Question

Simulations with a general circulation model (GCM) have been used to

investigate the climate sensitivity to large changes in atmospheric ozone.

Explain qualitatively the results below.   

A simulation in which all O₃ above 30 km altitude is removed shows a large

tropospheric warming (+1-3^oC) and a very large stratospheric cooling (up to

-80^oC).

A simulation where all O₃ in the upper troposphere is removed shows a 1^oC

cooling of the Earth’s surface, while a simulation where the same amount of O₃ is

removed but in the lower troposphere shows no significant temperature change.

Answer 1

Solution:

As per the simulation steps given in the statement, the reason for temperature difference between troposphere and stratosphere is of the involvement of ozone molecules the sun rays from stratosphere to troposphere gets trapped by free radicals on breaking down of ozone molecules.As the free radicals deflects the sunrays the temperature buildup makes the temperature rise of 1-3 in centigrade, whereas stratosphere only paves the way for clean tansit of sun rays with no deflection hence no effect in temperature is found.

In second case the oxone molecule removal in upper troposphere paves the heat tranfer of temperature reduction by transfer of cooling process from stratosphere results in cooling of troposphere which ultimately impacts the temperature in earths surface hence one degree reduction is observed.

In third case only lower troposphere ozone is removed which does not have significant change as earths surface is facing temperature trap from greenhouse gas molecules which traps temperature which is in equilibrium with troposphere lower layer hence negligible changes (or) no significance is observed in temperature change of lower troposphere.