Influence of model resolution on the atmospheric transport of &amp;lt;sup&amp;gt;10&amp;lt;/sup&amp;gt;Be

Heikkilä, U.; Smith, A. M.

doi:10.5194/acp-12-10601-2012

Cited by 11 publications

(25 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 12 illustrates the source-to-archive distribution of 10 Be for each of the simulations. The general distribution in these simulations is very similar to the previously studied present-day situations (Heikkilä and Smith, 2012, their Percentage of 10 Be, produced in a given atmospheric compartment (x-axis, 'STR' indicates the stratosphere), which is deposited at a given latitude band (legend) in the 'ctrl', '10k', '11k' and '12k' simulations. mainly transported into the troposphere via the mid-latitudes and deposited equally between the 0-30 • and 30-60 • latitude bands in each hemisphere.…”

Section: U Heikkilä Et Alsupporting

confidence: 77%

“…The fairly large differences in atmospheric circulation found within the 10k, 11k and 12k simulations do not influence 10 Be transport as much as between the control and any of the deglaciation simulations. These differences are comparable in amplitude with those caused by different model resolutions or realisations in Heikkilä and Smith (2012).…”

Section: U Heikkilä Et Alsupporting

confidence: 55%

“…three weeks in the troposphere (e.g. Heikkilä and Smith, 2012;Koch et al, 2006;Land and Feichter, 2003). The total content of 10 Be in the stratosphere and the troposphere in these simulations is slightly larger than modern values due to the higher production rate.…”

Section: Global Means and Budgetsmentioning

confidence: 63%

“…The model output was analysed monthly. In order to analyse the atmospheric transport path of 10 Be from source to archive, the source regions of 10 Be were divided into 6 compartments: polar, mid-latitude and tropical in both the stratosphere and the troposphere, following Heikkilä et al (2009) and Heikkilä and Smith (2012). 10 Be produced in these source regions was treated as a separate tracer, and therefore the exact location and timing of deposition could be followed.…”

Section: Description Of the Simulationsmentioning

confidence: 99%

“…30 yr (see e.g. Heikkilä and Smith, 2012). Table 1 summarises the global mean temperatures and precipitation rates over each 30 yr period.…”

Section: Description Of the Simulationsmentioning

confidence: 99%

See 4 more Smart Citations

10Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on 10Be deposition

2013

Self Cite

View full text Add to dashboard Cite

Abstract. Reconstruction of solar irradiance has only been possible for the Holocene so far. During the last deglaciation, two solar proxies ( 10 Be and 14 C) deviate strongly, both of them being influenced by climatic changes in a different way. This work addresses the climate influence on 10 Be deposition by means of ECHAM5-HAM atmospheric aerosolclimate model simulations, forced by sea surface temperatures and sea ice extent created by the CSIRO Mk3L coupled climate system model. Three time slice simulations were performed during the last deglaciation: 10 000 BP ("10k"), 11 000 BP ("11k") and 12 000 BP ("12k"), each 30 yr long. The same, theoretical, 10 Be production rate was used in each simulation to isolate the impact of climate on 10 Be deposition. The changes are found to follow roughly the reduction in the greenhouse gas concentrations within the simulations. The 10k and 11k simulations produce a surface cooling which is symmetrically amplified in the 12k simulation. The precipitation rate is only slightly reduced at high latitudes, but there is a northward shift in the polar jet in the Northern Hemisphere, and the stratospheric westerly winds are significantly weakened. These changes occur where the sea ice change is largest in the deglaciation simulations. This leads to a longer residence time of 10 Be in the stratosphere by 30 (10k and 11k) to 80 (12k) days, increasing the atmospheric concentrations (25-30 % in 10k and 11k and 100 % in 12k). Furthermore the shift of westerlies in the troposphere leads to an increase of tropospheric 10 Be concentrations, especially at high latitudes. The contribution of dry deposition generally increases, but decreases where sea ice changes are largest. In total, the 10 Be deposition rate changes by no more than 20 % at mid-to high latitudes, but by up to 50 % in the tropics. We conclude that on "long" time scales (a year to a few years), climatic influences on 10 Be deposition remain small (less than 50 %) even though atmospheric concentrations can vary significantly. Averaged over a longer period, all 10

show abstract

Section: U Heikkilä Et Alsupporting

confidence: 77%

Section: U Heikkilä Et Alsupporting

confidence: 55%

Section: Global Means and Budgetsmentioning

confidence: 63%

Section: Description Of the Simulationsmentioning

confidence: 99%

“…30 yr (see e.g. Heikkilä and Smith, 2012). Table 1 summarises the global mean temperatures and precipitation rates over each 30 yr period.…”

Section: Description Of the Simulationsmentioning

confidence: 99%

See 3 more Smart Citations

10Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on 10Be deposition

2013

Self Cite

View full text Add to dashboard Cite

show abstract

Production rate and climate influences on the variability of ¹⁰Be deposition simulated by ECHAM5‐HAM: Globally, in Greenland, and in Antarctica

Heikkilä

Smith

2013

JGR Atmospheres

Self Cite

View full text Add to dashboard Cite

Ice core concentrations of 10Be are used as a proxy for solar activity, but they might be affected by atmospheric transport and deposition and their changes. During the Holocene, the influence is likely to be small, but during glacials it has to be accounted for. First, the climate influence has to be understood during the present climate. This study uses an ECHAM5‐HAM 30‐year climatological simulation of 10Be to investigate the production and climate‐related influences on 10Be deposition with focus on Greenland and Antarctica. We examine the climate modes driving snow accumulation and hence potentially 10Be deposition over a climatologically relevant period. The North Atlantic Oscillation (NAO) is found to be the main driver of changes in precipitation and 10Be deposition in Greenland, in agreement with previous studies. In Antarctica, the picture is more complex as precipitation and 10Be deposition are only weakly correlated with the Southern Annular Mode (SAM), El Niño‐Southern Oscillation (ENSO), or Zonal Wave 3 pattern (ZW3). The results suggest that on seasonal scale, 10Be deposition is linked with both precipitation rate and tropopause height, mainly due to the similar seasonal cycle. However, the correlation with tropopause height persists on the annual time scale. All in all, 10Be variability in Antarctica is an interplay of several processes whose contribution varies in time and space. When interpreting 10Be ice core records for solar activity, the time scale is essentially important. On seasonal scale, the 10Be signal is dominated by weather influences, but on multiannual scales, the production rate is the main driver. On multidecadal scale, large long‐term trends in climatic factors have the potential to distort the signal again as is seen in 10Be records during glacials. This study shows how climate modes connect to 10Be variability and how this connection could be used to correct for the climate impact. The established connections during present climatic conditions can be used as a basis to investigate these connections during glacial climate in a glacial model simulation.

show abstract

Volcanic sulfate deposition to Greenland and Antarctica: A modeling sensitivity study

2013

View full text Add to dashboard Cite

[1] Reconstructions of the atmospheric sulfate aerosol burdens resulting from past volcanic eruptions are based on ice core-derived estimates of volcanic sulfate deposition and the assumption that the two quantities are directly proportional. We test this assumption within simulations of tropical volcanic stratospheric sulfur injections with the MAECHAM5-HAM aerosol-climate model. An ensemble of 70 simulations is analyzed, with SO 2 injections ranging from 8.5 to 700 Tg, with eruptions in January and July. Modeled sulfate deposition flux to Antarctica shows excellent spatial correlation with ice core-derived estimates for Pinatubo and Tambora, although the comparison suggests the modeled flux to the ice sheets is 4-5 times too large. We find that Greenland and Antarctic deposition efficiencies (the ratio of sulfate flux to each ice sheet to the maximum hemispheric stratospheric sulfate aerosol burden) vary as a function of the magnitude and season of stratospheric sulfur injection. Changes in simulated sulfate deposition for large SO 2 injections are connected to increases in aerosol particle size, which impact aerosol sedimentation velocity and radiative properties, the latter leading to strong dynamical changes including strengthening of the winter polar vortices, which inhibits the transport of stratospheric aerosols to high latitudes. The resulting relationship between Antarctic and Greenland volcanic sulfate deposition is nonlinear for very large eruptions, with significantly less sulfate deposition to Antarctica than to Greenland. These model results suggest that variability of deposition efficiency may be an important consideration in the interpretation of ice core sulfate signals for eruptions of Tambora-magnitude and larger.Citation: Toohey, M., K. Kru¨ger, and C. Timmreck (2013), Volcanic sulfate deposition to Greenland and Antarctica: A modeling sensitivity study,

show abstract

Influence of model resolution on the atmospheric transport of <sup>10</sup>Be

Cited by 11 publications

References 54 publications

<sup>10</sup>Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on <sup>10</sup>Be deposition

<sup>10</sup>Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on <sup>10</sup>Be deposition

Production rate and climate influences on the variability of ¹⁰Be deposition simulated by ECHAM5‐HAM: Globally, in Greenland, and in Antarctica

Volcanic sulfate deposition to Greenland and Antarctica: A modeling sensitivity study

Contact Info

Product

Resources

About

Influence of model resolution on the atmospheric transport of &lt;sup&gt;10&lt;/sup&gt;Be

Cited by 11 publications

References 54 publications

&lt;sup&gt;10&lt;/sup&gt;Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on &lt;sup&gt;10&lt;/sup&gt;Be deposition

&lt;sup&gt;10&lt;/sup&gt;Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on &lt;sup&gt;10&lt;/sup&gt;Be deposition

Production rate and climate influences on the variability of 10Be deposition simulated by ECHAM5‐HAM: Globally, in Greenland, and in Antarctica

Volcanic sulfate deposition to Greenland and Antarctica: A modeling sensitivity study

Contact Info

Product

Resources

About

Influence of model resolution on the atmospheric transport of <sup>10</sup>Be

<sup>10</sup>Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on <sup>10</sup>Be deposition

<sup>10</sup>Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on <sup>10</sup>Be deposition

Production rate and climate influences on the variability of ¹⁰Be deposition simulated by ECHAM5‐HAM: Globally, in Greenland, and in Antarctica