Chapter 03 Drivers

The climate drivers

The climate system is regulated by three main processes, like radio tuning buttons:

  • solar radiation
  • reflectance
  • greenhouse gases

Maureen Raymo youtube uploads

ClimateBlab - Climate Science Web Laboratory

But inside the atosphere-land-ocean system, there are many processes that can eother reiforce or mitigate an initial change in climate. Traditionally these “steering” processes are called “cybernetics” (from greek steering). Those that stabilize (oppisng and change) are popularly called negative feedbakcs, those that reinforce an intina change are coled positive feedbacks.

The Urey cycle

Back in YYYY, XYZ Urey published a famous story on how geological processes regulate the atmospheric composition of CO2. At the the core of his idea is the different chemistry involved in the formation, breakdown and transformation betwwn the two types of rockes that exists: sedimentary rocks built from dead organisms and their shells and rocks formed bu cooling of the Earths magma (igneos rocks). Rocks that are partly refomred by processes at the interface between the surface (where the sedmintary rocks are formed) and the deeper magma (where completely molten magma is formed) is a thitd type, valled metamoorphic.

Sedimentary rock is to a large extent composed by dead shellss build from calcium carbonate - like the shells of snails, octopos and amny microorganisms seen best in a microscope. Calcium carbonate of course contains carbon, and when the dead shell carrying creature dies and sinks to the bottom of the sea, the carbon follows. And a miniscule amount of carbon is removed from the ocean. As the carbon in the ocean is directly related tp the carbon in the atmosphere, the death and sinking of millions and then billion and trilions of shell carrying creaturs, eventually suck the carbon from the atsmophere. You can safel skip the chemical reaction for this, but if you want it her it is:

Co2 +++CO2 C=2 + CA ++ CaCO3

The formation of igneous rock famously takes place along the mid atlantic ridges.

Albedo changes 2000 to 2019

Take all MODIS albedo, get annual mean and variation and then look for trends, significant and not.

The very long perspective

In the Eocene the CO2 was at 800 ppm. Over geological timescales the rock-cycle regulates the atmospheric C=2. THis has been known for more than a centory, Urey cycle. There is a constant trickle of data refining the balance of the Urey cycle. [I think I have a rather recent science article].

RS can be used for tracking the old “sutur” and assist in identifying the historical “ring of fire” tectonic activity and the exposture of weathering rocks.

The ice age driver - Milankovitch cycles

Maureen had a very cool illustration.

The frozen lasagna allegori - similogi for the lag in the system.

Paleo shoreline and the amount of water bound up (or not) in the polar ice. Look for ancient shores at different elevation in stable contientes (un-affected by iso-static uplift as a result of ice melt.) Landsat + lidar = DEM of landsruface with foreground (veg and buildings) removed. Maureen showed examples (Miami oolite)

Sunspot 11 year cycle

Good explanation and up-to-date article on sun spots in science:The calm before the storms. Link sunspots to climate indexes? The large blob?