A special collection entitled “The Earth’s energy imbalance and its implications” will be included in the Journal of Climate and all other journals of the American Meteorological Society. You are invited to submit articles for the special collection on observations and/or modeling of all aspects of Earth’s energy imbalance and the resultant heating of various components of the Earth system (ocean, land, atmosphere, and cryosphere).

Overview: Climate change poses a major threat to our livelihoods, economy, and ecological treasures. On a range of timescales, climate processes are controlled by energy exchanges within and among the different components of the Earth system. Monitoring these energy flows, and the global net accumulation of energy as a result of radiative forcing, is essential to advance our understanding of climate variability and change, and for developing reliable future predictions.

Anthropogenic radiative forcing of the climate system has given rise to a radiative flux imbalance at the top-of-atmosphere (TOA), referred to as Earth’s energy imbalance (EEI). Observing EEI is fundamental in determining the rate of climate change on a global scale. To date, the most reliable approach to estimate the absolute magnitude of EEI is through assessing changes in heat storage across all relevant Earth system components. Due to the dominant role of the oceans in Earth’s heat budget, EEI can be reliably estimated from changes in ocean heat content on annual and longer timescales, while satellite observations of TOA net radiative flux variability can provide information at shorter timescales. However, a complete understanding of Earth’s energy flows, particularly on sub-annual timescales, requires improved estimates of change in all system components storing heat: the ocean including the deep ocean; the land surface; the atmosphere; and the cryosphere. Regional energy exchange through the atmosphere-surface boundary, horizontal energy transport by the atmosphere and ocean, and diabatic heating by radiation and precipitation are also essential elements of Earth’s energy flows.

The World Climate Research Programme (WCRP) has identified the improved quantification and understanding of global mean EEI and its spatial and temporal variability to be major challenges in climate research across disciplines. To address these challenges, we invite contributions that improve estimates of EEI and energy uptake across all relevant disciplines and Earth system components, exploiting in-situ measurements, reanalysis, climate modeling, and remote sensing techniques. A particular interest is the discussion of uncertainty associated with measurement and retrieval errors, and assumptions in algorithms. Papers discussing results of inter-comparison studies that identify and quantify biases are encouraged. We also solicit studies on the spatial and temporal variability of global and regional energy budgets at the TOA, the surface and within the atmosphere and studies that improve our understanding of processes that perturb energy budgets and energy flows on various spatial and time scales. Furthermore, we invite authors to consider implications on key impact metrics of climate variability and change, such as sea level, the hydrological cycle, and regional climate extremes.

This special collection arose out of discussions at the WCRP workshop held in Toulouse during November 2018 and the workshop website may provide further useful context for authors. More information about the submission process is available on the GEWEX website. Authors are reminded that the IPCC AR6 has a deadline of 31 December 2019 for papers to be eligible for citation in the Working Group I report, but the collection itself will continue to accept submissions during 2020.

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Image by U. Leone from Pixabay