Volcanoes and climate - Climatology concepts.

Some details about climatology before talking over volcano-climatology:

Climatology, a branch of physical geography, is the study of climate, that is to say, the succession of weather over long periods of time ... versus meteorology, which studies the short-term climate.

In general, the climate does not change, or very little, in a given place in the world, over a period of the scale of the century. But in geological time, the climate can change dramatically. The study of past climates is paleoclimatology. This study based on human history called historical climatology.

Climatology ... a multidisciplinary science:
Cooling factors working on climate - doc. Climate and global environmental changes / Pearson Education, Harlow, UK 2000

The production of numerical climate models necessary for the understanding of climate variability and anticipation of its medium and long term changes, requires the mastery of many parameters that influence the climate system:
- the knowledge of the atmosphere and its structure

- control of the characteristics of the atmospheric circulation.
- knowledge of the interactions between the ocean and atmosphere :  different ocean currents, the IOD - Indian Ocean Dipole, ENSO - El Nino Southern Oscillation, NAO - North Atlantic Oscillation ..

This high resolution atmospheric model was created by the Discover supercomputer of the simulation center climate Goddard Space Flight Center of NASA, using the Goddard Model of the earth observation system, Version 5 (satellites Weather GOES-5) and thus presents the global distribution of aerosols.

Dust (red) is lifted from the surface, sea salt (blue) to the swirling cyclones, smoke (green) totaled lights and sulfate particles (white) are released by volcanoes and fossil fuel emissions. - Image credit: William Putman, NASA / Goddard

- solar energy, its contributions and variations
- the greenhouse effect and implications of human activities on it.

                  Solar radiation and greenhouse effect- doc. Robert A. Rohde

- the movements of the Earth also affect the climate. Various parameters involved:

- Precession (Changing of the direction of the axis of rotation of a body.) of the Equinoxes: the tilted axis of the earth, which justifies the existence of different seasons varies over time to describe a cone 25,868 years
- The precession of the perihelion: elliptical Earth orbit rotates.
- The inclination of the earth's axis is between 21° 59' and 24° 50' over 41,000 years. When the obliquity is 24° 50', entails harsh winters at midlatitudes. But when the obliquity is less important that promotes glaciation and reverse, when is more important.
- The influence of the sun and other planets leads to changes in the parameters of the Earth's orbit ... and a variation of the overall flow of solar radiation received by the planet.

Climatology is also based on historical records, both physicochemical, and obtained by the analysis of ice cores, that strictly bookish, and requiring the compulsion of archives and the crosscheck of quality informations.

Population curve and % of deaths and birth in Iceland between 1740 and 1820 - the peak of deaths and the decrease of the number of humans related to the eruption of 1783 is marked - doc. northernlite.ca

The volcano-climatology :

These complex systems that manage the climate and its historical evolution, is grafted by the impact of volcanoes and their emissions.

                                 Diagram of the effects of volcanic eruptions on climate

This new branch of volcanology will a fortiori be multidisciplinary and highly dependent of data processing, to manage vast amounts of  socio-historical as science data.

An example is given by the diagram below:

Multigraphe 2011 / Kelly O'Day - combining temperature anomalies, the effect Nino - the optical thickness of stratospheric aerosols - index sato - IEV and some major recent eruptions from 1960 to 2010.

Tomorrow, the impact of volcanoes on the climate ... and the impact of the climate on the volcanic activity.

Sources:

- La Climatologie - facteurs climatiques et types de climat.

- Volcanic air pollution and mortality in France 1783–1784 / Pollution atmosphérique volcanique et mortalité en France de 1783–1784 - by John Grattan, Roland Rabartin, Stephen Self , Thorvaldur Thordarson

- Atmospheric impact of the 1783–1784 Laki Eruption: Part II
Climatic effect of sulphate aerosol - by E. J. Highwood and D. S. Stevenson