Interannual variability in ASC and cross-slope heat transport

[adele-morrison]

Repeat much of the analysis (i.e. standard deviation on isobath, and correlations between ASC and heat transport for different regions) in this seasonal variability issue, but for annual averages in the IAF run. Also plot time series of the ASC and heat transport in different regions to see what the variability looks like and if there are trends.

[ongqingyee]

I have attempted to look at correlations between CSHT and the ASC speed in the IAF runs at specific regions/troughs in East Antarctica. This also follows on from analysis that Will and Adele did on the RYF run, looking at seasonal variability.

Below shows the monthly mean total average (depth and lat-lon) ASC speed over the 1km isobath, binned into 3 longitude degree bins, with the monthly vertically integrated CSHT, across the 1km isobath. I've selected specific regions in East Antarctica with vulnerable glaciers/troughs on the continental shelf.

There is a larger interannual variability in the ASC speed, but the seasonal cycle of the CSHT is huge in comparison. I then took the annual averages to compare.

Here are some correlations using the annually averaged data for each of the different regions - the correlation is very weak/non-existent.

The correlation is even worse for 60 years of monthly data.

Note that I've previously found it quite difficult to get domain-averaged correlations between poleward CDW transport and ASC speed, because the CDW transport is so irregular. IMO the next step would be to look at ASC speed and CSHT relations at different depths regionally, similar to Taimoor's analysis here. Any/all feedback would be super helpful.

[taimoorsohail]

Thanks @ongqingyee, I think that a layer-wise analysis would be great. My circumpolar correlations were really bad until I started looking in a layer-wise frame of reference, as the surface drowns out (what I've found to be strong) correlations below ~1km when correlating depth-averaged data.