Ξεκινάμε μια προσπάθεια να εμπλουτλισουμε περαιτέρω την βιβλιοθήκη μας ξεκινώντας με 2 βασικές έννοιες αυτής της θερμότητας και της θερμοκρασίας.

Αρχικά πρέπει να οριστεί η θερμοκρασία και η θερμότητα.

Θερμοκρασια είναι ένα μέγεθος που μας πληροφορεί πόσο ζεστό ή κρύο είναι ένα αντικείμενο σε σχέση με μια σταθερή τίμη.

Γνωρίζοντας ότι ο αέρας είναι ένα μείγμα αμέτρητων ατόμων και μορίων, αν ήταν ορατά θα διαπιστώναμε ότι δεν κινούνται όλα με την ίδια ταχύτητα, μέτρο και διεύθυνση. Η ενέργεια που σχετίζεται με την κίνηση αυτή λέγεται κινητική ενέργεια (θερμική ενέργεια). Η θερμοκρασία του αέρα είναι το μέτρο μέτρησης της κινητικής του ενέργειας. Πιο απλά, θερμοκρασία είναι το μέτρο της μέσης ταχύτητας των ατόμων και των μορίων, όπου υψηλότερες θερμοκρασίες αντιστοιχούν σε υψηλότερες μέσες ταχύτητες.

Δεδομένος όγκος αέρα, εάν ζεσταθεί τότε τα μόρια του κινούνται ταχύτερα απομακρυνόμενα μεταξύ τους και ο άερας γίνεται αραιότερος-θερμότερος. Το αντίστροφο συμβαίνει κατά την ψύξη του αέρα(πιο αργή κίνηση>πυκνότερος-ψυχρότερος αέρας) .

Εαν ψύξουμε σύνεχως τον αέρα μέχρι την ελάχιστη θερμοκρασία των -273° C που λέγεται απόλυτο μηδέν , τότε τα μόρια δεν έχουν καθόλου (θεωρητικά) θερμική κίνηση.

Θερμότητα είναι η ενέργεια που μεταφαίρεται από ένα αντικείμενο σε ένα άλλο εξ αιτίας της διαφορετικής θερμοκρασίας μεταξύ τους. Στην ατμοσφαίρα η θερμότητα διαδίδεται με αγωγή, μεταφορά και ακτινοβολία.

Κλίμακες Θερμοκρασίας

Για τη μέτρηση των χρησιμοποιούνται πολλές κλίμακες. Με βάση το απόλυτο μηδέν έχουμε την λεγόμενη ”απόλυτη κλίμακα” θερμοκρασίας ή κλίμακα Kelvin, από το βρετανό φυσικό Kelvin. Δύο άλλες κλίμακες που χρησιμοποιούνται σήμερα είναι οι κλίμακες Φαρενάιτ (Fahrenheit) και Κελσίου (Celsius). Η κλίμακα Φαρενάιτ ανακαλύφθηκε το 1700 από τον φυσικό Φαρενάιτ που προσδιόρισε τον αριθμό 32 ως την θερμοκρασία πήξης του νερού και το 212 ως το σημείο βρασμού του με 180 ίσες υποδιαιρέσεις που ονόμασε βαθμούς(℉) .

Η κλίμακα Κελσίου προσδιορίστηκε αργότερα τον 18ο αιώνα. Ο αριθμός (0) αντιστοιχεί με την θερμοκρασία πήξης του απιονισμένου νερού και 0 αριθμός 100 στη θερμοκρασία βρασμού του στο επίπεδο της θάλασσας, με 100 ίσες υποδιαιρέσεις που ονόμασε βαθμούς(° C).

Ο συσχετισμός των παραπάνω κλιμάκων θερμοκρασίας και οι εξισώσεις μετατροπής στις αντίστοιχες κλίμακες είναι.

°C=5/9*(℉-32)

K=° C + 273

 

EUROPE WEATHER OVERVIEW MAP MAY

The weather is going to change dramatically the upcoming week in central and mainly eastern Europe from Sunday (12/5/2019) presenting autumnal traits.

 

In particular, from Sunday and then, the Azores anticyclone will be gradually developed and established in western Europe with a centre over the UK. This will result in better (fair and dry) weather conditions in western Europe with hot for the season temperatures over south and west Iberia (up to 35-37°C).

This situation will push colder arctic air masses to invade north and eastern Europe. Snow will occur in north-central Scandinavia even on lower ground regions, while some snow may be observed over hills/mounts in the northern regions of central/eastern Europe (such as eastern Germany, Poland etc).

Next, the majority of eastern Europe, from Italy and further to the east, will be affected by stormy and colder than average weather with rain at times and afternoon thunderstorms mostly in central and western regions. The most severe weather, where hailstorms may occur, is expected in eastern Italy, western Balkans and possibly regions of northeastern Balkans far from the sea.

The weather will remain fair, dry and hot in Cyprus and eastern Turkey.

 

The weather may completely be reversed from 18/5/2019 and then with a possible heat wave in southeastern Europe and rainy weather for the western.

 

You can stay informed about the weather following our facebook group and youtube channel.

 

EUROPE WEATHER OVERVIEW MAP MAY

 

 

An African dust advection episode is in progress this week. Its maximum activity will be observed during Orthodox Good Friday (26/4/2019).

In particular, on Friday (26/4/2019) most countries of eastern Europe (see map) will be affected by this phenomenon. Italy, west Balkans, Greece and Turkey will be affected the most, while some dust may be observed even in southern Scandinavia.

This dust episode will remain on Saturday in these countries tending to weaken. However, on Sunday (Orthodox Easter) the dust load will be restricted around Greece and Turkey and maybe Ukraine and western Russia presenting a noticeably weaker intensity.

 

dust african map

 

Stormy weather for southern, slightly cold at south east, mostly dry in the north. This is an overview of the weather in Europe around the Catholic Easter (20-22/4/2019).

 

The driest conditions should be expected in central-southern UK, around North Sea, southern Scandinavia and central-northeaster Europe with temperatures up to 17-20°C. Dry weather in the Aegean Sea, a bit cloudy (chances for short/light showers) in northern Crete on Saturday (20/4/2019) with temperatures between 14-17°C.

The weather will be normally rainy and windy at times in Scotland, northern Ireland, Iceland and northern Scandinavia, with a possibility for some snow over mounts of the very north of Scandinavia. The temperature will not exceed 10-12°C.

Convective weather will dominate in Iberia, southern France and eastern-southern Balkans with thunderstorms or showers mainly in the afternoon. However, on Monday storms will expand over Italy and Adriatic, where rainy/stormy conditions will occur. The temperature ~15-20°C.

The weather will be colder in Turkey and Cyprus and the rest of southeastern Mediterranean Sea with rain and snow over mounts. The temperature around 8°C in Turkey, not higher than 15-17°C in southern.

 

You can stay informed about the weather following our facebook group and youtube channel.

 

At least nine people have been killed by flash floods in Rio de Janeiro.

The mayor has declared a crisis after the Brazilian city was battered by heavy rain on Monday and Tuesday.

More than 31cm of rain (13 inches) fell in some parts of the city within 24 hours, the mayor’s office said.

 

 

According to Globo TV, 245mm of rain were recorded within just a few hours in Copa Cabana, while the April precipitation average does not exceed 95mm.

 

The satellite images from MODIS-TERRA below show the extremely low-speed movement of the cloud zone that affected the region. This slow movement was one of the most important reasons of this natural disaster.

 

On the maps below showing the condition on Sunday 7/4/2019 (2100 UTC). In the first map, the shallow low pressure system causes a precipitation zone, which is collocated with the cloud zone in the satellite. In the second map, the CAPE index is fairly enhanced causing eventually a quite unstable regime, ideal for the formation of storms.

 

 

Source: MSN

Cold weather is expected in northern Europe and rainy/stormy in southern on 10-15/4/2019.

In particular, in the northern of the UK and continental Europe and the western of Scandinavia, the weather is expected to be dry and cold with chances for light snow showers or sleet. However, region of eastern Scandinavia and northeast Europe will face cold conditions with chances for heavy snowfalls at times. In the rest of the UK, western France, and north-west Iberia the weather will be dry and possibly slightly warmer than average at the beginning, but rainy later with strong winds at the northern areas. In the central and eastern regions of the Mediterranean Sea, the weather is expected to be rainy and stormy  with possibility for heavy rainfalls at times especially at western coasts of this area. The southeastern regions (green area) will face similar weather but with more frequent sunny spells. Finally, dry and warm weather will affect south and eastern Iberia.

 

 

You can stay informed about the weather following our facebook group and youtube channel.

 

SNOW SPAIN

Snow was observed in countries of central-west Europe the first week of April (2019) in Europe. Here, we present you some videos we found on youtube:

 

Snowfalls caused siginificant problems on higher grounds of Spain in the northern regions of Madrid on A1 highway:

 

In the next video, we can see a snow-hail episode in the city of Madrid:

 

 

In the meanwhile, heavy snowfalls occurred in Switzerland on last Thursday (4/4/2019) causing disruptions on the road network:

 

Snowfalls occurred even on lower grounds in Switzerland, such as in city of Zurich. Here, it is a video captured in a region close by the city of Bern:

This particular circulation pattern was being observed quite often this winter affecting with snow and cold weather the eastern Mediterranean. Here we analyse the scenarios for the last days of March 2019.

Gradually, within the last ten days of March, it seems that a strong anticyclonic system will be established over western Europe with its centre over the UK. If this happens, the colder air masses firstly located over Scandinavia will move southwards over eastern parts of Europe passing through Germany and Poland. In contrast, fair weather with foggy morning at places should be expected in the western parts of Europe (including the UK). Next, even if it is a bit of questionable, the cold air masses will move towards Balkans and eastern Mediterranean. Let’s see the three scenarios:

1. The cold air masses move to the west over Italy. In this scenario, the major activity will be observed in Italy and western Balkans with snow mainly over mounts and rainfalls for lower grounds. The cold air mass will be decayed and, thus, the temperature drop will not be significant.

2. The cold air masses move over Greece turning the weather into fairly wintry with low temperatures and snow in central-northern Greece and central-eastern Balkans over mounts and hills (possibility for snow on low grounds of northern regions).

3. The cold air masses move towards Aegean Sea and Turkey causing a short passage of cold weather and some rain (snow for higher grounds) in eastern Greece and heavy snowfalls in Turkey. Cyprus will be also affected with rain and snow over higher grounds.

 

In any of the cases, southern Iberia and northwestern coastal area of Africa will be affected by convection and storms.

 

You can stay informed about the weather following our facebook group and youtube channel.

You can monitor the current temperature observations in southern Balkans through our live maps HERE.

 

 

 

The greatest mushroom museum of Europe is located in Greece and, particularly, in Kalampaka of Trikala.

 

The Mushroom Museum has a rich collection. It consists of mushroom sculptures made one by one, maintaining an absolute color, shape and size similarity. Mushrooms are presented in three stages of development, so that the visitor forms a complete picture of their circle of life. Their presentation is based on the ecosystem that each species grows (beech, pine, fir, oak, meadow, etc.)

Wandering around a specially designed area, which simulates the real environment, visitors can gather information and get familiar with every mushroom.

The Museum organizes guided tours for groups, school classes of elementary, middle and high school students and other special groups. Visitors have the opportunity to become fully informed about the exhibits, the dangers that threaten the individual ecosystems and the environment in general. For the smooth operation of the Museum the tours will be scheduled after contacting us.

 

Below you can have a brief look of some parts of the exhibition:

 

 

More info in english on meteoramuseum.gr

ΧΙΟΝΟΣΤΙΒΑΔΑ ΚΟΛΟΡΑΝΤΟ ΗΠΑ

An avalanche was caught on camera barreling toward cars caught in I-70 traffic in Officer’s Gulch between Silverthorne and Copper Mountain.

According to the person who took the video, most of the snow did not make it to the road and no one was injured.