Download Jack Shaida Photo Journal

Climate and Weather Photo Journal.
Spring 2014.
By Jack Shaida
Table of Contents
Clouds............................................................................................................................................................ 4
Altocumulus .............................................................................................................................................. 4
Altostratus................................................................................................................................................. 5
Cirrocumulus ............................................................................................................................................. 6
Cirrus ......................................................................................................................................................... 7
Contrails .................................................................................................................................................... 8
Cumulonimbus .......................................................................................................................................... 9
Cumulus Humilis ..................................................................................................................................... 10
Fractus..................................................................................................................................................... 11
Nimbostratus .......................................................................................................................................... 12
Partial Lenticular ..................................................................................................................................... 13
Stratocumulus ......................................................................................................................................... 14
Stratus ..................................................................................................................................................... 15
Virga ........................................................................................................................................................ 16
Fog and Haze ............................................................................................................................................... 17
Dust Haze ................................................................................................................................................ 17
Ocean Haze ............................................................................................................................................. 18
Advection Fog ......................................................................................................................................... 19
Frontal Fog .............................................................................................................................................. 20
Radiation Fog .......................................................................................................................................... 21
Upslope Fog ............................................................................................................................................ 22
Valley Fog ................................................................................................................................................ 23
Heat and State Change ............................................................................................................................... 24
Conduction .............................................................................................................................................. 24
Radiation ................................................................................................................................................. 25
Condensation .......................................................................................................................................... 26
Condensation Nuclei ............................................................................................................................... 27
Evaporating Cumulus Clouds .................................................................................................................. 28
Melting .................................................................................................................................................... 29
Precipitation................................................................................................................................................ 30
Drizzle...................................................................................................................................................... 30
Rain ......................................................................................................................................................... 31
Snow........................................................................................................................................................ 32
Snow storm ............................................................................................................................................. 33
Light............................................................................................................................................................. 34
Albedo ..................................................................................................................................................... 35
Blue Sky/ Scattering ................................................................................................................................ 36
Diffraction ............................................................................................................................................... 37
Refraction................................................................................................................................................ 38
Reflection ................................................................................................................................................ 38
Sun Blocked ............................................................................................................................................. 39
Sunrise..................................................................................................................................................... 39
Sunset...................................................................................................................................................... 40
Twilight.................................................................................................................................................... 41
Wind ............................................................................................................................................................ 43
Cold Front................................................................................................................................................ 43
Sea breeze ............................................................................................................................................... 44
Westerly winds........................................................................................................................................ 45
PaleoClimate ............................................................................................................................................... 46
Colluvium ................................................................................................................................................ 46
Boulder Beach ......................................................................................................................................... 47
Ancient Boulder Beach............................................................................................................................ 48
Clay Bed Erosion...................................................................................................................................... 49
Crescentic Gouge .................................................................................................................................... 50
Glacial Striations ..................................................................................................................................... 51
Glacial U-Shaped Valley .......................................................................................................................... 52
Roche Moutonne .................................................................................................................................... 53
Work Sited................................................................................................................................................... 54
AltoCumulus Clouds
April 20th
4:00pm
West
An Altocumulus Cloud is a mid altitude cloud found between 2000m-6000m.
these clouds are composed of small water droplets that are forming small
convection cells. In this picture the clouds are clumped next to each other in a
thin layer.
(Ahrens, 2010)
Altostratus Clouds
10:00 AM
May 11th
View: South
Location: Witchhole Lake
Altostratus Clouds are similar to stratus clouds, but found at a higher elevation. A stratus cloud is only an alstostratus cloud if it is formed between 2000m-6000m. Altostratus
clouds are usually thinner than nimbostratus clouds but thicker than cirrostratus clouds.
Altostratus clouds are formed when a large moist air mass rises all at once, and the water
vapor in the air condenses into small water droplets. If an altostratus cloud becomes thick
enough to produce rain, it becomes an nimbostratus cloud.
(http://nenes.eas.gatech.edu/Cloud/Clouds.pdf
Ahrens, 2010)
Cirrocumulus
4:00PM
April 22nd
Southwest
Cirrocumulus clouds are thin, wispy clouds found at elevations above 5000m and below 12000m. Cirrocumulus clouds are composed of small convecting cells of ice crystals. Cirrocumulus clouds form when there is high moisture in the upper levels of the
troposphere, usually when the weather is cold, like in winter.
(http://www.crh.noaa.gov/lmk/soo/docu/cloudchart.pdf)
Cirrus
10:00 AM
May 11th
Northward at Witch Hole
Cirrus clouds are the highest classification of clouds. They are found between 6000m
and 12000m. Cirrus clouds are wispy streaks formed entirely of ice crystals. In this
picture the cirrus clouds are dispersed into a streaky web by strong winds in the upper
troposphere.
(http://nenes.eas.gatech.edu/Cloud/Clouds.pdf.
Ahrens, 2010)
Contrails
May 26th
View: North
Frenchman Bay
Contrails are clouds or vapor trails formed by the exhaust of an aircraft. The particles in
the exhaust of an airplane act as condensation nuclei that allow water vapor to condense
into relatively large water droplets. A contrail can be found at any elevation that planes fly
at, but usually only persist for long periods of time above 5000m. The time a contrail lasts
is dependent on the humidity and temperature of the air. The higher the relative humidity
the longer the contrail will remain in the sky. On low humidity, high temperature days,
contrails tend to evaporate within minutes.
(Ahrens, 2010)
Cumulonimbus
5:17 PM
May 20th
View: Northwest
at Witch hole
Cumulonimbus clouds are massive convection cells that start as low as 700m
and grow as high as the tropopause at 12000m. Cumulonimbus clouds are
huge, puffy clouds that cause large storms with heavy rain or hail, and sometimes lightning. Cumulonimbus clouds form when a steady supply of warm,
moist air rises in an unstable atmosphere, where the temperature of the
atmosphere decreases with height. This cumulonimbus cloud in this picture
was formed by air being pushed upwards by a cold front. This air rose very
high and condensed before falling down in the cloud in a convection cycle.
As the cloud continues to grow the water particles from the top of the cloud
droplets and merge with other droplets and become larger. By the time the
droplets reach the bottom of the large clouds they formed into large rain
drops that fall to the earth.
(Ahrens, 2010)
Cumulus Humilis
2:54 PM
May 8th
View: South
Cumulus Humulis are low altitude clouds found below 2000 meters that are wider than
they are tall. Cumulus humulis clouds are usually formed when the sun heats a parcel
of are that rise, expands, cools, and condenses, often with the help of condensation
nuclei, forming a cloud. In a cumulus humulis cloud is a thermal convection cell, in
which warm water droplets, heated by realizing latent energy, rises to the top of the
cloud, cools and falls back down to the bottom of the cloud again in continuous cycle.
(http://nenes.eas.gatech.edu/Cloud/Clouds.pdf)
Fractus
12:59 PM
May 14th
On the Western Mountain from Sargent Mountain
Fractus clouds are low lying, tattered, clouds that are formed by wind shear of a larger
cloud. In this picture, precipitation from altostratus clouds cools the surface air where
the rain falls through. At the top of the Western Mountain, the air is cold enough to form
fractus clouds. These clouds are blown by strong winds into their fragmented shape.
These fractus clouds, along with most fractus clouds, formed and dissipated very quickly,
because of strong winds and rapidly changing air temperature and humidity.
(http://www.crh.noaa.gov/lmk/soo/docu/cloudchart.pdf)
Nimbostratus
12:00 PM
April 27th
North East from Jordan Cliffs
Nimbostratus clouds are thick cloud layer found between 1000m and 6000m that produce rain. Nimbostratus clouds cause dreary rainy days, during which light to moderate
rain persists for a long period of time without major pause. Nimbostratus clouds are
often formed when altostratus clouds become thicker and move lower. Rain forms inside
nimbostratus clouds when either ice crystals, snowflakes, or rain falls to the bottom of
the cloud and become larger as they merge with more particles. These larger crystals,
flakes, drops are big enough to fall to the surface as precipitation without fully evaporating. In this picture, nimbostratus clouds are hanging over the sky throughout the entire
day, leading to cold, grey weather with frequent drizzles.
(http://nenes.eas.gatech.edu/Cloud/Clouds.pdf)
Partial Lenticular
5:00 PM
May 12th
View: Southeast towards Champlain Mountain
Bar Island
Lenticular clouds are a type of cloud that are usually form by orographic features. They
can be found at any elevation up to the Tropopause. The partial lenticular cloud that is
over Champlain Mountain in the photo is formed when moist air to the west of the mountain pushes into the mountain and is forced to rise. At the crest of the mountain, the air
expands and cooled to a temperature below its dew point, and condensation starts. The
vapor condenses into a wave shaped cloud. As the air parcel begins to fall down the mountain the water droplets in the cloud evaporate.
(Ahrens, 2010)
Stratocumulus Clouds
4:00pm
April 11th
View: North
Stratocumulus clouds are a type of clouds that are formed below 2000m and forms in
a low pressure environment. Stratocumulus clouds are similar to cumulus humilus
clouds, but are lower and grouped together in a layer.
(Ahrens, 2010)
Stratus
4:00 PM
April 18th
South towards Great Head
Stratus clouds are low clouds found below 2000 meters. Stratus clouds form in long layers.
Stratus clouds are composed of larger water droplets. These stratus clouds formed when a
large air parcel of warm, moist air moved over the region and was cooled to the point that
condensation occurred. In this photo a large blanket of stratus clouds cover the entire sky.
The stratus clouds are creating a grey, dim sky.
(Ahrens, 2010)
Virga
5:00 PM
May 21st
West from Sargent Mountain
A virga is a visible column of precipitation that evaporates, or sublimes in the case of
snow, before it reaches the ground. Virga’s are often found when the air below a precipitating cloud is significantly drier and/or hotter than the air in the cloud. In this photo, the
rain from the nimbostratus cloud evaporates before it reaches Somme’s Sound, because
the air above the Sound is warm enough to quickly evaporate the precipitation.
(http://www.crh.noaa.gov/lmk/soo/docu/cloudchart.pdf)
Dust Haze
6:20 PM
June 1st
View: Northwest towards Ellsworth
at Witchhole Overlook
In this photo the view of the distant landscape is obscured by haze caused by dust particles. After a little under a week of warm, dry weather, large amounts of dust were blown
into the air by strong winds. This dust acts as a condensation nuclei for water vapor, and
large amounts of vapor close to the surface produce a whiteness in the distant that obscures the view. This white haze appears only near the surface of the atmosphere in the
distance because the dust that causes the haze is only present in large quantities near the
surface.
(Ahrens, 2010)
Ocean Haze
1:30 PM
April 7th
View: South
Haze is a high concentration of particles that attract water vapors. If enough of these particles are present, then a large amount of water vapor will condense on these small particles,
creating a thin white cloud of vapor that obscures the view in whiteness. In this picture
salt from the ocean, that got into the air through ocean spray, is acting as a condensation
nuclei that is creating the haze in the distance.
(Ahrens, 2010)
Advection Fog
10:20 AM
June 5th
Sand Beach
Advection fog is a type of fog that looks similar to radiation fog but is formed under very
different circumstances. Advection fog is caused by the horizontal movement of warm,
moist air, that is usually from a body of water, over a cold dry surface. When the warm,
moist air meets the cold surface, the air is rapidly cooled below its dew point and water
vapor begins to condense, creating fog. In this picture moist air from the ocean is blowing
from the south onto southern MDI, the surface of which became very cool in dry during
the night. This fog persisted until mid day when the land warmed up enough to prevent
the condensation of the vapor in the maritime air.
(http://www.crh.noaa.gov/jkl/?n=fog_types)
Frontal Fog
6:00 PM
May 1st
College of the Atlantic
In this picture, frontal fog forms as warm raindrops from clouds above a warm front
evaporate as they fall into drier air. Once enough rain has vaporized, the once dry air becomes saturatated. The vapor starts condensing and forming fog right above the ground.
(http://www.crh.noaa.gov/jkl/?n=fog_types)
Radiation Fog
May 10th
Bar Harbor
Radiation fog is a type of fog that is formed by the cooling of air through conduction from
a cold air. Radiation fog usually occurs low to the ground. Radiation fog is formed during
cold, clear nights, where there is a temperature inversion. The air closest to the ground is
cooled through conduction, and the vapor in this air condenses into fog. This fog is most
visible during the early morning, before solar radiation warms the ground that in turn
heats the fog through conduction causing it to evaporate.
(Ahrens, 2010)
Upslope Fog
3:00 PM
May 18th
Dorr Mountain
In this picture warm moist air is forced up the east side of Dorr mountain by prevailing
winds. As the air rises it cools. Halfway up the mountain the air becomes saturated and
the vapor begins to condense. This condensation forms thick fog. The lapse rate is very
high, as evidenced by the rapid transition from unsaturated air with water vapor to saturated air with fog that occurs strikingly on the slopes of Dorr.
(http://www.crh.noaa.gov/jkl/?n=fog_types)
Valley Fog
8:00 AM
May 30th
View:Southwest
at Eagle Lake
Valley fog is a type of radiation fog that occurs in the contained space of valleys. Valley fog
is notable because the fog is trapped by mountains close to the valley floor. It often persists
much longer than other types of radiation fog, because the walls of the valley keep fog
from mixing with warmer or drier air. In this picture, fog formed in Pemetic and Sergeant
mountains in the early morning, when the cold valley floor cooled the surface air through
conduction until the vapor within the air condensed into fog. Cold air temperatures, cloud
cover blocking the sun, and the mountains keep the fog from warming and condensing.
(Ahrens, 2010)
Conduction
2:40 PM
April 14th
Monument Cove
Conduction is the transfer of thermal energy throug the direct contact and collision of
particles. When two particles with different temperatures collide, heat is transfered from
the particle with the higher temperature to the particle with the lower temperature. In
this picture the air just above the warm rock, that is being heating by solar radiation,
is colliding against the warmer rock particles. When the rock and the air touch heat
is transfered from the rock to the air. This conduction is only taking place in the a few
centimeters above the rock, where the air is dense and close enough to frequently collide
with the rock. Once the surface air is hot, it begins to rise and transfer heat to more air
through convection.
(Ahrens, 2010)
Solar Radiation
3:30 PM
May 8th
View: North
Champlain Mountain
In this photo, the rocks, trees, ocean, and the person are all being heated by solar radiation. The radiation is especially strong on this day as no clouds are impeeding the radiations progress to Earth’s surface.
Radiation heat is the process during which heat is transfered from electromagnetic
energy waves to matter as thermal energy. When electromagnetic waves contact certain
substances they are absorbed and converted in thermal energy, that raises the temperature of the substance (in most circumstances). Almost all of the energy on Earth’s surface
began as solar radiation that penetrated the atmosphere and heated Earth. The heat that
originates as thermal energy is dispersed through the atmosphere through conduction,
advection, and convection, on both local, regional, and global scales.
(Ahrens, 2010)
Condensation
3:50
May 8th
View: West
Champlain Mountain
Condensation is a state change from a gas to a liquid. Water condenses from vapor into
liquid, often in the form of droplets. Like all state changes a large amount of energy is
involved when water condenses. Vapor molecules have very high internal energy. In order
for the vapor to condense into liquid, that internal energy has to be transfered to another
colder substance. Therefore condensation has a warming effect on the surrounding environment.
In this photo, warm air rose, cooled, and expanded until the vapor in the air condensed into liquid droplets that form the cumulus clouds.
(Ahrens, 2010)
Condensation Nuclei
3:30 pm
Maay 8th
View: Southeast
at Champlain mountain
In this photo, there is a motor boat emitting a large amount of exhaust next to a tiny
island in Frenchman’s Bay. The particles in the exhaust are acting as condensation nuclei. These condensation nuclei attract water vapor to their surface, and help the vapor to
condense on their surface into liquid droplets. Salts, dust, and pollution particles are all
condensation nuclei. Many clouds, haze, fog, and contrails are formed with the help of
condensation nuclei. In this picture, Wind blowing from the south is pushing the exhaust
over the surface of the ocean, that has a high relative humidity. These exhaust particles
then gather condensing vapor onto them, creating a cloud streak.
(Ahrens, 2010)
Snow Melt
April 24th
Compass Harbor
Melting is the state change of a substance from a solid to a liquid. In this picture, water is
melting from its solid state of ice into liquid water. At an molecular level, melting occurs when the molecules of water that are crystallized in a locked position are heated to
a point, at 32°, where water molecules begin to break off the edges of the ice structure as
free flowing droplets of molecules that stick together with weak bonds. A large amount of
heat energy has to be transfered from the environment into the ice in order for melting to
occur. This latent heat required for the transformation, explains why ice can stick around
for suck long periods of time after temperatures rise above the melting/freezing point of
32°. In this picture day time temperatures have not dropped below 32° in two weeks, but a
large pack of ice still remains near the shore.
(Ahrens, 2010)
Evaporating Cumulus Cloud
April 1s
2:30pm
View: East
In this picture a lone cumulus cloud is evaporating on a sunny day. Earlier, this
parcel of air rose, expanded, and cooled, causing the water vapor to condense
into liquid droplets. The air around the parcel is heated by convection on this
warm day. Eventually the air surrounding the parcel got warm enough to begin
evaporating the liquid in the cloud. As the temperature rises, the droplets in
the cloud continue to evaporate, untill the cloud is completley dissapated.
(Ahrens, 2010)
Drizzle
6:00 PM
April 23rd
College of the Atlantic
Drizzle is a form of liquid precipitation. Precipitation is classified as drizzle if the drop size is
significantly smaller than .5mm diameter, the size of typical rain drops. Drizzle is normally
produced by low stratus and stratonimbus clouds that are not very thick, when droplets at
the top of those clouds fall and coalesce. However unlike larger rain that developes in bigger
stratonimbus or cumulonimbus clouds, drizzle droplets do not grow that much, and fall to
the surface as much smaller droplets that frequently evaporate before reaching the ground.
In the picture, the drizzle has coated the buds of the tree, forming water droplets about 1mm
in diameter, the size of medium to large rain drops.
(Ahrens, 2010)
Rain
11:00 AM
May 10th
Bubble Pond
In this picture a large a storm swept through mount desert island, leading to heavy rain
with droplets the bigger than 1mm in diameter. This rain was formed in a tall cumulonimbus cloud, in which a convecting cycle brought water droplets to the top of the cloud. Once
at the top of the cloud these droplets fell through the cloud coalescing with other rain
droplets, and growing in size. Once the drops are large and heavy enough, they fell to the
surface of the earth as rain.
(Ahrens, 2010)
Cyrstalised snow
9:00am
March 31st
Cyrstalised snow. In this picture there is a thin layer of spring snow that has partially melted and refroze over the course of a day. The blade of grass that is surrounded by the snow
is two inches long. Unlike most snow that is composed of small and flat flakes that are
formed in the sky, the snow in this pictures and its flake structure with it melted, creating
slush. In the cold night this slush refreezed, making a snow structure resembling small
hail.
(Ahrens, 2010)
Snow Storm
March 31st
6:00 PM
Bar Harbor
This picture shows an earlier spring snowstorm that came through Bar Harbor in the early
evening, leaving three inches of wet and heavy snow. The snow began to fall when the surface temperature was 40°. At first the snow melted on immediate contact with the ground
but eventually as the ground was cooled by the melting of the snow, the snow began to
stick and accumulate on the ground. These snowflakes formed in large stratonimbus
clouds with a temperature just below to 32°. The snow began to form when condensation
nuclei caused water vapor to first condense on the nuclei and then freeze into crystals.
As the temperature became colder, water droplets and water vapor merges with the snow
crystals to make the snowflakes larger. Eventually the snowflakes became too heavy to stay
aloft in the cloud in fell to the earth.
Ahrens, 2010)
Albedo
3:30 PM
May 5th
View: East
Bar Harbor
Albedo is the “whiteness” or reflectivity of a surface. The higher a surface’s albedo, the
higher the percentage of incoming light that it reflects in a scattered manner. The large cumulus cloud in the right of the photo has a high albedo, probably around 70%. Most of the
light that hits it is scattered or reflected. The remaining light is either absorbed as energy
or passes through the cloud. The albedo of clouds and also snow plays an important role
to prevent incoming solar radiation from heating the earth.
(Ahrens, 2010)
Blue Sky
4:00 PM
April 20th
View: North
During a clear day, when the sun is shining at a high angle, the sky appears blue. The sky
takes this color because the atmosphere selectively scatters small wavelength blue light
more frequently than larger wavelength yellow or red light wavelengths. This scattered
blue light can reach our eyes from all directions, not just from the atmosphere directly
un-der the sun. The higher part of the sky in the top of the picture is a deeper shade of
blue than the lower part of the sky because the atmosphere in the top of the sky is
thicker than in the lower part. A thicker atmosphere scatters more light than a thinner
atmosphere. More scattering leads to a deeper blue color.
(Ahrens, 2010)
Refraction
April 1st
Monument Cove
In this picture of the sun, light from the sun is being refracted as it passes through the
lens of the camera. Refraction is the optical phenomena of the change in direction of light
waves as the light passes from one medium to another. In the case of this picture, light is
passing through the air, into the glass of the camera lens. Glass is a thicker medium than
air. When the light passes from air to glass, the light bends, or its direction is changed,
closer to the perpendicular. In the photo, this refraction creates the ring of light seen in
the center of the frame. The ring corresponds to the location of the sun, but it appears to
be offset from the sun due to refraction.
(Ahrens, 2010)
Water Reflectivity
2:30 PM
May 8th
View: East
Beehive
The Reflective Properties of Water. Light from the sun is hitting the trees on the far side of the lake and are
scattered and reflected towards the water. The reflected light is striking the calm surface of the lake at a low
angle. Because of this low angle of incidence, the light is
reflected at the same angle it initially struck the water at,
instead of going through the water. However the lake is not a
perfectly smooth surface, and a lot of the original light
scattered by the water. This phenomenom can be witnessed
by the dark green outlines on the water that are mirror images of the trees closest to the
shore.
(Ahrens 2010)
Diffraction
April 2nd
3:50 PM
Dorr Mountain East Face
The large shadow cast by the ice in this picture is an example of difraction, the bending of light
around objects. In the picture the sun is in the western sky, on a mostly clear day. The tall ice
mass blocks the the sun from directly shining on the are immediately to the right of the icemass.
However the light waves bend around the ice mass, and shine on the area to the right of it with
diminished intensity.
(Ahrens, 2010)
Blocked Sun
2:30
April 14th
View: West
A thin layer of clouds are partially blocking the Sun . Unlike most of the particles and
gas-es in the atmosphere, condensed water in the form of clouds can absorb and reflect
the entire visible light spectrum. Clouds tend to look white because all of the
wavelengths of visible light, that are reflected off of the earth, or come from the sun
bounce off of it and hit our eyes. Thicker clouds prevent more light from passing
through them than thinner ones. In this picture a thin layer of clouds block the sun, but
they do not prevent most visible sunlight from passing through. The center of the
picture is the sun with clouds in front of it. This region of clouds is brighter than the thin
white clouds that are more spread apart on the left, and much brighter than the thicker
grey clouds on the left.
(Ahrens, 2010)
Sunrise
4:30 AM
May 30th
COA
This picture shows a sunrise in late spring over the bay near Bar Harbor. This sunrise
began when the sun got to an angle, at which sunlight strikes the upper atmosphere but
not the surface. The sunrise produces red and orange lights because particles in the atmosphere selectivley scatter blue light, preventing it from reaching the viewers eyes. Instead
only red, orange, and purple light illuminates the sky during sunrises. This sunrise lasts
for about an hour untill the sun is high enough above the horizon, that white light can
reach the surface without all of its blue wavelengths being scattered.
(Ahrens, 2010)
Sunset
8:00 PM
May 23rd
View: Northwest
The Bar
A sunset after the sun is below the horizon over the east side of Mount Desert Island.
During a sunset, incoming solar radiation strikes the atmosphere at a very low angle.
Because the sunlight is coming to the surface of the earth at a very low and indirect angle,
the light travels through a thick transect of the atmosphere. The particles in the atmosphere are selectively scattering the blue light that has shorter wave lengths. When the
light finally strikes the viewer, most of the blue light has been scattered, leaving only the
red light that produces the orange lights of sunset. \
(Ahrens)
Twilight
8:36 PM
May 30th
View: East
This picture shows Twilight, during a late spring night. Although there is no direct sunlight still shining, the slow setting sun in the west lightly illuminates the sky in the east.
During this twilight, Bar Harbor and the surrounding area are neither completely lit nor
dark. In the west the sun is at an angle between 12-17 degrees below the horizon. The twilight is produced by the scattering of the sunlight in the upper atmosphere. This twilight is
an astronomer’s twilight, the last phase of twilight before dusk and the start of night.
(http://www.wunderground.com/about/faq/twilights.asp)
Horizon
18° angle
When the sun is between the angles of 0°
and 18° below the horizon, it is twilight.
At these angles below the horizon, sunlight strikes the upper atmosphere and
is scattered, thus producing illumination
and multi colored lights.
(http://www.wunderground.com/about/
faq/twilights.asp)
A Passing Cold Front
May 2nd
8:00AM
East
In the morning following a day of rain from Nimbostratus clouds,
a cold air mass from the east pushed the remaining clouds to the
west. The air behind the cold front is colder and dried and under
relativley higher pressure than the air infront of the cold front to
the east. This high pressure behind the cold front creates winds
that push the airmass ahead of the airmass to the east and
prevents clouds from forming. Because of this front the weather
changed from overcast grey and humid, to dry and sunny in less
than 40 minutes.
(Ahrens, 2010)
Prevaling Westerly Winds
10:00 AM
West St, Bar Harbor
March 31st
West to East
The kinetic energy of wind. On this very windy day, there is enough energy of motion in
the air, in the direction of West to East (left to right in the picture), that when the air
contacts the branches of the tree it transfers enough force to move the tree and sway it.
Because of the trade winds, strong winds usually blow from west to east not the other
way around.
(Ahrens, 2010)
Seabreeze
3:00 PM
June 3rd
Bar Beach
A sea breeze or an onshore breeze is a wind that blows from a cold high pressure area
above the sea or a body of water onto a warm low pressure area on shore. Sea breezes are
common on warm, sunny summer days during which the ground at the shore becomes
very hot and heats the air through radiation. The air above the land becomes much warmer than the air over the water, that has maintained a stable temperature. The warm air
over the land begins to rise and the cool air over the water rushes to take its place, creating a moderate wind. The air forms a convection cycle, outlined in the image above.
(Ahrens, 2010)
Colluvium Field
May 30th
Beach Cliffs
This picture shows a field of Calluvium at the base of Beach Cliffs. Calluvium
is rocks and sediment debris that was brought down from the slopes of the
valley by water erosion. The calluvium at beach cliffs was most likely created
by water run off from large storms carrying the rocks and sediments from the
top of Beach Cliffs.
(http://soilweb.landfood.ubc.ca/landscape/parent-material/colluvial-environment)
Boulder Beach
June 5rd
Monument Cove
This boulder beach is formed by waves crash into the shore and remove rock. This rock is
constantly tossed around and reshaped by strong storm surges and waves, until medium
sized smooth boulders cover the entire beach.
Ancient Boulder Beach
June 5th
Gorham Mountain
Between 12,000 and 14,000 years ago, when sea levels were higher than they are today,
boulder beaches were formed by powerful waves in areas that are now up to 100 feet above
sea level. These ancient boulder beaches were formed in areas that once were the coast,
by waves that eroded and shaped the rocks of the shore into large round boulders. Most
of the ancient beaches on Mount Desert Island are obscured by sediment, moss, or other
growth, but the boulders in this picture at the base of Gorham Mountain are kept clean
because they are part of a trail.
(http://geographyas.info/coasts/sea-level-change/)
Clay Bed Erosion
June 5th
Sand Beach
When sea levels on Mount Desert Island were much higher than they are today 12,000 years
ago, the ocean created many clay deposits in areas that are currently above the sea. Unlike
sandy or rocky beaches that form with the help of tides and strong wave, clay beds form in
deeper, less turbulent areas of water. These clay beds are impermeable by water, but erode
if enough water runs over them. In this picture, a clay bed on the hill above sand beach is
being eroded by streams and floods.
(http://geographyas.info/rivers/river-processes/)
Crescentic Gouge
June 5th
Sand Beach
Glacial Path
A crescentic gouge is a mark left on bderock by glacial chipping. A glacier pushes small
rock fragments into the bedrock, creating depressions. Usually the rock sediment that is
abrading the bedrock will get stuck and pluck upwards, causing the gouge to slowly sink
and then sharply rise.
( http://www.landforms.eu/Central%20Park/Crescentic%20gouge.htm)
Glacial Striations
May 30th
Eagle Lake
Glacial Striations are abrasions caused by glacier movement over rock. During the last glacial
maximum 18 thousand years ago, fragments of rock underneath the glacier that covered eagle
lake were pushed against the bedrock. These fragments,under stress from the inexurable pressure of the glacier scratched marks into the bed rock. These striations correspond to the general
direction that the glacier was moving. In this instance, the striations run from the north on the
left side of the picture to the south on the right side of the picture, the same direction the glacier
moved.
(http://www.geography-site.co.uk/pages/physical/glaciers/stria.html)
Glacial U-Shaped Valley
April 21st
Jordan Pond
During the last period of major glaciation that began to end 18 thousand years ago, large glaciers covered all of Mount Desert Island. These glaciers were at least one mile thick and slowly moved southward. The glacier flowed through the valley previously carved by the stream.
As the glacier moved downhill its immense weight grinds and removes rock and sediment
from the valley. The glacier sculpted a u-shaped valley, with a slow curving bottom and steep
sides. In the Jordan Pond valley, when the glacier began retreated it left a moraine of rock at
the end of its path. This moraine damed up the streams flowing out of the valley creating the
pond.
(http://www.nature.nps.gov/geology/usgsnps/glacier/uvalley.html)
Roche Moutonne
April 24th
Bald Porcupine Island from Compass Harbor
Ice Flow
A Roche Moutonne is a glacial formation of rock with a gentle upslope and a
steep downslope. Bald Porcupine Island, is a Roche Moutonne formed when
a glacier, coming from the north (the left side of the island in this picture)
advanced up the island, until the ice attaches to the lee side (downstream side)
of the island on the right and plucks the rock off, forming a steep cliff like
slope. The pluck most likely happened because, ice at the bottom of the glacier
was melted by the heat of friction, and then refroze to the rock on the lee side,
pulling it off of the island.
(http://www.geography-site.co.uk/pages/physical/glaciers/stria.html)
Works Cited
Ahrens, C. Donald. Meteorology Today : An Introduction to Weather, Climate, and the
Environment. Minneapolis/St. Paul: West Pub., 2010. Print.
http://www.nature.nps.gov/geology/usgsnps/glacier/uvalley.html
http://www.wunderground.com/about/faq/twilights.asp
http://www.landforms.eu/Central%20Park/Crescentic%20gouge.htm
http://www.crh.noaa.gov/jkl/?n=fog_types
http://nenes.eas.gatech.edu/Cloud/Clouds.pdf
(http://soilweb.landfood.ubc.ca/landscape/parent-material/colluvial-environment
http://geographyas.info/coasts/sea-level-change/
http://geographyas.info/rivers/river-processes/)