Climate Dynamics

https://link.springer.com/journal/382

List of Papers (Total 902)

Season-dependent predictability barrier for two types of El Niño revealed by an approach to data analysis for predictability

The real-time prediction skill for El Niño-Southern Oscillation has not improved steadily during the twenty-first century. One important reason is the season-dependent predictability barrier (PB), and another is due to the diversity of El Niño. In this paper, an approach to data analysis for predictability is developed to investigate the season-dependent PB phenomena of two types...

Impact of model resolution on Arctic sea ice and North Atlantic Ocean heat transport

Arctic sea-ice area and volume have substantially decreased since the beginning of the satellite era. Concurrently, the poleward heat transport from the North Atlantic Ocean into the Arctic has increased, partly contributing to the loss of sea ice. Increasing the horizontal resolution of general circulation models (GCMs) improves their ability to represent the complex interplay...

Characterization of European wind speed variability using weather regimes

The aim of this paper is threefold. Firstly, to present a representative set of large-scale weather regimes for each month of the year over the Euro-Atlantic region and compare them amongst three commonly employed global reanalyses. Secondly, to measure the impact of the weather regimes on near-surface wind speed variability. Lastly, to validate the regime’s ability to...

Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system

A high-resolution coupled ocean atmosphere model is used to study the effects of seasonal re-emergence of North Atlantic subsurface ocean temperature anomalies on northern hemisphere winter climate. A 50-member control ensemble is integrated from 1 September 2007 to 28 February 2008 and compared with a parallel ensemble with perturbed ocean initial conditions. The perturbation...

Oceanic heat transport into the Arctic under high and low \(\hbox {CO}_2\) forcing

Enhanced ocean heat transport into the Arctic is linked to stronger future Arctic warming and polar amplification. To quantify the impact of ocean heat transport on Arctic climate, it is imperative to understand how its magnitude and the associated mechanisms change in other climate states. This paper therefore assesses the ocean heat transport into the Arctic at \(70^{\circ...

Importance of background seasonality over the eastern equatorial Pacific in a coupled atmosphere-ocean response to westerly wind events

Coupled atmosphere-ocean response to westerly wind events (WWEs), which sometimes trigger El Niños, was investigated using a coupled general circulation model to clarify its dependence on the timing and location of WWEs. Twelve sets of 20-member ensembles were made with an idealized single WWE imposed in different months from January to July and at different longitudes from 160...

ENSO feedbacks and their relationships with the mean state in a flux adjusted ensemble

The El Niño Southern Oscillation (ENSO) is governed by a combination of amplifying and damping ocean–atmosphere feedbacks in the equatorial Pacific. Here we quantify these feedbacks in a flux adjusted HadCM3 perturbed physics ensemble under present day conditions and a future emissions scenario using the Bjerknes Stability Index (BJ index). Relationships between feedbacks and...

Circulation analogues and uncertainty in the time-evolution of extreme event probabilities: evidence from the 1947 Central European heatwave

The science of extreme event attribution has rapidly expanded in recent years, with numerous studies dedicated to determining whether and to what extent anthropogenic climate change has increased the likelihood of specific extreme weather events occurring. However, the majority of such studies have focussed on extreme events which have occurred in the recent past (usually within...

AMOC sensitivity to surface buoyancy fluxes: the role of air-sea feedback mechanisms

We interrogate the sensitivity of the Atlantic Meridional Overturning Circulation (AMOC) to surface heat and freshwater fluxes over the Subpolar Gyre in an ocean general circulation model and its adjoint. Surface heat loss out of the Subpolar Gyre in the winter strengthens the AMOC at a lead time of approximately 6 months. However, the same surface heat flux anomaly in the summer...

Detecting human influence on the temperature changes in Central Asia

The ecosystem and societal development in arid Central Asia are highly vulnerable to climate change. During the past five decades, significant warming occurs in Central Asia, but whether the influence of anthropogenic forcing is detectable remains unclear. Therefore, we employ the optimal fingerprinting method to address the question in this study. The observed annual mean...

The contribution of North Atlantic atmospheric circulation shifts to future wind speed projections for wind power over Europe

Wind power accounts for a large portion of the European energy mix (17% of total power capacity). European power systems therefore have a significant-and growing-exposure to near-surface wind speed changes. Despite this, future changes in European wind climate remain relatively poorly studied (compared to, e.g., temperature or precipitation), and there is limited understanding of...

Quasi-biweekly impact of the atmospheric heat source over the Tibetan Plateau on summer rainfall in Eastern China

We investigated the intraseasonal relationship between the atmospheric heat source over Tibetan Plateau (TP) and summer rainfall in eastern China. A quasi-biweekly oscillation (QBWO) is the common dominant periodicity over both the TP and eastern China. Crucially, the TP heat source QBWO leads rainfall QBWO over its downstream region by 2–8 days. The QBWO over the TP shows a...

Climatology and dynamics of the link between dry intrusions and cold fronts during winter, Part II: Front-centred perspective

The conceptual picture of an extratropical cyclone typically includes a cold front and a dry intrusion (DI) behind it. By objectively identifying fronts and DIs in ECMWF ERA-Interim data for 1979–2014, Part I quantified the climatological relationship between cold fronts and DIs. Driven by the finding that front intensity and frontal precipitation are enhanced in the presence of...

Climatology and dynamics of the link between dry intrusions and cold fronts during winter. Part I: global climatology

Cold fronts are a primary feature of the day-to-day variability of weather in the midlatitudes, and feature in conceptual extratropical cyclone models alongside the dry intrusion airstream. Here the climatological frequency and spatial distribution of the co-occurrence of these two features are quantified, and the differences in cold front characteristics (intensity, size, and...

Thermodynamic controls of the Western Tibetan Vortex on Tibetan air temperature

The “Western Tibetan Vortex” (WTV)—also termed the Karakoram Vortex—dominates the middle-to-lower troposphere and the near-surface air temperature variability above the western Tibetan Plateau (TP). Here, we explore the thermodynamic mechanisms through which the WTV modulates air temperature over the western TP by diagnosing the three major terms of the thermodynamic energy...

Forced summer stationary waves: the opposing effects of direct radiative forcing and sea surface warming

We investigate the opposing effects of direct radiative forcing and sea surface warming on the atmospheric circulation using a hierarchy of models. In large ensembles of three general circulation models, direct \(\hbox {CO}_2\) forcing produces a wavenumber 5 stationary wave over the Northern Hemisphere in summer. Sea surface warming produces a similar wave, but with the opposite...

Skilful seasonal prediction of winter wind speeds in China

We demonstrate robust skill in forecasting winter (DJF) mean 10 m wind speeds for the period 1992/3–2011/12 over south-eastern China and the South China Sea (SE China) and northern-central (NC) China, with correlations exceeding 0.8 and 0.6 respectively. High skill over these regions is seen in two independent initialised ensembles which cover different time periods. The NC China...

Attribution of the Last Glacial Maximum climate formation

To better understand what determines the Last Glacial Maximum (LGM) cold and dry climate, a suite of numerical experiments with the Nanjing University of Information Science and Technology Earth System Model version 1 are conducted to assess the relative contributions of individual external forcings, including greenhouse gases (GHGs), ice sheets (IS), land-sea configuration (LSC...

Effect of El Niño on the response ratio of Hadley circulation to different SST meridional structures

The role of El Niño in influencing the response of the Hadley circulation (HC) to different tropical sea surface temperature (SST) meridional structures is investigated over the period 1979–2016. The explained variance of the equatorially asymmetric principal mode of HC variability is enhanced during El Niño events that are characterized by equatorially symmetric El Niño SST...

Metrics for understanding large-scale controls of multivariate temperature and precipitation variability

Two or more spatio-temporally co-located meteorological/climatological extremes (co-occurring extremes) place far greater stress on human and ecological systems than any single extreme could. This was observed during the California drought of 2011–2015 where multiple years of negative precipitation anomalies occurred simultaneously with positive temperature anomalies resulting in...

Assessing natural variability in RCM signals: comparison of a multi model EURO-CORDEX ensemble with a 50-member single model large ensemble

Uncertainties in climate model ensembles are still relatively large. Besides scenario and model response uncertainty, natural variability is another important source of uncertainty. To study regional natural variability on timescales of several decades and more, observations are often too sparse and short. Regional Climate Models (RCMs) can be used to overcome this lack of useful...

Improved climatological precipitation characteristics over West Africa at convection-permitting scales

The West African climate is unique and challenging to reproduce using standard resolution climate models as a large proportion of precipitation comes from organised deep convection. For the first time, a regional 4.5 km convection permitting simulation was performed on a pan-African domain for a period of 10 years (1997–2006). The 4.5 km simulation (CP4A) is compared with a 25...

Dominant patterns of winter-time intraseasonal surface air temperature over the CONUS in response to MJO convections

The dominant patterns of the intraseasonal surface air temperature (SAT) over the Contiguous United States (CONUS) during wintertime (December–March) are investigated in the period of 1979–2014 in the present study. The first two leading modes revealed by the empirical orthogonal function (EOF) analysis sufficiently represent the patterns by explaining nearly 80% of the total...