Dana Magdalena Micu

Climate of the Romanian Carpathians

1. Introduction 2. Theoretical background 2.1 Mountain regions - key issues in environmental research 2.1.1 Mountain regions and climate change 2.1.2 Mountain research in the Carpathian region 2.2 Weather and climate of the Romanian Carpathians: a literature review References 3. Study area 3.1 Geographical location of the Romanian Carpathians within the Carpathian Chain 3.2 General morphological settings 3.3 Paleogeographic evolution and geological constitution 3.4 Hydrology and hydrogeology 3.5 Zonation of vegetation and soils References 4. Data 4.1 Datasets 4.2 Mountain meteorological network References 5. Methods 5.1 Homogenization 5.2 Statistical methods 5.2.1 Mann-Kendall trend test 5.2.2 Kendall-Theil slope estimate 5.2.3 Spearmans rank correlation coefficient 5.3 Spatialization of climatic information 5.4 Regional climate models References 6. Geographical and synoptic control on the climate 6.1 Latitude 6.2 Topography 6.2.1 Altitude 6.2.2 Slope aspect 6.2.3 Slope angle 6.2.4 Landforms 6.3 Regional atmospheric circulation References 7. Regional climatic patterns 7.1 Solar radiation 7.2 Air temperature 7.2.1 Average air temperature lapse rate 7.2.2 Vertical thermal zonation 7.2.3 Annual variation of average temperature 7.2.4 Lapse rates of minimum and maximum temperatures 7.2.5 Spatial distribution of minimum and maximum temperatures 7.2.6 Annual variation of minimum and maximum temperatures 7.2.7 Extreme temperature records 7.3 Precipitation 7.3.1 Vertical zonation and spatial distribution 7.3.2 Wind-induced bias 7.3.3 Annual variation 7.3.4 Precipitation type 7.3.5 Precipitation absolute records 7.4 Wind 7.4.1 Surface wind direction 7.4.2 Surface wind speed 7.4.3 Maximum wind speed 7.4.4 Atmospheric calm 7.4.5 Local winds 7.5 Snowfall and snowpack 7.5.1 Atmospheric circulation patterns related to snowfall events 7.5.2 Snowfall occurrence interval 7.5.3 Snowfall frequency 7.5.4 Snow showers 7.5.5 Snow cover interval 7.5.6 Snow depth 7.5.7 Snow water equivalent References 8. Observed variability trends from instrumental records 8.1 Air temperature 8.2 Precipitation 8.3 Wind 8.4 Snowpack 8.5 Influence of large-scale circulation References 9. Changing climate extremes in the last five decades 9.1 Change in air temperature extremes 9.2 Change in precipitation extremes 9.3 Change in snow extremes References 10. Projections of future changes in climate of the Romanian Carpathians 11. Conclusions Index

A morphogenetic insight into a multi-hazard analysis: Bâsca Mare landslide dam

Slope–channel coupling in geomorphologically active regions represents a topic with numerous implications, from both fundamental and applied perspectives. Landsliding and erosion combine under the influence of the morphostructural and lithological, seismic, climatic, and anthropic factors, and their interaction may materialize in landslide dams, forms which are conditioning the future slope and river morphology and morphodynamics. The proper understanding of the predisposition and preparing and triggering factors in case of landslide dams could provide significant information in the risk analysis, assessment, and management. The occurrence in July 2013 of a landslide dam in the Buzău Mountains (along the Bâsca Mare river), caused by the partial reactivation of a dormant deep-seated landslide, allowed the outlining of the entire agents–forms–processes framework, offering in the meantime the background data for a future multi-hazard assessment. Since the Vrancea seismic region (area that comprises the Curvature Carpathians of Romania) represents one of Europe’s most slope/channel/seismically active regions, the case–study offers important insight information that allows in the meantime the analysis of multi-hazard at a regional scale.

Regional Climatic Patterns

This chapter provides a description of the main climatic conditions of the Romanian Carpathians region based on the analysis of the regime of the most important climatic parameters such as air temperature, precipitation, wind and snow. The regional climatic patterns are discussed in terms of elevation effect, influence of the prevailing atmospheric circulation and seasonality, aiming at distinguishing between the climate variation particularities emerging between three main units. The analysis highlights the climatic differentiations between the areas above 800 m and those below 800 m, generally including most of the intra-Carpathian depressions. The absolute climatic records derived from in situ measurements are presented in tabular form.

Climate Change Projections for a Medium-Size Urban Area (Baia Mare Town, Romania): Local Awareness and Adaptation Constraints

Numerous studies worldwide emphasize the impacts that cities now face due to increasing variability of weather extremes associated with climate change, exacerbating the urban heat island effect, air pollution and health impacts. In this respect, cities need to cope with these new threats and get prepared. One way of doing this is to develop climate change mitigation and adaptation strategies, focusing on local vulnerabilities in relation to the current societal development needs and adaptation options. There are many recent initiatives and examples for climate change adaptation strategies and plans for large cities, but only a few examples for small and medium-size cities. This paper investigates the mid-(2021–2050) and far-future (2071–2100) climate change signals in an urban area located in northern Romania (Baia Mare town), with around 200,000 inhabitants, exploring the results of some CORDEX GCMs under the new IPCC RCPs (RCP2.6, RCP4.5 and RCP8.5). The study analyzes these signals in relation to the local awareness of key institutional stakeholders, as well as to the current social and economic constraints towards considering the climate change adaptation. The findings, based on a survey, highlight how the local authorities perceive and include climate change aspects in their activities as an important step towards real implementation of specific climate-based decisions, as well as their needs in terms of climate information and data. The study provides useful scientific insights about future climate and expected impacts in the Baia Mare Urban System to stakeholders, which could increase their awareness and knowledge in terms of climate change.

Geographical and Synoptic Controls on the Climate

This chapter outlines the importance of three major factors and the effects of their joint action in defining local and regional climatic features of the Romanian Carpathians: latitude and longitude, topography and the regional atmospheric circulation. The chapter summarizes the role of latitude and longitude in shaping the distribution of the direct and global solar radiation across the Romanian Carpathians and highlights the main influences of regional atmospheric circulation in defining local weather aspects and the regional climatic patterns in this mountain range. The complexities introduced by the main topographic characteristics of the underlying mountain terrain (e.g. altitude, slope aspect and angle, landforms) on climate state variables, are addressed here based on the key findings of several previously published works, focusing on local climate contrasts and climate zonation aspects within the Romanian Carpathians. A major focus is on the altitude effect, imposing the overall climatic zonation, as revealed by on the key findings of several previously published works.

Projections of Future Changes in Climate of the Romanian Carpathians

This chapter briefly presents the changes of the air temperature and precipitation amounts predicted by Regional Climate Models for the next decades over the Romanian Carpathians. The analysis refers to the IPCC Scenario A1B, and exploits the outputs of several European projects developed in the recent years. The air temperature is likely to increase in all seasons, while the precipitation amounts will generally vary with ±10 % as compared to the present climate, at different spatial rates. The most significant temperature increasing is expected to occur in summer; over most Carpathian areas, the period 2021–2050 will be 2.5–3.0 °C warmer than 1961–1990. As regards the precipitation, the winter will be sensibly drier, while increasing trends are specific to the autumn.

Observed Variability and Trends from Instrumental Records

This chapter analyses the recent climatic trends in the Romanian Carpathians, with an accent on seasonal changes. Temperature trends are increasing in winter, spring and summer, while they are completely absent in autumn, which is the single stable season from a thermal point of view. On the other hand, autumn is the only season when significant increasing trends in precipitation have been found. The average wind speed is decreasing in all seasons, confirming most of the findings regarding the general tendency in the Northern Hemisphere. Snow-related trend analysis shows general decreasing trends in mean snow depth, number of days with snow cover, number of days with snowfall, and continuous snow cover duration. The increase in temperature at most of the locations, together with the slight decrease in winter precipitation explains the reduction of the snowfall days. The number of snowfall days, snow duration and mean snow depth present strong negative correlations with the NAO index for the same period (DJF). The large-scale circulation over the North Atlantic has a considerable effect on the winter season in the Romanian Carpathians.

Changing Climate Extremes in the Last Five Decades (1961–2010)

Several indices of climate extremes – based on minimum and maximum temperature, daily precipitation and daily snow cover – were used in order to check for changes over 1961–2010. The most important changes were found in maximum and (to a lesser extent) in minimum seasonal temperature. The warming signal is well retrieved in the trends in thermal-related extreme indices. Autumn is the only stable season with respect to changes in temperature extremes. Precipitation extremes exhibit no consistent change, leading to the conclusion that the decreasing trends in the snow-related indices, especially the maximum length of snowfall spells are rather related to recent warming.