J.I. López-Moreno

• Spanish National Research Council

The Greenland Ice Sheet (GrIS) meltwater runoff has increased considerably since the 1990s, leading to implications for the ice sheet mass balance and ecosystem dynamics in ice-free areas. Extreme weather events will likely continue to occur in the coming decades. Therefore, a more thorough understanding of the spatiotemporal patterns of extreme me...

Snowfall is a crucial climate variable in mountainous regions: it influences hydrological and ecosystem dynamics and has a major impact on socioeconomic activities. This study examines the future changes (2024 to 2100) in winter (December, January and February, included) snowfall and extreme snow events in the Pyrenees, using a high-resolution data...

Climate warming is changing the magnitude, timing, and spatial patterns of mountain snowpacks. A warmer atmosphere may also induce precipitation phase shifts, resulting in a decreased snowfall fraction (Sf). The combination of Sf and snowpack directly influences the frequency and intensity of rain-on-snow (ROS) events, a common cause of flash-flood...

The temporal concentration of snowfalls has direct implications on the management of water resources as well as on the economic activity of mountain areas, conditioning, for example, the seasonal performance of ski resorts. This work uses the daily concentration index (CI) for analysing the frequency concentration of snowfalls in the Iberian Penins...

Snow patterns in ice-free areas of Greenland play important roles in ecosystems. Within a changing climate, a comprehensive understanding of the snow responses to climate change is of interest to anticipate forthcoming dynamics in these areas. In this study, we analyze the future snowpack evolution of a polar maritime Arctic location, Qeqertarsuaq...

Europe has experienced severe drought events in recent decades, posing challenges to understand vegetation responses due to diverse vegetation distribution, varying growth stages, different drought characteristics, and concurrent hydroclimatic factors. To analyze vegetation response to meteorological drought, we employed multiple vegetation indicat...

Resumen: En este estudio se analizan los datos de asistencia diaria de es-quiadores en tres estaciones de esquí en el Pirineo aragonés y su relación con la disponibilidad de nieve, las condiciones meteorológicas y el ca-lendario vacacional durante el período 2003-2013. Los resultados mues-tran una gran variabilidad interanual en la duración de la t...

As with other mountain areas in Europe, the subalpine belt of the Central Spanish Pyrenees (approximately 1600–2200 m a.s.l.) has undergone constant deforestation since the Neolithic era and particularly during the Late Middle Ages, in favour of livestock management and grazing in summer. This furthered the rise of transhumance between the lowlands...

A key problem in explaining the mountain landscapes of the Mediterranean region is the relationship between the development of transhumance (seasonal movement of livestock over long distances) and deforestation of the subalpine and upper montane belts at 1350–2200 m above sea level (m a.s.l.). We examined this relationship in the Central Southern P...

Spatial and temporal variability of drought in Oman was assessed for the period 1979–2014 using the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) at both seasonal (3-month) and annual (12-month) timescales. Changes in drought characteristics (e.g. frequency, duration, intensity, severity,...

This study assesses the spatial and temporal characteristics of nighttime surface urban heat island (SUHI) effects over Greater Cairo: the largest metropolitan area in Africa. This study employed nighttime land surface temperature (LST) data at 1 km resolution from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua sensor for the period...

The Sierra Nevada of Santa Marta (12ºN) hosts a unique glaciated environment (6.5 km²) only 40 km distant from the Caribbean Sea. However, the remoteness of the glaciers and restricted access to the region has so far prevented onsite field work research from being undertaken. We worked with several very high resolution airborne and satellite images...

Following the Holocene Thermal Maximum, dated between 11 and 6 ka, the Neoglacial period was one of the progressive, fluctuating cooling that peaked during the Little Ice Age (LIA). The almost total absence of glacial tills prior to the LIA in the Pyrenees forces recourse to a high variety of proxies, including lacustrine sediments, palynological r...

The North Atlantic Oscillation (NAO) is considered to be the main atmospheric factor explaining the winter climate and snow evolution over much of the Northern Hemisphere. However, the absence of long-term snow data in mountain regions has prevented full assessment of the impact of the NAO at the regional scales, where data are limited. In this stu...

Spatial and temporal changes of daily temperature extremes are investigated over Egypt using a standard set of 23 indices. Our analysis uses a database consisting of complete, high quality and homogeneous daily maximum and minimum air temperature records at 40 stations, spanning the period from 1983 to 2015. The trends were assessed using a least s...

This study presents the first comprehensive evaluation of the performance of three globally high‐resolution remotely sensed products in replicating the main characteristics of rainfall over the Middle East, with special emphasis on extreme wet events. Specifically, we employed daily observational data from a network of rain gauges (N = 217), spanni...

Estudios recientes han revelado un descenso significativo de la velocidad del viento (“stilling”) en los últimos 30-50 años. El impacto de la deriva de los anemómetros (desgaste en los rodamientos) en el debilitamiento observado en la velocidad del viento ha sido discutido como una causa parcial de este descenso. Sin embargo, hasta la fecha, ningun...

Estudios recientes han revelado un descenso significativo de la velocidad del viento (“stilling”) en los últimos 30-50 años. El impacto de la deriva de los anemómetros (desgaste en los rodamientos) en el debilitamiento observado en la velocidad del viento ha sido discutido como una causa parcial de este descenso. Sin embargo, hasta la fecha, ningun...

En el marco del proyecto , financiado por el programa POCTEFA (Programa INTERREG V-A España-Francia-Andorra), se realizó una recuperación de datos climáticos históricos de 25 estaciones de alta montaña en el Pirineo por parte de la Delegación Territorial de AEMET en Aragón y la Universidad de Zaragoza. Entre estas estaciones la serie más singular,...

Seasonal and annual extreme precipitation over the Peruvian Andes have been mapped for the first time. Maps were developed using the most complete, quality-controlled and homogenous daily precipitation records in Peru from 1973 to 2016. For each observed rain gauge series, we defined parameters as the de-clustered daily intensity, total precipitati...

Recent studies on observed wind variability have revealed a decline (termed “stilling”) of near-surface wind speed during the last 30–50 years over many mid-latitude terrestrial regions, particularly in the Northern Hemisphere. The well-known impact of cup anemometer drift (i.e., wear on the bearings) on the observed weakening of wind speed has bee...

This study analyses variability and trends of atmospheric evaporative demand (AED) across Uruguay in the past four decades. Changes were assessed using pan evaporation measurements from 10 meteorological stations and compared to PenPan model calculations, which is a physically based model that employs meteorological data as input. Results demonstra...

Abstract: The study of the spatial and temporal variability of snow cover is of great importance because it is key to explaining ecological and human processes in mountain areas. Remote sensing and models data has allowed to obtain information and data of snow cover easily. In this work we conduct a comparative analysis of snow cover estimation ret...

This study assessed changes in the maximum and minimum surface air temperatures across Peru during the period 1964-2014. For this purpose, we employed the most complete records of air temperature series that were also subjected to a rigorous quality control and homogenization protocol. Based on the homogenized series, we created a monthly gridded d...

This study demonstrated the usefulness of very long-range terrestrial laser scanning (TLS) for analysis of the spatial distribution of a snowpack, to distances up to 3000 m, one of the longest measurement range reported to date. Snow depth data were collected using a terrestrial laser scanner during 11 periods of snow accumulation and melting, over...

Abstract: A realistic estimation of how surface temperatures vary with elevation is important for climatic, hydrological and ecosystem studies. A fixed lapse rate of 6.5ºC/1.000 meters is generally assumed for the whole conditions and locations, but surface temperature lapse rates vary in space and time due to wind, relative humidity or local topog...

In this study, we analyzed the influence of El Niño–Southern Oscillation (ENSO) on the spatio-temporal variability of droughts in Ecuador for a 48-year period (1965–2012). Droughts were quantified from 22 high-quality and homogenized time series of precipitation and air temperature by means of the Standardized Precipitation Evapotranspiration Index...

In this study we analyzed the annual and seasonal variability of snowfall events in the Spanish Pyrenees, and the relationship between different weather types and normal (between P30 and P80) and intense (> P80) snowfall events. Data for the hydrological years 2008-2013 were obtained from 10 telenivometers (TNMs) managed by the ERHIN Program networ...

The impact of observed changes in air temperature and precipitation from 1969 to 2013 and climate projections for 2050 and 2080 at Ny-Ålesund, an arctic research station on Spitzbergen Island in the Svalbard Archipelago on snow hydrological processes, were analyzed using snow accumulation and ablation algorithms in the physically based Cold Regions...

This paper analyses the influence of different atmospheric circulation indices on the multi-scalar drought variability across Europe by using the Standardized Precipitation Evapotranspiration Index (SPEI). The monthly circulation indices used in this study include the North Atlantic oscillation (NAO), the East Atlantic (EA), the Scandinavian (SCAN)...

A long-term (1960−2013) assessment of the variability of continentality and aridity conditions over the Middle East and North Africa (MENA) region was undertaken. Monthly gridded temperature and precipitation data from the Climate Research Unit (CRU) (TS3.22 version) were used to compute the Johansson Continentality Index (JCI) and the Marsz Oceani...

Dams modify downstream hydrology because they alter natural river regimes and divert river flows. The Segre Basin is one of the main tributaries of the Ebro River in Northeastern Spain, and has a drainage area of 13,000km2. In this study, we used data on long-term (1951-2013) river flows and climatic series to analyze the downstream cumulative effe...

Here we present an analysis of drought occurrence and variability in Ethiopia, based on the monthly precipitation data from the Climate Research Unit (CRU-v3.22) over the period from 1960 to 2013. The drought events were characterized by means of the Standardized Precipitation Index (SPI) applied to precipitation data at a temporal scale of 12 mont...

A Lagrangian approach was used to identify the moisture sources for fourteen ice-core sites located worldwide for the period 1980–2012. The sites were classified into three domains: Arctic, Central (Andes, Alps and Kilimanjaro), and Antarctic. The approach was used to compute budgets of evaporation minus precipitation by calculating changes in the...

This study detects climate trends and variability from precipitation and temperature observations in Ecuador and assesses their links to the El Niño Southern Oscillation (ENSO) for the period 1966–2011, using the El Niño 1+2 and El Niño 3.4 indices. Excluding the Amazonian region (for which there is a lack of data), two main regions were distinguis...

During the melting of a snowpack, snow water equivalent (SWE) can be correlated to snow-covered area (SCA) once snow-free areas appear, which is when SCA begins to decrease below 100%. This amount of SWE is called the threshold SWE. Daily SWE data from snow telemetry stations were related to SCA derived from moderate-resolution imaging spectroradio...

This paper analyzes the evolution of the Monte Perdido Glacier, the third largest glacier of the Pyrenees, from 1981 to the present. We assessed the evolution of the glacier's surface area by use of aerial photographs from 1981, 1999, and 2006, and changes in ice volume by geodetic methods with digital elevation models (DEMs) generated from topogra...

We review the effects of climate variability and land use / land cover changes in the Central Spanish Pyrenees at different spatial and temporal scales. Paleoclimatic studies based upon multi-proxy analyses of lacustrine, glacial and speleothematic deposits, among others, have demonstrated the occurrence of intense climatic fluctuations not only du...

This work analysed the changes in air temperature in 25 meteorological stations in the Altiplano and the surrounding Andean slopes of Bolivia and Peru, and their relationship with El Niño-Southern Oscillation (SO) and the Pacific Decadal Oscillation (PDO). The analysis focused on annual, warm season (DJF) and cold season (JJA) maximum and minimum t...

Erosion and deposition processes in badland areas are usually estimated using traditional observations of topographic changes, measured by erosion pins or profile meters (invasive techniques). In recent times, geomatic techniques (non-invasive) have been routinely applied in geomorphology studies, especially in erosion studies. These techniques pro...

This study presents monthly and annual climate maps for relevant hydroclimatic variables in Bolivia. We used the most complete network of precipitation and temperature stations available in Bolivia, which passed a careful quality control and temporal homogenization procedure. Monthly average maps at the spatial resolution of 1?km were modeled by me...

Se han simulado los caudales de cinco cabeceras de ríos en los Pirineos centrales españoles, considerando diferentes escenarios de cambio climático y de uso del suelo. Los caudales fueron simulados utilizando el modelo hidroecológico RHESSys (Regional Hydro-Ecologic Simulation System). Los resultados muestran que los cambios proyectados por un conj...

During the last two decades climate studies have reported a tendency toward a decline in measured near-surface wind speed in some regions of Europe, North America, Asia and Australia. This weakening in observed wind speed has been recently termed "global stilling", showing a worldwide average trend of -0.140 m s -1 dec -1 during last 50-years. The...

The Marbore Cirque, which is located in the southern Central Pyrenees on the north face of the Monte Perdido Peak (42 degrees 400N; 0.5 degrees 0W; 3355m), contains a wide variety of Holocene glacial and periglacial deposits, and those from the Little Ice Age' (LIA') are particularly well developed. Based on geomorphological mapping, cosmogenic exp...

In this study we analyzed the spatial distribution, temporal variability and trends in reference evapotranspiration (ET0) in Spain from 1961 to 2011. Twelve methods were analyzed to quantify ET0 from quality controlled and homogeneous series of various meteorological variables measured at 46 meteorological stations. Some of the models used are temp...

In this study, the spatio-temporal variability and trends of droughts across Bolivia between 1955 and 2012 were investigated using two climate drought indices: the Standardized Precipitation Index (SPI), which is based on precipitation data, and the Standardized Precipitation Evapotranspiration Index (SPEI), which is based on the difference between...

In this study we analyzed the relations between terrain characteristics and snow depth distribution in a small alpine catchment located in the central Spanish Pyrenees. Twelve field campaigns were conducted during 2012 and 2013, which were years characterized by very different climatic conditions. Snow depth was measured using a long range terrestr...

The interpretation of stable isotopes in speleothems in terms of past temperature variability or precipitation rates requires a comprehensive understanding of the climatic factors and processes that influence the delta O-18 signal in the way through the atmosphere to the cave, where carbonate precipitates acquiring its final isotopic composition. T...

Near-surface wind speed trends recorded at 67 land-based stations across Spain and Portugal for 1961–2011, also focusing on the 1979–2008 subperiod, were analyzed. Wind speed series were subjected to quality control, reconstruction, and homogenization using a novel procedure that incorporated the fifth-generation Pennsylvania State University–Natio...

We use high quality climate data from ground meteorological stations in the Iberian Peninsula (IP) and robust drought indices to confirm that drought severity has increased in the past five decades, as a consequence of greater atmospheric evaporative demand resulting from temperature rise. Increased drought severity is independent of the model used...

In this study we analyzed the relations between terrain characteristics and snow depth distribution in a small alpine catchment located in the central Spanish Pyrenees. Twelve field campaigns were conducted during 2012 and 2013, which were years characterized by very different climatic conditions. Snow depth was measured using a long range terrestr...

This paper presents the methodology used to develop snow depth distribution maps for a small catchment in the Central Spanish Pyrenees covering 55 ha in a 1:10,000 scale. The Main Map was obtained using LiDAR (light detection and ranging) technology from a long-range Terrestrial Laser Scanner (TLS) in six field surveys undertaken during the 2012 win...

We use high quality climate data from ground meteorological stations in the Iberian Peninsula (IP) and robust drought indices to confirm that drought severity has increased in the past five decades, as a consequence of greater atmospheric evaporative demand resulting from temperature rise. Increased drought severity is independent of the model used...

In this study we assessed the impact of meteorological droughts on streamflow droughts in 187 river basins of the Iberian Peninsula. For each basin we correlated the 1 mo to 48 mo standardized precipitation index (SPI) with the standardized streamflow index to assess the response time of streamflow droughts to the SPI, and to determine the best cli...

This paper evaluates the response of stream flow and other components of the water balance to changes in climate and land-use in a Pyrenean watershed. It further provides a measure of uncertainty in water resources forecasts by comparing the performance of two hydrological models: Soil and Water Assessment Tool (SWAT) and Regional Hydro-Ecological...

The aim of this study was to analyse the effect of slope aspect on the response of snowpack to climate warming in the Pyrenees. For this purpose, data available from five automatic weather stations were used to simulate the energy and mass balance of snowpack, assuming different magnitudes of an idealized climate warming (upward shifting of 1, 2 an...

We analyzed the evolution of surface relative humidity (RH) and specific humidity (q) in Spain, based on complete records available from the State Meteorological Agency of Spain. The surface RH records used span the period 1920–2011, but because of spatial and temporal constraints in the dataset we used a subset of the data, covering the period 196...

This paper presents the application of a long range terrestrial laser scanner for monitoring snow accumulation and evolution of glaciers in the Pyrenees. With this study we are showing the great potential of the methodology presented for studies in mountain environments, particularly in research related to the cryosphere monitoring in relation to c...

Changes on river flow regimes downstream of reservoirs or multireservoir systems located in the Central Pyrenees (between Aragón river and Noguera Pallaresa river) is studied. The reservoir management aims to store water during a part of the year in order to release relatively high flows for agricultural or hydropower purposes. A high variability i...

Se estudia el régimen del embalse de Yesa, en la cuenca alta del río Aragón. El embalse se destina predominantemente a abastecer las áreas de regadío de las Bardenas, entre Navarra y Zaragoza, por lo que la gestión del embalse tiende a conseguir el máximo volumen de agua almacenada durante el mes de mayo, para liberar caudales durante todo el veran...

[EN] This paper deals with the effects of the Yesa reservoir on the intensity and temporal distribution of floods in the Aragón River. The results confirm that the frequency of floods downstream the dam clearly decreased. The reduction mainly depended on two factors: i) the water sto - rage level, and ii) the season of the year. Floods were very we...

An accurate assessment of snow depth and snow density is essential to determine that amount of water stored in the snowpack, i.e., snow water equivalent (SWE). The measurement of snow density is much more difficult and time consuming than snow depth. The variability in snow density is evaluated for a 5.4-km stretch of the Rio Esera headwaters in th...

Snowpack density is one of the most difficult hydroclimatic variables to be monitored in mountain environments. Snow pillows are a commonly used tool for this purpose. Despite they have been widely used in North America, Scandinavia, and several mountains areas, they had not been installed yet in any Spanish mountain system. In 2005, a snow pillow...

In this study, we assess the role of altitude in determining the relative performance of temperature and precipitation as predictors of snowpack variability in Switzerland. The results indicate a linear relationship between altitude and the correlation of temperature (precipitation) with snowpack depth and duration. We identify a threshold altitude...

An exceptional rainfall and hydrological event occurred on 19–21 October 2012 in the central western Pyrenees and was particularly significant in the Upper Aragón River basin and its tributaries, mainly the Irati River. Analysis of historical records showed that, considered separately, the event of 19 and 20 October ranked between the second and fi...

This study analyzes spatial variability of snow depth and density from measurements made in February and April of 2010 and 2011 in three 1–2 km2 areas within a valley of the central Spanish Pyrenees. Snow density was correlated with snow depth and different terrain characteristics. Regression models were used to predict the spatial variability of s...

Few parts of Antarctica are not permanently covered in ice. The retreat of the ice sheet from Byers Peninsula on western Livingston Island, Maritime Antarctica, has provided a new area of seasonal snow cover. Snow surveys were conducted in late November 2008 at the time of peak accumulation across the 1 km2 Lake Limnopolar watershed. Topographic va...

The study examines climate change scenarios of precipitation extremes over the Mediterranean region for the late 21st century (2070-99) in an ensemble of high-resolution regional climate model (RCM) simulations. Precipitation extremes are considered at a wide range of time scales from hourly to multi-day amounts and in individual seasons (DJF, MAM,...

Spatial and temporal variability of the most extreme temperatures during extended winter (November–February, NDJF) and summer (May–August, MJJA) have been analyzed over northeast Spain. This work employed a high-quality daily temperature dataset of 128 station records spanning the period from 1959 to 2006. The upper-most (99th) percentile of daily...

This paper gives the complete details of the protocols applied for developing a spatially and temporarily high-resolution dataset of temperature for northeastern Spain. Our methodologies used data from a large number of observatories (1583) spanning some portions of the period between 1900 and 2006. The raw dataset was first tested for internal and...

We analyzed 19 annual Landsat Thematic Mapper images from 1984 to 2011 to determine changes of the glaciated surface and snow line elevation in six mountain areas of the Cordillera Huaytapallana range in Peru. In contrast to other Peruvian mountains, glacier retreat in these mountains has been poorly documented, even though this is a heavily glacia...

In this study we analyzed the spatiotemporal variability of streamflow droughts in the Iberian Peninsula from 1945 to 2005. Streamflow series belonging to 187 homogeneously distributed gauging stations across the study area were used to develop a standardized streamflow index (SSI), which facilitated comparison among regimes and basins, regardless...

We evaluated the response of the Earth land biomes to drought by correlating a drought index with three global indicators of vegetation activity and growth: vegetation indices from satellite imagery, tree-ring growth series, and Aboveground Net Primary Production (ANPP) records. Arid and humid biomes are both affected by drought, and we suggest tha...

The study examines climate change scenarios of precipitation extremes over the western, central and part of the eastern Mediterranean region for the late 21st century (2070–99) in an ensemble of high-resolution regional climate model (RCM) simulations from the ENSEMBLES project. Precipitation extremes are considered at a wide range of time scales f...

In this study, the authors provide a global assessment of the performance of different drought indices for monitoring drought impacts on several hydrological, agricultural, and ecological response variables. For this purpose, they compare the performance of several drought indices [the standardized precipitation index (SPI); four versions of the Pa...

Snow cover in Spanish mountains is crucial for ensuring water availability in spring and summer months, for the success of winter tourism or for the maintenance of biodiversity in mountain ecosystems. A changing climate may affect the volume of snow cover even in high mountains, where weather conditions are usually favorable for snow accumulation....

We are currently experiencing a period of global climatic changes that are affect-ing the biosphere and the ecosystem services that sustain our societies. The re-lationships and feedbacks between the different abiotic and biotic elements that compound the Earth's global ecosystem, such as climate, oceans, glaciers and rivers, biodiversity and human...

A deep spectral investigation of the monthly time series of Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) in 45 meteorological stations in the Ebro basin (Spain) from 1950 to 2006 for timescales ranging from 1 to 48 months was performed. In order to summarize the results for the whole basin, t...