Publications by Tim Palmer


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

CLIMATE DYNAMICS 49 (2017) 1833-1845

B Huddart, A Subramanian, L Zanna, T Palmer


The impact of stochastic physics on tropical rainfall variability in global climate models on daily to weekly time scales

JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 122 (2017) 5738-5762

PAG Watson, J Berner, S Corti, P Davini, J von Hardenberg, C Sanchez, A Weisheimer, TN Palmer


Climate SPHINX: evaluating the impact of resolution and stochastic physics parameterisations in the EC-Earth global climate model

GEOSCIENTIFIC MODEL DEVELOPMENT 10 (2017) 1383-1402

P Davini, J von Hardenberg, S Corti, HM Christensen, S Juricke, A Subramanian, PAG Watson, A Weisheimer, TN Palmer


Stochastic Parameterization and El Nino-Southern Oscillation

JOURNAL OF CLIMATE 30 (2017) 17-38

HM Christensen, J Berner, DRB Coleman, TN Palmer


Introducing independent patterns into the Stochastically Perturbed Parametrization Tendencies (SPPT) scheme

Quarterly Journal of the Royal Meteorological Society 143 (2017) 2168-2181

HM Christensen, SJ Lock, IM Moroz, TN Palmer

© 2017 Royal Meteorological Society The Stochastically Perturbed Parametrization Tendencies (SPPT) scheme is used at weather and climate forecasting centres worldwide to represent model uncertainty that arises from simplifications involved in the parametrization process. It uses spatio-temporally correlated multiplicative noise to perturb the sum of the parametrized tendencies. However, SPPT does not distinguish between different parametrization schemes, which do not necessarily have the same error characteristics. A generalization to SPPT is proposed, whereby the tendency from each parametrization scheme can be perturbed using an independent stochastic pattern. This acknowledges that the forecast errors arising from different parametrizations are not perfectly correlated. Two variations of this ‘independent SPPT’ (iSPPT) approach are tested in the Integrated Forecasting System (IFS). The first perturbs all parametrized tendencies independently, while the second groups tendencies before perturbation. The iSPPT schemes lead to statistically significant improvements in forecast reliability in the Tropics in medium-range weather forecasts. This improvement can be attributed to a large, beneficial increase in ensemble spread in regions with significant convective activity. The iSPPT schemes also lead to improved forecast skill in the extratropics for a set of cases in which the synoptic initial conditions were more likely to result in European ‘forecast busts’. Longer 13 month simulations are also considered to indicate the effect of iSPPT on the mean climate of the IFS.


Variability in seasonal forecast skill of Northern Hemisphere winters over the 20th century

Geophysical Research Letters American Geophysical Union (AGU) (2017)

C O'Reilly, MacLeod, A Weisheimer, T Palmer, T Woollings


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


The primacy of doubt: Evolution of numerical weather prediction from determinism to probability

JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS 9 (2017) 730-734

T Palmer


Ensemble superparameterization versus stochastic parameterization: A comparison of model uncertainty representation in tropical weather prediction

JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS 9 (2017) 1231-1250

AC Subramanian, TN 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 Duben, T Palmer


Single Precision in Weather Forecasting Models: An Evaluation with the IFS

MONTHLY WEATHER REVIEW 145 (2017) 495-502

F Vana, P Duben, S Lang, T Palmer, M Leutbecher, D Salmond, G Carver


Variability in seasonal forecast skill of Northern Hemisphere winters over the twentieth century

GEOPHYSICAL RESEARCH LETTERS 44 (2017) 5729-5738

CH O'Reilly, J Heatley, D MacLeod, A Weisheimer, TN Palmer, N Schaller, T Woollings


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 Batte, L Bengtsson, A de la Camara, HM Christensen, M Colangeli, DRB Coleman, D Crommelin, SI Dolaptchiev, CLE Franzke, P Friederichs, P Imkeller, H Jarvinen, S Juricke, V Kitsios, F Lott, V Lucarini, S Mahajan, TN Palmer, C Penland, M Sakradzija, J-S von Storch, A Weisheimer, M Weniger, PD Williams, J-I Yano


A study of reduced numerical precision to make superparameterization more competitive using a hardware emulator in the OpenIFS model

JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS 9 (2017) 566-584

PD Duben, A Subramanian, A Dawson, TN Palmer


Stochastic Subgrid-Scale Ocean Mixing: Impacts on Low-Frequency Variability

JOURNAL OF CLIMATE 30 (2017) 4997-5019

S Juricke, TN Palmer, L Zanna


Impact of stochastic physics on tropical precipitation in the coupled ECMWF model

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 143 (2017) 852-865

A Subramanian, A Weisheimer, T Palmer, F Vitart, P Bechtold


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)

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.

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