how does insolation changes over the course of a year?

by Prof. Mittie Runte DVM 10 min read

The amount of insolation that an area receives can vary over the course of a day or over a year. The highest point of the Sun's path in the sky is the time when the maximum amount (intensity) of insolation for the day reaches a location. The warmest part of the day is usually a few hours later.

How does duration of insolation vary with seasons?

The duration of insolation varies with latitude and the season of the year. Maximum insolation occurs in the Northern Hemisphere around June 21st (Summer Solstice). 3. Maximum Surface temperature occur at the Earth's surface after the maximum duration of insolation.

Why do solar insolation angles change throughout the year?

The Earth's axis of rotation tilts about 23.5 degrees, relative to the plane of Earth's orbit around the Sun. As the Earth orbits the Sun, this creates the 47° declination difference between the solstice sun paths, as well as the hemisphere-specific difference between summer and winter.Dec 31, 2021

What is the effects of insolation in the season?

Solar energy received over the planet's surface varies according to season, latitude, transparency of the atmosphere, and aspect or ground slope. Insolation affects temperature. The more the insolation, the higher the temperature. In any given day, the strongest insolation is received at noon.

How does the angle of insolation change between summer and winter months?

With greater insolation and duration, the Northern Hemisphere gets warmer; with less insolation and shorter duration, the Southern Hemisphere gets colder. If you were on the equator on the summer solstice, the sun would not be overhead at noon, but 23.5 degrees to the north.Apr 30, 2017

Why does insolation change with increasing latitude?

Because the angle of radiation varies depending on the latitude, surface temperatures on average are warmer at lower latitudes and cooler at higher latitudes (even though higher latitudes have more hours of daylight during the summer months).Dec 2, 2019

What causes the intensity and duration of solar radiation received at any place to vary throughout?

The seasons occur because Earth's axis is inclined and remains parallel with itself during the revolution of Earth about the Sun. The result is that the intensity and duration of sunlight, and hence atmospheric heating, varies throughout the year at any particular place.Dec 19, 2021

How does precipitation change with latitude?

Precipitation decreases as one moves away from the Equator toward the poles. Because temperature affects the amount of moisture air can hold, the rate at which precipitation falls typically reduces with the increase in latitude, with lower latitudes usually experiencing more precipitation.Feb 10, 2022

How does insolation affect the weather and climate of a place?

Answer: Solar energy received over the planet's surface varies according to season, latitude, transparency of the atmosphere, and aspect or ground slope. Insolation affects temperature. The more the insolation, the higher the temperature.Jan 11, 2021

What is insolation and factors affecting insolation?

The major factors which influence the amount of insolation received are: Rotation of the earth on its axis. The angle of incidence of the sun's rays. Duration of the day. Transparency of the atmosphere.Jan 26, 2017

How does the difference between summer and winter insolation vary with latitude?

Even during the summer, large zenith angles prevent insolation from increasing too much. … The mid-latitudes have some sunlight and darkness every day, with longer days and lower zenith angles during the relatively warm summer. The winter has shorter days and larger zenith angles, so it is colder than the summer.Dec 10, 2021

How does the angle of the sun's rays make the insolation more intense?

The intensity of solar radiation is largely a function of the angle of incidence, the angle at which the Sun's rays strike the Earth's surface. If the Sun is positioned directly overhead or 90° from the horizon, the incoming insolation strikes the surface of the Earth at right angles and is most intense.

Why is the solar zenith angle lower during summer than in winter?

Variation over the Year The Earth progresses through its seasons because its north-south axis has a 23.5-degree tilt. During the summer, the solar altitude will be at its maximum. During the winter, the solar altitude will be at its minimum.May 9, 2018

What is the equatorial zone?

The equatorial zone encompasses the Equator and covers the latitude belt roughly 10° north to 10° south. Here the Sun provides intense insolation throughout most of the year, and days and nights are of roughly equal length. Spanning the Tropics of Cancer and Capricorn are the tropical zones, ranging from latitudes 10° to 25° north and south.

How long is the Sun in the sky?

At the Equator, the Sun is always in the sky for 12 hours, but its noon angle varies through the year. At the Tropic of Capricorn, the Sun is in the sky longest and reaches its highest elevations at the December solstice. Based on this analysis, daily insolation will vary strongly with season at most latitudes.

What is the latitude of the Arctic and Antarctic?

The arctic and antarctic zones lie between latitudes 60° and 75° N and S , astride the Arctic and Antarctic Circles . These zones have an extremely large yearly variation in day lengths, yielding enormous contrasts in insolation over the year.

Abstract

Long-term climatic changes, such as glacial–interglacial cycles, are usually explained in term of changes in solar energy received at the top of the atmosphere. In particular, daily insolation in the high Northern Hemisphere latitudes during summer is widely used in interpreting palaeoclimate records.

1. Introduction

In the classical Milankovitch astronomical theory of palaeoclimates [1], summer insolation in the high Northern Hemisphere latitudes is invoked as the main forcing controlling glacial–interglacial variations.

2. Some properties of insolation, integrated over the year or over the seasons

The energy available at any latitude φ on the Earth at the top of the atmosphere and assuming a constant solar output depends upon the so-called solar constant, S0, and upon the Earth’s orbital and rotational parameters.

3. Data and climate modelling

Recently planktonic foraminifera and alkenone measurements were used to reconstruct the North Atlantic SSTs during the last interglacial period [5], [14], which is defined by a minimal and constant ice volume (deglaciation and glacial inception are not considered).

4. From conceptual ideas to more complex model results

Climate models can be very complex tools, built in an effort to understand how the climate system reacts to insolation forcing. They are forced at every time step by the insolation for each grid point of the model. However, an ‘oversimplified’ model may already suggest some answers.

5. Conclusions

The Milankovitch astronomical theory was developed to explain how the large Northern Hemisphere ice sheets could grow and shrink, depending on the insolation forcing.

Acknowledgements

The authors would like to thank Michel Crucifix, Jean-Claude Duplessy and Laurent Labeyrie for comments, questions and suggestions that significantly improved this manuscript. They also warmly thank Gabrielle Dreyfus for valuable inputs. D.P., F.V. and E.C. thank CNRS-INSU/PNEDC, IRD and CEA for financial support. [BARD]