Atoc 4720 class20
1 / 25

ATOC 4720 class20 - PowerPoint PPT Presentation

  • Uploaded on

ATOC 4720 class20. Clouds and storms 1. Cloud morphology 2. Types of clouds 3. The air-mass thunderstorm. From class-19:. [1]. Thermoelectric effect in ice: T- degree C; V--mV. [2] Supercooled water in clouds. Class-19:. 3. Lightning and thunder.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' ATOC 4720 class20' - duaa

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Atoc 4720 class20
ATOC 4720 class20

  • Clouds and storms

    1. Cloud morphology

    2. Types of clouds

    3. The air-mass thunderstorm

From class-19:


Thermoelectric effect in ice:

T- degree C; V--mV


Supercooled water in clouds

3 lightning and thunder


3. Lightning and thunder

Dielectric breakdown: V>3MV/m (dry) V>1MV/m

Moist with 1mm in radius;

Lightning: T--30,000K;

Thunder: Shock waves;

1 cloud morphology
1. Cloud morphology

Clouds: Mechanisms of formation

[1] Convective clouds: local ascent of warm,

conditionally unstable air;

0.1-10km in diameters;

Vertical velocity w: a few m/s;

Liquid water or ice content:

[2] Layer clouds: stratus

Forced lifting of stable air:

Examples: fog is forced lifted upwards;

cold fronts lift warm air mass

Hundres--thousands km;

Lifting rates: a few cm/s;

Water: a few tens

Tens of hours

[3] Orographic clouds

Forced lifting of air by hills or mountains

Uplifting velocity depends on windspeed and direction,

And mountain height. Can be a few m/s;

Water: a few tens

Can be transitory, or can stay for long if winds are


Lee waves can also produce orographic clouds;

[4] Advection fog:

Cooling of air below its dew point due to warm air is

Advected to a colder surface.

[5] Arctic sea-smoke (steam fog)

Meeting of two parcels of air with different temperatures;

both close to be saturated.

[6] Funnel clouds

Adiabatic expansion and cooling due to a rapid local

Reduction in pressure.

Tornadoes or water spouts.

[7] Instabilities (Kelvin-Helmholtz instabilities)

Strong wind-shear modify cloud shape;

Types of clouds
Types of clouds

Many types: (International cloud Atlas)





(combination) Cirrostratus