Social Science

Improved Complete Ensemble Empirical Mode Decompositions with Adaptive Noise of Global, Hemispherical and Tropical Temperature Anomalies, 1850-2021


Abstract

New investigations in the Western Caucasus contribute to the understanding of granite pseudokarst (sensu lato) and megaclasts linked to river erosion. A plot on the bank of the Belaya River (Mountainous Adygeya, Western Caucasus) was selected to examine diverse and abundant pseudokarst features (small rock basins, hollows, potholes, and channels) and large clasts. Morphological analysis of these features clarifies their general characteristics and genetic interpretations. Pseudokarst features can be classified into two major categories, namely the relatively small (<1 m) and large (>1 m) features. Potholes, which are usually 1–3 m in size, are the most characteristic features occurring on two levels, i.e., on steep walls of the gorge (half-filled with river water) and on slightly inclined surfaces of a terrace-like landform (subaerial exposure). In both cases, their walls from the side of the river are broken. Apparently, these potholes were formed on the river bottom. Subsequent incision of the gorge elevated potholes and the river has eroded them from one side. Apparently, some pseudokarst features are related to macroturbulent flood flows and granite weathering. Due to its scientific uniqueness and aesthetic attractiveness, this granite pseudokarst constitutes geoheritage, which can be exploited for the purposes of geoscience research and geotourism development.

Key Questions

What is the Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (ICEEMDAN)?

ICEEMDAN is an advanced signal processing technique used to decompose complex time-series data into intrinsic mode functions (IMFs). It improves upon earlier methods by reducing noise and providing a more accurate analysis of non-linear and non-stationary data, such as temperature anomalies.

What are temperature anomalies, and why are they important?

Temperature anomalies represent deviations from a long-term average temperature, typically over a 30-year baseline. They are important for understanding climate change, as they highlight trends and variations in global, hemispherical, and regional temperatures over time.

How does ICEEMDAN improve the analysis of temperature anomalies?

ICEEMDAN improves the analysis of temperature anomalies by effectively separating noise from the signal, identifying underlying patterns, and providing a clearer understanding of trends and variability in temperature data over time.

What time period does the study cover, and why is it significant?

The study covers the period from 1850 to 2021, which is significant because it includes the pre-industrial era, the industrial revolution, and the modern era of rapid climate change. This long-term perspective helps identify trends and shifts in global, hemispherical, and tropical temperatures.

What are the key findings of the study regarding global temperature anomalies?

The study identifies significant warming trends in global temperature anomalies, with accelerated warming in recent decades. ICEEMDAN analysis reveals distinct modes of variability and long-term trends that contribute to these changes.

How do hemispherical temperature anomalies differ in the study?

The study finds that the Northern Hemisphere exhibits stronger warming trends compared to the Southern Hemisphere, likely due to differences in landmass distribution, ocean currents, and anthropogenic influences.

What does the study reveal about tropical temperature anomalies?

The study highlights that tropical temperature anomalies show consistent warming trends, with significant variability influenced by phenomena such as El Niño and La Niña. The tropics play a critical role in global climate dynamics.

How does ICEEMDAN handle noise in temperature anomaly data?

ICEEMDAN adaptively reduces noise by iteratively decomposing the signal and isolating noise components. This results in a clearer representation of the underlying temperature trends and variability.

What are the implications of the study for climate change research?

The study provides a robust framework for analyzing temperature anomalies, offering insights into long-term trends and variability. This enhances our understanding of climate change and supports the development of more accurate climate models.

How does the study contribute to the understanding of natural vs. anthropogenic climate influences?

By decomposing temperature anomalies into intrinsic modes, the study helps distinguish between natural variability (e.g., solar cycles, volcanic activity) and anthropogenic influences (e.g., greenhouse gas emissions), providing a clearer picture of human impact on climate.

What are the limitations of using ICEEMDAN for climate data analysis?

Limitations include the computational complexity of the method, the need for careful parameter selection, and the challenge of interpreting the physical meaning of some intrinsic mode functions (IMFs) in the context of climate data.

How does the study address uncertainties in temperature anomaly data?

The study addresses uncertainties by using ICEEMDAN to separate noise from the signal, providing a more accurate representation of temperature trends. It also highlights the importance of high-quality, long-term datasets for reliable analysis.

What are the potential applications of ICEEMDAN beyond climate science?

ICEEMDAN can be applied to other fields, such as finance, medicine, and engineering, where the analysis of non-linear and non-stationary time-series data is required. Its ability to reduce noise and identify patterns makes it a versatile tool.

How does the study compare to previous methods of analyzing temperature anomalies?

The study demonstrates that ICEEMDAN outperforms earlier methods, such as EMD and EEMD, by providing more accurate decompositions with reduced noise and better resolution of intrinsic modes in temperature anomaly data.