RAPID Climate Change
1. Preliminary model experiments
Performed with North Atlantic coarse resolution isopycnal model (MICOM 1.7):
1.4 deg. horisontal resolution (Mercator grid),
6 sigma layers (26.0, 27.0, 27.5, 27.7, 27.8, 27.9).
The model is forced by annual mean winds, initial conditions are
taken from Levitus. Isopycnal interfaces are relaxed to Levitus
in the northernmost part (61-65N). In oreder to preserve the mean vertical
stratification implicit diapycnal mixing is introduced, which compensates
for the dense water inflow from the northern boundary.
Isopycnic diffusion/mixing parameters:
biharmonic thickness diffusion; diffusion velocity 0.5 cm/s
Laplacian tracer diffusion; diffusion velocity 0.5 cm/s,
momentum mixing velocity 1 cm/s with deformation dependence.
The model is run for 110 years
with deep northern tracer released during the last 10 years - this is
the set-up for the standard or reference run. Twin experiment is
run during the last 10 years, which is forced to produce extra deep
water by gradual uplift of upper interfaces of layer 4 and 5 -
120m/10 days over the north relaxation region. After this perturbation,
the interfaces are kept at the new positions.
Download movie (1.9Mb)
Layer thickness - tracer
Left pannel: perturbed layer thickness (shaded), deep transport (contours in Sv)
Right pannel: Labrador sea tracer after 10 years
Time series
Layer thickness (solid lines) ; Labrador Sea tracer (dashed lines)
Green - reference ; black - perturbed experiment
Hovmueller diagram
Difference in interface depths (pressure) of layer 27.85 (reference-perturbed)
Labrador tracer - contours
Download EGS2003 poster (0.4Mb)
2. High resolution model experiments
The model set-up is same as the coarse resolution model, but the horisontal
resolution is increased to 0.28 deg. (~30km at the EQ, 15km at 60N).
The model is run for 44 years
with deep northern tracer released during the last 4 years - this is
the set-up for the standard or reference run. Twin experiment is
run during the last 4 years, similar to the coarse resolution experiments.
Download movie (1.7Mb)
Time series
Layer thickness: green - reference ; black - perturbed experiment
; red - Labrador Sea tracer
Hovmueller diagram
Difference in interface depths (pressure) of layer 27.75 (reference-perturbed)
Correlation patterns
Download 2004 PPT presentation (1.4Mb)
Download 2004 poster (PPT 1.3Mb)
Transport anomaly
Monthly mean wind forcing experiment: the model is run for 44 years, forced by
ECMWF monthly mean fields. The thermohaline forcing is kept constant. Last four years have been subsampled every 5 days and diagnosed.
Download movie (2.9Mb)
Download 2005 PPT presentation (2.2Mb)
3. Recent experiments
The model set-up is similar, but the
resolution is increased to 0.23 deg. in horisontal and 16 vertical layers.
The model domain is extended: 35S - 67N.
Model topography
Kinetic energy
SSH
25W section
Anomaly propagation
Transport anomaly monthly forcing
Transport anomaly annual mean forcing
SSH/SST movie - monthly mean forcing
SSH/SST movie (5.6 MB QuickTime Movie)
SST movie - monthly mean forcing
Download EGS2006 poster
Download RAPID2006 poster
Download RAPID2007 poster
Download RAPID2008 poster
Download RAPID2010 poster
Download RAPID2011 poster
This page is under construction!! Maintained by V. Roussenov, vassilr@liv.ac.uk
Last changed 08 July 2011