Arctic sea ice export

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Satellite-derived sea ice export and its impact on Arctic ice mass balance

Robert Ricker1, Fanny Girard-Ardhuin2, Thomas Krumpen1, Camille Lique2

1 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research

2 Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Oceanographie Physique et Spatiale (LOPS), IUEM, Brest, France

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Arctic sea ice export

Transpolar Drift Beaufort

Gyre

Credit: NASA

(3)

Arctic sea ice export

Gyre

Fram Strait

Credit: NASA

(4)

Arctic sea ice export

Nares Strait Transpolar Drift

Beaufort Gyre

Fram Strait

Credit: NASA

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Arctic sea ice export

Nares Strait Nares Strait

Fram Strait Ice Area Export

Gyre

Fram Strait

Credit: NASA

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Arctic sea ice export

Gyre

Fram Strait

Credit: NASA

Credit: NOAA/Tschudi

Late March 1990

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Arctic sea ice export

Gyre

Fram Strait

Credit: NASA

Credit: NOAA/Tschudi

Late March 1990 Late March 2016

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Motivation and objectives

•

Fram Strait ice export represents approximately 25% of the total fresh water export to the North Atlantic

•

Changes in the export rates could affect the global ocean thermohaline circulation

•

Impact of ice export on Arctic sea ice mass balance

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Motivation and objectives

•

Fram Strait ice export represents approximately 25% of the total fresh water export to the North Atlantic

•

Changes in the export rates could affect the global ocean thermohaline circulation

•

Impact of ice export on Arctic sea ice mass balance

•

CryoSat-2 ice thickness data are used to estimate winter sea ice export through Fram Strait over 7 years between 2010 and 2017

•

We aim to examine the variability of ice volume export

•

We quantify the impact of winter ice volume export on Arctic sea ice mass balance, considering Arctic net monthly ice volume changes

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Calculating Arctic ice volume flux

•

Arctic-wide volume Flux (V) is derived by V = G H D C Grid cell length (G=25 km)

Sea ice thickness (H)

• monthly AWI

CryoSat-2 retrievals

Sea ice drift (D)

• low resolution ice drift products IFREMER, OSISAF, NSIDC

Ice Concentration (%)

Sea ice concentration (C)

• OSISAF

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Calculating ice volume flux export

First-Year Ice Multiyear Ice 2016/2017

Beaufort Gyre

Transpolar Drift

Zonal Meridional

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Sea ice thickness in the Fram Strait

2010/2011 2011/2012

2012/2013 2013/2014

2014/2015 2015/2016

2016/2017 Apr

Oct

Apr

Oct Apr

Oct

Apr

Oct

Apr

Oct

Apr

Oct

80.5°

Lat

-12° Lon 20°

82°

Meridional Zonal

zonal meridional

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Sea ice drift in the Fram Strait

2010/2011 2011/2012

2012/2013 2013/2014

2014/2015 2015/2016

2016/2017 Apr

Oct

Apr

Oct Apr

Oct

Apr

Oct

Apr

Oct

Apr

Oct

80.5°

Lat

-12° Lon 20°

82°

Meridional Zonal

zonal meridional

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Variability of the input parameters

•

We compare and quantify the extent of variability of the three parameters (ice thickness, drift and concentration).

•

Their relative standard deviation (RSD) is the ratio of the standard deviation to the mean.

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Ice volume export through Fram Strait

O NDJ F MA O NDJ F MA O NDJ F MA O NDJ F MA O NDJ F MA O NDJ F MA O NDJ F MA

Multiyear Ice First-Year Ice

•

Monthly sea-ice volume export through Fram Strait (October-April).

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Seasonal and Interannual variations of ice volume export

•

Ice drift is the main driver of seasonal and interannual

variability of ice volume export.

•

The seasonal trend of ice volume export is driven by ice thickness.

Sea Ice Concentration (%) Sea Ice Drift (km/d)

Sea Ice Thickness (m)

•

Seasonal means of ice volume export are linked to Arctic

Oscillation (AO) and North Atlantic Oscillation (NAO)

80.5°

Latitude

-12° Longitude 20°

82°

(a) ^Q^EX,OSISAF ^Q^EX,IFREMER (b)

QEX,NSIDC

April 2012 November - April

Mean NAO Index Mean AO Index

r²(QEX,OSISAF,NAO) = 0.74 r²(QEX,OSISAF,AO) =0.87

QEX,IFREMER

QEX,OSISAF QEX,NSIDC

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The impact of ice volume export on Arctic multiyear ice (MYI) mass balance

dVMYI/dt = Q_ExMYI + ( dVtherm, MYI/dt + dVresid, MYI/dt ) Arctic MYI

volume change

Ice volume

export Thermodynamic

volume growth Residual

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Summary & Conclusions

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Summary & Conclusions

•

Sea-ice volume export through Fram Strait shows a seasonal mean of 230 km³/month.

Bodensee

5 x

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Summary & Conclusions

•

Bodensee

5 x

•

Ice drift is the main driver of seasonal and interannual variability of ice volume export.

(b) This Study (2010-2017)

Kwok et al. (1991-1999) Spreen et al. (2003-2008)

(a)

Sea Ice Concentration (%) Sea Ice Drift (km/d) Sea Ice Thickness (m)

Vinje et al. (1990-1996)

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Summary & Conclusions

•

Bodensee

5 x

•

(b) This Study (2010-2017)

(a)

Vinje et al. (1990-1996)

•

Interannual variations of ice volume export can be

explained by large scale variability of the atmospheric circulation captured by the Arctic Oscillation and North Atlantic Oscillation indices.

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Summary & Conclusions

•

Bodensee

5 x

•

(b) This Study (2010-2017)

(a)

Vinje et al. (1990-1996)

•

Interannual variations of ice volume export can be

explained by large scale variability of the atmospheric circulation captured by the Arctic Oscillation and North Atlantic Oscillation indices.

•

54 % of the variability of Arctic MYI volume over the

December-March period can be explained by ice volume export through the Fram Strait.

Dec Jan Feb Mar

Multiyear ice First-year ice

r² = 0.16

r² = 0.54

D J F M D J F M D J F M D J F M D J F M D J F M

MEAN (dVMYI/dt) dVMYI/dt

Q_ExMYI MEAN (Q_ExMYI) MEAN (dVFYI/dt) dVFYI/dt

Q_ExFYI MEAN (Q_ExFYI)

dVFYI/dt (10³ km³/month) QExFYI(103 km3/month)QExMYI(103 km3/month)

dVMYI/dt (10³ km³/month)