HadCRUT
Encyclopedia
HadCRUT is the dataset of monthly temperature record
s formed by combining the sea surface temperature records compiled by the Hadley Centre
of the UK Met Office
and the land surface temperature records compiled by the Climatic Research Unit (CRU)
of the University of East Anglia
.
The data is variance
corrected and gaps in the records are filled by reduced space optimum interpolation
to provide a smooth and continuous time series
which initially spanned the period 1871–1998, covering the globe in a grid of points between the latitude
s 65° North and 35° South.
had as an early priority the objective of filling gaps in available information "to establish the past record of climate over as much of the world as possible, as far back in time as was feasible, and in enough detail to recognise and establish the basic processes, interactions, and evolutions in the Earth's fluid envelopes and those involving the Earth's crust and its vegetation cover". Through the 1970s the unit worked on interpreting documentary historical records. From 1978 onward CRU began production of its gridded data set
of land air temperature anomalies based on instrumental temperature record
s held by around the world. In 1986 sea temperatures were added to form a synthesis of data which was the first global temperature record, demonstrating unequivocally that the globe has warmed by almost 0.8°C over the last 157 years. From 1989 this work proceeded in conjunction with the Met Office
Hadley Centre for Climate Prediction and Research
, and their work demonstrated global warming
of almost 0.8°C over the last 157 years.
Access to temperature records was often under formal or informal confidentiality agreements that restricted use of this raw data to academic purposes. From the 1990s onwards the unit received requests for raw data made by those critical of the scientific understanding of global warming
, and after the UK Freedom of Information Act
(FOIA) came into effect in 2005, there were Freedom of Information requests to the Climatic Research Unit
for this raw data. On 12 August 2009 CRU announced that they were seeking permission to waive these restrictions, and on 24 November 2009 the university stated that over 95% of the CRU climate data set had already been available for several years, with the remainder to be released when permissions were obtained. In a decision announced on 27 July 2011 the Information Commissioner's Office (ICO) required release of raw data even though permissions had not been obtained or in one instance had been refused, and on 27 July 2011 CRU announced release of the raw instrumental data not already in the public domain, with the exception of Poland which was outside the area covered by the FOIA request.
Temperature record
The temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time. The most detailed information exists since 1850, when methodical thermometer-based records began. There are numerous estimates of temperatures since the end of the...
s formed by combining the sea surface temperature records compiled by the Hadley Centre
Hadley Centre for Climate Prediction and Research
The Met Office Hadley Centre for Climate Change — named in honour of George Hadley — is part of, and based at the headquarters of the Met Office in Exeter...
of the UK Met Office
Met Office
The Met Office , is the United Kingdom's national weather service, and a trading fund of the Department for Business, Innovation and Skills...
and the land surface temperature records compiled by the Climatic Research Unit (CRU)
Climatic Research Unit
The Climatic Research Unit is a component of the University of East Anglia and is one of the leading institutions concerned with the study of natural and anthropogenic climate change....
of the University of East Anglia
University of East Anglia
The University of East Anglia is a public research university based in Norwich, United Kingdom. It was established in 1963, and is a founder-member of the 1994 Group of research-intensive universities.-History:...
.
The data is variance
Variance
In probability theory and statistics, the variance is a measure of how far a set of numbers is spread out. It is one of several descriptors of a probability distribution, describing how far the numbers lie from the mean . In particular, the variance is one of the moments of a distribution...
corrected and gaps in the records are filled by reduced space optimum interpolation
Interpolation
In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points....
to provide a smooth and continuous time series
Time series
In statistics, signal processing, econometrics and mathematical finance, a time series is a sequence of data points, measured typically at successive times spaced at uniform time intervals. Examples of time series are the daily closing value of the Dow Jones index or the annual flow volume of the...
which initially spanned the period 1871–1998, covering the globe in a grid of points between the latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
s 65° North and 35° South.
HadCRUT3
HadCRUT3 is the third major revision of this dataset. This extended coverage to the period 1850–2007. Its spatial grid squares are 5° of latitude and longitude.History of CRU Climate Data
The Climatic Research UnitClimatic Research Unit
The Climatic Research Unit is a component of the University of East Anglia and is one of the leading institutions concerned with the study of natural and anthropogenic climate change....
had as an early priority the objective of filling gaps in available information "to establish the past record of climate over as much of the world as possible, as far back in time as was feasible, and in enough detail to recognise and establish the basic processes, interactions, and evolutions in the Earth's fluid envelopes and those involving the Earth's crust and its vegetation cover". Through the 1970s the unit worked on interpreting documentary historical records. From 1978 onward CRU began production of its gridded data set
Data set
A data set is a collection of data, usually presented in tabular form. Each column represents a particular variable. Each row corresponds to a given member of the data set in question. Its values for each of the variables, such as height and weight of an object or values of random numbers. Each...
of land air temperature anomalies based on instrumental temperature record
Instrumental temperature record
The instrumental temperature record shows fluctuations of the temperature of the global land surface and oceans. This data is collected from several thousand meteorological stations, Antarctic research stations and satellite observations of sea-surface temperature. Currently, the longest-running...
s held by around the world. In 1986 sea temperatures were added to form a synthesis of data which was the first global temperature record, demonstrating unequivocally that the globe has warmed by almost 0.8°C over the last 157 years. From 1989 this work proceeded in conjunction with the Met Office
Met Office
The Met Office , is the United Kingdom's national weather service, and a trading fund of the Department for Business, Innovation and Skills...
Hadley Centre for Climate Prediction and Research
Hadley Centre for Climate Prediction and Research
The Met Office Hadley Centre for Climate Change — named in honour of George Hadley — is part of, and based at the headquarters of the Met Office in Exeter...
, and their work demonstrated global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
of almost 0.8°C over the last 157 years.
Access to temperature records was often under formal or informal confidentiality agreements that restricted use of this raw data to academic purposes. From the 1990s onwards the unit received requests for raw data made by those critical of the scientific understanding of global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
, and after the UK Freedom of Information Act
Freedom of Information Act 2000
The Freedom of Information Act 2000 is an Act of Parliament of the Parliament of the United Kingdom that creates a public "right of access" to information held by public authorities. It is the implementation of freedom of information legislation in the United Kingdom on a national level...
(FOIA) came into effect in 2005, there were Freedom of Information requests to the Climatic Research Unit
Freedom of Information requests to the Climatic Research Unit
Freedom of Information requests to the Climatic Research Unit featured in press discussions of disputes over access to data from instrumental temperature records, particularly during the Climatic Research Unit email controversy which began in November 2009....
for this raw data. On 12 August 2009 CRU announced that they were seeking permission to waive these restrictions, and on 24 November 2009 the university stated that over 95% of the CRU climate data set had already been available for several years, with the remainder to be released when permissions were obtained. In a decision announced on 27 July 2011 the Information Commissioner's Office (ICO) required release of raw data even though permissions had not been obtained or in one instance had been refused, and on 27 July 2011 CRU announced release of the raw instrumental data not already in the public domain, with the exception of Poland which was outside the area covered by the FOIA request.
See also
- Climatic Research UnitClimatic Research UnitThe Climatic Research Unit is a component of the University of East Anglia and is one of the leading institutions concerned with the study of natural and anthropogenic climate change....
- EdGCMEdGCMThe Educational Global Climate Model or ' is a fully functional global climate model that has been ported for use on desktop computers...
- NASANASAThe National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
Goddard Institute for Space StudiesGoddard Institute for Space StudiesThe NASA Goddard Institute for Space Studies , at Columbia University in New York City, is a component laboratory of NASA's Goddard Space Flight Center Earth-Sun Exploration Division and a unit of The Earth Institute at Columbia University... - NCAR Community Climate System ModelCommunity Climate System ModelThe Community Climate System Model is a coupled Global Climate Model developed by the University Corporation for Atmospheric Research with funding from the National Science Foundation, Department of Energy, and NASA...
- NOAA GFDL CM2.XGFDL CM2.XGFDL CM2.X is a coupled atmosphere-ocean general circulation model developed at the NOAA Geophysical Fluid Dynamics Laboratory in the United States...
- Earth SimulatorEarth SimulatorThe Earth Simulator , developed by the Japanese government's initiative "Earth Simulator Project", was a highly parallel vector supercomputer system for running global climate models to evaluate the effects of global warming and problems in solid earth geophysics...
External links
- Met Office Hadley Centre observations datasets
- HadCRUT3 and CRUTEM3 datasets at Climatic Research Unit Climatic Research UnitThe Climatic Research Unit is a component of the University of East Anglia and is one of the leading institutions concerned with the study of natural and anthropogenic climate change....