This study revisits the impacts of different types of El Niño on East Asian summer precipitation (EASP) with observed and re-analyzed data from 1958 to 2015. It focuses on the boreal summer preceding peaks of El Niño when prominent SST anomalies are mainly situated in the tropical Pacific. Distinct responses of EASP are obtained for the three identified types of SST anomalies noted as summer EP (Eastern

In 2012, extreme anomalous climate conditions occurred around the globe. Large areas of North America experienced an anomalously hot summer, with large precipitation deficits inducing severe drought. Over Europe, the summer of 2012 was marked by strong precipitation anomalies with the UK experiencing its wettest summer since 1912 while Spain suffered severe drought. What caused these extreme climate

We use an unprecedented ensemble of regional climate model (RCM) projections over seven regional CORDEX domains to provide, for the first time, an RCM-based global view of monsoon changes at various levels of increased greenhouse gas (GHG) forcing. All regional simulations are conducted using RegCM4 at a 25 km horizontal grid spacing using lateral and lower boundary forcing from three General Circulation

A multi-parameter, absolute-dated lacustrine record from the eastern Tibetan Plateau provides a continuous history of the Asian summer monsoon (ASM) over the past ~ 6000 years. The record broadly follows the trend in northern hemisphere summer insolation. However, it diverges during a period of increased moisture and thermal conditions during the past ~ 1300 years, broadly corresponding to the ASM

Global temperature increases are most clearly detected in the shifting distribution of extreme events. Australia’s warming climate has resulted in significant changes in the frequency of temperature extremes, with a general increase in heatwaves and a reduction in the number of cold days. Here, we present the longest historical analysis of daily Australian temperature extremes and their societal impacts

Future changes in the sign and intensity of ocean–land–atmosphere interactions have been insufficiently studied, despite implications for regional climate change projections, extreme event statistics, and seasonal climate predictability. In response to this deficiency, the present study focuses on projected responses to the enhanced greenhouse effect in: (1) the mean state of the atmosphere and land

This study examines the interdecadal variations in the frequency and intensity of tropical cyclones (TCs) making landfall in South China (SC) during the period 1975–2018. The annual frequency shows a decrease in 1997 but rises again since 2008 and the annual maximum landfall intensity (MLI) shows an increase since 2012. According to these variations, three subperiods, 1975–1996 (higher frequency but

Changes in the characteristics of austral winter (June–July–August) synoptic activity in three domains (Africa, Australia and South America) of the extratropical Southern Hemisphere projected with the Regional Climate Model version 4 (RegCM4) are presented. The model is nested in three global climate models (GCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5) under the Representative

The use of coupled Backward Lyapunov Vectors (BLV) for ensemble forecast is demonstrated in a coupled ocean–atmosphere system of reduced order, the Modular Arbitrary Order Ocean–Atmosphere Model (MAOOAM). It is found that overall the most suitable BLVs to initialize a (multiscale) coupled ocean–atmosphere forecasting system are the ones associated with near-neutral and slightly negative Lyapunov exponents

Seasonal prediction of western North Pacific summer monsoon rainfall (WNPSMR) is in great demand but remains challenging, because the relationships between the Asian monsoon system and precursors are nonstationary and exhibit significant decadal changes. The present study aims to (1) examine decadal variations of the relationships between the WNPSMR and predictors used in previous studies and (2) establish

The study assesses the performance of 24 model runs from five COordinated Regional climate Downscaling Experiment (CORDEX) regional climate models (RCMs) in simulating East Africa’s spatio-temporal precipitation characteristics using a set of eight descriptors: consecutive dry days (CDD), consecutive wet days (CWD), simple precipitation intensity index (SDII), mean daily annual (pr_ANN), seasonal (pr_MAM

We evaluate how hotspots of different types of extreme summertime heat change under global warming increase of up to \(4\,^\circ \hbox {C}\); and which level of global warming allows us to avert the risk of these hotspots considering the irreducible range of possibilities defined by well-sampled internal variability. We use large samples of low-probability extremes simulated by the 100-member Max Planck

State-of-the-art climate change projections of the CMIP5 simulations suggest a fairly complex pattern of global precipitation changes, with regions of reduced and enhanced precipitation. Conceptual understanding of these projected precipitation changes is difficult if only based on coupled general circulation model (CGCM) simulations, due to the complexity of these models. In this study we describe

A plausible simulation of the global energy balance is a first-order requirement for a credible climate model. Here I investigate the representation of the global energy balance in 40 state-of-the-art global climate models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6). In the CMIP6 multi-model mean, the magnitudes of the energy balance components are often in better agreement

The summer Guinean Coast (GC) rainfall (GCR) displays a strong variability on different timescales that are driven by Sea Surface Temperature (SST) variations and amplified by land–atmosphere processes. However, the relationships between the GCR and SST modes of variability in the pre-monsoon (March–May, MAM), post-monsoon (October–November, ON) and Harmattan (December–February, DJF) seasons are not

In this paper, we generalize the concept of “external forcing” to include any mechanism that modulates the long-term evolution of a meteorological variable but is not directly related to the internal variability of the climate system. Applying this concept, the corresponding ‘external forcings’ are removed from several long record datasets of oceanic and atmospheric variables at the surface in the

Recent studies indicated that the internal climate variability plays an important role in various aspects of projected climate changes on regional and local scales. Here we present results of the spreads in projected trends of wintertime North American surface air temperature and extremes indices of warm and cold days over the next half-century, by analyzing a 50-member large ensemble of climate simulations

Recent studies have started to explore coupled data assimilation (CDA) in coupled ocean–atmosphere models because of the great potential of CDA to improve climate analysis and seamless weather–climate prediction on weekly-to-decadal time scales in advanced high-resolution coupled models. In this review article, we briefly introduce the concept of CDA before outlining its potential for producing balanced

The El Niño-Southern Oscillation (ENSO) is one of the most significant climate variability signals. Studying the changes in ENSO-induced precipitation variability (ENSO precipitation) in the past climate offers a possibility to a better understanding of how they may change under future climate conditions. This study uses simulations performed with the European community Earth-System Model (EC-Earth)

Recently, much attention has been devoted to better understand the internal modes of variability of the climate system. This is particularly important in mid-latitude regions like the North-Atlantic, which is characterized by a large natural variability and is intrinsically difficult to predict. A suitable framework for studying the modes of variability of the atmospheric circulation is to look for

Observations indicate that two types of El Niño events exist: one is the EP-El Niño with a warming center in the eastern tropical Pacific, and the other is the CP-El Niño with large positive SST anomalies in the central tropical Pacific. Most current numerical models are not able to accurately identify the different types of El Niño. The present study examines the dynamic properties of the ENSO forecast

Extreme rainfall over Southwestern United States/Northwestern Mexico (SWUNWM) has been mostly investigated during wet seasons, while no or little attention has been paid to extreme rainfall during dry seasons despite its vital importance for sustaining vegetation and ecosystems. Here we examine the top 1% rainfall over SWUNWM in June, the driest month on average, and assess how it is affected by the

Sea surface temperature (SST) biases in the tropical Atlantic are a long-standing problem among coupled global climate models (CGCMs). They occur in equilibrated state, as well as in initialised seasonal to decadal simulations. The bias is typically characterised by too high SST in upwelling regions and associated errors of wind and precipitation. We examine the SST bias in the state-of-the-art CGCM

Understanding the spatial–temporal evolution of China haze pollution (HP) and identifying its precursory signals is of central importance. Based on observational data across central-eastern China (CEC) for the period of 1980–2015, this study finds that HP interannual variations in the CEC region during the most polluted season (December–January) are mainly dominated by a homogeneous pattern with maximum

Using the JRA-55 reanalysis datasets and radiosonde observations, the impact of the quasi-biennial oscillation (QBO) on the downward extension of stratospheric Northern Annular Mode (NAM) signals in its positive and negative phases (positive and negative NAM hereafter) is examined. The results show that the average number of days per month on which stratospheric negative NAM signals extend downward

The spatio-temporal characteristics and driving mechanisms of the Asian summer monsoon (ASM) during the early and middle Holocene remain unclear. Moreover, the timing of maximum monsoon precipitation in the Asian monsoon margin of northwest China during this period is also a subject of considerable debate. Herein, we analyzed phytolith assemblages within 55 calcareous root tube (CRT) samples from the

Based on the daily ERA-Interim reanalysis, interactions between the winter North Pacific storm track (WNPST) and the East Asian trough (EAT) on the interannual scale are further explored from the perspective of energy conversion and the simplified quasi-geostrophic potential vorticity equation. There is a prominent out-of-phase relationship between the EAT and WNPST on the interannual scale. It is

High-resolution hydroclimate proxy records are essential for distinguishing natural hydroclimate variability from possible anthropogenically-forced changes, since instrumental precipitation observations are too short to represent the whole spectrum of natural variability. In Northern Europe, progress in this field has been hampered by a relative lack of long and truly moisture-sensitive proxy records

To understand the effect of the time step on the physics–dynamics interaction in a model, we used an idealized tropical cyclone test to evaluate the sensitivities to the physics time step in the Community Atmosphere Model Version 5 (CAM5). The investigated time steps were 450, 900 and 1800 s at a resolution of 1°, and 225, 450, 900 and 1800 s at a resolution of 0.25° in the corresponding ensemble simulations

Annual precipitation over Central America and large areas of Mexico is typically characterised by its bimodal distribution, with a precipitation minimum in July to August that occurs between two separate maxima from May to July and August to October. Several theories have been proposed to explain this phenomenon, which is often termed the mid-summer drought (MSD), but most fail to address the different

The anticyclonic high-pressure systems over the southern-hemisphere, subtropical oceans have a significant influence on regional climate. Previous studies of how these subtropical anticyclones will change under global warming have focused on austral summer while the winter season has remained largely uninvestigated, together with the extent to which the dominant mechanisms proposed to explain the multi-model-mean

Onset and demise of the Indian summer monsoon (ISM) and intraseasonal variability (ISV) embedded within the ISM are dominant climatological phenomena observed over the Indian region. In this study, a quantitative relationship between these two phenomena is assessed and the performance of a regional coupled model in simulating the relationship in the ISM is examined. An objective definition of the local

As evidence of climate change strengthens, knowledge of its regional implications becomes an urgent need for decision making. Current understanding of regional precipitation changes is substantially limited by our understanding of the atmospheric circulation response to climate change, which to a high degree remains uncertain. This uncertainty is reflected in the wide spread in atmospheric circulation

North Africa experienced a severe heatwave in April 2010 with daily maximum temperatures (\(T_{max}\)) frequently exceeding \(40\,^{\circ }\mathrm{C}\) and daily minimum temperatures (\(T_{min}\)) over \(27\,^{\circ }\mathrm{C}\) for more than five consecutive days in extended Saharan and Sahelian areas. Observations show that areas and periods affected by the heatwave correspond to strong positive

Observations over the last 40 years show that the Atlantic Ocean salinity pattern has amplified, likely in response to changes in the atmospheric branch of the global water cycle. Observational estimates of oceanic meridional freshwater transport (FWT) at 26.5° N indicate a large increase over the last few decades, during an apparent decrease in the Atlantic Meridional Overturning Circulation (AMOC)

The Earth’s planetary albedo (PA) has an essential impact on the global radiation budget. Based on 14 years of monthly data from the Clouds and the Earth’s Radiant Energy System energy balanced and filled (CERES-EBAF) Ed4.1 dataset and atmosphere-only simulations of the Coupled Model Intercomparison Project Phase6 (CMIP6/AMIP), this study investigates the ability of CMIP6/AMIP model in reproducing

Abundant mixed-phase clouds exist over the Arctic and the Tibetan Plateau. Salient differences in their seasonal cycle and in their vertical structure and cloud radiative effects (CREs, which includes shortwave CRE, longwave CRE and net CRE) imply different influences on the climate system. The maximum incidence of mixed-phase clouds appears during the late spring and early winter over the Arctic Ocean

This study derived twelve Extreme Rainfall Indices (ERIs) such as the Maximum Dry Spell (MDS) and Maximum Wet Spell (MWS) from daily rainfall observed over the period 1961–1990 at nine locations across East Africa. Capacity of six CO-ordinated Regional Climate Downscaling EXperiment (CORDEX) Africa Regional Climate Models (RCMs) driven by twenty six Climate Model Intercomparison Project phase 5 (CMIP5)

Understanding the impact of various climate features on wave climate is important for effective coastal climate adaptation and mitigation strategy planning. In the present study, the effect of tropical and extra-tropical climate modes such as Indian Ocean Dipole (IOD), El Niño Southern Oscillation (ENSO) and Southern Annular Mode (SAM) on wind-wave climate of the Indian Ocean (IO) is studied using

Ningaloo Niño/Niña is the dominant mode of interannual variability of sea surface temperature (SST) in the southeastern Indian Ocean. According to previous studies, both local air-sea interaction and remote forcing contribute to generation and amplification of the Ningaloo Niño/Niña. The latter forcing includes the atmospheric teleconnection and oceanic wave propagation through the Indonesian archipelago

In this study, the forecast quality of 1993–2014 summer seasonal predictions of five global coupled models, of which three are operational seasonal forecasting systems contributing to the Copernicus Climate Change Service (C3S), is assessed for Arctic sea ice. Beyond the Pan-Arctic sea ice concentration and extent deterministic re-forecast assessments, we use sea ice edge error metrics such as the

South Asian outflow over the adjoining marine regions is most pronounced during winter season, whereas the prevalence of strong winds aloft can transport the influences from inter-continental sources. Here, we investigate the tropospheric carbon monoxide (CO) distribution over the northern Indian Ocean (IO) combining shipborne measurements carried out during the Integrated Campaign for Aerosols, gases

The leading pattern of boreal spring 250-hPa meridional wind anomalies over the North Atlantic and mid-high latitude Eurasia displays an obvious wave train. The present study documents the structure, energy source, relation to the North Atlantic sea surface temperature (SST), and impacts on Eurasian climate of this wave train during 1948–2018. This atmospheric wave train has a barotropic vertical structure

We investigate the global distribution of hourly precipitation and its connections with the El Niño–Southern Oscillation (ENSO) using both satellite precipitation estimates and the global sub-daily rainfall gauge dataset. Despite limited moisture availability over continental surfaces, we find that the highest mean and extreme hourly precipitation intensity (HPI) values are mainly located over continents

Stratospheric water vapour (SWV), as a greenhouse gas, modulates the radiative energy budget of the climate system. It is sensitive to, and plays a significant role in the climate change. In this study, we investigate the SWV response to CO2 increase with the Whole Atmosphere Community Climate Model (WACCM). In addition, we study its possible feedback on stratospheric temperature and relevant mechanisms

This study evaluated the performance of 25 earth system models (ESMs), statistically and dynamically downscaled to a high horizontal resolution (0.25° of latitude/longitude), in simulating extreme climate indices of temperature and precipitation for 1980–2005. Datasets analyzed include 21 statistically downscaled ESMs from the National Aeronautics and Space Administration (NASA) Earth Exchange Global

Column-integrated moist static energy (MSE) budgets associated with the northward-propagating boreal summer intraseasonal oscillation (BSISO) are diagnosed for the Bay of Bangel (BoB) and western North Pacific (WNP) regions. While an active BSISO convection is in phase with a positive column-integrated MSE perturbation, the MSE tendency exhibits a marked north–south asymmetry about the convection,

Precipitation is one of the major challenges in climate modeling. Among various factors, the large-scale atmospheric circulation plays an important role in modulating regional precipitation through dynamic processes that has been widely discussed in previous studies. However, few efforts have been made to investigate the relationship of model abilities to simulate precipitation and vector winds. Such

High-frequency interactions between the ocean and atmosphere have the potential to affect lower frequency or mean state climate in various regions. Here we examine the importance of sub-daily air-sea interactions over the Maritime Continent region to the rectification of longer timescale variation. In order to determine the importance of these high-frequency interactions, we conducted two regional

Climate models tend to underestimate rainfall intensity while producing more frequent light events, leading to significant bias in extreme precipitation simulation. To reduce this bias and better understand its underlying causes, we tested an ensemble of 25 physics configurations in the regional Climate-Weather Research and Forecasting model (CWRF). All configurations were driven by the ECMWF-Interim

Three sub-regions of the Indian Ocean in which SSTs significantly influence the equatorial East African short rains on interannual timescales are identified, and the physical processes of this influence are studied using regional climate model simulations from the Weather Research and Forecasting model (WRF). Five 20-year ensemble integrations are generated to represent a control climate and to simulate

The El Niño-Southern Oscillation (ENSO) drives substantial variability in precipitation and drought risk over Australia. Understanding the combined effect of anthropogenic forcing and ENSO on Australian precipitation extremes over the coming century can assist adaptation efforts. Here we use 24 CMIP5 climate models to examine externally forced changes in the frequency of “droughts”, when precipitation

Coarse resolution global climate models (GCMs) cannot resolve fine-scale drivers of regional climate, which is the scale where climate adaptation decisions are made. Regional climate models (RCMs) generate high-resolution projections by dynamically downscaling GCM outputs. However, evidence of where and when downscaling provides new information about both the current climate (added value, AV) and projected

The study examines the influence of external climate forcings, and atmosphere–ocean–sea–ice coupled interaction on the Southern Hemisphere (SH) atmospheric circulation variability. We analysed observed and simulated changes in view of Antarctic sea–ice and Southern Ocean surface temperature trends over recent decades. The experiment embraces both idealised and comprehensive methods that involves an

Freshwater flux (FWF) at the sea surface, defined as precipitation minus evaporation, is a major atmospheric forcing to the ocean that affects sea surface salinity (SSS) and buoyancy flux (QB). Physically, there exist two pathways through which interannual FWF variability can affect the ocean: one through SSS and the other through QB. The roles of the interannual FWF variability in modulating the El

The North American Regional Climate Change Assessment Program (NARCCAP) represents the next step in investigating the behavior of weather phenomena in current and future climate. Specifically, variations in mid-latitude cyclone tracks attributable to a warming climate have potential socio-economic consequences via the redistribution of precipitation on regional spatial scales. This manuscript assesses

Despite the efforts of the modelling community to improve the representation of the sea surface temperature (SST) over the South Eastern Tropical Atlantic, warm biases still persist. In this work we use four different configurations of the fully-coupled AWI Climate Model (AWI-CM) which allow us to gain physics-based insight into the role of the oceanic and atmospheric resolutions of the model in the

This study compares the impacts of the El Niño–Southern Oscillation (ENSO) on sea surface temperatures (SSTs) in the tropical North Atlantic Ocean and the tropical Indian Ocean during 1958–2004. It is found that the tropical atmospheric processes mediating the ENSO impacts are different between the two oceans for two reasons. First, the ENSO-induced anomalous Walker circulation is more extensive over

Analyses of in situ and reanalysis output are performed to examine linkages between surface sensible heat fluxes over the central and eastern Tibetan Plateau (CETP) and indices of the East Asian winter monsoon (EAWM) and wintertime near-surface air temperatures over China. The results demonstrate that the sensible heat fluxes over CETP exhibit substantial decadal variability with positive, negative

Seasonal cycle of China summer precipitation has significant impacts on its subseasonal predictability; yet current understanding of seasonal evolution of the intraseasonal variability (ISV) remains limited. Here, we show that the ISV of China summer precipitation features a distinct three-stage evolution during early summer, Meiyu season, and late summer. There are two common leading ISV modes: a