{Annoucement} 080702 ENSO Wrap-Up

ENSO Wrap-Up

Summary: Neutral ENSO conditions likely to persist

July 2, 2008
Neutral ENSO conditions are now firmly established in the tropical Pacific. Over the past two weeks most indicators of ENSO have weakened further. Sea surface temperatures are now close to normal (generally within 1°C) across the entire basin, including close to the dateline where the last remnants of the La Niña had persisted. The Trade Winds have moderated further, cloudiness near the dateline has been near-normal and the SOI has also been in the neutral range since May. Temperatures in the sub-surface of the tropical Pacific Ocean have also moderated in the centre and west of the basin but weak warming has occurred in the east. All ENSO indicators are now neutral.


Climate model forecasts of ENSO show that neutral conditions are likely to continue thoughout 2008. Most models show some warming in the coming season. None suggest a redevelopment of a La Niña and only a minority predict an El Niño developing. Those forecasts that do were based on conditions in early June when Trade Winds had weakened, a situation that has now eased. More recent forecasts favour neutral conditions. As winter is a period of relatively high predictability the persistence of neutral conditions is considered the most likely scenario in the coming months. However, there is still a small chance of an El Niño in 2008, as events have been known to evolve late in the year. The Pacific will continue to be monitored closely for any signs of El Niño growth.


The Indian Ocean is currently in a positive phase of the Indian Ocean Dipole (IOD), but the index used to measure the IOD has weakened considerably since its peak in early June. Those models that forecast the IOD show it persisting but moderating further throughout the rest of the year. As a positive IOD is known to increase the chance of below normal winter-spring rainfall in southeast Australia, its evolution will also be closely monitored.

Source: http://www.bom.gov.au/climate/enso/

Comments

Post a Comment

Popular posts from this blog

{Paper} 081116! Recent intensification of tropical climate variability in the Indian Ocean

Recent intensification of tropical climate variability in the Indian Ocean Nature Geoscience Published online: 16 November 2008 doi:10.1038/ngeo357 Nerilie J. Abram 1 , 2 , Michael K. Gagan 1 , Julia E. Cole 3 , Wahyoe S. Hantoro 4 & Manfred Mudelsee 5 The interplay of the El Niño Southern Oscillation, Asian monsoon and Indian Ocean Dipole (IOD) 1, 2, 3 drives climatic extremes in and around the Indian Ocean. Historical 4, 5 and proxy 6, 7, 8, 9 records reveal changes in the behaviour of the El Niño Southern Oscillation and the Asian monsoon over recent decades 10, 11, 12 . However, reliable instrumental records of the IOD cover only the past 50 years 1, 3 , and there is no consensus on long-term variability of the IOD or its possible response to greenhouse gas forcing 13 . Here we use a suite of coral oxygen-isotope records to reconstruct a basin-wide index of IOD behaviour since AD 1846. Our record reveals an increase in the frequency and strength of IOD events during the tw...
Read more

{News} 080804 Haze returns to region as Sumatra's illegal fires rage

Haze returns to region as Sumatra's illegal fires rage The Straits Times, Aug 4, 2008 Despite fire-fighting efforts, visibility just 2km in Riau; air over Malaysia worsens By Teo Cheng Wee, In Kuala Lumpur and Salim Osman, Indonesia Correspondent In Jakarta HAZE shrouded parts of the region yesterday after fires scorched forest and plantation land in Sumatra over the weekend, enveloping the Riau capital of Pekanbaru and parts of Peninsular Malaysia. The authorities have squarely blamed Indonesian farmers and plantation workers, who are clearing the land using slash-and-burn methods that have been banned since 1999. The number of hot spots in Sumatra surged from 351 to 531 on Saturday, before dipping to 360 yesterday, according to the Indonesian Meteorology and Geophysics Agency (BMG). This was confirmed by Singapore's National Environment Agency. BMG analyst Selamat Triyadi told The Straits Times that Riau alone accounted for some 136 hot spots, while Pelalawan and Rokan Hulu h...
Read more