The Azimuth Project Earth science (Rev #11, changes)

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Contents

Idea

This page is about earth sciences, these are sciences concerned with planetary processes:

an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, the Earth being the only known life-bearing planet. There are both reductionist and holistic approaches to Earth sciences. The formal discipline of Earth sciences may include the study of the atmosphere, oceans and biosphere, as well as the solid earth. Typically Earth scientists will use tools from physics, chemistry, biology, chronology and mathematics to build a quantitative understanding of how the Earth system works, and how it evolved to its current state.

Details

From Sammonds and Thompson:

Understanding the response of the Earth’s climate system to anthropogenic perturbation is a pressing priority for society. To be successful in this enterprise we need to analyse climate change within an allencompassing “Earth system” framework; the suite of interacting physical, chemical, biological, and human processes that, in transporting and transforming materials and energy jointly determine the conditions for life on the whole planet. To illustrate the integrative thinking that is required we review the diverse roles played by atmospheric transport of mineral ‘dust’, particularly in its capacity as a key pathway for the delivery of nutrients essential to plant growth, not only on land, but more importantly, in the ocean.

Here, the global importance of dust arises because of the control it exerts on marine plant productivity and thus the uptake of $CO_2$ from the atmosphere. The complex way in which dust biogeochemically links land, air, and sea presents us with new challenges in understanding climate change and forces us to ask questions that transcend the traditional scientiﬁc disciplines

We are just embarking on a radical new integrated view of how the Earth system functions on a range of timescales [Schellnhuber (1999)]. This holistic view will be critical if we are to understand the complex and sometimes unexpected behaviour of the climate system that arises out of a high level of interaction and interconnectedness. Indeed, even individual sub-systems such as that involving dust can exhibit highly complex and nonlinear behaviour, because dust is much more than simply as a passive communicator of events between components of the Earth system

Schematic view of the linking of land, air, and sea (and climate) by dust. Highlighted are four critical components of the Earth system, (clockwise from top); state of the land surface and dust material availability (‘land’), atmospheric aerosol loading and dust deposition (‘air’), marine plankton productivity (‘sea’), and climatic state (e.g. mean global surface temperature). The biogeochemical connections between them can have a positive correlation (e.g. increased atmospheric aerosol loading and dust deposition results in increased in marine productivity) indicated by a ﬁlled arrowhead, or a negative correlation (e.g.increased marine productivity leads to lower atmospheric $CO_2$ and a colder climate), indicated with an open circle. An open arrowhead indicates where the sign of the correlation is uncertain. The ‘taps’ represent where a mechanism aﬀects the strength of a connection between two components rather than aﬀecting a component directly. A change in global precipitation strength altering the eﬃciency with which entrained dust is transported out to the open ocean is a good example of this. Shown back-highlighted (grey lines) is the positive feedback; atmospheric aerosol loading→marine productivity→ climatic state → dust availability → atmospheric aerosol.

References

Geoscientific Model Development (GMD) is an international scientific journal dedicated to the publication and public discussion of the description, development and evaluation of numerical models of the Earth System and its components. Manuscript types considered for peer-reviewed publication are:

Geoscientific model descriptions, from box models to GCMs; Development and Technical papers, describing development such as new parameterisations or technical aspects of running models such as the reproducibility of results; Papers describing new standard experiments for assessing model performance, or novel ways of comparing model results with observational data; Model intercomparison descriptions, including experimental details and project protocols.box models to GCMs; Development and Technical papers, describing development such as new parameterisations or technical aspects of running models such as the reproducibility of results; Papers describing new standard experiments for assessing model performance, or novel ways of comparing model results with observational data; Model intercomparison descriptions, including experimental details and project protocols.