OSeaIce issueshttps://git.smhi.se/david.docquier/oseaice/-/issues2020-03-25T07:52:40Zhttps://git.smhi.se/david.docquier/oseaice/-/issues/1Understanding the decrease in Atlantic OHT south of 60N2020-03-25T07:52:40ZDavid DocquierUnderstanding the decrease in Atlantic OHT south of 60NAs can be seen in Fig. 1 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments), the mean Atlantic OHT increases north of 60N but decreases south of 60N for the wide and middle domain experiments. We...As can be seen in Fig. 1 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments), the mean Atlantic OHT increases north of 60N but decreases south of 60N for the wide and middle domain experiments. We think that is due to a decrease in the North Atlantic mixing (Fig. 8 of the [SST restoring experiments](../wikis/SST restoring experiments)) and weakening of the Atlantic Meridional Circulation (Figs. 9 and 10 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)), following the SST increase. Interestingly, the vertical profiles of the Atlantic meridional stream function (AMSF) show a weakening at all depths south of 60N and an increase in the upper layer (first 500m) north of 60N with a weakening below in the wide and middle domain experiments (Fig. 10 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)).https://git.smhi.se/david.docquier/oseaice/-/issues/2Increasing the SST in the Atlantic or Pacific results in relatively similar s...2020-05-28T07:28:55ZDavid DocquierIncreasing the SST in the Atlantic or Pacific results in relatively similar sea-ice lossComparing the paired Atlantic and Pacific experiments (wide, middle and small domains) together, the sea-ice area and volume losses are relatively similar (Figs. 3-4 in the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pac...Comparing the paired Atlantic and Pacific experiments (wide, middle and small domains) together, the sea-ice area and volume losses are relatively similar (Figs. 3-4 in the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)), as well as the spatial patterns of sea-ice concentration and thickness (Figs. 11-13 in the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)). In terms of spatial patterns, the March sea-ice concentration loss is concentrated at the sea-ice edges while the March sea-ice thickness loss appears everywhere in the Arctic. This suggests that the region in which the SST is increased does not really matter for the sea-ice loss.https://git.smhi.se/david.docquier/oseaice/-/issues/3Sea-ice loss clearly linked to ocean heat transport increase2020-04-03T16:03:52ZDavid DocquierSea-ice loss clearly linked to ocean heat transport increaseOn the one hand, the strong decrease in sea-ice area (SIA) and volume (SIV) in the wide Atlantic experiment (Figs. 3-4 left panels of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)) is clearly l...On the one hand, the strong decrease in sea-ice area (SIA) and volume (SIV) in the wide Atlantic experiment (Figs. 3-4 left panels of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)) is clearly linked to the strong increase in ocean heat transport (OHT) at the Barents Sea Opening (Fig. 6 top panel of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)). On the other hand, the strong decrease in SIA and SIV in the wide Pacific experiment (Figs. 3-4 right panels of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)) is clearly linked to the strong increase in OHT at the Bering Strait (Fig. 7 bottom panel of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)).https://git.smhi.se/david.docquier/oseaice/-/issues/4The OHT changes are mainly driven by temperature changes2020-03-25T08:10:05ZDavid DocquierThe OHT changes are mainly driven by temperature changesThe ocean heat transport (OHT) changes through all Arctic straits are mainly driven by the changes in temperature and the temperature-velocity covariance (Fig. 19 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacifi...The ocean heat transport (OHT) changes through all Arctic straits are mainly driven by the changes in temperature and the temperature-velocity covariance (Fig. 19 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)). The OHT changes at the Barents Sea Opening (BSO) in the Atlantic experiments are first driven by the changes in temperature, with considerable influence of the velocity and covariance contributions for the wide Atlantic experiment, while these changes are shared by all 3 contributions in the Pacific experiments (Fig. 20 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)). The OHT changes at the Bering Strait are relatively small in the Atlantic experiments and are mainly driven by the changes in temperature in the Pacific experiments (Fig. 21 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)).https://git.smhi.se/david.docquier/oseaice/-/issues/5The sea-ice loss in the Bering Strait experiment is relatively high2020-05-28T09:26:10ZDavid DocquierThe sea-ice loss in the Bering Strait experiment is relatively highAlthough the ocean heat transport (OHT) at the Bering Strait is relatively small compared to the one at the Barents Sea Opening (BSO), i.e. 4.5 times lower in our control run, the impact of the Bering Strait experiments on sea-ice loss i...Although the ocean heat transport (OHT) at the Bering Strait is relatively small compared to the one at the Barents Sea Opening (BSO), i.e. 4.5 times lower in our control run, the impact of the Bering Strait experiments on sea-ice loss is relatively high compared to the BSO experiment (Figs. 3-4 and 11-13 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)). The OHT at the Bering Strait increases by 35% (Fig. 7 bottom panel of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)) and the AMOC slightly increases (Fig. 10 bottom panel of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)) in the Bering Strait experiments, while the OHT at the BSO increases only by 13% (Fig. 6 top panel of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)).https://git.smhi.se/david.docquier/oseaice/-/issues/6Salinity dipole in the Arctic2020-08-20T12:12:07ZDavid DocquierSalinity dipole in the ArcticThe surface salinity changes in all the SST experiments show a marked dipole in the Arctic, with a freshening of the western Arctic and a salinity increase in the eastern Arctic (Fig. 14 of the [Atlantic and Pacific SST experiments](../w...The surface salinity changes in all the SST experiments show a marked dipole in the Arctic, with a freshening of the western Arctic and a salinity increase in the eastern Arctic (Fig. 14 of the [Atlantic and Pacific SST experiments](../wikis/Atlantic and Pacific SST experiments)). The freshening is linked to the sea-ice melting, while the salinity increase is probably linked to the freshwater being exported across Fram Strait and mixing.https://git.smhi.se/david.docquier/oseaice/-/issues/7Vertical profiles of ocean temperature2020-04-03T08:46:40ZDavid DocquierVertical profiles of ocean temperatureVertical profiles of ocean temperature show that it clearly increases in the first 800-1000m (maximum increase at 200m) in the wide domain experiments in both the Atlantic part of the Arctic Ocean (first figure below) and the Pacific par...Vertical profiles of ocean temperature show that it clearly increases in the first 800-1000m (maximum increase at 200m) in the wide domain experiments in both the Atlantic part of the Arctic Ocean (first figure below) and the Pacific part of the Arctic Ocean (second figure below). This suggests that the ocean heat propagates through the whole Arctic in both the North Atlantic and North Pacific experiments. While the temperature increase is less pronounced in the middle and small domain experiments, there is also suggestion of heat propagation through the Arctic Ocean.
![thetao_atlarc_diff_APSST](/uploads/353e3db1cc66c11b3c518b44ec97f7f4/thetao_atlarc_diff_APSST.png)
**Vertical profiles (longitudinally-averaged) of the Arctic Ocean potential temperature (Atlantic part) in the control run (top left panel) and of the difference in the ocean temperature between the Atlantic (middle row) / Pacific (bottom row) experiments and the control run, averaged over 50 years**
![thetao_pacarc_diff_APSST](/uploads/7d11694fdd66302e58026d7e7e2159bf/thetao_pacarc_diff_APSST.png)
**Vertical profiles (longitudinally-averaged) of the Arctic Ocean potential temperature (Pacific part) in the control run (top left panel) and of the difference in the ocean temperature between the Atlantic (middle row) / Pacific (bottom row) experiments and the control run, averaged over 50 years**https://git.smhi.se/david.docquier/oseaice/-/issues/8Changes in the atmosphere2020-06-29T12:51:12ZDavid DocquierChanges in the atmosphereThe time series of global annual mean surface temperature shows that the wide domain experiments are about 0.5-1K warmer than the control run, while the middle and small domain experiments have a much lower warming (see figure below).
!...The time series of global annual mean surface temperature shows that the wide domain experiments are about 0.5-1K warmer than the control run, while the middle and small domain experiments have a much lower warming (see figure below).
![tas_timeseries_APSST](/uploads/162eda4801a3b8a1a7cf959888b5166f/tas_timeseries_APSST.png)
The movie below shows the difference in monthly mean surface temperature (averaged over 50 years) between the Atlantic (top panels) / Pacific (bottom panels) SST restoring experiments and the control run for each month, centered on the North Pole. The wide domain experiments (left column) show a strong warming (more pronounced in the Arctic) during all months, with a cooling in central eastern Asia in winter. The middle and small domain experiments (middle and right columns) show a warming over the Arctic and a cooling over central eastern Asia and parts of North America.
![Maps_tas_diff_APSST](/uploads/f60f732f71b6d6f331d3cab133d42653/Maps_tas_diff_APSST.gif)