PRECIPITATION

Hydrologic Cycle

The continuous movement of water within the Earth and atmosphere, involving processes such as evaporation, condensation, precipitation, and runoff.

Hydrologic Cycle

Cycle that involves the continuous circulation of water in the Earth-atmosphere system.

Precipitation

Water being released from clouds as rain, sleet, snow, or hail.

Precipitation

Begins after water vapor, which has condensed in the atmosphere, becomes too heavy to remain in atmospheric air currents and falls.

One-fourth

Total precipitation that falls on continental areas is turned to the seas by direct runoff and underground.

965 to 4,064 millimeters of rainfall

Average amount amount of rainfall every year. This range varies significantly across different regions and climates.

175

Average number of rainy days with measurable precipitation in a year, indicating a climate with frequent rain.

Condensation

Process of water vapor change into liquid.

Condensation

Water vapor in the air rises mostly by convection (warm, humid air will rise, while cooler air will flow downward).

Precipitation

Deposition of liquid water droplets and ice particles that are formed in the atmosphere and grow to a sufficient size so that they are returned to the Earth's surface by gravitational settling .

Precipitation

Maybe solid or liquid.

Precipitation

Cooling of the air mass sufficient to bring it to or near saturation.

Hydrometeor

Any product of condensation of atmospheric water vapor formed in the free air or at earth’s surface.

Drizzle or Mist

Tiny liquid water droplets, 0.1 to 0.5 mm in diameter; it falls at a rate of <1 mm/hr (appear to float).

Glaze

Ice coating formed on exposed surfaces by the freezing of supercooled water deposited by rain or drizzle.

Rain

Consists of liquid water drops mostly larger than 0.5 mm in diameter.

Rime

White, opaque deposit of ice granules more or less separated by trapped air and formed by rapid freezing of supercooled water drops impinging on exposed objects.

Snow

Composed of ice crystals, chiefly in complex, branched hexagonal form, and often agglomerated into snowflakes.

Hail

In the form of balls of ice, produced in convective clouds.

Sleet

Consists of transparent, globular, solid grains of ice formed by the freezing of raindrops or refreezing of largely melted ice crystals falling through a layer subfreezing air near the earth’s surface.

Convective Lifting

Caused by unequal heating of land masses.

Orographic Lifting

Mechanical lifting over mountain barriers.

Frontal Lifting

Lifting of warm air on one side of a frontal surface over colder, denser air on the other side front – bounding surface.

Between two distinct air.

FRONTAL LIFTING TALAGA TO

When cold air meets with stationary warm air.

Cyclonic Lifting

Lifting of air converging into a low- pressure area.

Raindrops

Include water particles as large as 7 mm ф.

Raindrops

High-intensity storm has more large-diameter raindrops, and also has a wider range of raindrop diameters.

Raindrops

Velocity of fall depends on size, large drops fall more rapidly.

5 m/s for a 1-mm

Terminal velocity of drops varies from about ____.

9 m/s for a 5-mm

Drop to about _____ raindrop.

Intensity

Expressed in mm/hr.

Average rainfall depth that falls per time increment.

Duration

Very intense storms last for short period and cover small areas.

Not frequent in areas having high total annual rainfall.

Rain Gauge

Meteorological instrument used to measure precipitation in its liquid form in a specific

area over a predetermined period of time.

Rain Gauge

It is typically used as part of a weather station to measure current and determine future weather conditions, as well as monitoring the water cycle.

Non-recording Rain Gauge

A type of rain gauge that measures precipitation amount without recording data.

Recording Rain Gauge

A rain gauge that measures and records precipitation amounts automatically.

8” Diameter Standard Rain Gauge

Has a measuring tube 1/10 of the area of the collector; Used for measuring rainfall depth (mm).

Tipping Bucket Rain Gauge

For measuring rainfall intensity (mm/hr). It consists of a funnel that directs rainwater into a tipping bucket mechanism, where each tip corresponds to a specific amount of rainfall collected.

Weighing Type Float Recording (rise of)

Rise of the accumulated rain float with increasing catch rainfall is recorded.

8” Diameter Standard Rain Gauge (graduated)

Also known as Graduated Cylinder Rain Gauge.

8” Diameter Standard Rain Gauge (COLLECTED)

Collected by a cylindrical funnel, from where it flows directly into the graduated cylinder or captured by a container and then poured into a measured cylinder.

Tipping Bucket Rain Gauge

Automated rain meter that uses a "tipping bucket" mechanism to measure rainfall.

Tipping Bucket Rain Gauge

This instrument is further suited for digitalizing the output signal.

Tipping Bucket Rain Gauge

Electric circuit causing the movement of pen to mark on clock driven receiving drum which carries a recorded sheet. These electric pulses generated are recorded at the control room far away from the rain gauge station.

Weighing Bucket Rain Gauge

Receiving bucket mounted on a weighing device, usually a mechanical mechanism such as a spring.

Weighing Bucket Rain Gauge

The rain accumulates in the container, and the increased weight compresses the springs.

Weighing Bucket Rain Gauge

The amount of compression gets measured and used to calculate the weight of the water.

Optical Rain Gauge

Consists of a laser/infrared diode and photosensitive sensor situated in enclosed spaces on opposites sides and below a row of funnels that receive rainfall.

Optical Rain Gauge

Advantage of not only measuring the amount of rainfall but also the intensity and frequency of the rain through precise detection by the photosensitive detector.

Acoustic Rain Gauge

Also known as hydrophones.

Acoustic Rain Gauge

Used to measure the rainfall over large bodies of water like dams, lakes, and the ocean.

Acoustic Rain Gauge

The device itself gets place underneath the water's surface. The hydrophone can

sense and measure the impact of the raindrops hitting the surface of the water.

Floating or Natural Syphon Type Rain Gauge

This type of rain gauge operates similarly to a weighing bucket rain gauge. Rainwater is funneled into a rectangular container, where a float at the bottom rises as the water level increases.

Floating or Natural Syphon Type Rain Gauge

When the water level rises, the float ascends to its maximum point, activating a siphon that drains the water through a connecting pipe and empties the container. This rain gauge is the standard recording device used in India, and the data collected is utilized to plot a rainfall mass curve.

Floating or Natural Syphon Type Rain Gauge

The float's movement is recorded by a pen that marks a recording drum, which is powered by a clock mechanism.

Size and shape

Raindrops have sizes ranging from0.5 to up to approximately 6 mm mean diameter, above which they tend to break up.

Intensity

amount of rain in a certain time( (depth/time) i.e. (mm/hr)

Duration

The length of time it rains

Depth

Volume of rain over an area

Frequency

How often it rains, or the return period

Seasonal distribution

When rainfall occurs throughout the year