GEO102a final part 2

What was the number of wildfires in the US in 1980? What is it now (2017)?

10, 160

How many days longer is the CA wildfire season than it was in the 1980's?

105, on average

Sea level has risen 1 foot from ____ to ____

1800-2000

What is the median projected sea level rise, and what does that mean for the coast line? Also, what is the slope of the coast line?

2.5 ft, which means 125-250 ft of coast line retreat (slope of coast is 1/50-1/100 generally)

How fast is sea level rising per year; how does that compare to the deglaciation period after the last ice age

3 mm/year; it is much slower

How do hurricanes form?

A positive feedback: There is a disturbance over the atlantic where air begins to rise because it is warm When this air rises it sucks in new air behind it which is also warm and then it rises If the air is warm enough and holds enough water vapor, it will rise quickly and the precipitation will allow it to rise even faster, and this makes a positive feedback system

Where can you find bands of low cloud cover?

Bands of low cloud cover are where the hadley and ferrel cells meet

Describe ITCZ phenomena for the past 70 years:

Because of the "global dimming" caused by heavy coal burning in the 60s and 80s without cleanly burning it, tons of sulfate aerosols were put into the atmosphere, increasing albedo and slowing the relative warming of the northern hemisphere As a result, the ITCZ shifted southward; the northern patch of the wet Africa and the monsoon in asia area got less rain because the belt moved lower There was an Ethiopian Famine (from 1983-1985) Between 400k and 1M people died because of the weakened African monsoon However, those aerosols are not being produced anymore, so the albedo effect will either stabilize or become less in the next century, the ITCZ will rebound to a northward position again Summer monsoons in northern africa, india and east asia will intensify Northern hem will warm slightly faster than southern hem

What are some of the consequences of increased wildfires in CA?

Cost Air quality Particulate matter smaller than 2.5 microns = PM2.5 In the east, it has gone down because of burning a bit less coal but also cleaning up the coal burning, which significantly reduced the amount of sulfate aerosols Fixed acid rain problems as well The west should have felt this decrease too, but instead they got an increase due to the increase in carbon aerosols from wildfires

What is the name for all the different types of ice on Earth?

Earth's cryosphere

Both 30 N and S, the air is blowing to the (East/West): these are called the ______!

East, westerlies

How can there be a glacier in Ecuador?

Ecuador has a high altitude mountain

What place demonstrates through settlements the way that the ITCZ shifted throughout the Holocene?

Egypt

Where do clouds reach the highest altitudes? How can we see on a map that they are the highest?

Equator; they look the whitest

Why might it be difficult to predict how rapidly sea ice will decline?

Feedbacks; The ice/albedo feedback is inherently difficult to quantify

How will global warming affect hurricane storm strength?

Given that hotter air has a higher water-carrying capacity, and assuming that the T decrease upon air rising is constant, it seems that more rain will fall in future hurricanes and those storms will be stronger + speed of intensification will increase

Where are ice sheets currently located?

Greenland and Antarctica

What explains the green area of Africa?

ITCZ; Rainforests of the Earth located here

Which type of ice has the most volume, and how thick is that ice?

Ice sheets on land (almost all ice volume is here), 3 km thick

What is the edge of land ice called?

Ice shelf

Define ice shelves

Ice shelves are what happen when glaciers make their way to the oceans

What is perennial ice?

Ice which exists year-round

What will be the impact on Earth's climate if Earth's ice melts, and why?

If earth's ice melts, the albedo of Earth will decrease and cause even further warming

America has regions which are typically dryer and regions which are wetter. However, what effect will confound with global warming to cause more persistent droughts in regions where crops need to be grown

In the summer, this structure of the wet areas v dry moves northward because of the contact zones between the cell regions move northward in the summer

What are SI units? What are our units called? Convert feet to meters

International system of units, e.g. m, cm; Imperial units are feet and inches, 1 meter = 3.3 ft

What will happen to the ITCZ under a warmer climate?

It will become more intense, because Raising the temp of air increases its water vapor holding capacity more when air starts at a higher T

Name two exceptions to the subtropical dry region in the NH

Monsoon area in India/Asia and bottom of America?

Given that the sea level has risen 1 foot in the past 200 years, what do you think sea level rise will be in the next two hundred? Be precise, if possible.

More than a foot; sea level rising rate projected to increase We cannot be precise because what we thought was the upper limit for sea level rise keeps on getting higher

Have we ever seen Arctic summer sea ice change in amount this rapidly, even if we reconstruct it back to 1400 years ago?

No

Will we see 64 m sea level rise in the next century?

No, because we know from the last interglacial that corals were 6-9 m above sea level when the Earth was 1 degree warmer

We are expecting 2-4 degrees C increase in temp over next century, so can we say that the sea level rise in that time will be more like 20 m?

No, it will only be a little bit. The feedbacks take time to reach equilibrium

because of the ITCZ being further north at the beginning of the holocene, that meant there was then a stronger monsoon in ___ ___ known as ___ _____

Northern Africa; Green Sahara (cave cartoons show animal husbandry and grazing, herding of cattle, goats, sheep and trading, with transport by donkey)

With our knowledge of wet-->wetter and dry-->dryer, what can we say are the main exceptions to this rule?

Overall, poles will get wetter ITCZ will shift northward (uncertain) South America precipitation will decrease (amazon rainforest decline) - uncertain!

Define permafrost

Permafrost is frozen ground where all the pore spaces where there is water in the soil is frozen In some places, there is an active layer at the top of the ground which can melt but the base layer is always frozen ("perma"=permanent)

Where does the snow line occur?

Places with high altitude and/or low temperatures

Is the ice/albedo feedback positive or negative?

Positive

When and where do hurricanes form?

Right above the equator, the warm humid air in the Atlantic And then they travel west because of the coriolis effect (northern hemisphere) In Aug, September, october; Hurricanes need a continuous availability of warm surface water in order to gain sensible and latent heat from it and move across the ocean, and the water warms from the caribbean to the us in the summer/fall creating the perfect path of travel

What are some dry places which are going to get wetter near the equator, or vice versa, and why?

Sahara Desert may get wetter in some regions because the equatorial area will shift northward Amazon basin (loss of tropical rainforest)

What two types of ice cover Earth (yearly)?

Seasonal and perennial ice

In addition to general locations getting wetter or dryer during global warming, what other natural phenomenon will experience wet→wetter and dry→ dryer?

Seasons: Wet seasons can often be thought of as period prone to ascent of moist air Storms are individual events of rising air, compensated by longer intervals of slowly descending air Individual storms → more severe, while period sof low rainfall will become longer

What must be true for an ice sheet which is not changing size?

Snow accumulation at the top == ablation at the sides

At what point of the year is the coriolis effect strongest?

The Coriolis effect is not stronger or weaker at any time of year. But WINDS are stronger in winter or in colder years. Temperature gradients are higher during winter as a result, and this brings faster wind

What happens in the ITCZ because of all the rainfall that occurs there?

The air rises super high

What determines the strength of the ice/albedo feedback?

The area that the ice covers, latitude, season of occurrence, albedo of the TYPE of ice, albedo of the surface the ice is covering e.g. Melting sea ice leaves you with ocean, which matters a lot because the ocean is so dark

Why does the wind in a hurricane happen and twist?

The coriolis effect: center of the system is low pressure (rising air = low pressure = sucking air in) pulling air in from all sides But the air cannot go straight into the center because the effect of the rotation of the Earth is to cause air to veer off Causes super strong, destructive winds Once the air is veered off, there is a balance of the coriolis effect and the low pressure effect, so the air just goes round and round until it eventually gets to the eye

Define Archimedes Principle:

The exact volume that the ice was displacing is equivalent to the amount of mass that the ice will melt and give

Consider land ice and floating sea ice. Which will affect sea level if melted?

The land ice, because the volume of the sea ice is equal to the volume of water it already displaces

What is one piece of evidence that the Holocene has been cooling over the last 10,000 years?

There is evidence of dried up lakes in Africa which shows that the ITCZ has moved south over the last 10,000 years as the NH increased in temperature (i.e. The NH used to be hotter relative to the SH)

In California, the time of maximal precipitation is in the winter (which, under global warming, will increase) -- why is this a bad thing?

Unfortunately, most of this will be rain, not snow, which means it will not be stored over the winter for the summer Then, the dry period, which is the summer, will get dryer, which means the periods of no rain will be more extensive (longer) So that means there will be more fires and less agriculture.

What are the Competing rules of wet-->wetter and dry-->dryer?

Warming causes higher precipitation at high latitudes, including the dry polar regions Warming causes in net higher precipitation on land Wet and dry regions can migrate northward and southward

Do we know anything about the amount of sea ice in Arctic/antarctica from the past several decades?

We know mostly about the Arctic, which has had rapid sea ice decline since the 70's (summer sea ice is half what it was in 70's)

What are the names of the ice sheets in Antarctica and how do you identify them?

West and East Antarctic ice sheets West is head of duck, rest is body

Area is more important than volume for assessing the impact of ______

albedo

Describe how ice forms on the sea

at first, thin → the ice groups together (pancake ice) → thicker first year ice→ multi-year ice which has structure and creates a bolder-looking situation

In the future, we will be able to understand the relative importance of these three factors better when we can study the Arctic compared to the Antarctic more -- why?

because the albedo feedbacks have not been happening there, so we will be able to isolate the impact of latent heat transport on melting; i.e. Antarctica has had less change in albedo

Between 1993 and 2003, how much sea level rise did we have per year, and what were the contributors? Which of these contributors is easily predicted?

between 1993 and 2003, we had 2.5 mm/year, due in equal part to land ice loss and thermal expansion of the ocean Thermal expansion effect is easily predicted, but not land ice loss effect because this is highly dependent on glacier behavior

What causes high albedo in an ice age?

colder conditions, and thus ice

The annual mean precipitation map from 1990 is well-explained by the components of the convection cell diagram: what are these components? What are some exceptions to this?

dry polar regions, mid-latitude storm tracks, subtropical highs, ITCZ; Monsoon area in India/Asia and bottom of America

Latent heat acts like an _____

elevator

What is a main reason that Earth is colder during the ice ages?

high albedo

What is a common example of an extreme precipitation event?

hurricane

What is the ice shelf called if it breaks off?

ice berg

Rank the four types of ice in order of thickness

ice sheets on land, mountain glaciers, sea ice, snow

What three factors have caused atmospheric temperature increase to be amplified in the Arctic (polar amplification) since the 1800's?

ice/albedo feedback, permafrost/forest feedback, and latent heat transport

What will happen if permafrost declines in terms of climate?

if permafrost declines, the tundra will stop growing and will be replaced by forests which have much lower albedo which will amplify the warming

During Hurricane Florence, flooding actually reduced the amount of drinking water available in North Carolina - how can this happen?

if the rain from the storm floods chemical plants and those chemicals drain into the drinking water

Why does floating ice stick out of the water even if it does not raise sea level at all when the ice melts?

it is less dense than the water

When water precipitates it gives off _____ and makes the climate ______ than it otherwise would be.

latent heat; warmer

What are the two types of glaciers and which one represents more of the total glacier volume on Earth?

mountain glaciers (ice caps) and ice sheets; Ice sheets represent the vast majority of glacier volume

Recent history of land ice contributions to sea level rise: mountain glaciers v. ice sheets -- which has contributed more? Is that surprising?

mountain glaciers have contributed much more, which is surprising considering that mountain glaciers represent less than 1% of the total volume of ice on Earth. However it is less surprising when we consider that the snow line has been rising globally, so that most ice caps rest below it now. So they are shrinking much faster

In both antarctic and the arctic, ice is formed in winter and lost in the summer; if ice persists through the summer, what is it called?

multi-year or perennial ice

Is the tundra/forest albedo feedback fast?

no, it is slower than the ice/albedo feedback

What is PM2.5?

particulate matter smaller than 2.5 microns

What are the two types of permafrost and what type of vegetation can grow on permafrost?

patchy and continuous; tundra

What will be two other impacts of ice melting besides the albedo effect?

rising sea level, and changed water resources and ecosystems

What are the four different types of ice on earth?

sea ice, land ice, permafrost, and snow

Volume is more important than area for assessing the impact of ____

sea level rise

What are the five potential sources of sea level rise in order of least to most rise?

sea thermal expansion; mountain glaciers, Greenland ice sheet, West Antarctic ice sheet, East Antarctic ice sheet

Wet and dry regions shift with the ______

seasons

How do glaciers work?

snow accumulates until the pressure is so high on the bottom ice that it begins to behave like a fluid and flow towards areas of lower pressure (the margins)

Antarctica is entirely above the _________

snow line

Look at desert in North Africa: what cell region is this corresponding to?

subtropical high

Why do polar jets look curved?

the Coriolis effect

Wherever air is rising, we get high precipitation (rainfall/snow) -- why?

the air is rising, cooling, and that causes it to precipitate because it is now at a lower water carrying capacity

Define the snow line

the elevation above which snow can accumulate, depends on latitude and altitude

How does the ITCZ control where different types of land biomes are located in the tropical region?

the land biomes exist where they get enough rain; Zoom in on africa's tropical rainforests → Further north and south of the rainforests, you have woodland, and then further out you have grasslands. And then desert

Where does a glacier flow the fastest?

the margins

When are the mid-latitude storm tracks the strongest in the Northern Hemisphere? Why?

the mid-latitude storm tracks are strongest in our winter, Jan-Feb, because this is the time when we have the biggest temp gradient between high and low latitudes so the winds will be strongest

What affects the shape and size of an ice sheet?

the slipperiness of the bedrock it rests on; If sticky, the ice sheet will be steep because it builds up If slippery, more gradual If sticky, cannot flow as much, so it melts slower If slippery, can change size very fast

Why are we not worried about the impact of ice shelves' water volume?

the volume they will give is equal to the volume that they displace, so they will not raise the sea level any more when melted or broken off; we are worried about them breaking off and making way for more land ice, however

What two attributes of sea ice in the Arctic are indicative of rapid future melting?

there is much less ice in the summer, but it also means the type of ice in the Arctic is transforming from mostly multi-year ice to much thinner first-year ice

In order to see which types of ice will impact sea level rise, we look at the ones with the most ___

volume

The ITCZ goes north and then south following _____

warm conditions

How can we use water-carrying capacity to describe how wet areas will get wetter and dry areas will get dryer

warming will cause: More vapor to be carried upward at the equator (and more tropical rainfall) More water vapor will be added to the atmosphere where air descends towards the surface in the subtropics (less precipitation in the subtropics) More water vapor transport from low to high latitudes (more high latitude precipitation)

We have 40% more heavy precipitation events in the US now than in the early 1900s. So why are we concerned about droughts?

we haven't seen a significant increase in AVERAGE rainfall; This means that this rainy event got wetter, but dry areas are even dryer You have extreme wet events separated by longer periods of dry

What makes hurricanes so dangerous/damaging?

wind knocks things down, causes surge; rain causes flood

Where does the wet-->wetter and dry-->dryer rule work really well? where does it not, and why?

works well til about 40 degrees N and S. Above this latitude, the dry polar regions will just be getting wetter because more water is being brought to higher latitudes

Review: Is there a history of albedo change affecting climate? (5 examples)

yes. 1) Year without a Summer 2) ice ages over last 3 million years 3) snowball Earth 4) Aerosols from coal burning - stable climate between 1940 and 1980 are a result of the offset between sulfate aerosols and CO2 emissions 5) Early to Middle Holocene warm period (10k to 5k years ago)

If all the potential ice sources of sea level rise happened, how much sea level rise would there be?

~64 m, up to the armpit of the statue of liberty