The Southern Kalahari: a potential new dust source in the Southern Hemisphere?

Bhattachan, Abinash; D’Odorico, Paolo; Baddock, Matthew C.; Zobeck, Ted M.; Okin, Gregory S.; Cassar, Nicolas

doi:10.1088/1748-9326/7/2/024001

Cited by 69 publications

(65 citation statements)

References 44 publications

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“…2) tentatively supports the hypothesis that dust emissions from active sands might have been globally important sources of dust in past climates, and that emissions from active sands might 15 increase in the future because of the reactivation of inactive sand dunes (Mason et al, 2003;Thomas et al 2005;Bhattachan et al, 2012). Many stable dunes have accumulated extensive clay-mineral coatings (Bowler, 1973;Gardner and Pye, 1981;Muhs et al, 1997), and, if activated, these dunes could produce substantial fine dust emissions through sandblasting-induced removal of clay-mineral coatings (Bullard et al, 2007;Swet et al, 2018).…”

Section: Implications Of Dust Emissions From Oceano Dunes State Vehicmentioning

confidence: 52%

Fine dust emissions from active sands at coastal Oceano Dunes, California

Huang¹,

Kok²,

Martin³

et al. 2018

Preprint

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Abstract. Sand dunes and other active sands generally have a low content of fine grains and, therefore, are not considered to be major dust sources in climate models. However, recent remote sensing studies have indicated that a surprisingly large fraction of dust storms are generated from regions covered by sand dunes, leading these studies to propose that sand dunes might be globally-relevant sources of dust. To help understand the dust emission potential of sand dunes and other active 15 sands, we present in situ field measurements of dust emission under natural saltation from a coastal sand sheet at Oceano Dunes in California. We find that saltation drives substantial dust emissions from this setting. Laboratory analyses of sand samples suggest that these emissions are produced by aeolian abrasion of feldspars and removal of coatings of clay minerals on sand grains. We further find that this emitted dust is substantially finer than dust emitted from non-sandy soils and dust observed in situ over North Africa. As such, dust emitted from the sand sheet, and potentially from other active sands 20 affected by similar dust emission processes, could have potent impacts on climate, the hydrological cycle, and human health.These measurements thus support the hypothesis that considerable emissions of fine dust can be generated by the reactivation of inactive dunes with accumulated clay minerals. This might occur due to future land-use changes and desertification, and is not currently represented in most climate models.

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Section: Implications Of Dust Emissions From Oceano Dunes State Vehicmentioning

confidence: 52%

Fine dust emissions from active sands at coastal Oceano Dunes, California

Huang¹,

Kok²,

Martin³

et al. 2018

Preprint

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“…(Note that fathoming the full range of uncertainty is beyond the scope of this manuscript.) The rationale behind this experiment is as follows: in a warming world the amount of airborne dust is increasing due to vegetation loss, dune remobilization (e.g., Bhattachan et al, 2012) and glacier retreat (e.g., Bullard, 2013). In line with this reasoning, modelaided estimates by Mahowald et al (2010) suggest that the increase may well correspond to a doubling over the 20th century over much of the globe.…”

Section: Sensitivity Experiments -Iron Supplymentioning

confidence: 94%

Simulating natural carbon sequestration in the Southern Ocean: on uncertainties associated with eddy parameterizations and iron deposition

2017

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Abstract. The Southern Ocean is a major sink for anthropogenic carbon. Yet, there is no quantitative consensus about how this sink will change when surface winds increase (as they are anticipated to do). Among the tools employed to quantify carbon uptake are global coupled ocean-circulationbiogeochemical models. Because of computational limitations these models still fail to resolve potentially important spatial scales. Instead, processes on these scales are parameterized. There is concern that deficiencies in these so-called eddy parameterizations might imprint incorrect sensitivities of projected oceanic carbon uptake. Here, we compare natural carbon uptake in the Southern Ocean simulated with contemporary eddy parameterizations. We find that very differing parameterizations yield surprisingly similar oceanic carbon in response to strengthening winds. In contrast, we find (in an additional simulation) that the carbon uptake does differ substantially when the supply of bioavailable iron is altered within its envelope of uncertainty. We conclude that a more comprehensive understanding of bioavailable iron dynamics will substantially reduce the uncertainty of modelbased projections of oceanic carbon uptake.

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“…Vegetation typically increases both the stability and moisture level of soils, reducing dust flux. 255,256 Reductions in vegetation due to both climate change and land use (e.g.…”

Section: Land Use Change Effects On Dustmentioning

confidence: 99%

Land Use Change Impacts on Air Quality and Climate

2015

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Introduction 4476 2. Land Use Change Impacts on Sources and Sinks of Short-Lived Atmospheric Pollutants 4478 2.1. Terrestrial Biogenic Volatile Organic Compounds 4478 2.1.1. Introduction 4478 2.1.2. Natural Land Use Change Effects on BVOC Emissions and Air Quality 4479 2.1.3. Anthropogenic Land Use Change Effects on BVOC Emissions and Air Quality 4481 2.2. Ozone Dry Deposition 4482 2.3. Ammonia 4482 2.3.1. Introduction 4482 2.3.2. Land Use Change Effects on Ammonia 4483 2.4. Nitrogen Oxides 4483 2.4.1. Introduction 4483 2.4.2. Land Use Change Effects on Nitrogen Oxide Emissions 4483 2.5. Smoke 4484 2.5.1. Introduction 4484 2.5.2. Land Use Change Effects on Smoke Emissions 4484 2.6. Dust 4485 2.6.1. Introduction 4485 2.6.2. Land Use Change Effects on Dust 4485 2.7. Terrestrial Primary Biological Aerosol Particles 4487 3. Global Radiative Effects of Land Use Change via Short-Lived Pollutants 4487 4. Local Land Use Change Scenarios 4489 5. Conclusions 4490 Associated Content 4490 Supporting Information 4490 Author Information 4490 Corresponding Author 4490 Notes 4490 Biographies 4490 Acknowledgments 4490 References 4490

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The Southern Kalahari: a potential new dust source in the Southern Hemisphere?

Cited by 69 publications

References 44 publications

Fine dust emissions from active sands at coastal Oceano Dunes, California

Fine dust emissions from active sands at coastal Oceano Dunes, California

Simulating natural carbon sequestration in the Southern Ocean: on uncertainties associated with eddy parameterizations and iron deposition

Land Use Change Impacts on Air Quality and Climate

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