You are here

Climate and environmental monitoring in the Italian mountains

Monitoring activities were devoted to the characterization of the current state of the climate and the environment in mountain regions. Here we present a few highlights of scientific results achieved by NextData.

Meteo-climatic data

(a) Quantitative assessment of atmospheric composition variability (atmospheric pollutants and climate-altering compounds) in the mountain regions of Italy.The activity is conducted at the Climate Observatory of Monte Cimone, the only "Global Station"of the GAW-WMO network in Italy, and at a nationwide network of measurement stations

Stratospheric O3 depleting substances (i.e. CFC, HCFCs, halons, CH3CCl3, CCl4, CH3Cl, CH3Br), observed at CMN since early 2000’s confirm the success of Montreal Protocol but at the same time point to the persistence of unaccounted emissions from European regions (especially for CH3CCl3, CCl4, CH3Cl, CH3Br). Non-CO2 greenhouse gases (HFCs, CH4 and N2O) included in Kyoto Protocol show significant increasing trends, while downward tendencies are observed for atmospheric compounds regulated by European air quality directives. In particular, over the period 1996 - 2016, a negative trend (significant at the 99% confidence level) of -0.21 ppb/year was calculated for near-surface O3. The largest trend decrease was detected for summer: this would reflect the decrease of O3 precursor emissions within Europe and northern Italy as confirmed by the non-methane volatile organic compound (NM-VOC) observations at CMN. For the period 2005 – 2013, we observed a statistically significant negative trend of -0.17 mg m-3 year-1 for equivalent black carbon (eqBC), an aerosol produced by the incomplete combustion of fossil fuels and biomass: heating systems, industries, traffic (in particular "Diesel" engines), agricultural and forest fires. Both, O3 and BC, besides to be atmospheric pollutants play a roles as short-lived climate forcers.

Summer variability of atmospheric pollutants/climate forcers were investigated by means of CMN observations. In particular, we identified three regimes which tagged the distance of anthropogenic sources: near outflow (23% of hourly data), far-outflow (38% of data) and background (39% of data). The highest levels of anthropogenic pollutants (e.g. O3, CO, eqBC, accumulation particles) were concomitant with fresh emissions from northern Italy under near-outflow conditions. As inferred by the integration of atmospheric transport modeling and continuous observations at CMN (2011-2017), we estimated that Italy is contributing to propane (C3H8) emissions for about 50 Gg/yr (about 50% from the Po basin), while the national contribution for benzene (C6H6) is about 22 Gg/yr (about 35% from the Po basin).

Continuous O3 measurements were activated at Col Margherita (MRG), in the Dolomite mountains. The first year of continuous observations provided hints about possible transport of air-masses influenced by anthropogenic emissions. Besides the existence of a diurnal cycle related with thermal mountain winds, a significant weekly cycle occurred at MRG during summer, with values increasing during the week. This would suggest the occurrence, during favorable weather conditions, of O3 build-up due to the impact of anthropogenic emissions. The Lagrangian tool STEFLUX was developed and used to diagnose the occurrence of deep SI events in four mountain regions over the Italian peninsula, spanning from the Alpine region to the southern Apennines. Both experimental (based on near-surface observations at high-mountain observatories) and STEFLUX detections agreed in describing the seasonal cycle of SI occurrence (maximum in winter and minima in summer). By using STEFLUX, we found positive tendencies in the SI occurrence during 1979–2017. In contrast to similar studies carried out in the Alpine region, the negative long-term trend of O3 in the northern Apennines did not appear to be related to the SI’s variability.

More details can be found in deliverable D1.1.B.

(b) Implementation of an integrated high-altitude network of climate monitoring in the mountain regions of Italy, starting from the global and regional GAW stations present in Italy

Nextdata was aimed at creating a network of atmospheric observatories in mountain and baseline locations over Italy  for the monitoring of atmospheric composition and ancillary data (meteorological parameters and solar radiation). The integration of the atmospheric background observational network passed by a number of activities:

•The implementation of new measurement programmes at the background stations;

•The definition of guidelines to harmonize the measurement methodologies, protocols, QA/QC procedures, including the adoption of common reference calibration scales (e.g. GAW-WMO, ICOS, ACTRIS);

•The implementation of automatic procedures for submitting essential climate variables (ECVs) recorded at Italian Atmospheric Observatories to WMO/GAW data centres (https://nextdata.bo.isac.cnr.it);

•The implementation of NRT data delivery and early warning services.

More details can be found in deliverables D1.1.A, D1.1.B and D.1.1.F.

(c) Estimation of Elevation Dependent Warming in the Italian mountains

In the Greater Alpine Region, the relationship between warming rates and elevation is well represented by a linear model. The season showing the most striking evidence of EDW in both the minimum and maximum temperature is autumn. In fact, the elevational gradients of warming rates in this season exhibit always a positive and statistically significant slope, except in a few cases, and the spread among the individual model realizations which we employed at each resolution is overall smaller than in the other seasons.

In general, our analysis shows that the more frequent EDW drivers in all seasons are the changes in albedo and in downward thermal radiation and this is reflected in both daytime and nighttime warming. It is clear that our picture omits other factors which may contribute to EDW in the different regions. It is interesting to observe that in the Alps, and at the coarsest horizontal resolutions only, a significant EDW signal related to albedo changes is observed in the DJF season. At the coarsest resolutions, the orography is smooth, and the highest elevations are not realistically represented in the climate model. This result seems to suggest that the “model’s highest elevations” might undergo an earlier (winter) transition from being snow covered to being snow free in the future in winter months. Of course this signal is an artifact typical of the coarsest resolutions and disappears at finer resolutions when the orography is represented with more accuracy. On the contrary, the finest resolutions are the only ones able to catch the change in albedo as an EDW driver in SON in the GAR. This result would suggest an added value of the finest resolution simulations in the Alpine area.

More details can be found in the D1.1.D Deliverable “Future elevation-dependent warming on Italian mountains and related database".

(d) Realization of a climatology of monthly temperature and precipitation at 1km spatial resolution for the Italian Alpine area, and reconstruction of monthly data-sets of temperatures and precipitation temporal series at the same spatial resolution for the past decades for the three national parks of Gran Paradiso, Stelvio, and Paneveggio / Pale di San Martino

A mean regional series is estimated for each National Park to evaluate any trend over the analysed period. Temperature mean series show a significant positive trend over the whole considered period (1951-2012) for all the three areas (0.17°C per decade for Gran Paradiso, 0.24 °C per decade for Stelvio and 0.23 °C per decade for Paneveggio – Pale di San Martino), which becomes stronger if the period after 1981 is considered (0.35 °C per decade for Gran Paradiso, 0.38 °C per decade for Stelvio and 0.40 °C per decade for Paneveggio – Pale di San Martino). On the contrary, precipitation mean series do not show any significant trend in any subdomain.

Water resources

(e) In situ measurements of sample glaciers and remote sensing observations, including satellite images, will provide information on the status of Alpine glaciers (areal extent with accuracy of 2% and volume estimates). An updated inventory of glaciers and a quantitative database of Italian glacial resources and their evolution in recent decades will be produced;

(f) Assessment of the current conditions of snow cover (thickness and extension) in specific Italian mountain areas, by means of in situ data analysis, satellite observations and climate modelling, with a spatial resolution of at least 10 km;

(g) Measurements of the hydrological cycle and of the status of surface and groundwater resources in mountain test sites, through the collection of existing data and new measurements during the project, including geological information and information on aquifers and their extension;

Ecosystems and biodiversity

(h) Collection of data on mountain ecosystems from the Italian sites contributing to ILTER (International Long-Term Ecological Research network) and LTER-Europe.

(i) Measurements and observations of biodiversity in high-altitude regions, through the collection of biodiversity data, distribution of animal species, population dynamics of important species (as keystone, flagship species);

(l) Quantitative estimate of biogeochemical flows (water, carbon) through soil, vegetation and atmosphere in test sites, for determining the dynamics and the carbon source/sink behavior in selected types of alpine ecosystems;

(m) Analysis of the dynamics of alpine meadows in the context of climate and land use changes, focusing on changes in sheep management and cattle grazing and on the interactions with wild ungulates, using in situ measurements and satellite observations.

This area of activity will lead to the construction of a system of distributed thematic archives, from which the data and the results produced by the project can be downloaded (thematic maps; results; climate, hydrological and ecosystem indices; and numerical simulation products). Particular attention will be given to the validation, quality control and harmonization of data, often coming from different sources.

The data will be analysed and interpreted in order to obtain a state of the art as complete as possible on the state and ongoing changes in the Italian mountains.