Wednesday, December 14, 2011

Prague's Past and Future

Present day Prague, Czech Republic




Throughout this blog, we have been discussing what the current weather patterns and climate is for Prague, Czech Republic and the climate factors that affect this city. But what about what this city would have been like 100 million years go? Would the weather still be the same? Would the climate controls be the same? The answer to this is, no! The Earth 100 million years ago was a much different place then it is today. Not just because humans were non-existent, but because the earth's plates where in much different areas then they are presently. The map below, shows Earth how it is thought to be 100 million years ago with Prague denoted with the red circle around it.




Europe 100 million years ago was not the body of land that it is today. Scandinavia was one large island, Italy its own, and multiple other countries made up their own islands in the Atlantic Ocean. The Czech Republic was itself its own island situated at about 40 degrees north longitude and 4 degrees east latitude compared to its coordinates today at 50°05"N longitude and 14°27"E latitude. Because Europe was not the large continent that it is today 100 million years ago, we can only speculate that this island was in fact the Czech Republic. It is very possible that the land that Prague sits on today, was buried under the sea. For educational purposes, we will assume that for this blog that this island was indeed the land that Prague is situated on today. (See current Prague climate graph below)



100 million years ago, Prague had much different weather. To begin, the centrally located city that it is today was, back then, situated on an island which brings us to the first major weather and climate change. Because of the land mass now being completely surrounded by water, the temperatures were much more warmer, there was much less variance in diurnal temperatures, and winters were much warmer than they are presently. As we know, water is the largest conductor of heat energy. During the day large radiation waves from the sun are emitted and absorbed by the water in the sea surrounding the island. This causes daytime temperatures to stay moderate to warm averaging around 83 degrees in the summer months down to around 65 degrees at night compared to a high of about 55 degrees in the winter during the day and 43 degrees at night for the low. (See climate graph below)



Prague was also a much wetter place then it is today because of the larger presence of the maritime tropical (mT) and continental tropical (cT) air masses that affected it. The presence of the mT air mass had the greatest effect on the island's weather which brought with it warm air but also the presence of precipitation especially during the winter months. Snow was nowhere around during these years as well due to the lack of the polar continantal and arctic maritime air masses seen today. Based on the Koppen-Geiger climate model, Prague 100 million years ago would have been classified as a warm temperate, dry summer, hot summer (Csa) climate. Much like most of the Mediterranean countries today.


What may be an even better question to ask is what Prague will be like 100 million years into the future. Just as no one knows for sure what it was like in the past, it is even more uncertain to determine what it will be like in the future. Based off of my observations, I have determined Prague's location in the future and denoted by the intersection of the red lines in the map below.





Based off of the video and map provided, I do not believe that Prague's location geographically will change very much, but it looks as though it may shift north-east. As the years progress, the continent of Europe is expected to collide with Northern Africa causing the Mediterranean Sea to disappear. This will cause great continentality among many of the countries currently affected by a lot of maritime air masses such as Spain and Italy. In Prague's case however, it will just increase the city's current continental locale.

I believe that Prague in the future is going to be much more affected by the continental polar and continental arctic air masses and much less, if at all, affected by the maritime tropical and maritime continental air masses because of its increasing continentality. This will cause diurnal temperatures to continue to fluctuate greatly and seasonal temperatures to be vastly difference as well. Snow in the winter months will also be slightly higher then they are now but due to the continued presence of the small mountain ranges surrounding the city, it still will not be a vast change. (See climate graph below)


Sources:
weather.com
http://www.youtube.com/watch?v=pGACbD4zbWs
http://www.cpgeosystems.com/105moll.jpg
http://www.youtube.com/watch?v=pGACbD4zbWs

Tuesday, December 6, 2011

Prague, Czech Republic VS Palm Desert, California

Comparing the climates of Prague and Palm desert is almost like comparing apples to oranges. On the one side on the globe (Prague) you have a very temperate climate with a vast diversity of vegetation and on the other, a very arid and dry desert climate that receives less than 5 inches of rainfall per year. Meso-Scale variables that affect Palm Desert include the presence of the San Jacinto Mountain Range to the immediate west which have an immense impact on the amount of precipitation that the area receives, or doesn't receive. The impact of orthographic lifting causes this region, along with its location geographically (33° 44′ 18″ North, 116° 21′ 50″ West) to be a very dry region of the United States along with it being located around the area of subtropical highs.

    Geographic Locations of Each City




Palm Desert City View                                                   Prague City View (note vegetation differences)











Photos courtesy of desertweather.com and stayamber.com






So if Prague and Palm Desert are both affected by orthographic lifting then why don't they share the same climate types? The biggest factor contributing to this difference is the distinct difference in each citys' geographical location. Palm Desert is located in an area that is highly dominated by continental tropical (cT) air masses that keep the land very hot, arid, and dry. Prague is affected by more continental polar (cP) and maritime polar (mP) air masses that make temperatures much cooler and humid than that of Palm Desert. Though substantial precipitation is not often seen in Prague, there is defiantly much more then in the desert.

Similarities in the two climates include the factor of continentality. Both locations are situated inland from water bodies which causes vast differences in annual and diurnal temperatures. Without any water bodies around to act as heat sinks by absorbing large amounts of solar radiation, both cities get much cooler at night and in the winter months. However, to the south of of Palm Desert lies a lake called Salton Sea which, though is not nearly as large as an ocean, may serve as a moderate temperature regulator for the area and might contain the average high under 100 degrees in the summer months.

    Palm Desert's Location and Proximity to Salton Sea
(Source: googlemaps.com)


Micro-scale variances in locals are somewhat similar in that humans have had a great impact on the climates experienced in the areas. While many would think that Palm Desert is in an area that is unsuitable for humans to live considering the many days of unbearable heat and lack of water and vegetation, this area is actually home to a decent sized population of about 50,000 people and about another 45,000 people 11 miles to the East in the popular city of Palm Springs. People moving into this area have had effect on the landscape by increasing water in the area through plumbing and sprinkler systems used to water non-nativel vegetation brought to the area for lawns, planters, trees, etc., which puts moisture into the atmosphere through evaporation. In Prague, temperatures in the city have increased due to the urban heat island effect and the city's history as having a moderately large industrial sector.

                                 This is a great ariel photo of non-native vegitation in thhe desert.
                               Photo courtesy of: vigorousnorth.com


Palm Desert Average Monthly Temps.                 VS      Prague Average Monthly Temps.

(Source weather.com)


Palm Desert Average Yearly Rainfall                               Prague Average Yearly Rainfall

(Source weather.com)


Koppen-Geiger Classification Comparisons
(Locations marked with Red dots)



As you can see in the comparison above (though it may be hard to tell for Palm Desert), Prague is classified as a Cfb climate which represents a warm-temperate climate that is fully humid with warm summers. Palm Desert on the other hand is classified as being a Bwh climate which represents a dry climate that is a desert in terms of precipitation and is very hot in the summers and temperatures always average above the freezing point.


Sources:
4.

Thursday, December 1, 2011

Climate Controls

When examining Prague's current climate conditions and weather patterns, it is important to understand it's meso-scale and micro-scale climate controls. Meso-scale controllers are those that are at a regional scale that affect the location such as geographical local while micro scale controllers are those that are more localized.

Prague's geographical location at 50°05"N and 14°27"E puts the city right in the heart of the mid-latitude climate which can cause great changes in seasonal temperatures. The city can also receive decent amounts of rainfall during the summer months, however, due to some orthographic lifting and its far location from the ITCZ, large and continuous rainfall is rare. Because of it's location, the area is often affected by Icelandic Lows and Azores highs that are common in the Northern Hemisphere. The Azores highs can bring in dry, warm air into the region during the summer months but can be replaced by the onset of the Icelandic low which brings storms to the area.  Prague's locale, being a very central city on the continent of Europe, has a large effect on the temperature of the city as well. Due to continentality, the sun's long waves are absorbed by the ground and reflected back into the atmosphere. This causes the summer months to be relatively warm and the winter months to be cold as well as significant diurnal temperates as well.

Icelandic Low                                                                    Azores High









On a micro-scale level the area is in the bottom of the Bohemian Basin which casues a lot of differences in preciptation in the area when compared to areas in the mountains around. The city is also affected by the urban heat island effect due to the city's population of 1.3 million people. This causes temperatures the be warmer in the city then it might be in the country side or other smaller cities nearby.

When referring to the Koppen-Geiger classification (see image below), the city is classified as a warm-temperate climate that is fully humid with warm summers. This is common to most of Europe outside of the Mediterranean region and Scandinavia.









Weather Patterns from Dec. 2010 to Dec. 2011




Sources: