1. What is El-Nino and La-Nina phenomena?

El Nino is a band of anomalously warm ocean water temperatures that periodically develop off the pacific coast of South America. Extreme climate change pattern oscillations fluctuated weather across the Pacific Ocean which results in fluctuating droughts, floods, and crop yields in varying regions of the world.

There is a phase of 'El Nino–Southern Oscillation' (ENSO), which refers to variations in the temperature of the surface of the tropical eastern Pacific Ocean and in air surface pressure in the tropical western Pacific. The two variations are coupled: the warm oceanic phase, El Nino, accompanies high air surface pressure in the western Pacific, while the cold phase, La-Nina accompanies low air surface pressure in the western Pacific. Mechanisms that cause the oscillation remain under study.

Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected. El-Nino is Spanish for "the boy", and the capitalized term El Nino refers to the Christ child, Jesus, because periodic warming in the Pacific near South America is usually noticed around Christmas.

The first signs of an El Nino are: 1. Rise in surface pressure over the Indian Ocean, Indonesia and Australia. 2. Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean. 3. Trade winds in the south Pacific weaken or head east. 4. Warm air rises near Peru, causing rain in the northern Peruvian deserts. 5. Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.

El Nino's warm rush of nutrient-poor water heated by its eastward passage in the Equatorial Current, replaces the cold, nutrient-rich surface water of the Humboldt Current. When El Nino conditions last for many months, extensive ocean warming and the reduction in easterly trade winds limits upwelling of cold nutrient-rich deep water, and its economic impact to local fishing for an international market can be serious.

La Nina is a coupled ocean-atmosphere phenomenon that is the counterpart of El Nino as part of the broader El Nino–Southern Oscillation climate pattern. During a period of La Nina, the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3–5 °C. In the United States, an appearance of La Nina happens for at least five months of La Nina conditions. The name La Nina originates from Spanish, meaning "little girl," analogous to El Nino meaning "little boy."

La Nina, sometimes informally called "anti-El Nino", is the opposite of El Nino, where the latter corresponds instead to a higher sea surface temperature by a deviation of at least 0.5 °C, and its effects are often the reverse of those of El Nino. El Nino is known for its potentially catastrophic impact on the weather along the Chilean, Peruvian, New Zealand, and Australian coasts, among others. It has extensive effects on the weather in North America, even affecting the Atlantic Hurricane Season. La Nina often, though not always, follows an El Nino.

2. How both phenomena affects Malaysia climates?

El-Nino : Located near the equator, Malaysia's climate is categorised as equatorial, being hot and humid throughout the year. The average rainfall is 250 centimetres (98 in) a year and the average temperature is 27 °C (80.6 °F). The climates of the Peninsula and the East differ, as the climate on the peninsula is directly affected by wind from the mainland, as opposed to the more maritime weather of the East. Malaysia is exposed to the El Nino effect, which reduces rainfall in the dry season. Climate change is likely to have a significant effect on Malaysia, increasing sea levels and rainfall, increasing flooding risks and leading to large droughts.

Malaysia faces two monsoon winds seasons, the Southwest Monsoon from late May to September, and the Northeast Monsoon from November to March. The Northeast Monsoon brings in more rainfall compared to the Southwest Monsoon, originating in China and the north Pacific. The southwest monsoon originates from the deserts of Australia. March and October form transitions between the two monsoons.

Local climates are affected by the presence of mountain ranges throughout Malaysia, and climate can be divided into that of the highlands, the lowlands, and coastal regions. The coasts have a sunny climate, with temperatures ranging between 23 °C (73.4 °F) and 32 °C (89.6 °F), and rainfall ranging from 10 centimetres (4 in) to 30 centimetres (12 in) a month. The lowlands have a similar temperature, but follow a more distinctive rainfall pattern and show very high humidity levels. The highlands are cooler and wetter, and display a greater temperature variation. A large amount of cloud cover is present over the highlands, which have humidity levels that do not fall below 75%.

The highest temperature was recorded at Chuping, Perlis on 9 April 1998 at 40.1 °C (104.2 °F). The lowest temperature was recorded at Cameron Highlands on 1 February 1978 at 7.8 °C (46.0 °F). The highest rainfall recorded in a day was 608 mm (23.9 in) in Kota Bharu, Kelantan on 6 January 1967. The highest rainfall recorded in a year was 5,687 mm (223.9 in) at Sandakan, Sabah in 2006. Meanwhile, the lowest rainfall recorded in a year was 1,151 mm (45.3 in) at Tawau, Sabah in 1997. The wettest place in Malaysia is Kuching, Sarawak with an average rainfall of 4,128 mm (162.5 in) with 247 days of rain a year. The driest place in Malaysia is in Chuping, Perlis with average rainfall of only 1,746 mm (68.7 in) a year.

La-Nina : During La Nina years, the formation of tropical cyclones, along with the subtropical ridge position, shifts westward across the western Pacific ocean, which increases the landfall threat to China. In March 2008, La Niña caused a drop in sea surface temperatures over Southeast Asia by 2°C. It also caused heavy rains over Malaysia, the Philippines, and Indonesia.