1 of 27

An idealized model for the East Greenland Current

THORbjørn Østenby Moe

Kjersti Daae, Kjetil Våge, Stefanie Semper, & Tore Hattermann

THOR 2025

2 of 27

An idealized model for the East Greenland Current

Thorbjørn Østenby Moe

Kjersti Daae, Kjetil Våge, Stefanie Semper, & Tore Hattermann

3 of 27

Re-ventilation of Atlantic Water in the EGC

4 of 27

Re-ventilation of Atlantic Water in the EGC

5 of 27

Re-ventilation of Atlantic Water in the EGC

6 of 27

Re-ventilation of Atlantic Water in the EGC

7 of 27

Re-ventilation of Atlantic Water in the EGC

8 of 27

Previous model

  •  

9 of 27

+

=

EGC ?

-North [km]

East [km]

10 of 27

An Idealized Model for the EGC

Planned model configuration:

  • Atmospheric forcing & sea ice
  • Hydrography and boundary conditions
    • “Standard” vs. periodic
  • Next steps

​

11 of 27

The Idealized model: Atmospheric forcing & sea ice

  • Initially, the atmosphere only as forcing (no feedback)

Wind speed (along-slope)

Wind stress

Depth

SIC

 

 

 

 

Distance east [km]

 

 

Distance east [km]

12 of 27

The Idealized model: Atmospheric forcing & sea ice

  • Initially, the atmosphere only as forcing (no feedback)

Wind speed (along-slope)

Wind stress

Depth

SIC

 

 

 

 

Distance east [km]

 

 

Distance east [km]

13 of 27

The Idealized model: Atmospheric forcing & sea ice

  • Initially, the atmosphere only as forcing (no feedback)

Wind speed (along-slope)

Wind stress

Depth

SIC

 

 

 

 

Distance east [km]

 

 

Distance east [km]

14 of 27

The Idealized model: Atmospheric forcing & sea ice

  • Initially, the atmosphere only as forcing (no feedback)

​

Wind speed (along-slope)

Wind stress

Depth

SIC

 

 

 

 

Distance east [km]

 

 

15 of 27

The Idealized model: Atmospheric forcing & sea ice

  • Initially, the atmosphere only as forcing (no feedback)
  • Iteratively add complexity

(1st order feedbacks)

  • Cooling is suppressed if freezing should occur

HF

T2m

SST

SIC

 

 

 

 

Distance east [km]

 

 

16 of 27

The Idealized model: Hydrography & boundary conditions

17 of 27

The Idealized model: Hydrography & boundary conditions

”Standard configuration”

18 of 27

The Idealized model: Hydrography & boundary conditions

”Standard configuration”

19 of 27

  • First attempt

​

  • Initially “deep” ML

​

  • PSW expelled offshore

Hydrography & boundary conditions

”Standard configuration”

20 of 27

  • First attempt

​

  • Initially “deep” ML

​

  • PSW expelled offshore

​

  • Hard to tell when the “EGC” is equilibrated & calculate diagnostics 🡪 Periodic BC’s?

​

​

1250 km north

400 km north

1250 km north

400 km north

1250 km north

400 km north

Hydrography & boundary conditions

”Standard configuration”

21 of 27

The Idealized model: Hydrography & boundary conditions

Western BC

Eastern BC

Periodic boundary

Periodic boundary

Periodic configuration

22 of 27

The Idealized model: Periodic boundary

Periodic configuration

23 of 27

The Idealized model: Periodic boundary

Periodic configuration

  • Run until steady state before applying scenario-based forcing

​

​

​

​

​

24 of 27

The Idealized model: Periodic boundary

Si et al., 2022

25 of 27

The Idealized model: Periodic boundary

  • “feasibility test” with no HF

​

  • Periodic boundary doesn’t work

​

  • The hydrographic structure looks promising

​

​

​

​

26 of 27

Plan & future decisions

Atmospheric forcing:

  • Work toward higher complexity - feedbacks
  • Settle on a reference configuration

​

Boundary conditions: Pros & cons

“Standard”

  • Ease of implementation
  • When is the “EGC” in equilibrium?

​

Periodic

  • Meridionally averaged diagnostics
  • Obtaining satisfactory hydrography & “EGC”

​

27 of 27

Plan & future decisions

  • Additional complexity?
    • Realistic bathymetry (or just canyons and ridges)?
    • Meridional gradients

​

  • “tinker” with vertical mixing scheme

​

  • Case studies based on observational survey(s)

​

  • Past, present, and future scenarios?

​

​