A pseudoproxy is a synthetic dataset used in
paleoclimatology
Paleoclimatology (American and British English spelling differences, British spelling, palaeoclimatology) is the study of climates for which direct measurements were not taken. As instrumental records only span a tiny part of Earth's history, the ...
to test methods of reconstruction of global or hemispherical
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
from
temperature record
The global temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time. There are numerous estimates of temperatures since the end of the Pleistocene glaciation, particularly ...
s, developed for reconstructing the
temperature record of the past 1000 years
The temperature record of the last 2,000 years is reconstructed using data from climate proxy records in conjunction with the modern instrumental temperature record which only covers the last 170 years at a global scale. Large-scale reconstruct ...
using
proxies for periods before the
instrumental temperature record
The instrumental temperature record is a record of temperatures within Earth's climate based on direct, instrument-based measurements of air temperature and ocean temperature. Instrumental temperature records are distinguished from indirect rec ...
. In May 2002
Michael E. Mann
Michael Evan Mann (born 1965) is an American climatologist and geophysicist. He is the director of the Center for Science, Sustainability & the Media at the University of Pennsylvania. Mann has contributed to the scientific understanding of his ...
and
Scott Rutherford
Scott may refer to:
Places Canada
* Scott, Quebec, municipality in the Nouvelle-Beauce regional municipality in Quebec
* Scott, Saskatchewan, a town in the Rural Municipality of Tramping Lake No. 380
* Rural Municipality of Scott No. 98, Saskat ...
published a paper introducing this method of adding artificial noise to actual temperature records or to
climate model
Numerical climate models use quantitative methods to simulate the interactions of the important drivers of climate, including atmosphere, oceans, land surface and ice. They are used for a variety of purposes from study of the dynamics of the ...
simulations to produce what they called "pseudoproxies". When the reconstruction
algorithm
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing ...
s were used with these pseudoproxies, the result was then compared with the original record or simulation to see how closely it had been reconstructed. They discussed the issue that
regression methods of reconstruction tended to underestimate the amplitude of variation.
[; ]
References
*.
*{{citation
, last1= Mann , first1= Michael E.
, year= 2012
, title= The Hockey Stick and the Climate Wars: Dispatches from the Front Lines
, publisher=
Columbia University Press
Columbia University Press is a university press based in New York City, and affiliated with Columbia University. It is currently directed by Jennifer Crewe (2014–present) and publishes titles in the humanities and sciences, including the fi ...
, isbn= 978-0-231-15254-9
.
Paleoclimatology