Publications by Tim Palmer


Stochastic parameterization and El Niño-southern oscillation

Journal of Climate 30 (2017) 17-38

HM Christensen, J Berner, DRB Coleman, TN Palmer


Atmospheric seasonal forecasts of the twentieth century: multi-decadal variability in predictive skill of the winter North Atlantic Oscillation (NAO) and their potential value for extreme event attribution

Quarterly Journal of the Royal Meteorological Society 143 (2017) 917-926

A Weisheimer, N Schaller, C O'Reilly, DA MacLeod, T Palmer


On the use of scale-dependent precision in Earth System modelling

Quarterly Journal of the Royal Meteorological Society 143 (2017) 897-908

T Thornes, P Düben, T Palmer


Single precision in weather forecasting models: An evaluation with the IFS

Monthly Weather Review 145 (2017) 495-502

F Váňa, P Düben, S Lang, T Palmer, M Leutbecher, D Salmond, G Carver


Stochastic parameterization toward a new view of weather and climate models

Bulletin of the American Meteorological Society 98 (2017) 565-587

J Berner, U Achatz, L Batté, L Bengtsson, A De La Cámara, HM Christensen, M Colangeli, DRB Coleman, D Crommelin, SI Dolaptchiev, CLE Franzke, P Friederichs, P Imkeller, H Järvinen, S Juricke, V Kitsios, F Lott, V Lucarini, S Mahajaajaajan, TN Palmer, C Penland, M Sakradzijaja, JS Von Storch, A Weisheimer, M Weniger, PD Williams, JI Yano

© 2017 American Meteorological Society. Stochastic parameterizations-empirically derived or based on rigorous mathematical and statistical concepts-have great potential to increase the predictive capability of next-generation weather and climate models.


Seasonal and decadal forecasts of Atlantic Sea surface temperatures using a linear inverse model

Climate Dynamics (2016) 1-13

B Huddart, A Subramanian, L Zanna, T Palmer


A personal perspective on modelling the climate system.

Proceedings. Mathematical, physical, and engineering sciences 472 (2016) 20150772-

TN Palmer

Given their increasing relevance for society, I suggest that the climate science community itself does not treat the development of error-free ab initio models of the climate system with sufficient urgency. With increasing levels of difficulty, I discuss a number of proposals for speeding up such development. Firstly, I believe that climate science should make better use of the pool of post-PhD talent in mathematics and physics, for developing next-generation climate models. Secondly, I believe there is more scope for the development of modelling systems which link weather and climate prediction more seamlessly. Finally, here in Europe, I call for a new European Programme on Extreme Computing and Climate to advance our ability to simulate climate extremes, and understand the drivers of such extremes. A key goal for such a programme is the development of a 1 km global climate system model to run on the first exascale supercomputers in the early 2020s.


Oceanic stochastic parameterizations in a seasonal forecast system

Monthly Weather Review 144 (2016) 1867-1875

M Andrejczuk, FC Cooper, S Juricke, TN Palmer, A Weisheimer, L Zanna


The role of the tropical West Pacific in the extreme Northern Hemisphere winter of 2013/2014

JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 121 (2016) 1698-1714

PAG Watson, A Weisheimer, JR Knight, TN Palmer


Assessing the role of insulin-like growth factors and binding proteins in prostate cancer using Mendelian randomization: Genetic variants as instruments for circulating levels.

International journal of cancer 139 (2016) 1520-1533

C Bonilla, SJ Lewis, MA Rowlands, TR Gaunt, G Davey Smith, D Gunnell, T Palmer, JL Donovan, FC Hamdy, DE Neal, R Eeles, D Easton, Z Kote-Jarai, AA Al Olama, S Benlloch, K Muir, GG Giles, F Wiklund, H Grönberg, CA Haiman, J Schleutker, BG Nordestgaard, RC Travis, N Pashayan, KT Khaw, JL Stanford, WJ Blot, S Thibodeau, C Maier, AS Kibel, C Cybulski, L Cannon-Albright, H Brenner, J Park, R Kaneva, J Batra, MR Teixeira, H Pandha, M Lathrop, RM Martin, JM Holly

Circulating insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) are associated with prostate cancer. Using genetic variants as instruments for IGF peptides, we investigated whether these associations are likely to be causal. We identified from the literature 56 single nucleotide polymorphisms (SNPs) in the IGF axis previously associated with biomarker levels (8 from a genome-wide association study [GWAS] and 48 in reported candidate genes). In ∼700 men without prostate cancer and two replication cohorts (N ∼ 900 and ∼9,000), we examined the properties of these SNPS as instrumental variables (IVs) for IGF-I, IGF-II, IGFBP-2 and IGFBP-3. Those confirmed as strong IVs were tested for association with prostate cancer risk, low (< 7) vs. high (≥ 7) Gleason grade, localised vs. advanced stage, and mortality, in 22,936 controls and 22,992 cases. IV analysis was used in an attempt to estimate the causal effect of circulating IGF peptides on prostate cancer. Published SNPs in the IGFBP1/IGFBP3 gene region, particularly rs11977526, were strong instruments for IGF-II and IGFBP-3, less so for IGF-I. Rs11977526 was associated with high (vs. low) Gleason grade (OR per IGF-II/IGFBP-3 level-raising allele 1.05; 95% CI: 1.00, 1.10). Using rs11977526 as an IV we estimated the causal effect of a one SD increase in IGF-II (∼265 ng/mL) on risk of high vs. low grade disease as 1.14 (95% CI: 1.00, 1.31). Because of the potential for pleiotropy of the genetic instruments, these findings can only causally implicate the IGF pathway in general, not any one specific biomarker.


Stochastic and Perturbed Parameter Representations of Model Uncertainty in Convection Parameterization*

JOURNAL OF THE ATMOSPHERIC SCIENCES 72 (2015) 2525-2544

HM Christensen, IM Moroz, TN Palmer


Evaluation of ensemble forecast uncertainty using a new proper score: Application to medium-range and seasonal forecasts

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 141 (2015) 538-549

HM Christensen, IM Moroz, TN Palmer


Invariant set theory: Violating measurement independence without fine tuning, conspiracy, constraints on free will or retrocausality

Electronic Proceedings in Theoretical Computer Science, EPTCS 195 (2015) 285-294

TN Palmer


Modelling: Build imprecise supercomputers.

Nature 526 (2015) 32-33

T Palmer


Impact of hindcast length on estimates of seasonal climate predictability

Geophysical Research Letters 42 (2015) 1554-1559

W Shi, N Schaller, D Macleod, TN Palmer, A Weisheimer


Does the ECMWF IFS Convection Parameterization with Stochastic Physics Correctly Reproduce Relationships between Convection and the Large-Scale State?

JOURNAL OF THE ATMOSPHERIC SCIENCES 72 (2015) 236-242

PAG Watson, HM Christensen, TN Palmer


Architectures and precision analysis for modelling atmospheric variables with chaotic behaviour

Proceedings - 2015 IEEE 23rd Annual International Symposium on Field-Programmable Custom Computing Machines, FCCM 2015 (2015) 171-178

FP Russell, PD Düben, X Niu, W Luk, TN Palmer


Impact of hindcast length on estimates of seasonal climate predictability.

Geophysical research letters 42 (2015) 1554-1559

W Shi, N Schaller, D MacLeod, TN Palmer, A Weisheimer

It has recently been argued that single-model seasonal forecast ensembles are overdispersive, implying that the real world is more predictable than indicated by estimates of so-called perfect model predictability, particularly over the North Atlantic. However, such estimates are based on relatively short forecast data sets comprising just 20 years of seasonal predictions. Here we study longer 40 year seasonal forecast data sets from multimodel seasonal forecast ensemble projects and show that sampling uncertainty due to the length of the hindcast periods is large. The skill of forecasting the North Atlantic Oscillation during winter varies within the 40 year data sets with high levels of skill found for some subperiods. It is demonstrated that while 20 year estimates of seasonal reliability can show evidence of overdispersive behavior, the 40 year estimates are more stable and show no evidence of overdispersion. Instead, the predominant feature on these longer time scales is underdispersion, particularly in the tropics.Predictions can appear overdispersive due to hindcast length sampling errorLonger hindcasts are more robust and underdispersive, especially in the tropicsTwenty hindcasts are an inadequate sample size to assess seasonal forecast skill.


Opportunities for energy efficient computing: A study of inexact general purpose processors for high-performance and big-data applications

Proceedings -Design, Automation and Test in Europe, DATE 2015-April (2015) 764-769

P Duben, Parishkrati, S Yenugula, J Augustine, K Palem, J Schlachter, C Enz, TN Palmer


Solving difficult problems creatively: a role for energy optimised deterministic/stochastic hybrid computing.

Frontiers in computational neuroscience 9 (2015) 124-

TN Palmer, M O'Shea

How is the brain configured for creativity? What is the computational substrate for 'eureka' moments of insight? Here we argue that creative thinking arises ultimately from a synergy between low-energy stochastic and energy-intensive deterministic processing, and is a by-product of a nervous system whose signal-processing capability per unit of available energy has become highly energy optimised. We suggest that the stochastic component has its origin in thermal (ultimately quantum decoherent) noise affecting the activity of neurons. Without this component, deterministic computational models of the brain are incomplete.

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