Shanghai - Final Weather Blog

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Shanghai 100 Million Years Ago (-100my): Compared to other locales around the globe, China has remained relatively stationary for the last -100 my. China’s physical location and orientation has not changed much because it is part of the large Eurasian land mass and a part of the Eurasian plate.  Shanghai has remained an Eastern coastal city in the Northern hemisphere and is roughly located at the same longitude and latitude.  

Source: Lecture Slides

-100my Shanghai, like the rest of the planet was in the Late Cretaceous Period.  The Vostock Ice core sample shows that that period in earth’s history is an inter-glacial  period.  The lack of glaciers  are caused by several naturally occurring processes working in concert to prevent an ice age. The most important of these factors are Milankovitch cycles, which describe cyclic changes in the Earth's eccentricity (the shape of the Earth's orbit), the tilt of the Earth's axis and the “wobble” of the Earth as it spins around its axis.  Sometimes these factors align to bring the Earth closer to the sun, which would cause an increase in surface temperature on  Earth.
 
Since the planet was warmer, and there were no glaciers, we can assume the overall sea level was higher than present day.  It is very likely that Shanghai was under water 100 mya.  

Source:NOAA

For the remaining analysis I will provide a description of the climatic conditions for a generic coastal location in what is now modern day China.

Despite the fact that the Eurasian landmass did not change much, we can infer some likely Macro, Meso and Micro scale climatic perturbations.


Macro: The physical location is similar to modern China, however other continents have changed. The movement of other continental plates and lack of global glaciations would dramatically change oceanic and atmospheric streams.  The lack of glacial ice in the northern hemisphere, would lead to warmer summers and warmer winters. The global increase in temperature would likely have made coastal China a warm and tropical location. (make up climagraphy)

Source:Weatheronline

Meso: Euraisia, would have still been the largest continental mass on the planet and subject to monsoon type events.  My assumption is, monsoon season would be longer and more intense with warmer sea surface temperatures.  The summer time temperatures would have been higher, causing sea surface temperature rise and build up of higher pressure over the ocean. That warm moist air would move inland and dump torrents of rain on China during the spring, summer and fall months.  Without the cooling periods during the winter months, there would not be the continental High-pressure systems that pushed cold air toward the East China Sea.  That would likely lead to year round precipitation for coastal China. 

Micro: The assumption that the year round temperature would have been warmer and precipitation would have been higher would have dramatic impacts on the local environment.  The increase in temperature and precipitation would have possibly allowed for more biodiversity.  Canopy like jungle vegetation would have completely changed the ground cover albedo for the region. The increase in precipitation would have also likely caused the creation of lakes, marshes, rivers and higher sea level. The increase in water coupled with the increase in vegetation would lead to higher humidity and foggy conditions.  

Source: NOAA

Shanghai 100 Million Years from now (+100my): Over the course of the next +100 my, there will likely be as many changes as the past 100my.  Continental drift will continue to occur and Milankovitch cycles will continue to define glacial and interglacial periods of future.  The predicted tectonic models generally show the re-formation of a world island in the Northern hemisphere.  Changing the distribution of continents and oceans will have a dramatic impact on the climate of China.  Additionally, the assumption for this analysis is the northern hemisphere is tilted away from the sun and highly elliptical, resulting in a glacial period for locations above 60 degrees north.  

Further Assumptions: Although extrapolation of data is sometimes dangerous and misleading, I believe it’s safe to assume the planet  will continue to experience periods of glaciations and inter-glaciations. If the Milankovitch cycles are extrapolated for the next 100my, there are dozens of periods when the earth is under an ice age.  It is possible, if not likely, that anyone of those periods would cause an extinction of the human race. 

The analysis presented in this portion of blog is derived from several wild assumptions and the hypothetically timeline (below) to contextualize and frame my logic. 

Source: Vostock Ice Sample

It is highly unlikely that humans will exist on this planet 100 thousand years from now, much less +100 million years from now.  The basis in my claim is based on the degradation of resources and the climate itself.  By most reasonable estimates we will collectively exhausted fossil based fuel source within the next  200-300 years.  It is unclear to me what direction we will take on the path of alternative energy, but unless there is a massive leap forward in technology, it will fall short of replacing fossil fuel.  In either case, the amount of CO2 actively being emitted into the atmosphere will no longer come from anthropogenic sources.  Removing the acceleration of anthropogenic sources from the climate change equation, essentially changes nothing in the big picture.  In the history of the world, extinction is the rule not the exception. In my opinion, it is highly unlikely modern civilization will survive an ice age. 

Source:weatheronline

Macro: Despite the fact that humans will no longer remain a factor in future Shanghai, we can infer the macro scale climate based on future land and ocean distributions.  Tectonic models show the formation of a large world island in the northern hemisphere.  That will have a dramatic impact on the climate of Shanghai. Shanghai will no longer boarder the broad ocean, instead it will be cut off by Australia.  There will  be a sea separating Shanghai and Australia (at least for a while).  The sea will serve to somewhat moderate the temperature of Shanghai However, the fact that the majority of northern latitudes are currently glaciers, the sea would  most likely be very cold water and Shanghai would be a cold dry climate. 

Meso: The formation of the new super continent would have change the meso scale climate controls for Shanghai as well.  Shanghai would no longer have the same monsoon cycles that it currently has.  The reason, Shanghai would now essentially be  a continental location vs a coastal location.  My assumption is when Australia and China collide; a massive mountain range will form.  The mountain range will put Shanghai  on the leeward side of the range and in a rain shadow, essentially boxed in from the South and East. That would make Shanghai a very cold and semi arid climate.  The dominate atmospheric circulations would be cold air funneled from the northern artic regions. Under new conditions, Shanghai will receive most of its annual rainfall and snowfall as direct result of having their own sea.  During the short summer months, the sea may receive enough solar radiation to cause convective heating and cause local “lake effect rain”.  During the winter, as cold air passes over the top of the warmer sea air masses, lake effect snow would develop.

Micro: The new Shanghai has a harsh environment that is very cold and arid.  The mountains prevent warm air from the south from moving in to during the summer months.  The area is likely a snowfield for most of the year.  Being covered in snow means most of the solar radiation is immediately reflected and the area benefits little from the short summers.  Biodiversity is minimal and most plants and animals are not able to sustain life.


Conclusion: +100my from now our legacy on earth’s surface will be a dirty spot in the ice for future life forms to wonder about.  Essentially, current discussions of climate change and its cause is nearly pointless.  There is undeniable evidence that the earth’s climate is changing, and there is compelling evidence that anthropogenic activity is accelerating that change.  The reality is, it does not matter. 


The conversation should shift from a blame-based dialog to a solution-based dialog.  The climate has and will continue change whether humans are part of the problem or part of the solution. In the mean time, the underlying issue is how much human suffering will come at the expense of failing to plan for the inevitable impacts climatic changes. 














Sources:
http://www.yale.edu/ynhti/curriculum/units/1991/6/91.06.05.x.html
http://pubs.usgs.gov/gip/dynamic/dynamic.html
http://science.nasa.gov/science-news/science-at-nasa/2000/ast06oct_1/
http://www.scotese.com/earth.htm
http://earthguide.ucsd.edu/virtualmuseum/climatechange2/03_1.shtml
http://www.ncdc.noaa.gov/paleo/ctl/100k.html
http://www.ucmp.berkeley.edu/mesozoic/cretaceous/cretaceous.html
http://www.scotese.com/lcretcli.htm
http://www.ncdc.noaa.gov/paleo/ctl/beyond.html
http://www.ncdc.noaa.gov/paleo/ctl/resourcebeyond.html

Shanghai, China VS Lima, Peru

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Macro Scale Differences: The cities of Shanghai, China and Lima, Peru are affected by very different climatic controls. According to the Koppen scale, Shanghai is a Cfa (Warm, fully humid, hot summer), and Lima is Bwh (Arid, Desert, Hot).  Shanghai, is a North latitude city and on the Eastern coast. Lima is a South latitude city and on the Western Coast these factors are the primary conditions that define the differences between the two cities.

The difference in latitude causes Lima to experience their warmest conditions during the months that Shanghai is experiencing their coldest conditions.  There is also a considerable difference in the amount of direct solar radiation and impact of the ITCZ on the two locations. Shanghai, at latitude of 32 N, experiences relatively low solar angles dung their winter months and impart leads to lower temperatures.  Lima, at a attitude of 12 S, is near equatorial and experiences higher solar angles (and longer days) year round.  

Shanghai is on the Eastern coast and of the Asian continent and is influenced by the colder and Pacific oceanic currents. Lima is on a Western coast and is influenced by warmer currents of the Pacific ocean.  Interestingly, both sites are typically affected by a combination of Mp and Mt air masses originating from opposite hemispheres. 

Meso Scale Differences: Shanghai, experiences fairly dramatic temperature ranges and weather patterns primarily related to seasonality and pressure differentials.   The pressure differentials are caused by a seasonal change in High and Low pressure systems. This change is directly related to the size of the Asian land mass and the vast expanse of the Pacific Ocean.  The change in pressure causes  Shanghai to experience extreme monsoon weather patterns during their summer months.  There is little direct orographic impact on Shanghai, primarily because Shanghai is a low-lying coastal area and has no major mountain ranges.

Lima, has a very mild year round tropical climate. Their climate is primarily influenced by proximity to the Pacific Ocean and the cool air created by the Andes Mountains to the East.  Lima, similarly to Shanghai, receives most of their precipitation (though much less) during their summer months.  However, a different process causes their rain.  The primary process that causes rain in Lima is convective orographic lifting.  Lima is on the western slope of the Andes Mountains and does not typically receive much rain. The moisture producing air masses do not typically form rain clouds until the reach the mountains. Lima receives most of their water supply from runoff and snowmelt. 

For Current Lima Weather : Click
For Current Shanghai Weather: Click

Micro Scale Differences:  Both Shanghai and Lima are very large and industrialized cities. However, Shanghai has a population that is more than double that of Lima.  The increase in population and the decrees in vegetative cover can have a dramatic impact on the micro scale climate.  Both cities likely experience the effect of urban heat island and degraded natural environment. Lastly, both cities are low lying coastal cities and under current modeling predictions will likely be severely impacted by  by sea level rise. 

Meso and Micro Scale Climate Controls

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Climate Classification: According  to the Koppen/Geiger climate classification; Shanghai is a humid subtropical climate. This climate occurs primarily because of latitude, proximity of the Pacific Ocean and other dominate oceanic currents.  In addition, there are separate regional and local climate controls that influence climate and weather in Shanghai. 

Meso-Scale: The most important influence on Shanghai weather is China’s monsoon season; one of the most produced monsoons in the world.

Air Mass Dominance: The pairing of the planets larges land mass and the expanse of the Pacific ocean set the conditions for incredibly intense monsoon events.  During the months  of June-August, the continental land mass develops very low pressure. The high temperatures and oceanic currents cause the ocean to develop high-pressure systems pushing warm moist air inland.  This annual cycle defines much of Chinas weather, climate, history  and cultural geography. Modern Chinese history from 1900 to present has been (and likely before), has been plagued by severe flooding.  During the 1930s alone over 4.6 Million people died in flood events that were related to seasonal monsoon rains.  In more recent years, intense monsoon flooding has displaced hundreds of millions of Chinese and caused Billions of dollars in damage.   Current and ongoing research indicates there is a statistically significant link between years of intense monsoon flooding and El Niño years. 

Micro-Scale: Two naturally occurring factors that influence Micro-Scale Climate are local topography and proximity to water. 

Orographic Situation: As a coastal city, Shanghia has a very low elevation and is a drainage basin for air masses from the North and East. The karst topography  and valley regions to the South and West of the city likely serves as a blockade and prevents air masses from passing directly through the city. 

 Proximity to Large Water Bodies: The city of Shanghai is faces the East China Sea part and is bisected by the Huangpo River. The low elevation and abundance of waters sources in the region has several impacts on the Meso-scale climate.  The Huangpo River affects the weather by  serving as a cold air funnel to move cold mountain air from the north toward the East China Sea in the winter. Additionally, area lakes in conjunction with rivers and the ocean cause unbearable humidity in the summer.  The humidity also causes a great deal of fog in the area that interacts with the pollution to create poor air quality. 

Urban Heat Island: Several anthropogenic forces influence Shanghai’s weather.  The most notable is the development of a major heat island. Shanghai has essentially developed from a medium sized city into one of the world larges mega cities in the past 30 years. The rapid rural- to urban demographic shift and drive for industrialization has transformed Shanghai in to a city with a population of over 20 Million.

The rapid development has changed the natural vegetative cover, by replacing productive farming grounds with concrete and sky scrapers.  The change in local albedo will likely make the city retain daytime heat longer, achieve higher temperatures and potentially create uplift and thunderheads.  China has also “re-claimed” swamp and lake areas turned them in to business centers and housing developments.  The rate of growth and the intensity of production has had a entirely negative impact on the air quality and most days the sky is a soot grey soup.  The smog has the capability to influence the climate on its own. The soot can prevent long wave radiation from escaping the local atmosphere. Trapping the heat can further increase the local temperature and local humidity. 

Shanghai--- VS--- Los Angles

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Compare:  Los Angeles (LA) and Shanghai have similar geographic descriptors and at times have similar weather and climate characteristics.  Both locals are low latitude, LA is approximately 34 degrees N and Shanghai is around 31 degrees N.  The latitude affects the sub solar point and ultimately seasonality and hours of daily sunlight.  The two cities are separated by over 7,000 miles of broad ocean and are both highly influenced by temperature moderating oceanic currents.  Cool sea air moving inland helps moderate and keep both cities cooler than expected ( for a lower latitude city) in the summer. The urban footprint and large populations (Shanghai 20Mil / LA 10 Mil) have an impact on the natural balance.  Both cities are urban heat islands and expel excessive smog in to the atmosphere. 

 Contrast: Shanghai has much colder winters than Los Angeles.  The main reason is the impact of seasonal pressure differences in China.  In the winter months the high pressure over the continental land mass allows  arctic air masses from the north to move toward the South China Sea. The generally flat topography to the North of Shanghai allows the cold air to readily move in to the coastal area.  The mountains are not as defined as they are west of LA and serve to funnel cold air into the city.  In  Los Angles  on the other hand,  significant topography isolates the city from cold arctic air and in the winter time. LA is mostly subjected to the more moderate Santa Ana winds from the deserts to the west.

Hurricanes and Typhoons:
LA is located on the western cost of the United States is generally  protected from tropical storms and hurricanes. Storms that develop off the coast of LA usually dissipate or turn in to high precipitation events in the Pacific Northwest. Shanghai on the the opposite side of the Pacific Ocean has a very active tropic storm season from June- December.  Tropical storms and typhoon formation in China is caused by warm ocean currents to the south and east of Shanghai and track in to the South China Sea. The formation of typhoons and storm surge have histrically cost Shanghai billions of dollars and killed thousands of people.

Fronts, Ocean Currents and Topography

Frontal Systems: Shanghai weather is significantly impacted by frontal systems throughout the year. The seasonal shift in the sub solar point and the corresponding shift in continental pressure cause seasonal climatic and frontal variation to occur. October is a transitional month in local weather and predominantly influenced by late summer wind patterns. The current barometric pressure and  image serves to demonstrate the prevailing HIGHER pressure coming from the ocean. (See Figure 1)




 



Ocean Currents: Higher pressure leads to predominantly westerly winds (seaward) , which are generally warmer and influenced by tropical  Kurishio oceanic  currents and tropical air masses in the summer. In the coming months, the sub solar point and the impacts of the shifting ITCZ will allow cooler ocean currents and air masses to push in to the Shanghai area. The Oyashio current forces cooler ocean water move in to the South China Sea during the winter months. The combination of shifting and cooling ocean currents, southward movement of Continental Polar (cP) and Continental Artic (cA) air masses causes the land mass to drastically cool off during the winter (see figure 2). The cooling land mass will change the continental pressure and cause winds to shift to a cold easterly wind. As the cooler air moves toward the Sea, Shanghai weather will cool off and be less influenced by the Sea temperature.


Topography: Shanghai is generally in a basin with several major rivers flowing in to the area. The rivers funnel cold air from higher eastern elevations in the Shanghai region. There is very little topography to the North of Shanghai. The lack of topography will allow cold arctic air masses to move in to Shanghai. The mountain ranges to the South, South West and West of the region can possible serve to keep cold air trapped in the valley. (see Figure 3 and Figure 4).

WebCam: **It always seems to be hazy in Shanghai, part of the haziness is the impact of fog from the ocean. Heavy and rapid industrialization  and mass consumption of coal also contribute greatly to the Shanghai haze.

Shanghai Climate and Seasonality

Shanghai Skyline:
http://www.flickr.com

Introduction: Shanghai is a coastal Mega City with a population over 20 Million people and growing.  The city is one Chinas largest population  centers  and is often referred to as China’s showcase to modernity.   Located at 31 Degrees North Latitude and along the South China Sea; Shanghai’s weather and climate are highly influenced  geographic location and seasonal weather patterns.   

Seasonality:  Shanghai is a northern hemisphere location and seasonal climate paterns similar to what we experience in the United States.  Located at   31 degrees North latitude means Shanghai receives fairly high solar angles throughout the year.  Shanghai, experiences all 4 seasons with receives some temperature moderating impacts from the proximity to the ocean. The relatively low latitude also indicates that Shanghai has a semi-tropical and humid climate.  The humidity is typically higher during the spring and summer months, influenced  by the monsoon season.

Shanghai Climate graph contributed by climatetemp.info

Generalized Monsoon
meted.ucar.edu

High and Low Pressure:  Shanghai is located in the Yangtze River delta and experiences extreme  rainfall runoff  and drought cycles.  These cycles are defined by seasonal variations in atmospheric pressure between the continent and the ocean.  During the winter , cold dry  weather over the Asian continent creates high pressure systems that force westerly air masses toward the South China Sea.  In the summer an opposite effect occurs, low pressure over the Asian continent allows moist air to come inland. This process creates conditions for monsoon season. Monsoons in Shanghai are very pronounced and have detrimental impacts on the lives of the people living in the region.  Shanghai receives most of its annual rainfall in during the late summer months of July and August.