Securing Multidisciplinary UndeRstanding and Prediction of Hiatus and Surge events (SMURPHS)

Lead Research Organisation: NERC British Antarctic Survey
Department Name: Science Programmes


Climate is currently changing mostly because of additional greenhouse gases, emitted through human activity, which are heating up the planet. Since future warming of climate is likely to cause damage to societies, governments are coordinating efforts to reduce greenhouse gas emissions to avoid these damaging consequences. However, despite the continuing rises in atmospheric greenhouse gas concentrations, the rate of warming of the Earth's surface has declined somewhat since the 1990s. While it is tempting to find a simple reason for this slowing (or "hiatus") in global surface warming, the climate system is extremely complex and there are many factors which can explain the lumps and bumps in the surface temperature record which also include increases (or "surges") in the rate of warming. The goal of our proposed programme of research is to understand much more fully how all the contributing factors can explain past hiatus and surge (H/S) events and this will ultimately help improve predictions of future climate change over the coming decades and far into the future.

The potential causes of H/S events includes: natural (so-called unforced) climate variability, due to complex interplay between the atmosphere, oceans and land; natural climate change due to volcanic eruptions or changes in the brightness of the sun; changes in how heat is moved into the deep oceans due to natural variations or human-caused factors; changes in emissions of gases such as methane due to human activity; limitations in the distribution of temperature observations, such that the hiatus is partly an artefact of imperfect observations. Rather than one single cause it is likely that H/S events are caused by a combination of factors. This is why a large team with a broad range of expertise is required to evaluate the different processes together. Our project, Securing Multidisciplinary UndeRstanding and Prediction of Hiatus and Surge events (SMURPHS) has brought together a comprehensive community of researchers from 9 UK institutes supported by 5 project partners including the Met Office who are experts in the atmosphere, the oceans and the land surface.

SMURPHS has 3 broad objectives, achieved through 6 research themes, which exploit theory, observations and detailed computer modelling. Objective 1 is to build a basic framework for interpreting H/S events in terms of energy moving between the atmosphere and ocean and to determine characteristics of and similarities between H/S events. Objective 2 is to understand mechanisms that could trigger H/S events and extend their length, considering both human and natural factors. Objective 3 is to assess whether H/S events can be predicted and what information is needed for near-term prediction of climate over coming decades which is important for how societies adapt to change. To meet these objectives scientists from a range of different disciplines will work on each of these possibilities and communicate their findings across the team. SMURPHS will produce a wide-ranging synthesis of its results.

SMURPHS will have many beneficiaries. Beyond the global scientific community, improved understanding of H/S events is important at national and international levels for designing policies to control future greenhouse gas emissions and for effective adaptation to climate change. Intergovernmental Panel on Climate Change (IPCC) assessments have deeply influenced climate policy development at the international and national levels. Scientists involved in SMURPHS have contributed significantly to previous IPCC reports, and SMURPHS science and scientists would contribute significantly to future such assessments.

Planned Impact

1. The World Climate Research Program (WCRP) 6th Climate Model Intercomparison (CMIP6) Committee, participating climate research centres, and the international research community will benefit from new radiative forcing scenarios with quantified uncertainties promoted through WCRP/CMIP6 planning meetings. SMURPHS will contribute directly to the CMIP6 plans and host relevant meetings during the project. The SMURPHS webpage will provide the latest information to the international modelling centres and a contact list will be drawn up for provision of regular notifications.
2. International policy makers representing governments in the United Nations Framework Convention on Climate Change (UNFCCC) negotiations; National policy makers in the Department of Energy and Climate Change (DECC) and the Committee for Climate Change (CCC) and European Union counterparts; and International and national non-governmental organisations (NGOs) will benefit from improved understanding of decadal variability in global mean surface temperature rise and of the relationship between short term and longer term trends.
Two critical issues for these groups are: (i) implications of the recent hiatus for long term climate change (mitigation policy), and (ii) constraints on the rate of climate change over the next few decades (adaptation policy). We will organize two international workshops to synthesize research findings and bring together additional international perspectives to provide an overall assessment. Key outputs will be two assessment papers for input to the Sixth Assessment Report of the IPCC (AR6). Lack of complete understanding of the hiatus was a major gap in IPCC AR5, which SMURPHS will address directly. As part of these workshops, a discussion session will be held with invited policymakers from DECC and other government departments to explore the implications of our findings. We also plan to hold a side event on historic temperature trends at a UNFCCC Conference of the Parties (expected in December 2017).
3. The Met Office (MO) has strategic plans to improve near term prediction of climate change and with DECC/DEFRA and CCC will produce revised mitigation pathways to avoid dangerous climate change. The MO will benefit from improved quantification of past radiative forcing and understanding of variability in global-mean surface temperature rise, resulting in improved models and predictions. A close working relationship with the MO is established and a coordinated programme of work has been designed. MO colleagues will attend project meetings and SMURPHS PDRAs will spend time based at the MO. The Met Office Academic Partnership involving the Universities of Exeter, Leeds, Oxford and Reading provides an additional mechanism for collaboration.
4. The general public and the media. SMURPHS will benefit the interested public by enabling clearer and more precise explanations of the hiatus and implications for long-term climate change. Several media articles used poor understanding of the hiatus to challenge the Government's emission reduction targets in 2013. In response the Science Media Centre (SMC) prepared a briefing note on the hiatus with significant contributions from Forster, Sutton, Allan and Hawkins. We will work with the SMC to update this briefing note at the end of the project, and will discuss holding a briefing meeting for interested journalists. Shine is very active in ongoing Royal Society efforts to explain climate change science to a wide audience via a number of activities, and expects to continue to be so during SMURPHS. Outputs from the project will be written up in a form that is accessible for the interested general public on Hawkins' climate-lab-book blog which also provides a mechanism for public engagement and feedback. Key findings will be communicated on Twitter. All PIs and Co-Is have press experience and engagement with the media will continue throughout the project.


10 25 50
Description Model development: Adjoint model of the ECCOv4 setup of MITgcm is up and running on the ARCHER supercomputer.

I am producing and analysing ensembles of multi-year adjoint runs looking at the sensitivity of mixed layer mode water pools to surface forcings such as wind stress and heat fluxes.

I am also carrying out a smaller number of forward perturbation experiments, informed by the above adjoint runs, which investigate the pathways of the sensitivities directly and allow for assessment of how well the linear approximation in the adjoint run holds. Initial results show that the subtropics, notable the Indonesian throughflow play significant roles in setting mixed layer heat budgets.

In addition, we are in the early stages of collaborating with Simon Mueller and Florian Sevellec from NOCS on carrying out a comparison between the NEMO adjoint model and our adjoint, providing further context for our results.

Spinning up model using repeated CORE2 normal year forcing to use for SMURPHS work. Stability has now been achieved, along with sensible metrics for ACC transport and MOC core strength.
Exploitation Route This work will form the basis for comparisons with the external SMURPHS project to understand the ocean's role in setting the hiatus/surge interdecadal trends in global mean surface temperature. Furthermore, the adjoint tool and sensitivities of ocean internal heat to surface forcing has wide ranging application in the understanding of the ocean's role in climate beyond the SMURPHS project. Tie ins to the MetOffice's work on the UK-ESM and the NERC funded ORCHESTRA project are underway.
Sectors Education,Environment

Description Emma Boland took part in outreach at the University of Cambridge Primary School with Antarctic features for reception aged children. Emma Boland appeared on Cambridge 105: Women making Waves show talking about climate science. Emma Boland gave a seminar on climate science and oceanography for the University of Cambridge SIAM Student Chapter. Emma Boland has been mentoring the University of Cambridge AI4ER CDT guided team challenge on producing a future climate risk index.
First Year Of Impact 2019
Sector Education,Environment
Impact Types Societal,Policy & public services

Description Boland Cambridge Primary outreach 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Emma Boland took part in outreach at the University of Cambridge primary school in January on the topic of the Polar Regions with Reception-aged children.
Year(s) Of Engagement Activity 2018
Description Cambridge Science Festival 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Cambridge Science Festival event "Sensing the climate: how do we measure our changing planet?" as part of the Cambridge Centre for Climate Science. This includes a presentation on how oceanographers take observational measurements.
Year(s) Of Engagement Activity 2018