ENSO..Pacific Ocean basin 2016_2015_2014


I was reading and article by Max Gongalez of weatherzone news
about the possibility of an El Nino in 2014
Article here


El Nino

(the warm phase) occurs when warmer than average sea surface temperatures (SSTs) prevail over the central and eastern equatorial Pacific Ocean (from late winter to late autumn),

accompanied by high atmospheric pressure over the western Pacific.

This high atmospheric pressure typically leads to lower than average rainfall over Australia during El Nino years.

La Nina

(cool phase) on the other hand, occurs when cooler than average SSTs prevail over the central and eastern equatorial Pacific.

This is accompanied by a low atmospheric pressure over the western Pacific,

thus typically bringing above average rainfall to mainland Australia during La Nina years.

I thought l would follow this ENSO season by testing this hypothesis/ fact

I will post the global MSLP ( mean sea level pressure) anomalies in the Pacific every month and observe the changing surface MSLP anomaly pattern

The February 2014 MSLP anomalies show low pressure anomalies in both the east and west basin. Although there is a band of high pressure over Australia and the far west basin of the pacific

According to theory .. Low pressure in the east basin is a la Nina indicator

I’m not sure?
I thought low pressure was a symptom of warm SST anomalies..?

mslp global feb 2014



I will post MSLP updates each month for 2014 in the comments section below
Please click on the title to load the comments section if it is not there

Follow ENSO 2014 forum here


10 comments on “ENSO..Pacific Ocean basin 2016_2015_2014

  1. Some brush up on basics .
    “High pressure areas are normally caused by a phenomenon called subsidence, meaning that as the air in the high cools it becomes denser and moves toward the ground. Pressure increases here because more air fills the space left from the low. Subsidence also evaporates most of the atmosphere’s water vapor so high pressure systems are usually associated with clear skies and calm weather.

    Unlike areas of low pressure, the absence of clouds means that areas prone to high pressure experience extremes in diurnal and seasonal temperatures since there are no clouds to block incoming solar radiation or trap outgoing longwave radiation at night. Thus such areas have higher high temperatures and lower lows.”

    So..If the Pacific basin had anomalously low pressure Feb 2014

    That means there was more cloud and less solar radiation reaching the Pacific ocean in FEB… More rain with increased low pressure..

  2. Report on 2015 El Nino STRONG by BOM

    “Issued on 8 December 2015 | Product Code IDCKGEWW00

    The strong 2015 El Niño event is near its peak. While sea surface temperatures remain close to record-high values, some El Niño indicators are now showing signs of easing. However, the current El Niño is likely to persist well into 2016.

    El Niño indicators, notably sea surface and sub-surface temperatures, westerly wind anomalies in the central Pacific, and cloudiness near the Date Line, remain well above El Niño thresholds. The Southern Oscillation Index (SOI) has eased back into neutral values, though this may be short-lived: the SOI tends to be more variable during the northern Australian wet season (October–April). Model outlooks and the strength of the current event suggest El Niño thresholds may continue to be exceeded well into the southern hemisphere autumn.

    The 2015–16 El Niño is strong, and likely to rank in the top three events of the past 50 years. Presently, several key indicators fall short of their 1997–98 and 1982–83 values, both in the ocean (e.g. sub-surface temperatures, which have peaked around +8 °C this year, compared to +12 °C in 1997–98), and atmosphere (e.g. SOI, for which monthly values peaked around −20, while 1982–83 had several months at −30).

    El Niño’s influence on Australian rainfall is variable at this time of year, with both wetter and drier summers observed in past events depending on how quickly the event breaks down. However, on average an El Niño summer brings below-average rainfall across northern Queensland, and a slight drying influence across the southeast of Australia. Conversely, inland Western Australia often sees above-average rainfall at this time of year during El Niño.

    The Indian Ocean Dipole has little influence on Australian climate between December and April. However, Indian Ocean sea surface temperatures remain very much warmer than average across the majority of the basin. This basin-wide warmth may provide extra moisture for rain systems across Australia.

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