Wyatt on Earth

by Marcia Glaze Wyatt, Ph.D.

"Regime Evolution: the role of the stadium wave"

Figure RE1. Below is the Average Surface Global Temperature Trend (GISS), analogous to the Northern Hemisphere trend used in the Stadium-wave studies. Observation and Hypothesized Explanation and Implications follow:
Climate quasi-periodically oscillates over temperature record.

Hypothesized Cause:
Alternating multi-decadal climate regimes are scripted by hypothesized stadium-wave signal.

Implications of Stadium Wave for Climate Change:
Alternately enhances and dampens increasing linear trend.

It is unclear whether the stadium-wave signal simply amplifies and minimizes the linear trend or, if through related dynamics, impacts climate sensitivity.

Figures below show how the hypothesized stadium-wave signal scripts the oscillatory pattern superposed upon the increasing linear trend shown above.
Adapted from Wyatt and Curry (2013), figure 3
Figure RE2. Expanded stadium wave is annotated to show two things: 1) Arrows (red and blue) reflect increasing and decreasing NHT; 2) Roman Numerals I through IV (or negative counterparts) represent the four 'Stages' of climate-regime evolution as the stadium-wave signal propagates through the index Groups. [AMO plotted as -AMO]

Regimes = multi-decadal intervals of warming (red arrow) and cooling (blue arrow)
Regime Shifts coincide with:
1) Reversal of anomaly trend of AMO and
2) Reversal of polarity of anomalies of PDO.
Throughout warming regimes: AMO anomaly trend increasing; PDO  anomalies +
Throughout cooling regimes: AMO anomaly trend decreasing; PDO anomalies -

Adapted from Wyatt and Curry (2014) figure 11  
Figure RE3 
Schematic reflects index relationships at each of four stages of climate-regime evolution. Each Stage (Roman Numerals in top row) is marked by maximum (or minimum) activity in a collection of indices, or Group (labeled along vertical lines). Each collection of indices (Group) represents a dominant dynamic in a general region: e.g. Group I involves the ocean-ice coupling  in the Atlantic sector of the Arctic; while Group II includes ice-atmosphere coupling in the Atlantic-Eurasian sector; and Group III, Pacific-centered circulations; and indices of Group IV affect the entire hemisphere, reflecting cumulative impacts of ocean, ice, and atmospheric dynamics from the previous Stages. For simplicity, only single indices are used (left column) to represent a given Group.  Successive columns reflect Stages I through IV  (and -I through -IV). The horizontal arrows crossing the columns represent increasing (red arrows) trends and decreasing (blue arrows) trends of the Group indices between Stages of regime evolution. Narrow arrows at bottom of figure indicate the duration of either a warming or cooling regime as the signal propagates.
Dates are on the x-axis. In ~1918, a warming regime  'begins'. It is marked by peak activity in Group I, Stage I.  Between Stages I and II, all indices are positively (red arrow) trending (note AMO is + in this schematic (opposite from 'wave' plot)). When the signal reaches Stage II, Group II indices reverse trend. With each succeeding Stage, the next Group's trends reverse. Maximum Arctic temperature occurs at the last Stage of a warming regime. After a few-year transition, AMO reaches its peak and reverses trend, signaling the end of a warming regime. Stage -I marks this reversal; a cooling regime has begun. 

Please refer to WC manuscript for additional explanation.

More discussion on the stadium-wave's hypothesized mechanism can be found in the FAQ (near end). A figure of the mechanism (FAQ2) is provided in the FAQ section also.