Vietnam Meteorological Agency is particularly interested in the emergence of El Nino, dangerous weather phenomenon associated with drought, heat, upset people's lives. VnExpress just exchanged with TS. Hoang Duc Cuong, Head of Climate Department, Center for Climate and Meteorological Research, about this phenomenon.
- Sir, by mid-November, how likely is El Nino to appear again?
Dr. Hoang Duc Cuong.(Photo: HK)
- El Nino is an anomalous phenomenon in the warming direction of the Pacific equator. The target to confirm El Nino is the average equatorial temperature of the Pacific equator, which is about 0.5 degrees higher than the average for many years and that phenomenon lasts for at least 5-6 months. By the end of October, we had warned that the possibility of El Nino's arrival was 80%.
According to the latest report of the US Climate Prediction Center on November 9, El Nino's conditions are continuing, the Pacific equatorial sea surface has exceeded 0.5 degrees Celsius compared to normal, and observed in most of the Pacific equator. Compared to the previous half of the month, the sea water is even hotter and wider.
Data from July to October show that the temperature of the sea surface in the equatorial Pacific region increases rapidly. If progressive, this phenomenon has lasted for 5 months and it will be officially announced in December, lasting until 4-5 / 2007. The peak of El Nino is around the end of December and early January 2007.
- In Vietnam, what did the meteorological agency have recorded about the return of El Nino?
- The sign that winter is starting to slow down this year. Now is the time to enter the east (December 2006 and January 2007), but it is still not cold. Secondly, the storm season is much less this year, the number of storms that directly affect Vietnam is only 2-3, while the years are 5-6. Thirdly, according to statistics, the rainfall in the South Central Coast is much lower than the average. October-November is the rainy season of southern South Central Vietnam, from Binh Dinh to Ninh Thuan and Binh Thuan, in which October's rainfall accounts for 30-40% of the total rainfall of the year. But in October, rainfall is only half that of the same period.
- How will El Nino affect the weather in Vietnam?
- Normally the years of El Nino southwest monsoon intensity (summer) are weak and later than normal. Southwest wind is closely related to the rainy season in the South and Central Highlands. The late and weak monsoon season means that the rainy season in the two areas is later, normally in mid-April and later, it is possible that in late April and early May, even the 1997-1998 El Nino period must come June. This is very dangerous for agriculture, because before it was a dry period, less rain.
In El Nino years, the number of northeast monsoon winds affected the North less than usual, more concentrated in the middle of winter (December and January) and ended earlier. Normally, May 4-5 will have cold cold, but in the years when El Nino is no longer available. Thus, it can be said that the winter of 2006-2007 in the North will be warm, of course, do not exclude the cold and harmful cold wave. The situation of drizzle is less late in the winter and early spring. The Northern Delta, North Central and Northern Midlands are more likely to lack domestic and agricultural water, which must be taken into account.
When there is El Nino, storms and tropical depressions appear less, and a bit concentrated in the beginning of the season. But especially dangerous is the occurrence of storms, tropical depressions that operate in the wrong way, landing in places with little landing and tricky paths. For example, normally at the end of the year, the storm passes through the Philippines to the East Sea, due to the impact of cold air in the north, the storm tends to shift south. But when there is El Nino, that rule is completely reversed. For example, in 1997, El Nino appeared and Typhoon Linda landed in Ca Mau. Although the intensity of storms is not strong, but it landed on the position of hundreds of years without storms, causing great damage.
In El Nino years, the temperature will be about 1 degree C higher than normal and in all regions. Many places reach over 41-42 degrees C.
- If you do comparison with previous El Nino, how do you think about this El Nino?
- In the past 50 years, about 15-16 El Nino episodes have been recorded. In 1997-1998 was the highest record ever, affecting the global climate, causing economic recession in Asia. Most recently, the El Nino is weaker, the impact is softer in 2002 and 2004. If compared, the 2006-2007 El Nino is stronger than the El Nino in 2002 and 2004, but much weaker than in 1997- 1998.
Another feature, the 2006-2007 El Nino is extremely characteristic in terms of time, right at Christmas. The duration of 6 months is relatively short. Usually El Nino lasts 10-12 months.
- What is the continuity of El Nino's occurrence related to global climate change?
- There are two research directions, one that we strongly agree with is the phenomenon of climate change, the main manifestation is the increase in global temperature, leading to hotter sea surface, thereby leading to the rise of El. Nino. The second direction is that global warming increases the evaporation of seawater into the atmosphere, increasing the humidity in the atmosphere, leading to stronger convection, more rain, increasing La Nina.
In general, these two conclusions come to the most general conclusion that the extreme state of the ocean atmosphere in the Pacific region will increase more, either El Nino or La Nina. Both of these phenomena negatively affect the global climate. If El Nino is drought and hot, if La Nina is heavy rain and flood.
In the past 10 years, El Nino has caused nearly tens of thousands of billion dong damage
El Nino in 1997-1998: It took place in most of the country because the rainy season in 1997 ended 1 month early, the rainfall in the first 6 months was only 30-70% on average for many years, sometimes in 2-3 months without rain ;many prolonged heat waves;water levels in rivers and streams are low.
Winter-spring rice is limited to 253,988 ha, of which 30,739 ha are lost.The summer-autumn rice crop is 359,821 hectares, of which 68,590 hectares are lost.Seasonal rice is 153,072 hectares, in which 22,689 hectares are lost.Industrial crops and fruit drought 236,413 ha, of which 50,917 ha died.In the whole country, 3.1 million people lack clean water.The total value of damage is 5,000 billion VND.
El Nino in 2002 (from February to August): Total damage is VND 2,060 billion.
(Source: Department of Water Resources, Ministry of Agriculture and Rural Development)
Hong Khanh made