Jürg Luterbacher

World Meteorological Organization | WMO · Science and Innovation Department

This study compares gridded European seasonal series of surface air temperature (SAT) and precipitation (PRE) reconstructions with a regional climate simulation over the period 1500–1990. The area is analysed separately for nine subareas that represent the majority of the climate diversity in the European sector. In their spatial structure, an over...

Asian drylands encompass Arid Central Asia (ACA) and West Asia (WA), where water vapor transport is consistently governed by the westerlies. Recent research has identified a dipole pattern in Holocene hydroclimate changes between the ACA and WA, challenging previous assumptions of uniform hydroclimate shifts across the westerlies-dominated mid-lati...

Heatwaves (HWs) are extreme atmospheric events that produce significant societal and environmental impacts. Predicting these extreme events remains challenging, as their complex interactions with large-scale atmospheric and climatic variables are difficult to capture with traditional statistical and dynamical models. This work presents a general me...

The emergence of exascale computing and artificial intelligence offer tremendous potential to significantly advance earth system prediction capabilities. However, enormous challenges must be overcome to adapt models and prediction systems to use these new technologies effectively. A recent WMO report on exascale computing recommends “ urgency in de...

To manage Earth in the Anthropocene, new tools, new institutions, and new forms of international cooperation will be required. Earth Virtualization Engines is proposed as an international federation of centers of excellence to empower all people to respond to the immense and urgent challenges posed by climate change.

The year 2023 was characterized by record-breaking global surface air and sea surface temperatures (SSTs), the latter reaching a record 21° C in April (excluding the polar regions; Copernicus 2023). As June to October were the warmest on record globally (WMO 2023), extreme and long-lasting marine heatwave (MHW) events were observed, especially in t...

Tim Newfield (Georgetown University, USA) and co-authors provide a detailed analysis and review of current academic knowledge on the First Pandemic - the Justinianic Plague including palaeoclimatic and palaeoecological (pollen analysis) considerations.

The rescue, digitization, quality control, preservation, and utilization of long and high quality meteorological and climate records, particularly related to historical marine data, are crucial for advancing our understanding of the Earth’s climate system. In combination with land and air measurements, historical marine records serve as foundationa...

The rescue, digitisation, quality control, preservation and utilization of long and high quality meteorological and climate records, particularly related to historical marine data, are crucial for advancing our understanding of the Earth's climate system. In combination with land and air measurements, the historical marine records serve as foundati...

To manage Earth in the Anthropocene, new tools, new institutions, and new forms of international cooperation will be required. Earth Virtualization Engines are proposed as international federation of centers of excellence to empower all people to respond to the immense and urgent challenges posed by climate change.

Earth observations (EO) have successfully been used to train artificial intelligence (AI)-based models in the field of disaster risk reduction (DRR) contributing to tools such as disaster early warning systems. Given the number of in situ and remote (e.g., radiosonde/satellite) monitoring devices, there is a common perception that there are no limi...

Earth system modeling and prediction stands at a crossroads. Exascale computing and artificial intelligence offer powerful new capabilities to advance earth system predictions. However, models, assimilation and data processing systems are increasingly unable to exploit these new technologies due to scientific, software, and computational limitation...

The European continent is regularly affected by a wide range of extreme events and natural hazards including heatwaves, extreme precipitation, droughts, cold spells, windstorms, and storm surges. Many of these events do not occur as single extreme events, but rather show a multivariate character, the so-called compound events. Within the scope of t...

Seasonal differences of temperature are crucial components of the Earth’s climate system. However, the relatively short observational record, especially for East Asia, has limited progress in understanding seasonal differences. In this study, we identify ten tree-ring chronologies separately correlated with local winter (December–February) temperat...

The current drought conditions across the Parana-La Plata Basin (LPB) in Brazil-Argentina have been the worst since 1944. While this area is characterized by a rainy season with a peak from October to April, the hydrological year 2020-2021 was very deficient in rainfall, and the situation extended into the 2021-2022 hydrological year. Below-normal...

Résumé Avec l’efflorescence des approches paléoscientifiques du passé, les historiens ont été confrontés à une multitude de nouveaux indices sur des phénomènes tant humains que naturels, des maladies aux migrations en passant par les transformations du paysage et le climat. Ces données inédites exigent une réécriture des récits portant sur les péri...

Increasing atmospheric CO2 enhances plant biomass production and may thereby change nutrient concentrations in plant tissues. The objective of this study was to identify the effect of elevated atmospheric CO2 concentrations on nutrient concentrations of grassland biomass that have been grown for 16 years (1998–2013). The grassland biomass grown at...

The World Meteorological Organization (WMO) supports the National Meteorological and Hydrological Services in their mission to deliver operational hydrology services for achieving water security and the water-dependent/water-related Sustainable Development Goals. Operational hydrology is defined as "the real time and regular measurement, collection...

Accurate representation of the Atlantic-Mediterranean exchange in climate models is important for a reliable simulation of the North Atlantic ocean circulation. We evaluate the performance of ten global climate models in representing Mediterranean Overflow Water (MOW) over the recent period 1986 to 2005 by using various performance metrics. The met...

The COVID-19 pandemic has brought dynamics of compound hazards and risk-response feedbacks to the fore of hydrometeorological hazard preparedness and response. For example, lockdowns implemented to slow the hazard of COVID-19 transmission have the potential unintended side effect of isolating or demobilizing people in the face of an incoming compou...

Una sequía extrema y persistente que comenzó en 2019 todavía hoy sigue afectando a la Cuenca del Plata, la segunda cuenca hidrográfica más grande de Sudamérica y la quinta del mundo. En el presente informe se ofrece una visión general del episodio, su contexto climatológico, su evolución espaciotemporal, sus causas y características y sus impactos...

Uma seca persistente e extrema iniciada em 2019 está ainda em curso e tem vindo a afetar a bacia de La Plata, a segunda maior bacia hidrográfica da América do Sul e a quinta maior do mundo. Apresentamos aqui uma panorâmica do evento, do seu contexto climatológico, da sua evolução espaciotemporal, das suas causas e características, bem como dos seus...

Main modes of atmospheric variability exert a significant influence on weather and climate at local and regional scales on all time scales. However, their past changes and variability over the instrumental record are not well constrained due to limited availability of observations, particularly over the oceans. Here we couple a reconstruction metho...

As climate change accelerates, societies and climate sensitive socioeconomic sectors cannot continue to rely on the past as a guide to possible future climate hazards. Operational decadal predictions offer the potential to inform current adaptation and increase resilience by filling the important gap between seasonal forecasts and climate projectio...

El Niño–Southern Oscillation (ENSO) and the Indian summer monsoon (ISM) are the dominant modes of climate variability affecting the tropical and subtropical regions. In this study, we investigate the impact of ENSO episodes, through the modulation of the ISM configuration, on the Eastern Mediterranean (EMed) summer atmospheric circulation over the...

The question of how sensitive the regional and local climates are to different land cover maps and fractions is important, as land cover affects the atmospheric circulation via its influence on heat, moisture, and momentum transfer, as well as the chemical composition of the atmosphere. In this study, we used three independent land cover data sets,...

Until now, proxy records have been the primary tool for quantitative reconstructions of the physical world of the ancient and late antique Mediterranean. This chapter demonstrates the combined use of proxy datasets and the hitherto underutilized potential of earth system models in the scientific and historical study of past environmental variations...

Tree-ring width is one of the most widely used proxy in paleoclimatological studies. Due to various environmental and biological processes, however, the associated reconstructions often suffer from overestimated low-frequency variability. In this study, a new correction approach is proposed using fractional integral techniques that corrects for the...

A persistent and extreme drought started in 2019 is still ongoing and has been affecting the La Plata Basin, the second largest river basin in South America and the fifth in the world. Here we provide an overview of the event, its climatological background, its spatio-temporal evolution, its causes and characteristics, as well as its impacts on nat...

Background Psychiatric disorders constitute a major public health concern that are associated with substantial health and socioeconomic burden. Psychiatric patients may be more vulnerable to high temperatures, which under current climate change projections will most likely increase the burden of this public health concern. Objective This study inv...

Significance The variability of the Asian summer monsoon (ASM) is important for the functioning of ecological and societal systems at regional to continental scales, but the long-term evolution and interannual variability of this system is not well understood. Here, we present a stable isotope–based reconstruction of ASM variability covering 4680 B...

Data by the International Panel on Climate Change (IPCC) clearly showed that anthropogenic emissions of the three major greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) have increased significantly since the industrial revolution in the mid of the 18th century (IPCC, 2014, Jackson et al., 2020, Peters et al., 202...

The mechanisms of recent Elevation-Dependent Warming (EDW) remain debated because nearly all data sources are limited to past decades and subject to anthropogenic effects. Here, we study how temperature changed along the elevation gradient since the Last Glacial Maximum (LGM) and aim to shed lights on the mechanisms of EDW and implications for the...

Feedbacks of plant phenology to the regional climate system affect fluxes of energy, water, CO2, biogenic volatile organic compounds as well as canopy conductance, surface roughness length, and are influencing the seasonality of albedo. We performed simulations with the regional climate model COSMO-CLM (CCLM) at three locations in Germany covering...

The performance of a new historical reanalysis, the NOAA-CIRES-DOE 20 th Century Reanalysis Version 3 (20CRv3), is evaluated via comparisons with other reanalyses and independent observations. This dataset provides global, 3-hourly estimates of the atmosphere from 1806 to 2015 by assimilating only surface pressure observations and prescribing sea s...

Nearshore upwelling along the eastern North Atlantic margin regulates regional marine ecosystem productivity and thus impacts blue economies. While most global circulation models show an increase in the intensity and duration of seasonal upwelling at high latitudes under future human-induced warmer conditions, projections for the North Atlantic are...

Marine ecosystems: Despite covering only 0.82% of the ocean’s surface, the Mediterranean Sea supports up to 18% of all known marine species, with 21% being listed as vulnerable and 11% as endangered. The accelerated spread of tropical non-indigenous species is leading to the “tropicalization” of Mediterranean fauna and flora as a result of warming...

Early studies of weather, seasonality, and environmental influences on COVID-19 have yielded inconsistent and confusing results. To provide policy-makers and the public with meaningful and actionable environmentally-informed COVID-19 risk estimates, the research community must meet robust methodological and communication standards. When COVID-19 be...

The State of the Climate in Africa report is a multi-agency report involving key international and continental organizations. It provides a snapshot of climate trends, observed high-impact events and associated risks and impacts in key sensitive sectors. The report draws attention to lessons from climate action on the continent, including areas for...

In this paper, we describe the results of a climate data rescue (DARE) activity conducted at the Ukrainian Hydrometeorological Institute (Kyiv, Ukraine) in cooperation with the Justus Liebig University Giessen (Giessen, Germany), the World Meteorological Organization (WMO) and Met Office Hadley Centre (Exeter, United Kingdom). The focus of our work...

The influence that meteorological, climatological and environmental factors had on historical disease outbreaks is often speculated upon, but little investigated. Here, we explore potential associations between pandemic disease and climate over the last 2,500 years in Mediterranean history, focusing on ancient disease outbreaks and the Justinianic...

We simulate the response of Asian summer climate to Atlantic multidecadal oscillation (AMO)-like sea surface temperature (SST) anomalies using an intermediate-complexity general circulation model (IGCM4). Experiments are performed with seven individual AMO SST anomalies obtained from CMIP5/PMIP3 global climate models as well as their multimodel mea...

Background Previous studies suggest that people with mental disorders are more vulnerable to increased ambient temperatures (AT). In Switzerland, neuropsychiatric diseases contribute up to 35.1% of the total burden of disease. This burden could possibly increase in the future under current climate change scenarios, if no appropriate public health m...

Research into global change ecology is motivated by the need to understand the role of humans in changing biotic systems. Mechanistic understanding of ecological responses requires the separation of different climatic parameters and processes that often operate on diverse spatiotemporal scales. Yet most environmental studies do not distinguish the...

Despite the fact that tropospheric temperature inversions are thought to be an important feature of climate as well as a significant factor affecting air quality, low-level cloud formation, and the radiation budget of the Earth, a quantitative assessment of their representation in atmospheric reanalyses is yet missing. Here, we provide new evidence...

Modes of climate variability affect global and regional climates on different spatio-temporal scales, and they have important impacts on human activities and ecosystems. As these modes are a useful tool for simplifying the understanding of the climate system, it is crucial that we gain improved knowledge of their long-term past evolution and intera...

The summertime Eastern Mediterranean experiences among the highest worldwide near-surface ozone values often exceeding the EU air-quality standard for human health protection. Downward transport of stratospheric ozone-rich air masses through tropopause folds has been shown to significantly contribute to these high tropospheric ozone levels. The sum...

This study investigates mechanisms and nonlinearities in the response of the Asian Summer Monsoons (ASM) to high-latitude thermal forcings of different amplitudes. Using a suite of runs carried out with an intermediate-complexity atmospheric general circulation model, we find that the imposed forcings produce a strong precipitation response over th...

Meteorological droughts have large impacts on society and the environment. A better understanding and quantification of their occurrences can be highly relevant for the development of proper climate change mitigation, adaptation and resilience strategies. Here we examine meteorological droughts from observed data covering the 1971–2000 period for t...

The Mediterranean has been identified as particularly vulnerable to climate change, yet a high-resolution temperature reconstruction extending back into the Medieval Warm Period is still lacking. Here we present such a record from a high-elevation site on Mt. Smolikas in northern Greece, where some of Europe’s oldest trees provide evidence of warm...

To place recent hydroclimate changes, including drought occurrences, in a long-term historical context, tree-ring records serve as an important natural archive. Here, we evaluate 46 millennium-long tree-ring based hydroclimate reconstructions for their Data Homogeneity, Sample Replication, Growth Coherence, Chronology Development, and Climate Signa...

A global inventory of early instrumental meteorological measurements is compiled that comprises thousands of mostly nondigitized series, pointing to the potential of weather data rescue.

The Etesians are the dominant synoptically driven winds observed in the Eastern Mediterranean, usually from late spring to late summer. Due to the complex topography, the Etesians can be very strong and pose significant environmental hazards, especially over wildfire incidents. This study assesses the impacts of climate change on future Etesians by...

Large-scale palaeoclimate reconstructions can be very sensitive to the proxy records they are based on, and hence to the criteria used to select proxy records. Data selection rarely follows objective criteria that are applicable to all types of proxies, including both low- and high-resolution records. Thus, there is a need for a uniform and transpa...

Instrumental meteorological measurements from periods prior to the start of national weather services are designated “early instrumental data.” They have played an important role in climate research as they allow daily to decadal variability and changes of temperature, pressure, and precipitation, including extremes, to be addressed. Early instrume...

In the northeast of the Iberian Peninsula, few studies have reconstructed drought occurrence and variability for the pre-instrumental period using documentary evidence and natural proxies. In this study, we compiled a unique dataset of rogation ceremonies – religious acts asking God for rain – from 13 cities in the northeast of Spain and investigat...

The European summer of 1816 has often been referred to as a ‘year without a summer’ due to anomalously cold conditions and unusual wetness, which led to widespread famines and agricultural failures. The cause has often been assumed to be the eruption of Mount Tambora in April 1815, however this link has not, until now, been proven. Here we apply st...

Historical reanalyses that span more than a century are needed for a wide range of studies, from understanding large‐scale climate trends to diagnosing the impacts of individual historical extreme weather events. The Twentieth Century Reanalysis (20CR) Project is an effort to fill this need. It is supported by the National Oceanic and Atmospheric A...

Provisioning services from grassland ecosystems are strongly linked to physical and chemical grassland traits, which are affected by atmospheric CO2 concentrations ([CO2]s). The influences of increased [CO2]s ([eCO2]s) are typically investigated in Free Air Carbon dioxide Enrichment (FACE) studies via destructive sampling methods. This traditional...

The long-term relationship between temperature and hydroclimate has remained uncertain due to the short length of instrumental measurements and inconsistent results from climate model simulations. This lack of understanding is particularly critical with regard to projected drought and flood risks. Here we assess warm-season co-variability patterns...