Examining links between dust deposition and phytoplankton response using ice cores

Hooper, James; Mayewski, Paul Andrew; Marx, Samuel K.; Henson, Stephanie A.; Potocki, Mariusz; Sneed, Sharon B.; Handley, M.; Gassó, Santiago; Fischer, Matt J.; Saunders, Krystyna M.

doi:10.1016/j.aeolia.2018.11.001

Cited by 19 publications

(19 citation statements)

References 91 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, doubling the AIS Fe fluxes in the SOLUB10 experiment increases the C export by only ∼ 3.6 % compared to the SOLUB5 experiment (Table 3). Nevertheless, at a more local scale, the fertilization effect of the AIS induced by global warming could be drastically strengthened, with potentially important consequences for phytoplankton physiology, nutrient availability, and marine ecosystems (Boyd et al, 2010b(Boyd et al, , 2015Hopwood et al, 2017;Boyd, 2019).…”

Section: Referencesmentioning

confidence: 99%

“…Icebergs and ice shelves contain higher Fe concentrations than seawater (de Baar et al, 1995;Lin et al, 2011;Shaw et al, 2011;Herraiz-Borreguero et al, 2016), mainly as lithogenic material from glacial sediments (Raiswell et al, 2006;Shaw et al, 2011;Hopwood et al, 2017). The melting of icebergs and ice shelves releases Fe to seawater as particulate, dissolved, and potentially dissolvable forms (Raiswell et al, 2008(Raiswell et al, , 2016Hawkings et al, 2014;Herraiz-Borreguero et al, 2016;Hodson et al, 2017), fueling the water column in Fe (Lin et al, 2011;De Jong et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

“…The meltwa-ter pump is also estimated as a significant Fe supply mechanism in polynyas (St-Laurent et al, 2017 and in coastal regions (Cape et al, 2019). However, the mean supply of the bioavailable Fe fraction from icebergs and ice shelves is difficult to quantify because of the heterogeneous nature of the Fe distribution in these sources (Raiswell et al, 2016;Hopwood et al, 2017). Until recent years, very few data were available.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Sensitivity of ocean biogeochemistry to the iron supply from the Antarctic Ice Sheet explored with a biogeochemical model

et al. 2019

View full text Add to dashboard Cite

Abstract. Iron (Fe) delivery by the Antarctic Ice Sheet (AIS) through ice shelf and iceberg melting enhances primary productivity in the largely iron-limited Southern Ocean (SO). To explore this fertilization capacity, we implement a simple representation of the AIS iron source in the global ocean biogeochemical model NEMO-PISCES. We evaluate the response of Fe, surface chlorophyll, primary production, and carbon (C) export to the magnitude and hypothesized vertical distributions of the AIS Fe fluxes. Surface Fe and chlorophyll concentrations are increased up to 24 % and 12 %, respectively, over the whole SO. The AIS Fe delivery is found to have a relatively modest impact on SO primary production and C export, which are increased by 0.063±0.036 PgC yr−1 and 0.028±0.016, respectively. However, in highly fertilized areas, primary production and C export can be increased by up to 30 % and 42 %, respectively. Icebergs are predicted to have a much larger impact on Fe, surface chlorophyll, and primary productivity than ice shelves in the SO. The response of surface Fe and chlorophyll is maximum in the Atlantic sector, northeast of the tip of the Antarctic Peninsula, and along the East Antarctic coast. The iceberg Fe delivery below the mixed layer may, depending on its assumed vertical distribution, fuel a non-negligible subsurface reservoir of Fe. The AIS Fe supply is effective all year round. The seasonal variations of the iceberg Fe fluxes have regional impacts that are small for annual mean primary productivity and C export at the scale of the SO.

show abstract

Section: Referencesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sensitivity of ocean biogeochemistry to the iron supply from the Antarctic Ice Sheet explored with a biogeochemical model

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Mineral dust and aerosols play an important role in controlling atmospheric radiative forcing and thereby climate variability (IPCC, 2013; Kok et al, 2018). Dust is known as one of the major suppliers of nutrients to global ocean and support phytoplankton productivity and drawdown of atmospheric CO 2 , which have important implications on global climate change (Hooper et al, 2019; Johnson et al, 2011; Martin, 1990). In order to understand past climate variability and changes in the Southern Hemisphere (SH), several studies have been carried out on Antarctic ice core dust records (Delmonte et al, 2002; Delmonte et al, 2013; Delmonte et al, 2019; Laluraj et al, 2014; McConnell et al, 2007; Wegner et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Enhanced Dust Influx to South Atlantic Sector of Antarctica During the Late‐20th Century: Causes and Contribution to Radiative Forcing

et al. 2020

View full text Add to dashboard Cite

Atmospheric dust influences global climate and ocean biogeochemistry. Here we present a high-resolution ice core dust record (1905 from coastal Dronning Maud Land (71°20′S, 11°35′ E), East Antarctica, to understand dust flux variability, its causes, and potential contribution to radiative forcing during the 20th century in the South Atlantic sector of East Antarctica (SASA). The dust flux profile (sum of 1-25 μm size fractions) reveals three stepwise increase during 1905 -1929 , 1930-1979 , and 1980 with an average of 0.83, 4.7, and 12.88 mg·m −2 ·year −1 , respectively. Our investigation for such dramatic dust flux increase reveals that the increased aridity and favorable wind conditions over Southern South America (SSA), a potential dust source to Antarctica, caused increase in dust production and transport during the late 20th century. The dust flux variability in Southern Hemisphere is concomitant with in-phase relationship between El-Niño Southern Oscillation and Pacific Decadal Oscillations, which influenced the spatial distribution of global wet-dry phase (precipitation pattern). Further, shifting of Southern Annular Mode to positive phase made wind conditions more conducive for long-range dust transport from SSA to coastal Dronning Maud Land region. To the best of our knowledge, this is the first report of past radiative forcing estimates for Antarctica using ice core dust record into a radiative transfer model. Our estimates of radiative forcing corresponding to the enhanced dust flux yield nearly 30% increase in aerosol forcing during the late 20th century. This has resulted 40% decrease in atmospheric cooling rate, which contributed to net atmospheric warming over SASA.Plain Language Summary Atmospheric dust plays an important role in global climate variability through the changes in radiative forcing. Like other parts of Antarctica, the coastal Dronning Maud Land (cDML) in East Antarctic is vulnerable to such changes in radiative balance. However, causative factors for the dust deposition and impact of dust originated radiative forcing on this region remain unknown due to lack of long-term records of dust-derived radiative forcing estimates. Toward this, we have undertaken a systematic ice core-based study from cDML region to reconstruct past records of dust influx, its potential sources, causative factors for the dust production in the Southern Hemispheric continents, and understanding its role on the radiative forcing during the 20th century . Our radiative forcing estimates corresponding to approximately four fold increase in dust influx in the late 20th century indicate an increase in atmospheric warming. The present study would help to better understand the long-term Antarctic climate variability by providing radiative forcing input to the climate models and to improve our current knowledge about the role of dust in contributing to Southern Hemisphere warming during the 20th century.

show abstract

“…Evidence of long range transport is suggested by the observations of recent (spanning last decades) findings of dust in snow of the Antarctica Peninsula (McConnell et al, ; Pereira et al, ) and East Antarctica (Bory et al, ; Laluraj et al, ). Recently, Hooper et al () reported the presence of recent (last decade) deposition of dust in the east flank of a glacier in South Georgia Island directly downwind of Patagonia.…”

Section: Introductionmentioning

confidence: 99%

Temporal Characterization of Dust Activity in the Central Patagonia Desert (Years 1964–2017)

Gassó

Torres

2019

JGR Atmospheres

Self Cite

View full text Add to dashboard Cite

Dust emitted from the southern end of South America (SSA) is transported long distances over the Southern Ocean and deposited over this marine ecosystem. Whether the nutrients released through dissolution have a biogeochemical impact is a question with biological as well as climate implications, yet there is no clear answer. Additionally, the provenance of dust recently found in accumulated snow in East Antarctica is still a matter of debate. The Patagonia desert in SSA is the likely source, but there are no detailed records documenting dust activity in this area, thereby preventing any definite assessments. Here we provide a survey of modern dust activity of the largest dust source in SSA, the lake Colhué Huapi in central Patagonia. We analyzed five decades (1964–2017) of surface synoptic observations (World Meteorological Weather Present weather codes) and concurrent satellite aerosol detection (UV Aerosol Index from the Total Ozone Monitoring Sensor and Ozone Monitoring Instrument detectors, 1978–2017). We assessed the seasonal, year‐to‐year variability and periods of major dust activity. Several periods of enhanced activity were found with roughly 2‐ to 10‐year duration each (1970–1976, 1989–1994, 1996–1997, and 1999–2017). While dust activity peaks during summer months, wintertime activity during the most active years can well exceed the summer average of nonactive years. For a period of coincident satellite observations, the occurrence of at least three periods of high activity is confirmed. Since satellite detection is more sensitive to mesoscale dust events, the large events that occurred during these periods brought abundant dust into the SW South Atlantic. Satellites with polar orbits tend to under detect dust events in this region. Significant cloudiness obstructs the direct view of dust, and dust activity tends to occur late in the afternoon after the overpass of polar satellites. These observations have a time span adequate for comparison with transport models and modern records of dust samples collected in East Antarctica. The results contribute to a better understanding of the dynamic of modern dust transport in the Southern Hemisphere, the provenance of dust found in Antarctica, and the provenance of eolian nutrients into the Southern Ocean.

show abstract

Examining links between dust deposition and phytoplankton response using ice cores

Cited by 19 publications

References 91 publications

Sensitivity of ocean biogeochemistry to the iron supply from the Antarctic Ice Sheet explored with a biogeochemical model

Sensitivity of ocean biogeochemistry to the iron supply from the Antarctic Ice Sheet explored with a biogeochemical model

Enhanced Dust Influx to South Atlantic Sector of Antarctica During the Late‐20th Century: Causes and Contribution to Radiative Forcing

Temporal Characterization of Dust Activity in the Central Patagonia Desert (Years 1964–2017)

Contact Info

Product

Resources

About