D. P. Dee

D. P. Dee
European Center For Medium Range Weather Forecasts · Copernicus Department

PhD

About

133
Publications
41,066
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
41,906
Citations
Additional affiliations
September 2015 - present
European Center For Medium Range Weather Forecasts
Position
  • Deputy Head, Climate Change Service
August 2005 - August 2015
European Centre For Medium-Range Weather Forecasts
Position
  • Head of Department
July 1995 - August 2005
NASA Goddard Space Flight Center
Position
  • Researcher
Education
September 1977 - June 1983
New York University, Courant Institute of Mathematical Sciences
Field of study
  • Applied Mathematics
September 1974 - June 1977
Vassar College
Field of study
  • Liberal Arts

Publications

Publications (133)
Article
Full-text available
Within the Copernicus Climate Change Service (C3S), ECMWF is producing the ERA5 reanalysis, which embodies a detailed record of the global atmosphere, land surface and ocean waves from 1950 onwards once completed. This new reanalysis replaces the ERA‐Interim reanalysis that was started in 2006 (spanning 1979 onwards). ERA5 is based on the Integrate...
Article
Full-text available
Under the Paris Agreement progress of emission reduction efforts is tracked on the basis of regular updates to national Greenhouse Gas (GHG) inventories, referred to as bottom-up estimates. However, only top-down atmospheric measurements can provide observation-based evidence of emission trends. Today there is no internationally agreed, operational...
Article
Full-text available
The Global Land and Marine Observations Database aims to produce a comprehensive land-based meteorological data archive and inventory. This requires the compilation of available information on data from land-based meteorological stations from all known available in situ meteorological data repositories/sources at multiple timescales (e.g. sub-daily...
Article
Full-text available
To better understand and manage climate risks in climate-sensitive sectors such as agriculture, it is essential to have access to consistent and reliable data and information products. Tailoring these products to the needs of the users they want to serve facilitate informed decision-making and downstream applications. This requires an in-depth unde...
Article
Full-text available
The Global Land and Marine Observations Database aims to produce a comprehensive land based meteorological data archive and inventory. This requires the compilation of available land station meteorological data information from all known available in-situ meteorological data repositories/sources at multiple timescales (e.g. sub-daily, daily and mon...
Article
Full-text available
Extremely high temperatures pose an immediate threat to humans and ecosystems. In recent years, many regions on land and in the ocean experienced heat waves with devastating impacts that would have been highly unlikely without human-induced climate change. Impacts are particularly severe when heat waves occur in regions with high exposure of people...
Article
Decision makers need accessible robust evidence to introduce new policies to mitigate and adapt to climate change. There is an increasing amount of environmental information available to policy makers concerning observations and trends relating to the climate. However, this data is hosted across a multitude of websites often with inconsistent metad...
Article
Full-text available
CERA-20C is a coupled reanalysis of the twentieth century which aims to reconstruct the past weather and climate of the Earth system including the atmosphere, ocean, land, ocean waves, and sea ice. This reanalysis is based on the CERA coupled atmosphere-ocean assimilation system developed at ECMWF. CERA-20C provides a 10 member ensemble of reanalys...
Article
Full-text available
Global dynamical reanalyses of the atmosphere and ocean fundamentally rely on observations, not just for the assimilation (i.e., for the definition of the state of the Earth system components) but also in many other steps along the production chain. Observations are used to constrain the model boundary conditions, for the calibration or uncertainty...
Article
Full-text available
The European Reanalysis of Global Climate Observations 2 (ERA-CLIM2) is a European Union Seventh Framework Project started in January 2014 and due to be completed in December 2017. It aims to produce coupled reanalyses, which are physically consistent datasets describing the evolution of the global atmosphere, ocean, land surface, cryosphere, and t...
Article
In recent years a number of reanalysis datasets have been published that cover the past century or more, including the “Twentieth Century Reanalysis” 20CRv2 and the European Reanalysis of the twentieth century ERA-20C. These datasets are widely used, showing the need for, and possible benefit of, reanalysis data products designed for climate applic...
Article
Full-text available
To better understand the impacts of climate change, environmental monitoring capabilities must be enhanced by deploying additional and more accurate satellite- and ground-based (including in situ) sensors. In addition, reanalysis of observations collected decades ago but long forgotten can unlock precious information about the recent past. Historic...
Article
The ERA-Interim and JRA-55 reanalyses of synoptic data and several conventional analyses of monthly climatological data provide similar estimates of global-mean surface warming since 1979. They broadly agree on the character of interannual variability and the extremity of the 2015/16 warm spell to which a strong El Niño and low Arctic sea-ice cover...
Article
The representation of midlatitude winter atmospheric synoptic variability in centennial reanalysis products, which assimilate surface observations only, and atmospheric model simulations constrained by observation-based data sets is assessed. Midlatitude waves activity in twentieth century reanalyses (20CR, ERA-20C) and atmospheric model simulation...
Article
A coupled data assimilation system has been developed at the European Centre for Medium-Range Weather Forecasts (ECMWF), which is intended to be used for the production of global reanalyses of the recent climate. The system assimilates a wide variety of ocean and atmospheric observations and produces ocean-atmosphere analyses with a coupled model....
Article
The ECMWF twentieth century reanalysis (ERA-20C; 1900-2010) assimilates surface pressure and marine wind observations. The reanalysis is single-member, and the background errors are spatiotemporally varying, derived from an ensemble. The atmospheric general circulation model uses the same configuration as the control member of the ERA-20CM ensemble...
Article
The European Centre for Medium-Range Weather Forecasts (ECMWF) has developed a coupled assimilation system that ingests simultaneously ocean and atmospheric observations in a coupled ocean-atmosphere model. Employing the coupled model constraint in the analysis implies that assimilation of an ocean observation has immediate impact on the atmospheri...
Article
Full-text available
Between April 1925 and June 1927, the research vessel Meteor cruised the tropical and southern Atlantic Ocean in the framework of the German Atlantic Expedition. One purpose was to systematically explore the vertical structure of the atmosphere. To this end, the ocean was crossed in 14 profiles across parallels of latitude. 801 pilot balloons and 2...
Article
A coupled data assimilation system has been developed at the European Centre for Medium-Range Weather Forecasts (ECMWF), which is intended to be used for the production of global reanalyses of the recent climate. The system assimilates a wide variety of ocean and atmospheric observations and produces ocean-atmosphere analyses with a coupled model....
Conference Paper
Full-text available
ERA-Interim/Land is a global land-surface reanalysis dataset covering the period 1979–2010 recently made publicly available from ECMWF. It describes the evolution of soil moisture, soil temperature and snowpack. ERA-Interim/Land is the result of a single 32-year simulation with the latest ECMWF land surface model driven by meteorological forcing fr...
Article
Full-text available
This paper describes an ensemble of ten atmospheric model integrations for the years 1899 to 2010, performed at the European Centre for Medium-Range Weather Forecasts (ECMWF). Horizontal spectral resolution is T159 (about 125 km), using 91 levels in the vertical from the surface up to 1 Pa, and a time step of one hour. This ensemble, denoted by ERA...
Article
Full-text available
ERA-Interim/Land is a global land-surface reanalysis dataset covering the period 1979–2010. It describes the evolution of soil moisture, soil temperature and snowpack. ERA-Interim/Land is the result of a single 32-year simulation with the latest ECMWF land surface model driven by meteorological forcing from the ERA-Interim atmospheric reanalysis an...
Article
ERA-Interim/Land is a global land surface reanalysis data set covering the period 1979–2010. It describes the evolution of soil moisture, soil temperature and snowpack. ERA-Interim/Land is the result of a single 32-year simulation with the latest ECMWF (European Centre for Medium-Range Weather Forecasts) land surface model driven by meteorological...
Article
Full-text available
Radiance bias correction is an important and necessary step in the proper use of satellite observations in a data assimilation system. The original radiance bias-correction scheme used in the Gridpoint Statistical Interpolation (GSI) data assimilation system consists of two components: a variational air-mass dependent component and a scan-angle com...
Conference Paper
Full-text available
Efforts have been invested in enhancing the original radiance bias correction scheme in the Gridpoint Statistical Interpolation (GSI) Data Assimilation System at the National Centers for Environmental Prediction (NCEP). The enhanced scheme effectively consolidates the original two-step procedure into a single step variational procedure inside the G...
Article
Full-text available
Historical, i.e. pre-1957, upper-air data are a valuable source of information on the state of the atmosphere, in some parts of the world dating back to the early 20th century. However, to date, reanalyses have only partially made use of these data, and only of observations made after 1948. Even for the period between 1948 (the starting year of the...
Article
Low-frequency variability and trends in temperature from 1979 to 2012 are examined. Observational improvements are noted and near-surface behaviour of the ERA-Interim reanalysis is reviewed. Attention is then focussed on how closely ERA-Interim fits the upper-air data it assimilates, the bias adjustments it infers for satellite data, and its agreem...
Article
Full-text available
The ERA-Interim/Land is a global land-surface dataset covering the period 1979-2010 and describing the evolution of the soil (moisture and temperature) and snowpack. ERA-Interim/Land is the result of a single 32 yr simulation with the latest ECMWF land surface model driven by meteorological forcing from the ERA-Interim atmospheric reanalysis and pr...
Article
Full-text available
Historical, i.e. pre-1957, upper-air data are a valuable source of information on the state of the atmosphere, in some parts of the World back to the early 20th century. However, to date reanalyses have only partially made use of these data, and only of observations made after 1948. Even for the period between 1948 (the starting year of the NCEP/NC...
Article
The long observational record is critical to our understanding of the Earth’s climate, but most observing systems were not developed with a climate objective in mind. As a result, tremendous efforts have gone into assessing and reprocessing the data records to improve their usefulness in climate studies. The purpose of this paper is to both review...
Article
Stratospheric simulations from a chemistry transport model (CTM) are used to evaluate the stratospheric Brewer–Dobson circulation and mixing processes in different datasets produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). A comparison between ERA-40 and ERA-Interim shows that the recent ECMWF reanalysis greatly improves o...
Article
[1] We analyze the relation between atmospheric temperature and water vapor—a fundamental component of the global climate system—for stratospheric water vapor (SWV). We compare measurements of SWV (and methane where available) over the period 1980–2011 from NOAA balloon-borne frostpoint hygrometer (NOAA-FPH), SAGE II, Halogen Occultation Experiment...
Article
Full-text available
This article reviews past and current reanalysis activities at the European Centre for Medium-Range Weather Forecasts (ECMWF) and describes plans for developing future reanalyses of the coupled climate system. Global reanalyses of the atmosphere, ocean, land surface, and atmospheric composition have played an important role in improving and extendi...
Article
Analysing the long term time averaged atmospheric energy and hydrological cycles in atmospheric datasets provides a simple means of measuring the consistency and quality of these datasets. For the energy cycle, we assume that the long term change in storage of the total energy of the atmosphere is small. Energy is absorbed at the TOA at low latitud...
Article
Full-text available
Aside from improvements in the assimilation and numerical modelling schemes, new reanalyses can significantly profit from the recovery, imaging and digitisation of historical observations. Here, we present the status and selected examples of the digitisation of historical surface, aerological and radiation measurements in the framework of ERA-CLIM,...
Article
Stratospheric simulations carried out with a chemistry transport model (CTM) are used to evaluate the stratospheric Brewer-Dobson circulation and mixing processes in different datasets produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). A comparison between ERA-40 and ERA-Interim shows that the recent ECMWF reanalysis greatl...
Book
Full-text available
This report describes ERA-Interim/Land, a global land-surface data set covering the period 1979-2010. ERA- Interim/Land is the result of a land-surface model simulation using HTESSEL, with meteorological forcing from ERA-Interim and precipitation adjustments based on GPCP v2.1. ERA-Interim/Land preserves closure of the water balance and is therefor...
Chapter
Full-text available
This paper gives a general introduction to the parameter estimation problem for dynamical models. The basic formulation and methodology in a parameter estimation problem will be discussed and some rather simple examples will be presented. It will be shown that even for linear dynamics the parameter estimation problem becomes nonlinear and may becom...
Article
We study the global atmospheric budgets of mass, moisture, energy and angular momentum in the latest reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF), ERA-Interim, for the period 1989–2008 and compare with ERA-40. Most of the measures we use indicate that the ERA-Interim reanalysis is superior in quality to ERA-40. In...
Article
Full-text available
Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Niño phase at the beginning of the year to a cool La Niña phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin...
Article
Full-text available
Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Nino phase at the beginning of the year to a cool La Nina phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin...
Article
Full-text available
ERA-Interim is the latest global atmospheric reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). The ERA-Interim project was conducted in part to prepare for a new atmospheric reanalysis to replace ERA-40, which will extend back to the early part of the twentieth century. This article describes the forecast model,...
Article
Full-text available
Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Nino phase at the beginning of the year to a cool La Nina phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin...
Article
The value of using ECMWF reanalysis data for climate monitoring has progressively been demonstrated and there is increasing recognition by the climate science community of the relevance of reanalyses for climate change studies. Building on the experience acquired with the 45-year global ECMWF Re-Analysis (ERA-40), the ERA-Interim reanalysis covers...
Article
This article presents results of the assimilation of Global Positioning System (GPS) radio occultation (RO) bending-angle data from CHAMP, FORMOSAT-3/COSMIC and MetOp-A GRAS in the European Centre for Medium-range Weather Forecasts (ECMWF) global reanalysis ERA–Interim. We find that GPSRO data present the highest daily assimilation percentage rate...
Article
ECMWF has produced several generations of reanalysis products, beginning in 1981 with a reanalysis of observations collected for the First GARP Global Experiment (FGGE) conducted in 1979. The ECMWF reanalysis covering the longest period (1957-2001) so far is ERA-40, which has been and still is widely used. ERA-Interim is a much improved (but shorte...
Article
The new ESA Climate Change Initiative (CCI) approved in 2009 is in the process of being set up. The overall objective of the CCI, as laid out in the Programme declaration approved by ESA member states is: "To realize the full potential of the long-term global "Earth Observation" archives that ESA together with its Member states have established ove...
Article
It has long been known that one of the greatest sources of uncertainty in atmospheric analyses originates in the divergent wind. This leads to analyses containing spurious mass fluxes which are related to erroneous surface pressure tendencies. In this work, the mass budget and conservation of global dry mass are investigated using monthly mean diag...
Article
Full-text available
Evidence is presented of a reduction in relative humidity over low-latitude and midlatitude land areas over a period of about 10 years leading up to 2008, based on monthly anomalies in surface air temperature and humidity from comprehensive European Centre for Medium-Range Weather Forecasts reanalyses (ERA-40 and ERA-Interim) and from Climatic Rese...
Article
Reanalyses are an important resource for atmospheric scientists: they apply modern data assimilation techniques to historical measurements in order to produce multi-decadal timeseries of meteorological quantities. The latest ECMWF reanalysis, ERA-Interim, covers the data rich period since 1989, and it is now running close to real time. A key compon...
Article
This article describes the performance of the variational bias correction system for satellite radiance data in ERA-Interim, and considers implications for the representation of climate signals in reanalysis. We briefly review the formulation of the method and its ability to automatically develop bias estimates when radiance measurements from newly...
Article
Radiance measurements from the Stratospheric Sounding Unit (SSU) and the Advanced Microwave Sounding Unit (AMSU-A) are the primary source of information for stratospheric temperature in reanalyses of the satellite era. To improve the time consistency of the reanalyses, radiance biases need to be properly understood and accounted for in the assimila...
Article
A weak-constraint four-dimensional variational (4D-Var) analysis system designed to correct stratospheric model errors has been evaluated. Verifications against upper-level radiosonde temperature observations and Stratospheric Sounding Unit (SSU) radiance data show that the addition of a weak constraint in the stratosphere can greatly reduce analys...
Article
Variables that measure the gross properties of the atmosphere and are governed by simple physical constraints are useful in assessing the quality of atmospheric datasets such as reanalyses. Even though such global diagnostics do not give a detailed view of every point on the globe they do give an overview of the whole globe and are useful in provid...
Article
Off-line chemical transport models (CTMs) can be driven by meteorological fields from a data assimilation system (DAS) or from a general circulation model (GCM). The major advantage of using DAS fields is that results from the CTM are then directly comparable with observations on a particular day. However, the data assimilation process itself intro...