10
Reconstructing the Physics and Circulation
of the Atmosphere
Valérie Masson-Delmotte and Joël Guiot
The variability and evolution of the physical parameters of
atmospheric circulation are currently monitored in real time
and on a global scale thanks to a dense network of weather
stations (over 13,000 measurement sites on land and sea),
and to satellite observations of the Earth. This ‘instrumental’
period, during which the physical parameters of the atmosphere were directly monitored, began in the mid seventeenth century following the invention and use of
thermometers, barometers, rain gauges etc. However, standardization of measurement tools and their wide-scale use
took a long time and was due to a continuous effort by the
meteorological services. The outputs of ancient instruments
from before 1950 must be homogenized to modern observation standards, and gaps exist in regional temperature
information due to changes in the spatial monitoring network. The oldest meteorological series of data available are
in Europe, where temperature series for the center of England start in 1659. Intensive work was carried out on the
weather records of the Alpine region, providing access to
accurate measurements, from 1780, of average monthly
temperatures and cumulative monthly precipitations.
Work is underway to extend the use of these historical
measurements to study monthly variability in temperature
and precipitation, and to assess other parameters (pressure,
sunshine etc.). Use of these old measurements involves
working on documents of the time, computerizing the data,
and statistical analysis of regional databases. With the
exception of Europe, where instrumented measurements
were conducted particularly early, weather information is
generally only available from 1860, except for the most
inaccessible areas, such as Antarctica, where systematic
meteorological monitoring did not start until the International Geophysical Year 1957–1958. The ‘instrumental
period’ is therefore very short compared to the time frame of
the climate system and does not permit an understanding of
the natural climate variability on a global scale for the period
prior to when human activities affected the composition of
the atmosphere.
In order to characterize natural climate evolution and to
place the climate change of recent decades within a broader
context, continental paleoclimatology has established methods of quantifying ancient climates by taking advantage of a
large number of natural archives, in soils, lakes, vegetation,
continental and polar ice. These archives have allowed qualitative or quantitative indices of the main parameters
describing climate to be defined. These indices are often
referred to as proxies. Below, we briefly review all the climate
parameters reconstructed from these continental archives.
The atmospheric parameters most commonly determined
from continental paleoclimate archives are surface air temperature (or surface lake water temperature) and parameters
related to soil hydrology (e.g. precipitation, drought indices,
etc.). In some cases, these parameters can be estimated over
a season, when a resolution of less than a year can be
detected in the archives (tree rings, ice cores in sites with a
high level of snow accumulation) or when the archive is
particularly sensitive to seasonal effects (temperature of the
coldest month, temperature of the growing season for vegetation, etc.). Most continental proxies do not directly record
the amount of precipitation, but reflect the local water balance (precipitation minus land-based evaporation, runoff into
lakes, net accumulation of snow on the glaciers at the drilling sites). Quantification of these climate parameters from
the records is often made difficult by the discontinuous
nature of geological recording, for example, the process of
sedimentation in lakes. Some records, such as tree rings,
function as threshold systems and identify an atmospheric
signal once the threshold is reached (low temperature, dry
V. Masson-Delmotte (&)
Laboratoire des Sciences du Climat et de l’Environnement,
LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, 91190
Gif-sur-Yvette, France
e-mail: valerie.masson@lsce.ipsl.fr
J. Guiot
Centre for Research and Teaching in Environmental Geoscience
CEREGE, Aix-Marseille University, CNRS, IRD, INRAE,
Collège de France, BP 80 13545 Aix-en-Provence Cedex 04,
France
© Springer Nature Switzerland AG 2021
G. Ramstein et al. (eds.), Paleoclimatology, Frontiers in Earth Sciences,
https://doi.org/10.1007/978-3-030-24982-3_10
137
Reconstructing the Physics and Circulation
of the Atmosphere
Valérie Masson-Delmotte and Joël Guiot
The variability and evolution of the physical parameters of
atmospheric circulation are currently monitored in real time
and on a global scale thanks to a dense network of weather
stations (over 13,000 measurement sites on land and sea),
and to satellite observations of the Earth. This ‘instrumental’
period, during which the physical parameters of the atmosphere were directly monitored, began in the mid seventeenth century following the invention and use of
thermometers, barometers, rain gauges etc. However, standardization of measurement tools and their wide-scale use
took a long time and was due to a continuous effort by the
meteorological services. The outputs of ancient instruments
from before 1950 must be homogenized to modern observation standards, and gaps exist in regional temperature
information due to changes in the spatial monitoring network. The oldest meteorological series of data available are
in Europe, where temperature series for the center of England start in 1659. Intensive work was carried out on the
weather records of the Alpine region, providing access to
accurate measurements, from 1780, of average monthly
temperatures and cumulative monthly precipitations.
Work is underway to extend the use of these historical
measurements to study monthly variability in temperature
and precipitation, and to assess other parameters (pressure,
sunshine etc.). Use of these old measurements involves
working on documents of the time, computerizing the data,
and statistical analysis of regional databases. With the
exception of Europe, where instrumented measurements
were conducted particularly early, weather information is
generally only available from 1860, except for the most
inaccessible areas, such as Antarctica, where systematic
meteorological monitoring did not start until the International Geophysical Year 1957–1958. The ‘instrumental
period’ is therefore very short compared to the time frame of
the climate system and does not permit an understanding of
the natural climate variability on a global scale for the period
prior to when human activities affected the composition of
the atmosphere.
In order to characterize natural climate evolution and to
place the climate change of recent decades within a broader
context, continental paleoclimatology has established methods of quantifying ancient climates by taking advantage of a
large number of natural archives, in soils, lakes, vegetation,
continental and polar ice. These archives have allowed qualitative or quantitative indices of the main parameters
describing climate to be defined. These indices are often
referred to as proxies. Below, we briefly review all the climate
parameters reconstructed from these continental archives.
The atmospheric parameters most commonly determined
from continental paleoclimate archives are surface air temperature (or surface lake water temperature) and parameters
related to soil hydrology (e.g. precipitation, drought indices,
etc.). In some cases, these parameters can be estimated over
a season, when a resolution of less than a year can be
detected in the archives (tree rings, ice cores in sites with a
high level of snow accumulation) or when the archive is
particularly sensitive to seasonal effects (temperature of the
coldest month, temperature of the growing season for vegetation, etc.). Most continental proxies do not directly record
the amount of precipitation, but reflect the local water balance (precipitation minus land-based evaporation, runoff into
lakes, net accumulation of snow on the glaciers at the drilling sites). Quantification of these climate parameters from
the records is often made difficult by the discontinuous
nature of geological recording, for example, the process of
sedimentation in lakes. Some records, such as tree rings,
function as threshold systems and identify an atmospheric
signal once the threshold is reached (low temperature, dry
V. Masson-Delmotte (&)
Laboratoire des Sciences du Climat et de l’Environnement,
LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, 91190
Gif-sur-Yvette, France
e-mail: valerie.masson@lsce.ipsl.fr
J. Guiot
Centre for Research and Teaching in Environmental Geoscience
CEREGE, Aix-Marseille University, CNRS, IRD, INRAE,
Collège de France, BP 80 13545 Aix-en-Provence Cedex 04,
France
© Springer Nature Switzerland AG 2021
G. Ramstein et al. (eds.), Paleoclimatology, Frontiers in Earth Sciences,
https://doi.org/10.1007/978-3-030-24982-3_10
137