A5067900460- Climate variability and models
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Hydrology and Drought Analysis
- Tropical and Extratropical Cyclones Research
- Forecasting Techniques and Applications
- Oceanographic and Atmospheric Processes
- Flood Risk Assessment and Management
- Arctic and Antarctic ice dynamics
- Wind and Air Flow Studies
- Atmospheric Ozone and Climate
- Complex Systems and Time Series Analysis
- Climate change impacts on agriculture
- Financial Risk and Volatility Modeling
- Cryospheric studies and observations
- Mosquito-borne diseases and control
- Plant Water Relations and Carbon Dynamics
- Climate Change Policy and Economics
- Soil Geostatistics and Mapping
- Nanopore and Nanochannel Transport Studies
- Risk and Safety Analysis
- Microfluidic and Capillary Electrophoresis Applications
- Marine and coastal ecosystems
- Climate change and permafrost
- Geophysics and Gravity Measurements
University of Exeter
2016-2025
University of Reading
2000-2025
Intergovernmental Panel on Climate Change
2025
Phillips Exeter Academy
2023
Adelphi University
2022
Met Office
2012-2020
University of Warwick
2014-2018
Google (United States)
2006-2016
National Centre for Atmospheric Science
2011-2015
Physical Sciences (United States)
2015
[1] A suite of climate change indices derived from daily temperature and precipitation data, with a primary focus on extreme events, were computed analyzed. By setting an exact formula for each index using specially designed software, analyses done in different countries have been combined seamlessly. This has enabled the presentation most up-to-date comprehensive global picture trends results number workshops held data-sparse regions high-quality station data supplied by numerous scientists...
There has been a paucity of information on trends in daily climate and extremes, especially from developing countries. We report the results analysis temperature (maximum minimum) precipitation data 14 south west African countries over period 1961–2000. Data were subject to quality control processing into indices extremes for release global community. Temperature show patterns consistent with warming most regions analyzed, large proportion stations showing statistically significant all...
The definition and interpretation of the Arctic oscillation (AO) are examined compared with those North Atlantic (NAO). It is shown that NAO reflects correlations between surface pressure variability at its centers action, whereas this not case for AO. pattern can be identified in a physically consistent way principal component analysis applied to various fields Euro-Atlantic region. A similar identification found Pacific region Pacific–North American (PNA) pattern, but no such here AO does...
We use an empirical statistical model to demonstrate significant skill in making extended-range forecasts of the monthly-mean Arctic Oscillation (AO). Forecast derives from persistent circulation anomalies lowermost stratosphere and is greatest during boreal winter. A comparison Southern Hemisphere provides evidence that both time scale predictability AO depend on presence just above tropopause. These most likely affect troposphere through changes waves upper troposphere, which induce...
Abstract The response of North Atlantic and European extratropical cyclones to climate change is investigated in the models participating phase 5 Coupled Model Intercomparison Project (CMIP5). In contrast previous multimodel studies, a feature-tracking algorithm here applied separately quantify responses number, wind intensity, precipitation intensity cyclones. Moreover, statistical framework employed formally assess uncertainties projections. Under midrange representative concentration...
Decadal predictions have a high profile in the climate science community and beyond, yet very little is known about their skill. Nor there any agreed protocol for estimating This paper proposes sound coordinated framework verification of decadal hindcast experiments. The illustrated hindcasts tailored to meet requirements specifications CMIP5 (Coupled Model Intercomparison Project phase 5). chosen metrics address key questions information content initialized hindcasts. These are: (1) Do...
Abstract Empirical orthogonal function (EOF) analysis is a powerful tool for data compression and dimensionality reduction used broadly in meteorology oceanography. Often the literature, EOF modes are interpreted individually, independent of other modes. In fact, it can be shown that no such attribution generally made. This review demonstrates general individual (i) will not correspond to dynamical modes, (ii) kinematic degrees freedom, (iii) statistically (iv) strongly influenced by...
Abstract Research and development of new verification strategies reassessment traditional forecast methods has received a great deal attention from the scientific community in last decade. This effort arisen need to respond changes encompassing several aspects process, such as evolution forecasting systems, or desire for more meaningful approaches that address specific user requirements. Verification techniques account spatial structure presence features fields, which are designed...
A simple and coherent framework for partitioning uncertainty in multimodel climate ensembles is presented. The analysis of variance (ANOVA) used to decompose a measure total variation additively into scenario uncertainty, model internal variability. This approach requires fewer assumptions than existing methods can be easily quantify related model–scenario interaction—the contribution arising from the across scenarios deviations ensemble mean. Uncertainty global mean surface air temperature...
further work is needed to explore the possibility of performing calibration taking nonstationarity in biases into account.
This study investigates ways of quantifying the skill in forecasts dichotomous weather events. The odds ratio, widely used medical studies, can provide a powerful way testing association between categorical and observations. A score be constructed from ratio that is less sensitive to hedging than previously scores. Furthermore, significance tests easily performed on logarithm test whether purely due chance sampling. Functions Peirce define general class scores are symmetric with respect...
Abstract The clustering in time (seriality) of extratropical cyclones is responsible for large cumulative insured losses western Europe, though surprisingly little scientific attention has been given to this important property. This study investigates and quantifies the seriality Northern Hemisphere using a point-process approach. A possible mechanism serial time-varying effect large-scale flow on individual cyclone tracks. Another generation by one “parent” or more “offspring” through...
Abstract This study investigates variability in the intensity of wintertime Siberian high (SH) by defining a robust SH index (SHI) and correlating it with selected meteorological fields teleconnection indices. A dramatic trend –2.5 hPa decade−1 has been found SHI between 1978 2001 unprecedented (since 1871) low values SHI. The weakening confirmed analyzing different historical gridded analyses individual station observations sea level pressure (SLP) excluding possible effects from conversion...
The North Atlantic Oscillation (NAO) is a major mode of large-scale climate variability which contains broad spectrum variations. There are substantial contributions from short-term 2–5 year variations, have clearly marked teleconnections. Decadal trends also apparent in the historical record NAO and may be due to either stochastic or deterministic processes. Evidence presented that suggests exhibits 'long-range' dependence having winter values residually correlated over many years. Several...
The amplitude of the El Niño‐Southern Oscillation (ENSO) would be normally distributed if coupled Pacific ocean‐atmosphere were a linear system forced by Gaussian weather noise. Moment estimates skewness and kurtosis demonstrate that this is not case for monthly mean anomalies in sea surface temperatures during 1950–97. noted predominance Niño events compared to La Niña related high eastern Pacific. Skewness both exhibit an intriguing geographical variation from positive negative western We...
Many variations such as the annual cycle in sea surface temperatures can be considered to smooth functions and are appropriately described using methods from functional data analysis. This study defines a class of autoregressive (FAR) models which used robust predictors for making forecasts entire future. The illustrated compared with pointwise SARIMA by applying them forecasting climatological El Nino–Southern Oscillation (ENSO) time series one year ahead. Forecasts period 1987–1996 suggest...
Abstract Verifying forecasts of rare events is challenging, in part because traditional performance measures degenerate to trivial values as become rarer. The extreme dependency score was proposed recently a nondegenerating measure for the quality deterministic binary events. This has some undesirable properties, including being both easy hedge and dependent on base rate. A symmetric also recently, but this too These two scores their properties are reviewed meanings several such base-rate...