Puricare Industrial Enterprises

Friday, April 2, 2021

La Nina - Spanish for "little girl," La Niña is the name given to the large-scale cooling of sea surface temperatures across the central and equatorial Pacific Ocean. It is one part of the larger and naturally occurring ocean-atmosphere phenomenon known as the El Niño/Southern Oscillation or ENSO (pronounced "en-so") cycle. La Niña conditions recur every 3 to 7 years and typically last from 9 to 12 months up to 2 years. One of the strongest La Niña episodes on record was that of 1988-1989 when ocean temperatures fell as much as 7 F below normal. The last La Niña episode occurred during late 2016, and some evidence of La Niña was seen in January of 2018. A La Niña event is the opposite of an El Niño event. Waters in the equatorial regions of the Pacific Ocean are unseasonably cool. The cooler waters affect the atmosphere above the ocean, causing significant changes in climate, though usually not as significant as the changes that occur during an El Niño. In fact, the positive effects on the fishing industry make La Niña less of a news item than an El Niño event. Both La Niña and El Niño events tend to develop during the Northern Hemisphere spring (March to June), peak during late fall and winter (November to February), then weaken the following spring into summer (March to June). El Niño (meaning "the Christ child") earned its name because of its usual appearance around Christmas time.

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What Is La Nina?

By Rachelle Oblack

Spanish for "little girl," La Niña is the name given to the large-scale cooling of sea surface temperatures across the central and equatorial Pacific Ocean.

It is one part of the larger and naturally occurring ocean-atmosphere phenomenon known as the El Niño/Southern Oscillation or ENSO (pronounced "en-so") cycle.

La Niña conditions recur every 3 to 7 years and typically last from 9 to 12 months up to 2 years.

One of the strongest La Niña episodes on record was that of 1988-1989 when ocean temperatures fell as much as 7 F below normal.

The last La Niña episode occurred during late 2016, and some evidence of La Niña was seen in January of 2018.

La Niña vs. El Niño

A La Niña event is the opposite of an El Niño event.

Waters in the equatorial regions of the Pacific Ocean are unseasonably cool.

The cooler waters affect the atmosphere above the ocean, causing significant changes in climate, though usually not as significant as the changes that occur during an El Niño.

In fact, the positive effects on the fishing industry make La Niña less of a news item than an El Niño event.

Both La Niña and El Niño events tend to develop during the Northern Hemisphere spring (March to June), peak during late fall and winter (November to February), then weaken the following spring into summer (March to June).

El Niño (meaning "the Christ child") earned its name because of its usual appearance around Christmas time.

What Causes La Niña Events

You can think of La Niña (and El Niño) events as water sloshing in a bathtub.

Water in the equatorial regions follows the patterns of the trade winds. Surface currents are then formed by the winds.

Winds always blow from areas of high pressure to low pressure; the steeper the gradient difference in the pressure, the faster the winds will move from highs to lows.

Off the coast of South America, changes in air pressure during a La Niña event cause winds to increase in intensity.

Normally, winds blow from the eastern Pacific to the warmer western Pacific. The winds create the surface currents that literally blow the top layer of water of the ocean westward.

As the warmer water is "moved" out of the way by the wind, colder waters are exposed to the surface off the western coast of South America.

These waters carry important nutrients from deeper ocean depths. The colder waters are important to fishing industries and the nutrient cycling of the ocean.

How La Niña Years Differ

During a La Niña year, the trade winds are unusually strong, leading to increased movement of water towards the western Pacific.

Much like a giant fan blowing across the equator, the surface currents that form carry even more of the warmer waters westward.

This creates a situation where the waters in the east are abnormally cold and the waters in the west are abnormally warm.

Because of the interactions between the temperature of the ocean and the lowest air layers, the climate is affected worldwide.

Temperatures in the ocean affect the air above it, creating shifts in climate that can have both regional and global consequences.

How La Niña Affects Weather and Climate

Rain clouds form as a result of the lifting of warm, moist air.

When the air doesn't get its warmth from the ocean, the air above the ocean is abnormally cool above the eastern Pacific. This prevents the formation of rain, often needed in these areas of the world.

At the same time, the waters in the west are very warm, leading to increased humidity and warmer atmospheric temperatures. The air rises and the number and intensity of rainstorms increase in the western Pacific.

As the air in these regional locations changes, so too does the pattern of circulation in the atmosphere, thereby affecting climate worldwide.

Monsoon seasons will be more intense in La Niña years, while the western equatorial portions of South America may be in drought conditions.

In the United States, the states of Washington and Oregon may see increased precipitation while portions of California, Nevada, and Colorado may see drier conditions.

Rachelle Oblack

Introduction

Rachelle Oblack:

Is a full-time science teacher.

Writes for major textbook companies about climate and space.

Is involved with the NASA Educator Astronaut Program, which motivates students and educators to study science, technology, engineering, and mathematics.

Has been listed in Who's Who Among America's Teachers.

Experience

Rachelle Oblack is a former writer for ThoughtCo who contributed articles for five years as well as a teacher and trainer who has written for major textbook companies about climate and space. She has been involved with NASA's Educator Astronaut Program, was a member of the Network of Educator Astronaut Teachers, and has written for the PBS Newshour Extra.

Education

Rachelle Oblack has a bachelor's degree in science and education from Wichita State University, Kansas, and a master's in education. She is certified to teach earth and space science, general science, biology, environmental science K-12, chemistry, and physical science.

Awards and Publications

Member of the Delta Kappa Gamma Society International, an honor society for women educators worldwide.

Listed in Who's Who Among America's Teachers.

ThoughtCo and Dotdash

ThoughtCo is a premier reference site focusing on expert-created education content. We are one of the top-10 information sites in the world as rated by comScore, a leading Internet measurement company. Every month, more than 13 million readers seek answers to their questions on ThoughtCo.

For more than 20 years, Dotdash brands have been helping people find answers, solve problems, and get inspired. We are one of the top-20 largest content publishers on the Internet according to comScore, and reach more than 30% of the U.S. population monthly. Our brands collectively have won more than 20 industry awards in the last year alone, and recently Dotdash was named Publisher of the Year by Digiday, a leading industry publication.

https://www.thoughtco.com/what-is-la-nina-3444117

Monday, March 29, 2021

FLYING THROUGH CLOUDS - Why Are They So Dangerous? - Weather conditions are a huge factor in aviation safety, and learning about cloud formations and their potential dangers when flying is a vital part of pilot training in New Zealand. Sometimes flying through clouds is just like driving through fog – you really can’t see much but nothing bad happens – but sometimes they can represent extreme danger for pilots, planes and passengers. Across the history of aircraft flight around the world planes have been damaged and even broken up when encountering severe thunderstorm clouds in-flight. Some clouds such as the cumulonimbus are definitely a direct danger to aircraft; some clouds simply indicate a potential problem and others have no effect at all. During flight and in pre-flight planning it is the pilot’s job to assess and evaluate weather conditions as to whether they are a threat to the aircraft or not. In order to accurately assess threat levels as a pilot it is important to know the different types of clouds and how they affect weather and flight conditions. Clouds are made up of tiny water droplets formed by rising water vapour as it cools. These tiny water droplets form clusters in which the air swirls about unpredictably due to the denser internal conditions compared to the surrounding external air. As a result complex updrafts and downdrafts are created. These cloud-borne updrafts and downdrafts result in rapid and unpredictable changes to the lift force on the wings of an aircraft.

Flying Through Clouds

Why Are They So Dangerous?

Southern Wings

Weather conditions are a huge factor in aviation safety, and learning about cloud formations and their potential dangers when flying is a vital part of pilot training in New Zealand.

Sometimes flying through clouds is just like driving through fog – you really can’t see much but nothing bad happens – but sometimes they can represent extreme danger for pilots, planes and passengers.

Across the history of aircraft flight around the world planes have been damaged and even broken up when encountering severe thunderstorm clouds in-flight.

Some clouds such as the cumulonimbus are definitely a direct danger to aircraft; some clouds simply indicate a potential problem and others have no effect at all.

During flight and in pre-flight planning it is the pilot’s job to assess and evaluate weather conditions as to whether they are a threat to the aircraft or not.

Types Of Clouds

In order to accurately assess threat levels as a pilot it is important to know the different types of clouds and how they affect weather and flight conditions.

While there are officially hundreds of types of clouds, here in New Zealand the Civil Aviation Authority (CAA) categorises ~~NZ cloud types~~ in the following 3 ways.

1. Low Level Clouds that form below 6500 feet

· Stratocumulus (Sc) – flattened heaped cloud

· Stratus (St) – low level dull grey layer cloud

· Cumulus (Cu) – heaped or piled cloud

· Towering Cumulus (TCu) – towering heaped cloud

· Cumulonimbus (Cb) – rainy thundery heaped cloud

2. Middle Clouds that usually form between 6500 feet and 20,000 feet

(Nimbostratus clouds may form at lower altitudes in some parts of NZ)

· Altocumulus (Ac) – billowy mid-level cloud

· Altostratus (As) – mid level layer cloud

· Nimbostratus (Ns) – rainy layer cloud

3. High Level Clouds that usually form above 20,000 feet over New Zealand

· Cirrus (Ci) – thin wispy hair-like high level cloud

· Cirrocumulus (Cc) – billowy or rippled wispy cloud

· Cirrostratus (Cs) – veil like high layer cloud

Turbulence When Flying Through Clouds

Why do aeroplanes jump up and down and lurch around when flying through clouds?

And can severe turbulence damage the plane?

To understand the answer to these questions we must first look at exactly what a cloud is and the also understand the forces acting on an aeroplane during flight.

Clouds are made up of tiny water droplets formed by rising water vapour as it cools.

These tiny water droplets form clusters in which the air swirls about unpredictably due to the denser internal conditions compared to the surrounding external air.

As a result complex updrafts and downdrafts are created.

These cloud-borne updrafts and downdrafts result in rapid and unpredictable changes to the lift force on the wings of an aircraft.

More or less lift and the difference between these changes is what causes the aircraft to lurch and jump about during flight, or turbulence as it is called within the industry.

While most encounters with turbulence are fairly routine (due to careful planning and skill), and aeroplanes are designed to cope with the forces and pressures placed upon them during these minor occurrences, it is the unpredictable nature combined with the low visibility that makes them a danger to pilots, aircraft and passengers.

What Happens In Severe Turbulence?

If a pilot is not skilled enough or experiences extreme levels of turbulence, this can cause them to lose control of the aircraft during flight.

This is a particular concern around Cumulonimbus clouds (thunderstorm clouds) which can be concealing severe turbulence, strong vertical motions, severe icing, thunderstorms and hail.

This is why pilots do not choose to fly through clouds if they are avoidable and plan their flight path in order to avoid certain weather patterns involving large and dangerous cloud formations (for larger passenger aircraft this means flying up above the cloud base).

How Do Planes Fly Through Clouds?

Even though clouds are dangerous it is not always possible to avoid them during flight, so how do planes fly through clouds?

First we need to understand the difference between flying using visual versus instrument based skills.

When training to be a pilot there are two sets of regulations that determine how and when pilots are able to fly their aircraft. These are using Visual Flight Rules (VFR) and using Instrument Flight Rules (IFR).

Visual flight rules allow pilots to basically look out the window and fly according to what they see.

Flying IFR only means you have to rely solely on the aircrafts on-board instruments to maintain flight as there are little or no external visual references.

Not all pilots are IFR rated (able to fly IFR only) as this requires extra training and skills.

The low visibility encountered when flying through clouds means using Instrument Flight Rules are necessary. This explains the need, not only legally but also practically to avoid clouds during flight if you are not IFR rated.

What Makes Flying Through Clouds So Dangerous?

Other than turbulence and having the right skills to navigate low visibility flight conditions there is one major thing that makes flying through clouds extremely dangerous.

This is the possibility of mid-air collision, mostly likely with other aircraft but also with protruding buildings or landmarks taking up the combined airspace.

For aircraft which are able to navigate using IFR like large passenger planes, it is impossible to avoid passing through clouds during their daily flight paths, so how do they avoid collisions with other aircraft?

The pilots are kept informed by ground based Air Traffic Control (ATC) which keep track of all aircraft in the area using on-board transponders and radio communications.

Should this fail some aircraft are equipped with on-board emergency Traffic Collision Avoidance Systems (TCAS).

Southern Wings is built on a heritage of flight training since 1935. It is one of New Zealand’s original aviation colleges, operated by people who are passionate about flying and assisting others to become pilots. The college operates a varied, well-maintained fleet suitable for all training purposes. The college’s main base is located at Invercargill Airport. Southland represents the largest uncontrolled airspace in New Zealand, with Invercargill Airport providing experience with Air Traffic Control in controlled procedural airspace. Our second base is located at Ardmore Airport in Auckland. Ardmore is New Zealand’s busiest aerodrome and is on the doorstep of North Island’s best attractions.

Southern Wings is accredited as a training provider with CAA Part 141 and also has certification in Air Transport Operations under CAA Part 135.

https://www.southernwings.co.nz/flying-through-clouds-why-are-they-so-dangerous/

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