Global Change- Quiz 2 Review

weather

day-to-day changes in atmospheric conditions

climate

30-year aggregate of weather patterns in a particular region

order weather scales from largest to smallest

macroscale, synoptic scale, mesoscale, microscale

order climate scales from largest to smallest

global, regional, local

how to calculate mean values

(Max - min)/2

how to calculate average values

max-min

anomaly

divergence in observed climate data from the mean

how weather data becomes climate data: temperature

1. record daily temp

2. calculate daily temp range

3. calculate daily mean temps

4. repeat using monthly then annual values

5. 30+ years of data becomes climate data

how weather data becomes climate data: precipitation

1. add precip depths from each day of the month for the monthly precipitation values

2. calculate mean monthly precip

3. calculate mean annual precip

4. 30+ years of data becomes climate data

Changes and trends in: Temperature

global surface values are increasing, greater increase over land than ocean

Changes and trends in: humidity

specific humidity increased faster over oceans, relative humidity decreased over continents

specific humidity

mass of water vapor in a unit mass of moist air

relative humidity

measure of the amount of water vapor in the air relative to the total amount of water vapor that air can “hold” at that specific temp

Changes and trends in: precipitation

has increased over land, storm tracks have shifted poleward in both hemispheres

Changes and trends in: glaciers and ice sheets

global retreat since the 1990s

Changes and trends in: sea ice

significant loss in Arctic and Antarctic regions

Changes and trends in: ocean pH

has decreased, more acidic

Changes and trends in: ocean oxygen

decreased in many upper regions

Changes and trends in: sea level

mean increase of 0.20m from 1901 to 2018

Changes and trends in: biosphere

climate zones have shifted poleward in both hemispheres, growing seasons are increasing in NH

paleoclimatology

study of past climates

proxies

information obtained from physical, chemical and biological materials preserved within the geological record that can be analyzed and correlated with climate/environmental parameters in the modern world

archives

the physical, chemical, or biological materials that can be used as proxies

physical proxies

include sediment composition, texture, structure, color, density, etc.

chemical proxies

include samples that can be analyzed for their chemical composition based on:

• Carbon or Oxygen stable isotopes

• Presence of particular elements

biological proxies

• remains of living organisms

  • Includes: pollen, foraminifera, mollusks, ostracodes, etc.

CO₂ concentrations are ____ now than at any other point in the last 2 million years

higher

CH₄ and N₂O concentrations are ____ now than at any other point in the last 800,000 years

higher

Global surface temperature has ____ faster since 1970s than any other 50-year period over the last 2,000 years

increased

Global mean sea level has ____ at a rate faster since 1900 than in any other century in the last 3,000 years

increased

phenology

study of how seasonal variations/ changes impact the life cycles of plants and animals

phenological shifts

changes in life cycle patterns and timing associated with them

climate models

use future scenarios(based on assumed emissions) in mathematical equations to project future climate conditions

Climate model limitations

parameterizations are all uncertain and imperfect due to clouds, turbulent eddies, thunderstorms, evapotranspiration

Climate models biases

temperature- arctic is too cold and oceans off West Coast are too warm

precipitation- large errors in tropics, moisture from West Coast forms “double ITCZ”

Representative concentration pathways (RCPs)

describe 4 different scenarios of 21st century GHG emissions, atmospheric concentrations, air pollutant emissions, and land use

shared socioeconomic pathways

a set of 5 emissions scenarios that explore climate response to a broader range of GHG, land-use, and air pollutant futures than RCPs

• Projections account for solar activity and background forcing from volcanoes

why does earth have seasons?

axis tilt of 23.5^o

atmosphere

gaseous envelope surrounding Earth

biosphere

living and dead organic components of Earth

geosphere

metallic core, solid rock, molten rock, soil, and sediments of Earth

Hydrosphere

water in all forms on Earth

eccentricity

extent of the elliptical shape of Earth’s orbit

• Timescale:~100,000 years

• More eccentricity, greater solar radiation variation

Obliquity

tilt of Earth’s axis

• Timescale: ~40,000

• Varies: 22.1-24.5º

• An increase in tilt means more extreme seasons (and vice versa)

precession

“wobble” of Earth’s axis

• Timescale: ~25,000 years

• impacts when each pole is tilted toward the sun

Several volcanic eruptions in Earth’s recent history led to global ____ for up to  years

cooling

ocean water moves from ____ to ____ and cooler water moves from ____ to ____

tropics, poles, poles, equator

positive feedback

amplifies the effects of a disturbance

negative feedback

diminish the effects of a disturbance

Greenhouse effect

Certain atmospheric gasas absorb significant amounts of longwave radiation emitted by Earth’s, some energy is radiated to space and some back towards Earth’s surface

• Overall effect: increased temperature of atmosphere

Earth’s atmosphere is ____ to most incoming radiation, but ____ exiting radiation

transparent, less transparent

Global warming potential (GWP)

measure of how much heat a GHG traps in the atmosphere over a specific period of time relative to CO₂

most abundant GHG

water vapor

List key GHGs from longest to shortest residence times:

Fluorinated gases, N₂O, CH₄, CO₂

Aerosols

solid o r liquid particles suspended in air

hydrophobic

repel water

hydroscopic

seeks water

hydrophilic

readily mix with water

radiative forcing

change in amount of radiation absorbed at Earth’s surface