Vodice

Climate change projections for Vodice with special emphasis on severe
impacting events

Authors: CMCC, ARPAE, DHMZ

contact person: enrico.scoccimarro@cmcc.it

Expected climate change presented in this short document is the summary of the ADRIADAPT D.3.3.1 document – Climate change projections for Vodice with special emphasis on severe impacting events. For more information on the data used, processing and analysis methods, graphical representations of the results and conclusions, we advise to look at this document.

1.1 Dynamically downscaled

In this section, we present future climate change of temperature and precipitation related indices and extra rare humidex projections for Vodice. All indices are calculated from the four available regional climate models for the model point representing the location of Vodice. Data set is obtained by interpolation of data from neighbouring points. Data are presented as follows:

  • Climate change diagram of an individual index in seasons: DJF standing for the months of the winter season, MAM for the months in spring, JJA for the summer months, and SON representing the autumn months. Data is presented furthermore and on annual basis for four future periods: 2021-2040, 2041-2060, 2061-2080 and 2081-2100 and for two emission scenarios: a moderate one called also stabilization scenario (RCP4.5) simulating a future world where considerable efforts have been put into mitigation policies and a high-emissions climate scenario (RCP8.5, often called pessimistic climate scenario) which simulates a future world without climate mitigation policies. We calculated indices representing the difference between present and future climate (called also future anomalies or changes). Reference period is 1985-2006 and a star marks such values for which changes are statistically significant.
  • Time series of the future anomaly (or changes) of an individual index for the winter (DJF) and summer season (JJA) for RCP4.5 and RCP8.5 emission scenarios. Anomaly is calculated concerning the reference period and shown for the individual models, the mean and the 5-year average. Statistical trend test is applied to the ensemble mean (for 95 % confidence level). A significant trend is marked with a star (ns if not significant).

2 Temperature related data

2.1 Results from dynamical downscaling (DD)

2.1.1 Averaged 2 meter air temperature

Averaged temperature change in Vodice shows an increase in all seasons and on annual scale, for all future periods (winter is an exception for two models in first two periods). Although each model gives different amplitude of change, in the ensemble mean the change is highest during summer and smallest in winter, for the moderate climate scenario. The temperature increase is more pronounced towards the end of the century with an increase of ensemble mean temperature of 1.4 °C in winter and 2.1 °C in summer. On annual scale temperature increase is for 1.7 °C. The amplitude of temperature change is more pronounced for high-emission scenario, reaching on annual scale 3.5 °C by the end of 21st century, 2.9 °C in spring and 4.2 °C in summer.

The linear trend of temperature anomaly (Figure-1) in the future shows increase which is statistically significant for both considered seasons and both scenarios; in winter it is 0.19 °C per decade for the moderate climate scenario and 0.53 °C per decade for the high-emissions scenario, in summer 0.18 °C per decade for the moderate climate scenario and 0.49 °C per decade for the high-emissions scenario.

Figure 1: Variability of future 2m air temperature anomaly (in °C) in Vodice for 2021-2100 obtained by dynamical downscaling for winter (DJF) and summer (JJA) and two emission scenarios, moderate (RCP4.5) and high-emissions (RCP8.5): individual models are in grey, the ensemble mean in red, 5-year moving average in black. A significant trend is marked with a star (ns if not significant).

2.1.2 Extreme high temperature

Extreme high temperatures (defined as 99th percentile of 2m air temperature) in Vodice are increasing from P1 to P4 future periods with the different amplitudes for each model. At the end of century, for the moderate scenario, the warming ranges from 1.0 °C in winter to 2.6 °C in summer, and by 2.5 °C in an annual mean. For the high-emissions scenario, the amplitude of temperature rise is as high as 4.4 °C for annual change at the end of 21st century, from 2.8 °C winter to 4.6 °C in autumn.

2.1.3 Extreme high maximum temperature

The change of extreme high maximum air temperature in Vodice (defined as 99th percentile of 2m maximum air temperature) is increasing from first to last periods with the different amplitudes for each model and season. Ensemble mean of change is positive for all periods. At the end of century, the change of extreme high maximum temperature ranges from 1.1 °C in winter to 2.7 °C in summer and autumn, 2.6 °C on annual scale for moderate climate scenario. The amplitude of change is more pronounced for high-emissions scenario and is between 2.9 °C in winter and 4.9 °C in autumn, 4.6 °C for annual change at the end of 21st century.

2.1.4 Extreme rare high temperature

Future change of 99.9th percentile of 2m air temperatures (extreme rare high temperature) in Vodice is increasing towards the end of the century with the different amplitudes for each model. A slightly negative change appears for some seasons and some models in two first periods, but the change of ensemble mean is positive for all periods (exception is P1 in winter for moderate scenario). At the end of century increase is from 0.7 °C in winter to 2.6 °C in spring, 2.5 °C on annual scale for moderate scenario. For the high-emissions scenario amplitude changes between 2.4 °C in winter and 4.9 °C in autumn, 4.1 °C on the annual scale at the end of 21st century.

2.1.5 Extreme rare high maximum temperature

Analysing the future change of extreme rare high maximum temperature (defined as 99.9th percentile of 2m maximum air temperature) in Vodice, we came to the same conclusion as for extreme rare high temperature. Some models show for some time slices small negative change, but in general, the ensemble mean for all seasons and annual change are positive (exception is winter in P1 for the moderate scenario). At the end of 21st century changes are between 1.2 °C in winter and 3.9 °C in spring, 2.7 °C on annual scale for the moderate scenario. The high-emissions climate scenario gives the change between 3.0 °C in winter and 5.7 °C in autumn, 4.2 °C on annual scale at the end of 21st century.

2.1.6 Extra rare humidex projections

The change in extra rare humidex (defined by 99.9th percentile of humidex) in the future in Vodice will slightly increase towards the end of 21st century. The ensemble mean will increase between 0.8 in JJA and 2.6 in SON, 1.7 on annual scale for moderate scenario. The high-emissions scenario gives slightly higher positive amplitudes, from 3.9 in summer to 6.3 in autumn, 4.7 on annual scale. Variability of extra rare humidex anomaly shows positive linear trend for both seasons and both considered scenarios. Trends are statistically significant.

3 Precipitation related data

3.1 Results from dynamical downscaling (DD)

3.1.1 Averaged precipitation 

Averaged precipitation obtained by dynamical downscaling is expressed in mm/day and its change in the future is shown as relative (in %) to the same period as for temperature. Precipitation is a much more variable parameter than temperature, therefore there is not a unique sign of change neither through the year nor from model to model (Figure 4). The change in the ensemble mean for Vodice shows for moderate climate scenario, an increase of precipitation in the cold part of the year at the end of century (7.8 % in winter, 10.8 % in autumn) and decrease in the warm part (-0.6 % in spring, -8.4 % in summer); annually it indicates an increase of 4.4 %. For the high-emissions climate scenario, precipitation will decrease in summer (-22.9 %) and increase in winter (13.6 %), annually slightly increase for 0.6 % at the end of century.

Figure 4: Averaged seasonal and annual precipitation obtained by dynamical downscaling for Vodice: Ref. mean is 20 years simulated period (1986-2005) for the ensemble mean in mmday-1; P1-P0, P2-P0, P3-P0, P4-P0 are the changes (in %) in the future for following periods P1: 2021-2040, P2: 2041-2060, P3: 2061-2080, P4: 2081-2100. Differences are shown for individual models. A significant change is marked by a star. Change is also shown as ensemble mean (ENSMEAN), not tested for significance. The left column is for the moderate scenario and the right one for the high-emissions scenario.

3.1.2 Intense precipitation

The amounts of intense precipitation (defined by 95th percentile of precipitation) in Vodice will increase in all seasons except summer. At the end of century, the increase will be the most pronounced in autumn for the moderate scenario (19.1 %) and in winter for the high-emissions scenario (16.6 %). In summer, the amount of intense precipitation will decrease for -5.5 % in case of moderate scenario and by -27.2 % for the high-emissions climate scenario. On an annual scale intense precipitation will increase, 8.6 % for moderate and 5.4 % for the high-emissions climate scenario.

3.1.3 Extreme precipitation

Extreme precipitation, defined by 99th percentile of precipitation in Vodice, shows an increase in all seasons (except in summer) and on an annual scale. The increase will range from 9.5 % in spring to 15.9 % in autumn, and amounts 15.5 % for annual scale for the moderate scenario. If we keep on doing business-as-usual, the amount of extreme precipitation will grow by 11.3 % in autumn and 30.7 % in winter, 18.0 % for annual scale at the end of 21st century. In summer, extreme precipitation will decrease for both scenarios, -2.2 % for moderate and -5.5 % for high-emissions climate scenario.

3.1.4 Heavy precipitation index

Heavy precipitation index, defined as number of days with precipitation greater than 10 mm, will change with no unique sign between models in all seasons. In ensemble mean change at the end of 21st century, heavy precipitation index will increase in all seasons from 3.4 % in spring to 17.7 % in DJF (except in JJA, -4.2 %) as well as on an annual scale by 6.7 % regarding the moderate scenario. The high-emission climate scenario shows an increase between 10.0 % in spring and 21 % in winter, decrease between -3.7 % in autumn and -24.7 % in summer, whereas on an annual scale heavy precipitation index will increase for 1.9 % at the end of 21st century.

3.1.5 Maximum number of consecutive dry days

Maximum number of consecutive dry days in Vodice will mostly increase in all periods for most models. The ensemble mean change for moderate scenario gives an increase in all seasons (except in spring, -1.5 %) and on annual scale at the end of 21st century. An increase will range from 6.5 % in autumn to 17.0 % in winter, 13.3 % on annual scale. For the high-emissions climate scenario increase is present in all seasons (from 4.8 % in spring to 34.1 % in summer) and on annual scale (27.9 %).