyword(s):  
Elemental Composition ◽  
Large Scale ◽  
Anthropogenic Activities ◽  
Chemical Characterization ◽  
Dust Event ◽  
Dust Deposition ◽  
High Concentration ◽  
Dust Transport ◽  
Aeolian Dust ◽  
Dust Events

In the last decade, the southwestern and western provinces of Iran have been heavily affected by aeolian dust deposition. As a result, the elemental composition of soil surfaces is influenced by dust transport as well as precipitation, wind speed and direction. The relationship between daily recorded dust events and the elemental composition of the dust is studied in this paper. Strong correlations were detected between dust deposition rate from most deposition sites (G01-G10, except for G05, G06) and the dust event frequency. Correlations of different strengths have been revealed between the dust event frequencies (DEF), and the elemental classification matrix based on airborne Metal Regulations. As expected, high correlation values indicate high concentration contributions of elemental values to the aerosol, such as Na, Mn, As, Pb, from large-scale depositions in the south including Cr and V in the west. These findings also suggest that the major contributors of V, Cr, Co, Ni, Cu, Zn, As, Se, Cd, Ba, and Pb in the elemental concentrations may depend on the meteorological situation and correlation magnitude are associated with elements emanating from local anthropogenic activities.

scholarly journals Aeolian dust deposition and the perturbation of phosphorus transformations during long-term ecosystem development in a cool, semi-arid environment

2019 ◽  
Vol 246 ◽  
pp. 498-514 ◽  
Author(s):  
Chunhao Gu ◽  
Stephen C. Hart ◽  
Benjamin L. Turner ◽  
Yongfeng Hu ◽  
Yong Meng ◽  
...  
Keyword(s):  
Arid Environment ◽  
Ecosystem Development ◽  
Dust Deposition ◽  
Aeolian Dust ◽  
Semi Arid

Oithona davisae: naturalization in the Black sea, inter-annual and seasonal dynamics, effect on the structure of the planktonic copepod community

2019 ◽  
Vol 59 (6) ◽  
pp. 1008-1015
Author(s):  
A. D. Gubanova ◽  
O. A. Garbazey ◽  
D. A. Altukhov ◽  
V. S. Mukhanov ◽  
E. V. Popova
Keyword(s):  
Black Sea ◽  
Coastal Waters ◽  
Native Species ◽  
Significant Decline ◽  
Acartia Tonsa ◽  
The Black Sea ◽  
Copepod Community ◽  
Oithona Davisae ◽  
Sevastopol Bay

Long-term (20032014) routine observations of zooplankton in Sevastopol Bay (the Black Sea) have allowed the naturalization of the invasive copepod Oithona davisae to be studied in the Black Sea coastal waters. Inter-annual and seasonal variability of the species and their impact on the native copepod community have been analyzed. The invasion of O. davisae and their undoubted dominance in terms of abundance were shown to alter the community structure but, at the same time, the abundances of the native species did not decrease, excepting the Black Sea earlier invader Acartia tonsa. A significant decline in A. tonsa numbers over the stages of O. davisae establishment and naturalization provided evidence of competition between the species. O. davisae have been demonstrated to gain competitive advantage over A. tonsa, that ensured their fast dispersal in the Black Sea, acclimatization in the new habitat and the successful competition over native species.

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