OBSERVATIONAL NETWORKS OBSERVATIONAL NETWORKS OPERATED BY THE NATIONAL OPERATED BY THE NATIONAL

OBSERVATORY OF ATHENSOBSERVATORY OF ATHENS

V. . Kotroni - K. LagouvardosV. . Kotroni - K. LagouvardosInstitute of Environmental ResearchInstitute of Environmental Research

National Observatory of AthensNational Observatory of Athens

OBSERVATIONAL NETWORKS OBSERVATIONAL NETWORKS OPERATED BY THE NATIONAL OPERATED BY THE NATIONAL

OBSERVATORY OF ATHENSOBSERVATORY OF ATHENS

V. . Kotroni - K. LagouvardosV. . Kotroni - K. LagouvardosInstitute of Environmental ResearchInstitute of Environmental Research

National Observatory of AthensNational Observatory of Athens

 

-NETWORK OF AUTOMATED SURFACE NETWORK OF AUTOMATED SURFACE METEOROLOGICAL STATIONSMETEOROLOGICAL STATIONS

-LIGHTNING DETECTION NETWORKLIGHTNING DETECTION NETWORK

-NETWORK OF AUTOMATED SURFACE NETWORK OF AUTOMATED SURFACE METEOROLOGICAL STATIONSMETEOROLOGICAL STATIONS

-LIGHTNING DETECTION NETWORKLIGHTNING DETECTION NETWORK

DESCRIPTION OF THE AUTOMATED DESCRIPTION OF THE AUTOMATED SURFACE METEOROLOGICAL SURFACE METEOROLOGICAL

STATIONS NETWORKSTATIONS NETWORK

DESCRIPTION OF THE AUTOMATED DESCRIPTION OF THE AUTOMATED SURFACE METEOROLOGICAL SURFACE METEOROLOGICAL

STATIONS NETWORKSTATIONS NETWORK

Build a low-cost real-time surface observation network with the aim to:

support scientific needs for studies related to weather and climate over Greeceinform citizens for the present weathersupport a variety of financial activities (e.g. tourism and leisure, agriculture, energy supply)

THE NETWORKTHE NETWORKTHE NETWORKTHE NETWORK

250 stations: 210 are property of NOA, while the rest are property of municipalities, operated under the supervision of NOA

20 stations are installed in elevation exceeding 1000 m, permitting thus the monitoring of weather in mountainous areas.

35 stations measure total solar radiation

THE STATIONTHE STATIONTHE STATIONTHE STATION

GEOGRAPHICAL COVERAGEGEOGRAPHICAL COVERAGEGEOGRAPHICAL COVERAGEGEOGRAPHICAL COVERAGE

AVAILABILITY OF DATAAVAILABILITY OF DATAAVAILABILITY OF DATAAVAILABILITY OF DATA

Real-time provision of data to all users through the web.

Provision of historical data through the web.

Provision of historical data / time series on request for scientific and/or technical applications.

www.meteo.gr/stations/naxos

REAL-TIME OBSERVATIONSREAL-TIME OBSERVATIONSREAL-TIME OBSERVATIONSREAL-TIME OBSERVATIONS

REAL-TIME OBSERVATIONSREAL-TIME OBSERVATIONSREAL-TIME OBSERVATIONSREAL-TIME OBSERVATIONS

REAL-TIME RAIN OBSERVATIONSREAL-TIME RAIN OBSERVATIONSREAL-TIME RAIN OBSERVATIONSREAL-TIME RAIN OBSERVATIONS

www.meteo.gr/meteosearch

HISTORICAL HISTORICAL DATADATA

HISTORICAL HISTORICAL DATADATA

HISTORICAL DATAHISTORICAL DATAHISTORICAL DATAHISTORICAL DATA

DESCRIPTION OF THE LIGHTNING DESCRIPTION OF THE LIGHTNING DETECTION NETWORKDETECTION NETWORK

DESCRIPTION OF THE LIGHTNING DESCRIPTION OF THE LIGHTNING DETECTION NETWORKDETECTION NETWORK

A long-range lightning detection network with receivers located at six sites over Europe (Birmingham in UK, Roskilde in Denmark, Iasi in Romania, Larnaka in Cyprus, Athens in Greece and Mazagon in Spain).

The network is operated by the National Observatory of Athens since 2005. The location of flashes are given in real-time at NOA’s web-site:http://www.noa.gr/forecast/lightning.gif

ZEUS NETWORKZEUS NETWORKZEUS NETWORKZEUS NETWORK

ZEUS receivers record the radio noise (sferics) emitted by cloud-to-ground lightning discharges in the very-low-frequency (between 7-15 kHz). The VLF signal is preamplified at each receiver site and the signal is synchronized to GPS time. At each receiver site an identification algorithm is executed and is capable of capturing up to 70 sferics per second. Then the lightning location is retrieved (at the central station of the network) using the ATD triangulation technique. The ATD values represent positions between two outstations with the same time difference, and their intersection defines a sferic fix.

LIGHTNING METEOROLOGYLIGHTNING METEOROLOGYLIGHTNING METEOROLOGYLIGHTNING METEOROLOGY

The ZEUS lightning detection network operated by the National Observatory of Athens is/has been used in order to study among others the :

relationship between lightning activity and physiographic characteristics relationship between lightning and cloud microphysical properties relationship between lightning and rainfall use of lightning as a nowcasting tool use of lightning for assimilation in NWP models.

LIGHTNING AND PHYSIOGAPHIC LIGHTNING AND PHYSIOGAPHIC CHARACTERISTICSCHARACTERISTICS

LIGHTNING AND PHYSIOGAPHIC LIGHTNING AND PHYSIOGAPHIC CHARACTERISTICSCHARACTERISTICS

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.

LIGHTNING AND PHYSIOGAPHIC LIGHTNING AND PHYSIOGAPHIC CHARACTERISTICSCHARACTERISTICS

LIGHTNING AND PHYSIOGAPHIC LIGHTNING AND PHYSIOGAPHIC CHARACTERISTICSCHARACTERISTICS

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.

MonthEver-green need-leaf

forest

Decidu-ous

broad-leaf

forest

Mixed forest

Wood-land

Wooded grass-

land

Closed shrub-land

Open shrub-land

Grass-land

Crop-land

Bare ground

DJF 0.7 0.6 0.5 1.1 0.9 2.4 1.7 0.9 0.9 0.9MAM 1.2 1.4 1.4 1.2 1.2 1.0 0.8 1.0 1.3 0.4JJA 1.8 1.5 1.7 1.5 1.3 0.5 0.4 1.1 1.4 0.1SON 1.0 0.7 0.6 1.2 1.2 1.5 1.3 1.1 0.9 0.8

LIGHTNING CLIMATOLOGYLIGHTNING CLIMATOLOGYLIGHTNING CLIMATOLOGYLIGHTNING CLIMATOLOGY

Thunderstorms and the accompanied lightning activity might be dangerous for :

- human life (loss of 1 person/year)

- the physical environment (forest fires)

- the economic environment (damages to infrastructure, cultivations, …) when heavy rain rates / rainfall produce severe flood events.

The knowledge of the spatial and temporal distribution of lightning activity is important for public authorities and for the design of the lightning protection of infrastructure.

FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)

FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)

FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)FLASH DENSITY (#/km2/year)