The Dynamics of Co-behaviour of Climate Processes
Abstract
The study aims to develop an approach to assess the collective co-behaviour of climate processes. Although literature has established the individual roles of key climate processes that influence regional climate, it is however deficient in addressing the collective co-behaviour of multiple climate processes. Hence the understanding of how these processes co-behave to govern the regional climate is critical. In order to achieve this, we have employed a host of methods. The first, Self-Organizing Map (SOM), based on artificial neural network has already been introduced to climatology and has aided in classifying circulation patterns. The second, varimax rotated Principal Component Analysis (PCA) is a multivariate statistical technique used frequently in statistics and climatology to identify strongly associated patterns across data while bootstrapping their statistical significance. We study co-behaviour using three important processes of the southern African climate; El-Niño Southern Oscillation (ENSO), Antarctic Oscillation (AAO) and Inter-Tropical Convergence Zone (ITCZ). Through these methods, the combinatory impact of these processes on influencing circulation patterns are identified and mapped to precipitation and near-surface temperature patterns across regions with distinct climate over southern Africa. Using a varimax rotated PCA, we identify 8 possible modes of co-behaviour and we examined how these influence surface expressions. We find a negative AAO active mode coupled with El-Niño active mode introduces a significant warming in the west of region 1 and regions 2 and 3. However, the east of region 1 experienced a non-significant reduced warming. Regions 2 and 3 received a statistically significant increase in precipitation while experiencing La-Niña and under a positive AAO influence
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMGC51K0932Q
- Keywords:
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- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCESDE: 9305 Africa;
- GEOGRAPHIC LOCATIONDE: 1616 Climate variability;
- GLOBAL CHANGEDE: 1878 Water/energy interactions;
- HYDROLOGY