Annalisa Cherchi

National Institute of Geophysics and Volcanology | INGV

Mediterranean climate‐type regions (MCRs) are characterised by warm‐to‐hot dry summers and mild‐wet winters. These regions are typically found on the western or southern edges of continents, for example, in the Mediterranean Basin, the west coast of North and South America, southern Africa and southwest Australia. The MCRs are vulnerable to climate...

Change over recent decades in the world's five Mediterranean Climate Regions (MCRs) of quantities of relevance to water resources, ecosystems and fire are examined for all seasons and placed in the context of changes in large-scale cir- culation. Near-term future projections are also presented. It is concluded that, based upon agreement between obs...

Change over recent decades in the world's five Mediterranean Climate Regions (MCRs) of quantities of relevance to water resources, ecosystems and fire are examined for all seasons and placed in the context of changes in large‐scale circulation. Near‐term future projections are also presented. It is concluded that, based upon agreement between obser...

The observed winter Barents-Kara Sea ice concentration (BKS SIC) has shown a close association with the second empirical orthogonal function (EOF) mode of Eurasian winter surface air temperature (SAT) variability, known as Warm Arctic Cold Eurasia (WACE) pattern. However, the potential role of BKS SIC on this WACE pattern of variability and on its...

The main drivers of the continental Northern Hemisphere snow cover are investigated in the 1979–2014 period. Four observational datasets are used as are two large multi-model ensembles of atmosphere-only simulations with prescribed sea surface temperature (SST) and sea ice concentration (SIC). A first ensemble uses observed interannually varying SS...

The observed winter Barents-Kara Sea ice concentration (BKS SIC) has shown a close association with the second empirical orthogonal function (EOF) mode of Eurasian winter surface air temperature (SAT) variability, known as Warm Arctic Cold Eurasia (WACE) pattern. However, the potential role of BKS SIC on this WACE pattern of variability and on its...

For the first time in the latest Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), water has been the focus of dedicated chapters in both Working Group 1 (Chapter 8) and 2 (Chapter 4). Nevertheless, we argue here that water has not yet received the full attention it deserves from both scientists and policymakers for several...

The role of surface ocean anomalies for the continental Northern Hemisphere snow cover is investigated, together with the interactions between snow cover and atmosphere. Four observational datasets and two large multi-model ensembles of atmosphere-only simulations are used, with prescribed sea surface temperature (SST) and sea ice concentration (SI...

The El Niño Southern Oscillation (ENSO) is one of the most prominent modes of coupled variability with sizable impacts on global climate and weather patterns, which makes the ability to predict the occurrence and development of ENSO events of fundamental importance. In order to achieve accurate and timely predictions, a well-established strategy is...

This chapter assesses multiple lines of evidence to evaluate past, present and future changes in the global water cycle. It complements material in Chapters 2, 3, and 4 on observed and projected changes in the water cycle, and Chapters 10 and 11 on regional climate change and extreme events. The assessment includes the physical basis for water cycl...

This Annex describes the fundamental features of the main modes of large-scale climate variability assessed across chapters in the AR6 WGI report. Modes are defined as recurrent space-time structures of variability of the climate system with intrinsic spatial patterns, seasonality and timescales. They can arise through the dynamical characteristics...

A monsoon refers to a seasonal transition of regimes in atmospheric circulation and precipitation in response to the annual cycle of solar insolation and the distribution of moist static energy (Wang and Ding, 2008; Wang et al., 2014; Biasutti et al., 2018). A global monsoon can be objectively identified based on precipitation contrasts in the sols...

The Working Group I (WGI) contribution to the Intergovernmental Panel on Climate Change Sixth Assessment Report (AR6) assess the physical science basis of climate change. As part of that contribution, this Technical Summary (TS) is designed to bridge between the comprehensive assessment of the WGI Chapters and its Summary for Policymakers (SPM). It...

The positive Indian Ocean Dipole (IOD) event in 2019 was among the strongest on record, while the Indian Summer monsoon (ISM) was anomalously dry in June then very wet by September. We investigated the relationships between the IOD, Pacific sea surface temperature (SST) and ISM rainfall during 2019 with an atmospheric general circulation model forc...

Globally, thermodynamics explains an increase in atmospheric water vapor with warming of around 7%/°C near to the surface. In contrast, global precipitation and evaporation are constrained by the Earth's energy balance to increase at ∼2–3%/°C. However, this rate of increase is suppressed by rapid atmospheric adjustments in response to greenhouse ga...

This study analyzes future climate for the Mediterranean region projected with the high-resolution coupled CM2.5 model, which incorporates a new and improved land model (LM3). The simulated climate changes suggest pronounced warming and drying over most of the region. However, the changes are distinctly smaller than those of the CMIP5 multi-model e...

Significance Much work has been done to quantify tropical cyclone (TC)-induced precipitation and its role in determining flood events. We identify the role of tropical cyclones in reducing precipitation over particular areas of the tropical domain. The significant reduction in the precipitation over the Maritime Continent when the TC season is part...

Plain Language Summary Changing Arctic sea ice conditions since the late 1970s have exerted profound impacts on environment and ecosystem at the high latitudes and have been suggested to affect midlatitude weather and climate, although this topic has been controversial. In order to improve our understanding on how Arctic sea ice changes influence l...

We present an analysis of annual and seasonal mean characteristics of the Indian Ocean circulation and water masses from 16 global ocean–sea-ice model simulations that follow the Coordinated Ocean-ice Reference Experiments (CORE) interannual protocol (CORE-II). All simulations show a similar large-scale tropical current system, but with differences...

In recent years, the tropical Indian Ocean has experienced persistent warming larger than any other basin. Now research suggests that this may exert a stabilizing effect on the meridional overturning circulation in the north Atlantic Ocean by attenuating its recent weakening, with implications for climate change worldwide.

Euro-Mediterranean Centre on Climate Change coupled climate model (CMCC-CM2) represents the new family of the global coupled climate models developed and used at CMCC. It is based on the atmospheric, land and sea ice components from the Community Earth System Model coupled with the global ocean model Nucleus for European Modeling of the Ocean. This...

The realistic simulation of the summer Mediterranean climate requires not only refined spatial scales, but also an adequate representation of land-atmosphere interactions and teleconnections. Addressing all of these issues remains a challenge for most of the CMIP3/CMIP5 generation models. In this study we analyze high-resolution (~0.5° lat x lon) R...

Oceanic reanalyses are powerful products to reconstruct the historical 3D-state of the ocean and related circulation. At present a challenge is to have oceanic reanalyses covering the whole 20th century. This study describes the exercise of comparing available datasets to force Mediterranean Sea and global oceanic reanalyses from 1901 to present. I...

Purpose of Review Subtropical highs are an important component of the climate system with clear implications on the local climate regimes of the subtropical regions. In a climate change perspective, understanding and predicting subtropical highs and related climate is crucial to local societies for climate mitigation and adaptation strategies. We r...

The warming of the Indian Ocean (IO) of the last decades has evinced interest among the research community due to its important role in driving the global climate variability. The enhanced warming of the tropical IO due to climate change has caused a significant shift in the heat budget of the climate system. Here we investigate the differences in...

An ensemble of AMIP-type experiments with prescribed interannual varying sea surface temperature (SST) and different initial conditions is used to study the relationship between Indian summer monsoon extreme conditions and the El Nino Southern Oscillation (ENSO). Based on the selection of extreme monsoon rainfall years ‘In Phase’ or ‘Out of Phase’...

Description of development and improvement of continental biogeochemical processes within the CMCC-ESM2

The recent Indian Ocean (IO) warming and its relation with the El Niño Southern Oscillation (ENSO) is investigated using available ocean and atmospheric reanalyses. By comparing the events before and after 1976 (identified as a threshold separating earlier and recent decades with respect to global warming trends), our results indicate that the IO h...

Southern Europe (Italy and the surrounding countries) experienced an unusual wet summer in 2014. The monthly rainfall in July 2014 was 84% above (more than three standard deviation) normal with respect to the 1982–2013 July climatology. The heavy rainfall damaged agriculture, and affected tourism and overall economy of the region. In this study, we...

The term “monsoon-desert mechanism” indicates the relationship between the diabatic heating associated with the South Asian summer monsoon rainfall and the remote response in the western sub-tropics where long Rossby waves anchor strong descent with high subsidence. In CMIP5 twenty-first century climate scenarios, the precipitation over South Asia...

This study investigates the climate sensitivity to a strong CO2 atmospheric forcing focusing on the North Atlantic Ocean (NA). The analysis is based on a set of 600 years long experiments performed with a state-of-the-art coupled general circulation model (CGCM) with the 1990 reference value of atmospheric CO2 multiplied by 4, 8 and 16. Extreme inc...

Extreme climate events over the La Plata basin (LPB) can produce significant impacts due to the importance of its agriculture and hydroelectric power production for the local economy. Progresses on describing, projecting and understanding extremes in LPB, in the framework of the CLARIS-LPB Europe-South America Network for Climate Change Assessment...

A coupled aerosol-atmosphere–ocean-sea ice climate model is used to explore the interaction between aerosols and the Indian summer monsoon precipitation on seasonal-to-interannual time scales. Results show that when increased aerosol loading is found on the Himalayas slopes in the pre-monsoon period (April-May), intensification of early monsoon rai...

This work explores the impact of the development of global meridional and zonal SST gradients on the Mediterranean runoff variability during the Plio-Pleistocene transition, about 3 Ma. Results show that total annual mean Pliocene Mediterranean runoff is about 40% larger than during the pre-industrial period due to more increased extra-tropical spe...

The Indo-Pacific Ocean (i.e. region between 30°E and 150°E) has been experiencing a warming since the 1950s. At the same time, the large-scale summer monsoon rainfall over India and the moisture over the East Africa/Arabian Sea are both decreasing. In this study, we intend to investigate how the decrease of moisture over the East Africa/Arabian Sea...

Monthly and daily precipitation extremes over La Plata Basin (LPB) are analyzed in the framework of the CLARIS-LPB Project. A review of the studies developed during the project and results of additional research are presented and discussed. Specific aspects of analysis are focused on large-scale versus local processes impacts on the intensity and f...

This work explores the impact of orbital parameters and greenhouse gas concentrations on the climate of marine isotope stage (MIS) 7 glacial inception and compares it to that of MIS 5. The authors use a coupled atmosphere–ocean general circulation model to simulate the mean climate state of six time slices at 115, 122, 125, 229, 236, and 239 kyr, r...

Ensembles of retrospective 2-months dynamical forecasts initiated May 1st are used to predict the onset of the Indian Summer Monsoon (ISM) for the period 1989-2005. The Sub-Seasonal Predictions (SSPs) are based on a Coupled General Circulation Model and recently they have been upgraded by the realistic initialization of the atmosphere with initial...

The warm-temperate regions of the globe characterized by dry summers and wet winters (Mediterranean climate; MED) are especially vulnerable to climate change. The potential impact on water resources, ecosystems and human livelihood requires a detailed picture of the future changes in this unique climate zone. Here we apply a probabilistic approach...

Dry summers over the eastern Mediterranean are characterized by strong descent anchored by long Rossby waves, which are forced by diabatic heating associated with summer monsoon rainfall over South Asia. The large-scale teleconnection between rising and subsiding air masses is referred to as the “monsoon–desert mechanism.” This study evaluates the...

The present manuscript compares Marine Isotope Stage 5 (MIS 5, 125–115 kyr BP) and MIS 7 (236–229 kyr BP) with the aim to investigate the origin of the difference in ice-sheet growth over the Northern Hemisphere high latitudes between these last two inceptions. Our approach combines a low resolution coupled atmosphere–ocean–sea-ice general circulat...

An ensemble of nine experiments with the same interannually varying sea surface temperature (SST), as boundary forcing, and different initial conditions is used to investigate the role of tropical oceans in modulating precipitation variability in the region of La Plata Basin (LPB). The results from the ensemble are compared with a twentieth-century...

The Mediterranean climate is a major climate type of the Köppen classification that is characterized by hot, dry summers and cool, wet winters and located between about 30° and 45° latitude on the western sides of the continents (Koppen, 1900; Lionello 2012). By applying the latest development of the Koppen-Geiger classification scheme, we assessed...

The present manuscript compares the last two glacial inceptions, Marine Isotope Stage 5 (MIS5, 125-115 kyr BP) and MIS7 (236-229 kyr BP) with the aim to detect the relative impact of external forcing (orbitals and GHG) and ice-albedo feedbacks on the ice sheets growth and distribution in the Northern Hemisphere high latitudes. In order to investiga...

Global-scale variations in the climate system over the last half of the twentieth century, including long-term increases in global-mean near-surface temperatures, are consistent with concurrent human-induced emissions of radiatively active gases and aerosols. However, such consistency does not preclude the possible influence of other forcing agents...

The connection between Tropical Pacific and North Pacific variability is investigated in a state-of-the-art coupled ocean-atmosphere model, comparing two 20th century simulations at T30 and T106 atmospheric horizontal resolutions. Despite a better simulation of the frequency and the spatial distribution of the Tropical Pacific anomalies associated...

Indian summer monsoon (ISM) variability is forced from external factors (like the El Niño Southern Oscillation, ENSO) but it contains also an internal component that tends to reduce its potential for predictability. Large-scale and local monsoon indices based on precipitation and atmospheric circulation parameters are used as a measure of ISM varia...

During the last glacial cycle, the final volume and extent of the Laurentide ice sheet was larger than over Eurasia. According to ICE-5G multi-proxy and methods reconstruction (Peltier, 2004), the Laurentide (~ 74 m Sea Level Equivalent, SLE hereafter) was ~ 5 times larger than its Eurasian counterpart (~ 17 m SLE. The final eustatic sea level drop...

El Niño-Southern Oscillation (ENSO) is an important air-sea coupled phenomenon that plays a dominant role in the variability of the tropical regions. Observations, atmospheric and oceanic reanalysis datasets are used to classify ENSO and non-ENSO years to investigate the typical features of its periodicity and atmospheric circulation patterns. Amon...

Extreme precipitation (wet or dry) over La Plata Basin (LPB) can cause intense damage in several sectors as agriculture and hydroelectricity, and also has an impact on urban areas due to flooding and landslides. Extreme temperatures (cold incursions or heat waves) have impact on agriculture and health. The frequency and intensity of extremes can va...

Using an atmospheric general circulation model coupled to a slab ocean, the effects of ocean heat transport (OHT) on climate are studied by prescribing OHT from 0 to 2 times the present-day values. In agreement with previous studies, an increase in OHT from zero to present-day conditions warms the climate by decreasing the albedo due to reduced sea...

Increased atmospheric carbon dioxide concentration provided warmer atmospheric temperature and higher atmospheric water vapor content, but not necessarily more precipitation. A set of experiments performed with a state-of-the-art coupled general circulation model forced with increased atmospheric CO2 concentration (2, 4 and 16 times the present-day...

Understanding the historical and future response of the global climate system to anthropogenic emissions of radiatively active atmospheric constituents has become a timely and compelling concern. At present, however, there are uncertainties in: the total radiative forcing associated with changes in the chemical composition of the atmosphere; the ef...

The development of the INGV (Istituto Nazionale di Geofisica e Vulcanologia)-CMCC (Centro Euro-Mediterraneo per i Cambiamenti Climatici) Seasonal Prediction System (SPS) is documented. In this SPS the ocean initial conditions estimation includes a Reduced Order Optimal Interpolation procedure for the assimilation of temperature and salinity profile...

Recent studies have identified a pattern of variability of the Tropical Pacific, which is similar to El Niño Southern Oscillation (ENSO), but characterized by SST anomalies localized over the central Tropical Pacific, closer to the dateline. For this reason this pattern has been named "dateline El Niño", meanwhile the two patterns together have bee...

In this study dynamical seasonal forecasts are used to investigate the predictability of Indian Summer Monsoon (ISM) onset and withdrawal. Nine member ensemble forecasts performed with the latest version of the CMCC-INGV Seasonal Prediction System (SPS) are used. We applied objective large scale methods (both hydrological and circulation indexes) t...

A multi-model set of atmospheric simulations forced by historical sea surface temperature (SST) or SSTs plus Greenhouse gases and aerosol forcing agents for the period of 1950–1999 is studied to identify and understand which components of the Asian–Australian monsoon (A–AM) variability are forced and reproducible. The analysis focuses on the summer...

A coupled general circulation model has been used to perform a set of experiments with high CO2 concentration (2, 4, 16 times the present day mean value). The experiments have been analyzed to study the response of the climate system to strong radiative forcing in terms of the processes involved in the adjustment at the ocean–atmosphere interface....

The Indian summer monsoon (ISM) is one of the main components of the Asian summer monsoon. It is well known that one of the starting mechanisms of a summer monsoon is the thermal contrast between land and ocean and that sea surface temperature (SST) and moisture are crucial factors for its evolution and intensity. The Indian Ocean, therefore, may p...

This work presents a methodology to study the interannual variability associated with summertime months in which extremely hot temperatures are frequent. Daily time series of maximum and minimum temperature fields (T max and T min, respectively) are used to define indexes of extreme months based on the number of days crossing thresholds. An empiric...

A set of experiments forced with observed SST has been performed with the Echam4 atmospheric GCM at three different horizontal resolutions (T30, T42 and T106). These experiments have been used to study the sensitivity of the simulated Asian summer monsoon (ASM) to the horizontal resolution. The ASM is reasonably well simulated by the Echam4 model a...

resolution coupled GCM SINTEX-FRSGC (SINTEX-F1.0: ECHAM4.0/5 AGCM + OPA 8.2 OGCM + OASIS/PRISM Coupler) will be developed under the EU-Japan collaboration. Long model integration will be conducted to understand tropical phenomena IOD and ENSO, and their teleconnections. The coupled model also will be used in an intercomparison study with CFES to un...

The mean evolution of the Asian summer monsoon and its interannual variability have been studied using three simulations (from 1961 to 1994) with the ECHAM4 General Circulation Model (GCM). The results have been compared with observational data and with two reanalyses data sets: the ECMWF Reanalysis (ERA) and the NCEP-NCAR Reanalysis. The South Asi...

Teleconnection patterns, such as the Pacific/North American pattern, are the dominant modes of variability in the Northern Hemisphere winter. The sensitivity to different experiments made with an atmospheric general circulation model and a coupled model are shown. The patterns are sensitive to the horizontal resolution of the model, particularly an...

In the present study a coupled ocean-atmosphere general circulation model (CGCM) experiment is compared with an ensemble of atmospheric GCM simulations forced with observed interannual SSTs (AMIP-type experiments) and with available reanalysis products to describe the connection between El Nino Southern Oscillation (ENSO), the Indian Ocean Dipole (...