Hello and welcome to this presentation.
Today we are going to look at the correlation between OLR (Outgoing Longwave Radiation) ENSO (El Nino Southern Oscillation) and LTGT (Lower Tropospheric Global Temperatures).
The presentation will specifically focus on the following geographical coordinates of
5°n-5°s + 120-170°w along the Equatorial Pacific (ENSO + OLR).
OLR Parameters.
Negative (Positive) OLR are indicative of enhanced (suppressed) convection and hence more (less) cloud coverage typical of El Niño (La Niña) episodes. More (Less) convective activity in the central and eastern equatorial Pacific implies higher (lower), colder (warmer) cloud tops, which emit much less (more) infrared radiation into space.
ENSO Parameters.
Typical ENSO feedbacks are.
+0.5°C El Nino.
-0.5°C La Nina.
OLR + ENSO The connection
The following Graph shows the inverse correlation between OLR + ENSO state.
I.E negative values of OLR transpose as a positive reaction in ENSO and Visa Versa.
It is notable that a negative sustained value of OLR reflects in feedback from SST's in region 3.4 ENSO, Especially when values of OLR exceed negative 2.4°C . (8-12 months).
This is reversed during La Nina years, seen in the graph 1997/98 + 2015/16 El Nino Years and 1998/2010 El Nino years.(example only- other ENSO states are within the graph). 1997/98 + 2015/16 -2.5 W/mtr² although 1997/98 was not sustained as long as 2015/16 episode, hence the effect had less impact on SST's longevity.
OLR + GL (Outgoing Longwave Radiation + Global Temperature)
The Following Graph represents the correlation between OLR + Global Temperatures.
Again we see the influence of OLR on GL within the Lower Troposphere using the same index, Note the Lag period between Negative and Positive values is around 3-5 Months as an average over the period graphed.
I.E Negative -2.4Wmtr² in 1997 correlates to a positive peak in GL 3-5 months later again showing the inverse correlation between neg and pos values of OLR effect on GL.
note- the time spent in pos/ neg determines scale of fluctuation in GL.
ENSO + GL (El Nino Southern Oscillation/ Global Temperature in Lower Troposphere)
Here in the next graph we look at the connection between ENSO + GL, at the same coordinates, again the lag of 3-5 Months is evident and again ENSO effects on GL is undeniable, However El Nino effects of +2.5°C have a significant impact on GLT when sustained. 2010/11 La Nina was not sustained,( short lived) hence relative minor impacts on GLT. We can see the Hiatus from 1998/2014 quite well if we look at ENSO for this period with minor fluctuations reflected in GLT. Below, in fact if we take out ENSO feedbacks from the period 1998 + 2016 GLT is stable ( with minor fluctuations).
ENSO + GL + OLR.
The following graph in the series combines all the above indices into 1 readable Graph, and shows clearly the evidence to support my theory that GLT is governed by Ocean Atmospheric coupling. OLR + ENSO, SOI + PDO (Southern Oscillation/ Pacific Decadal Oscillation are coupled within these parameters and reflect in GLT, these are all part of the great ocean circulatory patterns that govern our climate via weather patterns and influence all continents Globally.
With thanks to Dr Waheed Uddin and his PHD students for taking the time to graph these plots and continued support throughout.
David I Birch.©2018.
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