Part I. Introduction: 1. Mediterranean-type climate (MTC) ecosystems and fire 2. Fire and the fire regime framework 3. Fire related plant traits Part II. Regional Patterns: 4. Fire in the Mediterranean basin 5. Fire in California 6. Fire in Chile 7. Fire in the Cape region of South Africa 8. Fire in southern Australia Part III. Comparative Ecology, Evolution and Management: 9. Fire-adaptive trait evolution 10. Fire and the origins of Mediterranean-type vegetation 11. Plant diversity and fire 12. Alien species and fire 13. Fire management of Mediterranean landscapes 14. Climate, fire and geology in the convergence of Mediterranean-type climate ecosystems References Index.

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Fire in Mediterranean Ecosystems: Ecology, Evolution and Management

. Fire is the primary disturbance factor in many terrestrial ecosystems. Wildfire alters vegetation structure and composition, affects carbon storage and biogeochemical cycling, and results in the release of climatically relevant trace gases including CO2, CO, CH4, NOx, and aerosols. One way of assessing the impacts of global wildfire on centennial to multi-millennial timescales is to use process-based fire models linked to dynamic global vegetation models (DGVMs). Here we present an update to the LPJ-DGVM and a new fire module based on SPITFIRE that includes several improvements to the way in which fire occurrence, behaviour, and the effects of fire on vegetation are simulated. The new LPJ-LMfire model includes explicit calculation of natural ignitions, the representation of multi-day burning and coalescence of fires, and the calculation of rates of spread in different vegetation types. We describe a new representation of anthropogenic biomass burning under preindustrial conditions that distinguishes the different relationships between humans and fire among hunter-gatherers, pastoralists, and farmers. We evaluate our model simulations against remote-sensing-based estimates of burned area at regional and global scale. While wildfire in much of the modern world is largely influenced by anthropogenic suppression and ignitions, in those parts of the world where natural fire is still the dominant process (e.g. in remote areas of the boreal forest and subarctic), our results demonstrate a significant improvement in simulated burned area over the original SPITFIRE. The new fire model we present here is particularly suited for the investigation of climate–human–fire relationships on multi-millennial timescales prior to the Industrial Revolution.

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A model for global biomass burning in preindustrial time: LPJ-LMfire (v1.0)

This study aims at quantifying seasonal biases of regional climate model outputs during southern African summer, against a dense in situ measurement network (daily rain-gauge and surface air temperature records, and 12 h UTC radiosondes), and uncertainties associated with some physical parameterizations. Using the non-hydrostatic Advanced Research Weather Forecast (WRF) laterally forced by ERA40 reanalysis, twenty-seven experiments configured with three schemes of cumulus (CU), planetary boundary layer (PBL) and microphysics (MP), are performed at 35 km horizontal resolution during the core of a summer rainy season (December 1993 to February 1994 season) representative of the South African rainfall climatology. WRF simulates accurately seasonal large-scale rainfall patterns, as well as seasonal gradients of South African rainfall and 2-m temperature, and seasonal vertical profiles of the air temperature and humidity. However seasonal biases fluctuate strongly from an experiment to another, denoting considerable uncertainties generated by the physical package. Rainfall amounts are the most sensitive parameter to the tested schemes. Their geography, intensity, and intraseasonal characteristics are predominantly sensitive to CU schemes, and much less to PBL and MP schemes. Some CU-PBL combinations produce additive effects, which can dramatically either reduce or increase biases. Satisfactory configurations are found for South African climate, which would not have been possible without testing numerous physical parameterizations.

Uncertainties in simulating regional climate of Southern Africa: sensitivity to physical parameterizations using WRF

[1] In the frame of this paper, 1-year of lightning data from the experimental network ZEUS operated by National Observatory of Athens is analyzed. The area of interest is the Mediterranean and surrounding countries. At a first stage, the ZEUS data are compared with the data provided by the UK Met Office long-range lightning detection network for the warm period of the year. It was found that although ZEUS system underestimates the nighttime and early morning activity, during the rest of the day ZEUS system detects increased number of lightning compared to ATD that suffers from saturation when the number of flashes exceeds a certain threshold. Furthermore, the possible relationship between lightning and elevation, terrain slope and vegetation is investigated. The analysis showed that during spring and summer there is a positive relationship of lightning activity with elevation, while this feature is not evident during the rest of the year. The lightning activity was found to be positively correlated with the elevation slope throughout the year except winter. As it concerns the vegetation cover, it was found that over bareground the lightning “yield” is low during the whole year, while the inverse is true for woodland areas. During the warm period of the year, due to drying of the Mediterranean surfaces, the forested and wooded areas that keep soil moisture present increased lightning “yield” in contrast with the shrubland areas that, for the same period, present a decreased lightning yield.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2008JD010605

Lightning occurrence in relation with elevation, terrain slope, and vegetation cover in the Mediterranean

. This paper introduces the development of a database of high-impact weather events that occurred in Greece since 2001. The selected events are related to the occurrence of floods, flash floods, hail, snow/frost, tornados, windstorms, heat waves and lightning with adverse consequences (excluding those related to agriculture). The database includes, among others, the geographical distribution of the recorded events, relevant meteorological data, a brief description of the induced impacts and references in the press. This paper further offers an extensive analysis of the temporal and spatial distribution of high-impact weather events for the period 2001–2011, taking into account the intensity of weather conditions and the consequent impact on the society. Analysis of the monthly distribution of high-impact weather events showed that they are more frequent during October and November. More than 80 people lost their lives, half of which due to flash floods. In what concerns the spatial distribution of high-impact weather events, among the 51 prefectures of the country, Attica, Thessaloniki, Elia and Halkidiki were the most frequently affected areas, mainly by flash floods. Significant was also the share of tornados in Elia, of windstorms in Attica, of lightning and hail events in Halkidiki and of snow/frost events in Thessaloniki.

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A database of high-impact weather events in Greece: a descriptive impact analysis for the period 2001-2011

During the last 10 years, the Institute for Environmental Research and Sustainable Development of the National Observatory of Athens has developed and operates a network of automated weather stations across Greece. The motivation behind the network development is the monitoring of weather conditions in Greece with the aim to support not only the research needs (weather monitoring and analysis, weather forecast skill evaluation) but also the needs of various communities of the production sector (agriculture, constructions, leisure and tourism, etc.). By the end of 2016, 335 weather stations are in operation, providing real-time data at 10-min intervals. This paper provides information about the logistics of this network, including real-time applications of the collected data as well as information on the quality control protocols, the construction of the station data and metadata repository and the means through which the data are made available to users.

https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/gdj3.44

The automatic weather stations NOANN network of the National Observatory of Athens: operation and database

Lightning activity over Greece during the warm season (May–September) of the years 2003–06 is investigated in relation to the synoptic meteorological conditions that prevailed in the region. The study is based on the use of cloud-to-ground lightning activity data from the Met Office Arrival Time Difference system and upper-air analyses from the European Centre for Medium-Range Weather Forecasts. Analysis of the spatial variability of lightning shows that the highest “relative” flash densities are observed in northern and western Greece and in central and western Peloponnissos. The relative flash density is correlated with elevation: it increases with elevation along the slopes of terrain features. The study of the synoptic patterns related to lightning is based on the analysis of 60 active days and 60 inactive days in terms of lightning activity over Greece. The days with high lightning activity are characterized by a short-wave trough at the 500-hPa level over the Ionian Sea. On the other hand, ...

Storms and Lightning Activity in Greece during the Warm Periods of 2003–06

The sensitivity of numerical forecasts to convective parameterization during the warm period and the use of lightning data as an indicator for convective occurrence

. The increasing maritime activity can be seriously affected by severe weather and sea conditions. To avoid serious damages to ships, marine structures and humans, a good weather and wave forecast is of primary importance. In general the meteorological and the wave models are used to produce forecasts at large scale like the global or the medium-size inner seas. For much smaller environments like the Greek maritime areas, characterized by complicated features like the orography and the presence of islands, the modelisation becomes a not simple task. This study is devoted to the validation of the performance of the WAM wave model over the Ionian and Aegean Seas. The period of validation refers to the first 12 months of operational use of the model at the National Observatory of Athens. The wave model is applied at a resolution of 1/16 degrees and is driven by the 10 m wind, produced by the BOLAM meteorological model operationally run over the same area. Two different sources of data have been used for the verification of the model results. The first dataset is provided by a network of buoys deployed over the Greek maritime areas and the second consists of altimeter data, provided by the OSTM/Jason-2 satellite platform. Although the study area is characterized by complex topography and a large number of islands, the implementation of the WAM model provides very encouraging results. In general, with the exception of the two buoys located in the Ionian Sea, the WAM model tends to underestimate the wave energy in the region of the Aegean Sea. The comparison with the altimeter data shows that the model has a tendency to overestimate the height for waves lower than 2.5 m and to underestimate the waves higher than 3 m.

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High-resolution wave model validation over the Greek maritime areas

. This study is devoted to the evaluation of the role of assimilation of conventional data on the quantitative precipitation forecasts at regional scale. The conventional data included surface station reports as well as upper air observations. The analysis was based on the simulation of 15 cases of heavy precipitation that occurred in the Eastern Mediterranean. The verification procedure revealed that the ingestion of conventional data by objective analysis in the initial conditions of BOLAM limited area model do not result in a statistically significant improvement of the quantitative precipitation forecasts.

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N. Mazarakis

Papers

The automatic weather stations NOANN network of the National Observatory of Athens: operation and database

Storms and Lightning Activity in Greece during the Warm Periods of 2003–06

The sensitivity of numerical forecasts to convective parameterization during the warm period and the use of lightning data as an indicator for convective occurrence

High-resolution wave model validation over the Greek maritime areas

Impact of the assimilation of conventional data on the quantitative precipitation forecasts in the Eastern Mediterranean