Paleoclimates eGuide

VIRTUAL RESEARCH INSTRUCTIONS

SOLAR IRRADIANCE ON EARTH: ADVANCED EXPERIMENTS

The Sun is the fundamental driving force for energy in the Earth's climate system. It is therefore of crucial importance to understand fully the conditions of its arrival at the top of the atmosphere, and as explored in Research Project #2, its transfer and transformation through the Earth system. The Earth's axial tilt with respect to the Sun imposes unique conditions on the time of arrival of maximum heating force from the Sun on different parts of the Earth's surface. The Earth's seasons are the main expression of this. By way of introduction, the following Website shows the maximum altitude of the Sun in the sky ("Meridian Transit") at specific latitudes:

http://cwx.prenhall.com/bookbind/pubbooks/lutgens3/chapter2/deluxe.html

However, the Sun's traverse across the sky may be sensed by the Earth's climate system not just at Meridian Transit, but during other hours, or a block of hours, throughout the day. This can result in altered annual responses of climate to the Sun's annual adjustment in its height and position in the local sky. These "hidden" variations are the subject of the following exploratory Excel program: InsolationExercise.xls