 Thank you. OK, so this is a talk which Ron Sutton advertised the other day. So he promised that I'll show you that the Norfolk antics about to return to the 1960s. I'm not sure I can quite promise that, but the Norfolk antics been doing some pretty interesting things recently. And I'm just going to take you through some of that now and some of the evidence. So this is work I've been doing with Pablo Ortegu and Ron Sutton ready. So thanks to Gokhan and Tom, os ydych chi'n gweld o'i eu cyfrofiadau'n meddwl i'r holl yn yng Ngwyllt Aeol. Felly, mae'n gweld o chyflodd arno i gyd yn ysgolwch a'i gael ei wneud o'r hwy. Mae'n gweld o'r ffordd a'i wneud o'r hwyl yn y Cymru, ac yn y Llywodraeth, ac arall o'r rhan i gyfrofiadau, mae'n gweld o'r hwyl yng Ngwyllt Aeol yn y Llywodraeth, ac y Llywodraeth yn y Llywodraeth, ac yn y Llywodraeth, but we're still not really sure what's been driving it. Of course, there's lots of evidence of the A mark in ocean circulation, it's important there's obviously evidence of arisol are important changes in surface fluxes, etc. However, what Rowan did show is that we're actually think we're getting quite confident we can predict certain aspects of this A and B. So in particular the ocean, the large ocean heat content changes in the sub-polo gyF our quite predictable. So this is a plot from one of my studies which just The black is the observations. This is large warming in the mid 90s which is so Shaded with this shift in the ANV SST. And this red lines and initialised prediction made with the U.K met office Model and so it's quite it captures it quite well. We see this in lots of other models as well so we have some confidence that we can predict these changes Ysgríut Oeward Cymraeg a Lleidwyr Change is now quite a few studies and the last couple of years has started to come out saying that we should be expecting a cooling so a flip in sign of this A and V, maybe even perhaps to this cold state. So the key question is if this will happen and when we might enter a cold phase. So we're gonna start this story in looking at this switch to the warm phase of A and V for the mid-1990s into the early 2000s. This plot here shows on the left is just a linear trend in SST data in the middle. effeithi blade head yw'r holl honi hwn yw'r ysgrifiad o gyllid y Llanthag Llanthag i wneud eich holl hyn arweinydd byddwch ar y holl 700 m ac mae'r holl hwn yn bryd y teimlo yn llunio'n cyffredig Felly, mae'r holl hwylol yn rhoi Llanthag Llanthag sportwyr nifer 90s y holl y postroff o'r holl y mae'r holl hwyl ffocaid ar y taithiaf a grannig gyda gynnog mae yna ni'n groes yma Wythno ar fy mwyaf yw'r holl hwyl You saw this really large change in ocean heat content, that you also see SST changes across the rest of the basin. And you also see this increase in salinity. If we look at what was happening in the atmosphere at the time, So there was this trend to negative NAA, which Tom was talking about. So here, you see a slackening of wind across the North Atlantic. This is all annual means by the way. ac mae'r cyhoeddi anodd yn ymhwyloedd yn ymweld a'r cyhoeddi anodd yn ymweld, a'r gwirdd yn cyfnodd yn ymddill o gyllidiaeth, ac mae'r cyfnodd yn ddorol, i'r ffordd yma, felly yn ymhyfru'r cyflwyno'n gyfrifiad, felly mae'r cyfrifiad yn ymweld. Mae'r cyfrifiad yn ymweld i'r cyfrifiad yn ymweld i'r cyfrifiad. Ond mae'n gwybod i'r gwerthu'r cyfrifiad o'r cyfrifiad o'r cyfrifiad. Mae'r oedden nhw'n meddwl ar y ffath, mae'r oedden nhw'n ei wneud ar y cyfnodau o'r cyflwytoedd o'r hyfforddiadau ar y dyfodol o'r newid yn ymddangos. Rydyn ni i'n cael ei adnod o'r cyflwytoedd, yn ymdweud yn ymddiadau'r cyflwytoedd. Wrth gwrs, ydych chi'n gweithio'r cyflwytoedd o'r cyflwytoedd o'r ddechrau, mae'n ddweud yn ym 2014, ac ydych chi'n gweithio'r cyflwytoedd o'r cyflwytoedd. ychydig o'r swyddo'r afglau'r cyd-ddiogel, ychydig o'r sefyllfa ar y Gair. A'r cyd-ddiogel yn oedon hefyd ac yn gwybod a'r s messiol, yn oedon hefyd. Mae'r gweithio bod yn anod ymhyng yn y gwirionedd yno. Mae'r cyd-ddiogel yn y Nôr Fylltig. A'i gydig i'r ysgrifenniau, sy'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi'n rhoi. Felly'r ystyried, mae gwneud drwy'r syrniol surwadol yn y clwydd diwrnod ar y cyfnod ond yma, ond ond ry'n golygu, yn y cael ddefnyddio'r awtioon yn ysgrifion ffeithleid. Mae'n rhoi yn ysgrifion yn y ffwrdd yw 4'n wedi'u cyfrif… …ö at ynfertydd—命afelau bwyr. Mae yna'r rai un o'n gwneud ydynt, fe wnaeth ein bodai'n gwneud y ffyrdd yma. Gyda'r gweithio'r ffwladol y ddoch. Mae'r gweithio'r ffwladol a'r ddysgu'r gweithio'r newid yn ddweud. Mae'r gweithio'r gweithio'r sphaneol wedi'i gwaith. Mae'n ddiwethaf, ac mae'n cael ei ddweud bod yn ei wneud yn dda'r ffwladol o'r oesig, ond mae'n cyfwladol yn gweithio'r oesig. Felly, sy'n bod yn ni fynd i'r gweithio, sy'n bod yn ni'n meddwl'r ddweud i'r negatif oedd FNAO, Over the last few years we have had these quite large, positive NAO-like events. Is this just some sort of inter-annual variability? It's quite sensitive to these years. If we just do something quite simple, we take out the last, well, the winter 2013-2014, which was quite extreme in the surface heat loss of the North Atlantic. What you find is that many of these trends are quite sensitive to this winter, especially SST, sea level pressure, wind chest curl, and surface heat flux. So if I just flick back and forth, does this work? Okay, so that's the full 10-year trend, and then this is the 9-year trend. You can see that the SST in particular is quite sensitive. But what's not sensitive is this change in the ocean heat content and the change in the salinity. So they're not sensitive really at all. So this does bring confidence. This is some kind of longer decade of timescale change which is going on in the North Atlantic at the moment. So what is going on? Well, so we know there's been some ocean circulation changes in the North Atlantic. So the top plot here is a plot from the rapid science team. So this is from the observations, the only continuous observations of AMOC trans basin, which is at 26 North. And this showed over since 2004 this declining trend in the AMOC in the North of Transport of the ocean. And so one of the things is the question is, is this wind force? Is it just random? Or is it some parts of some longer term trend? And we wrote this paper last year, which basically looks in the models. So Gokhan talked about this. One of the key predictors of AMOC in the models is this density in the Labrador Sea. So this shows on the left, density normally is averaged between 1,000 and 2,500 meters preceding a minimum in the AMOC. So it's a negative, negative density anomies preced a minimum in the AMOC. And you see that this Labrador Sea really sticks out basically. And if you take an average over this region in the observations, what you find is you see a peak in a density here in the mid 1990s, which is associated with this trend, a positive NAO, which peaked in the mid 1990s, increased surface heat fluxes, more dense water formation. But since then, this density index has really dropped off. So to the extent that if you believe these observations, it's now at its weakest point. So this would really suggest that there is kind of a large scale weakening of this kind of thermohaline circulation in the North Atlantic. So if we now kind of try and build on this and plot these two things together, so the red line now on this plot is this density index in the steep Labrador Sea region. The black line is temperatures in this North East Atlantic region. So the region which is cooling basically and the blue line is a salinity times by 10 just so to overlay. And so what you see is after this peak in a density in the mid 1990s, you see this warming of this region to its warmest ever levels observed. And then if this model relationship is true as we suggested, then we should get this cooling. And so this is what you see. So after 2005, you see this cooling. It's pretty large in this area of the ocean. So it's so the this this North East Atlantic region is actually cooled down to kind of conditions that we last saw in the early 1990s. I just before the shift to this positive A and B. It's about a cooling of almost half a degree C on average and about 1.5 times 10 to 22 joules. And that as it says that one that's equivalent to a surface flux economy about minus 4.5 watts per square over a decade or 0.05 petawatt. And that 0.05 petawatt is about half of the deficit that we're seeing at 26 north just for context. So it seems consistent anyway with this kind of idea of this firma hailine circulation forcing weakening. But is it similar to what we'd expect from the models? So we've also looked in the model. So Pablo has done this analysis. This is basically a composite analysis in the latest. Hadley centre model had gen three GC2. It's a high resolution couple climate model. We've got 300 or so years of this. And basically he's picked out the nine largest 15 year trends or declines in the Labrador Sea. And then composited the lagged trends onto that. So that we lagged the trends by five years in the model. And so what we see after you get a reduction of density in the Labrador Sea is a cooling in SST on the left, a decrease in heat content in the middle and this freshening on the right. And particularly in this eastern sub pelagia. And so if you correlate this across all of the timescales in the model, it's a correlation of about 0.5 between a Labrador Sea density index and this eastern sub pelagia region. So again, yeah, so this is consistent with the weakened heat and salt transport in the model. Surface fluxes do play a role again in the model. But you cannot explain this cooling that we see in the model. Just like in observations. So this is my last slide before a summary actually. So what are the implications? Well, so one of the things is that this density trend in the deep Labrador Sea is still negative. So if this model relationship is true between the ocean circulation and the ocean circulation and heat content is real then we'd expect this area of the ocean and the North Atlantic to cool further. If it does, we might expect to see a return to our anomalous cold SSTs over the next decade. But that's where the question mark lies. And so we'll be watching this space. But of course, if this does, given the big, the important climate impacts across a whole range of variables then of course this could have quite large impacts on the surrounding region. So that was my quick tour of what's been going on in the North Atlantic over the last 10 or say years or well, or longer. So the North Atlantic has did warm significantly in the mid 1990s and that followed this peak in this deep Labrador Sea index. So it's consistent with a spin up of the ocean circulation pumping more heat into the North Atlantic. But the North Atlantic heat content really peaked in 2005 and since then there's been quite a considerable warming in quite a large area of the North Atlantic to again to kind of to heat content levels that we last saw in the early 1990s. So this cooling is not simply explained by changes in the atmosphere, contemporaneous changes in the atmosphere. And it's consistent with what we'd expect at least from a reduction in the ocean circulation due to the deep Labrador Sea density. But that's where the big question lies. We're not really sure exactly from the observations what exactly what the changes in the ocean circulation are overturning compared to gyre, et cetera. So that's one of the big questions. And then finally this density trend has continued to decline. So we should expect further cooling over the next 10 or so years. So that's it. Thank you.