Fronts.pptx

FRONTOGENESIS, TYPES OF FRONTS,
WEATHER AND CLOUD ASSOCIATED WITH FRONT

1. AIR FRONTS (formation and classification) SUBMITTED BY MADHUSMITA SAHOO M.Sc., 1st Year (2 nd Semester) Roll No.-22GEOL018

2. INTRODUCTION FRONTOGENESIS TYPES OF FRONTS WEATHER AND CLOUD ASSOCIATED WITH FRONT OVERVIEW CONTENTS

3. “AIR FRONT” Front means Facing something / interaction between two things. So air front is basically interaction between two opposite air masses . Front is a three dimensional boundary zone between two converging air masses with different physical properties [ Temperature, humidity , density etc] when the 2 air masses meet ,due to the effect of the converging atmospheric circulation, they do not merge readily . Fronts are features of mid- latitude region [ temperate region i.e. 40 – 65 N and S ]. They are unusual in tropical and polar regions

4. FRONTOGENESIS (FRONT FORMATION ) The process of formation of a front is known as F rontogenesis and dissipation of a front is known as F rontolysis . Frontogenesis involves convergence of two distinct air masses. Frontolysis involves over riding of one of the air mass by another. Mid latitude/ temperate / extra tropical cyclones occur due to frontogenesis .

5. Why fronts are formed at 40◦ – 60◦ latitude ?

6. TYPES OF FRONT Based on frontogenesis and the associated weather, the fronts can be studied under the following types: COLD FRONT WARM FRONT STATIONARY FRONT OCCLUDED FRONT COLD FRONT It is formed when a cold air mass replaces a warm air mass. Cold front moves upto twice as quickly as warm fronts. Frontolysis begin when the warm air mass is completely uplifted by the cold air mass

7. WEATHER ALONG A COLD FRONT During the summer months Thunderstorms are common in warm sector. In some regions like u.S.A tornadoes occur in warm sector. CLOUD FORMATION ALONG A COLD FRONT Cirrus clouds, followed by lower, denser altocumulus and altostratus. At actual front, dark nimbus and cumulonimbus clouds cause heavy showers. A cold front passes off rapidly, but the weather along it is violent.

8. WARM FRONT It is a sloping frontal surface along which active movement of warm air over cold air takes place. (Warm air mass is too weak to beat the cold air mass) WEATHER ALONG A WARM FRONT The passage of warm front is marked by rise in temperature and pressure . Such fronts cause moderate to gentle precipitation over a large area over several hours.

9. CLOUDS FORMATION ALONG WARM FRONT Cirrus, stratus and nimbus (no cumulonimbus clouds as the gradient is gentle) Cirrostratus clouds ahead of the warm front create a halo around sun and moon .

10. STATIONARY FRONT In a stationary front two air masses meet and neither advances . The wind motion on both sides of the front is parallel to the front . Warm or cold front stops moving , so the name stationary front. A little rain may occur but this rarely causes heavy precipitation

11. WEATHER ALONG A STATIONARY FRONT Cumulonimbus clouds are formed, overrunning of warm air along such a front causes frontal precipitation . Frontal cyclones migrating along a stationary front can dump heavy amounts of precipitation .

12. OCCLUDED FRONT An occluded front occurs when a cold air mass moves so quickly that it overtakes a warm front. Frontolysis begin when warm sector diminishes. It has a warm front type or cold front type occlusion. Latin occlus ; ‘shut up ’ obstruction’ ’

13. A mixture of cold front and warm front type weather . Such fronts are common west europe . The formation mid-latitude cyclones { temperate / extratropical cyclones } involve the formation of occluded front WEATHER ALONG AN OCCLUDED FRONT

14. CLOUD FORMATION ALONG AN OCCLUDED FRONT A combination of clouds formed at cold front and warm front. Warm front clouds and cold front clouds are on opposite side of the occlusion.

15. STATIONARY FRONT NO CLEAR WINNER COLD FRONT COLD AIR MASS IS THE CLEAR WINNER WARM FRONT THE WARM AIR MASS PICKS UP A FIGHT. BUT FAILS TO BEAT THE COLD AIR MASS. COLD AIR MASS IS THE WINNER. OCCLUDED FRONT COLD FRONT + WARM FRONT DOUBLE WIN FOR COLD AIR MASS. COLD FRONT, WARM FRONT AND OCCLUDED FRONT ARE EXAMPLES OF TEMPERATURE INVERSION . OVERVIEW

16. REFERENCE:- https://www.clearias.com/fronts / https ://www.studyiq.com/articles/fronts / https ://www.pmfias.com/fronts-frontogenesis-stationary-front-cold-front-warm-front-occluded-front /

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