GPH Final Exam
Tropical Wet (Af)
"A" climates exists nearly exclusively between the Tropics of Cancer and Capricorn. Greater seasonality of precipitation in Belem relative to Singapore, but no dry period. Note uniformity of temperatures. Note high, but not extreme, temperatures because: - Moisture availability at surface - Presence of clouds
Thermal Comfort
"condition of mind that expresses satisfaction with the thermal environment; assessed by subjective evaluation" (ASHRAE Standard 55) Main factors influencing thermal comfort Environmental factors air temperature mean radiant temperature wind speed relative humidity Personal factors metabolic rate clothing insulation Psychological factors
Northeast Trade winds
(0° to 30°N)
Southeast Trade winds
(0° to 30°S)
The surface energy budgets of urban areas and their more rural surroundings will differ because of differences in...
(1) land cover and surface characteristics, and (2) level of human activity. Such differences can affect the generation and transfer of heat, which can lead to different surface and air temperatures in urban versus rural areas
Acceptable Comfort Range
(19° - 38°C) 66°F - 100°F
Westerlies
(30° to 60° in both hemispheres: slightly stronger in Southern Hemisphere because no landto block winds ("Roaring Forties")
Polar Easterlies
(60° to 90° in both hemispheres)
Pressure
- (closely related to density) is a result of the atmosphere's mass - The value of pressure reflects the mass of atmosphere above a given point. - Pressure decreases vertically, but not at a constant rate (decrease is most rapid near the surface).
Average Sea-level Pressure
- 1013.2mb • 29.92 in. Hg - US record low: 888 mb, Hurricane Gilbert 1988 - US record high: 1065 mb
Global Population is increasing...
- 7 billion already exceeded - 9 billion projected by 2050
Share of Urban relative to Rural dwellers Increasing...
- >50% of globe lives in urban dwellings - Majority of projected urban growth expected in Africa and Asia
Air is Compressible Fluid
- Air closest to surface will be compressed - Pushed into a given volume ----More mass in given volume closer to surface
Remnant Landforms
- All of Earth's landforms are the end result of processes that build up and wear down features at the surface (e.g., tectonic forces [Pangea]). - Mechanisms for eroding and depositing material, include the movement of water (e.g., streamflow), the slow-moving ice sheets expanding across the surface, wave action along coastlines, wind, and floating icebergs carrying land debris. - These mechanisms leave characteristics that scientists can use as evidence to infer climatic conditions at the time of erosion or deposition.
Paleocene-Eocene Thermal Maximum (PETM)
- Along the way toward its maximum, Earth warmed by ~5C in ~20K years. This WARMING event is unrivaled by any other in our planet's recorded (direct or indirect) history. ~15 MYA our current Ice Age began. - Snowball Earth (hypothesis): a condition whereby nearly the entire planet may have been covered by ice (e.g., snow in the tropics).
Thickness of the Atmosphere
- Although the density of the atmosphere decreases rapidly with height, the top of the atmosphere is undefined. -Overall, the majority of atmospheric mass is contained in a thin layer near the surface. --The atmosphere still contains an impressive sum of mass.
driving forces of circulation in atmosphere
- Gravity • Pressure Gradient Force • Coriolis Force • Friction Force
Circulation Cells
- Hadley: 0º - 30ºN/S - Ferrel: 30ºN/S - 60ºN/S - Polar: 60ºN/S - 90ºN/S
The geologic column
- Hierarchical system devised by scientists to divide the planet's natural history into distinct time frames. - Time segments are based on geologic and fossil evidence indicative of past environmental conditions (i.e., any time segment should not be considered to have uniform climate conditions). - Geologic column is periodically revised to reflect improved understanding.
Methods for Determining Past Climates
- Proxy (indicators) - Historical Data - Corals/Oceanic data - Pollen/Past vegetation - Ice cores - Oceanic/lake sediments - Tree rings
Oceanic Deposits
- Scientists extract deep cores of material that has been deposited over long periods, with more recent material constantly burying older material. - Cores include the bones and shells of plankton and other animal life. - The information contained in the oxygen in the calcium carbonate is most important for determining past climates (particularly the isotope ratios of O18 to O16), and specifically, time series of global ice volume.
ice core data
- Strong correlation between past temperature and concentrations of CO2 and CH4. - Gas concentration changes lag temperature changes by hundreds of years (up to ~1K) ... - Positive feedback - temperature increases, gas concentrations follow; temperature changes are amplified (i.e., they increase further).
sinking air
- Surface stops downward flow - Air has nowhere to go, so moves laterally north and south - Coriolis effect causes surface winds to deflect either right or left
troposphere
- The lowest layer of Earth's atmosphere named as this region promotes atmospheric overturning. - Layer of virtually all weather/climate processes. Warmed at the surface by solar radiation. - Identified by a steady temperature decrease with height and as the thinnest layer (but contains 80% of the mass). - Due to thermal expansion, the tropopause is roughly 16 km over the tropics, but only 8 km at poles.
rising air
- Tropopause stops upward flow - Air has nowhere to go, so moves laterally north and south - Air cools, begins to sink
Heat Mitigation
- Urban Greening - Urban Materials - Urban Form
Ice Cores
- temporal resolution of data obtained is variable; conditions of the past up to a few million of years can be inferred. - Scientists determine oxygen (O18 to O16) ratios for ice cores obtained from Greenland and Antarctic ice sheets and from alpine glaciers at lower latitudes through drilling up to several km deep - are used to obtain temperature data from isotope ratios, and provide information on the past chemistry of the atmosphere (e.g., trapped air bubbles) and on the incidence of past volcanic eruptions
Regional and Local Winds and Motion
-- Up, Over, and Down Mountains -- Up/Down Slopes and Valleys -- Land and Sea Breezes -- Monsoon Shifts
What is the wavelength range of visible light?
.4 - .7 micrometers
How long is the residence time (RT) of water vapor?
10 days
Of the past 2.5 years, what % of this time has our planet Earth spent in an ice age?
10-20%
Preferred Temperature
21°C
Mediterranean Climates (Csa, Csb)
300-600 in either hemisphere Occur as long and narrow strips of land along the west coasts of N. and S. America and surrounding the Mediterranean Sea. Subdivided into 3 groups
North Atlantic Oscillation
A climatic phenomenon in the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level between the Icelandic low and the Azores high.
La Nina
A cooling of the ocean surface off the western coast of South America, occurring periodically every 4 to 12 years and affecting Pacific and other weather patterns.
Pacific Decadal Oscillation (PDO)
A large pool of warm water that moves north and south in the Pacific Ocean every 30 years or so and has large effects on North America's climate.
What is hindcasting?
A method of testing a mathematical model by using data (observations) from a past event
Climate modeling
A set of rules, based on established physical principles, that are represented as computer code.
Paleocene-Eocene Thermal Maximum
A warming trend that began abruptly about 55 million years ago. - Along the way toward its maximum, Earth warmed by ~5C in ~20K years. This warming event is unrivaled by any other in our planet's recorded (direct or indirect) history. ~15 MYA our current Ice Age began. - Snowball Earth (hypothesis): a condition whereby nearly the entire planet may have been covered by ice (e.g., snow in the tropics).
Albedo
Ability of a surface to reflect light
barometer
An instrument that measures atmospheric pressure most common aneroid barometer • Units - millibars - inches of mercury
cup anemometer
An instrument used to measure wind speed Units - length per time - mph, ms, knots
ENSO variability truth agreed upon by top journals in the world is...
Analysis of coral reefs document highly variable ENSO activity with no evidence for a systematic trend in ENSO variance
Cool Phase of ENSO
Anomalously cool waters are referred to as La Niña
Cool Phase of ENSO:
Anomalously cool waters are referred to as La Niña
Warm Phase of ENSO
Anomalously warm waters are referred to as El Niño
Q
Anthropogenic Heating
Precipitation (PCP)
Any form of water that falls from clouds and reaches Earth's surface.
Within U.S. emerging/expanding megapolitans becoming primary areas of human migration
Arizona's "Sun Corridor" is one such emerging/rapidly expanding megapolitan (most rapidly expanding in the U.S.)
Grid cell communication
At the surface - ground temperature, water and energy fluxes In the atmospheric column - vertical exchange between levels - horizontal exchange between columns -- Wind vectors -- humidity -- clouds -- temperature -- height
Observed changes (in climate) and the prediction of possible futures, rely heavily on so-called..
Atmosphere-Ocean General Circulation Models (AOGCMs), Regional Climate Models (RCMs), etc
AOGCMs
Atmosphere-Ocean Global Climate Models
Ice Cap (EF)
Average temperature of the warmest month does not exceed melting point of ice (i.e., constant ice cover). Very low precipitation totals. ice is present ALL year
Warm Intervals and Ice Ages
Brief cold ice ages interrupted a generally warm climate, about 10-20% of the time in the last 2.5 billion years. For most of Earth's history, our planet's climate experienced temps 5-15°C warmer than present. For 20,000 years, global temperatures warmed by more than 5°C (9°F). Massive releases of carbon dioxide and methane from multiple sources led to the so-called Paleocene-Eocene Thermal Maximum (PETM).
Energy Transfer Mechanisms
Conduction Convection Radiation
Pressure Gradient Force (PGF)
Difference between pressure over distance - starts atmospheric motion - determines wind speed
Koeppen B
Dry (deserts). Potential evaporation exceeds precipitation
Weak walker circulation
El Niño, resulting in warmer ocean temperatures and reduced upwelling.
radio waves
Electromagnetic waves with the longest wavelengths and lowest frequencies
gamma rays
Electromagnetic waves with the shortest wavelengths and highest frequencies
A global climate model will have higher resolution than a regional climate model
False
Wien's law
For any radiating body, the wavelength of peak emission (in micrometers) is given by λmax = 2898/T
atmospheric pressure
Force exerted over some area - F=ma - the 'weight' of the atmosphere
For most of the Earth's history, our planet has been largely ________________
Free of permanent ice
General Atmospheric Circulation
Global wind pattern modified by continental masses, mountain ranges, seasons, Coriolis effect
Highland Climates (H)
Governed SOLELY by topography and not geographic (i.e., latitudinal) location
G
Ground Heat (flux)
Historical data
Harvests dates
Charles Houston
He was among the first to study High Altitude Pulmonary Edema (1958), and High Altitude Retinal Hemorrhage (1968). He authored numerous books and articles about mountain medicine. - Extreme shortness of breath or difficulty breathing that worsens when lying down - A feeling of suffocating or drowning - Wheezing or gasping for breath - Anxiety, restlessness or a sense of apprehension - A cough that produces frothy sputum that may be tinged with blood - Excessive sweating - Pale skin - Chest pain, if pulmonary edema is caused by heart disease - A rapid, irregular heartbeat (palpitations)
Subtropical Deserts (BWh)
High daily temperature ranges (and extreme high temperatures) with low dew points and relative humidity
Wavelength
Horizontal distance between the crests or between the troughs of two adjacent waves
Climate change can not be directly blamed for ...
Hurricanes
Radiation Effects
Increased particulates (e.g., aerosols) associated with urban activity absorb and scatter incoming solar radiation. Buildings (and their geometry), often a part of urbanized areas, impact the radiation balance by changing biophysical properties such as albedo and emissivity ... by changing the "sky view factor" (which impacts LWnet)
Key limitations of AMO
Instrumental SST data are short in length compared to the multidecadal timescale of the AMO; The SST-based AMO index does not directly capture aspects of the AMO related to coherent variations in subsurface temperature; Quantifying the relative importance of large scale ocean circulation (especially AMOC) vs. external radiative forcing in causing the AMO is challenging.
solar constant
Intensity of electromagnetic radiation is not depleted or reduced as it moves toward Earth. The intensity is reduced as a result of radiation being distributed over a large area, which reduces its intensity. Radiation intensity decreases in proportion to distance squared. We calculate this inverse square law for Earth's average distance from the Sun 1367 W/m2. Solar emission = Total Solar emission divided by surface area of imaginary sphere surrounding sun w/radius equal to mean Earth-Sun distance: 3.865 x 1026W / 4(1.5 x 1011m)2 = 1367 W/m2
Isobars
Isolines of equal pressure. The larger the pressure gradient the faster the wind. The closer the isobars the faster the wind.
Strong Walker circulation
La Niña, resulting in cooler ocean temperatures due to increased upwelling. associated with a high pressure system over the eastern Pacific Ocean, and a low pressure system over Indonesia.
Humid Continental (Dfa, Dfb, Dwa, Dwb)
Large annual temperature ranges. No true dry season as precipitation occurs year round. Summers are warm to hot. The more moderate (or temperate) of the two severe midlatitude climates (e.g., Chicago, New York City, Moscow).
LH
Latent Heat (flux)
Climate Research Unit (CRU)
Like NCDC but based out of the UK]
Marine West Coast (Cfb, Cfc)
Marine west coasts climates occur poleward of Csb (i.e., mild Mediterranean climates, which have a distinct summer dry season and whose precipitation season is concentrated in winter [e.g., San Francisco]); example: Seattle. Cold ocean current influence with mild summers and winters. Often has fog and/or low cloud cover. High frequency of rain days with low annual totals (though there are exceptions due to high elevation precipitation).
Koeppen C
Mild Midlatitude (temperate climates). The coldest month of the year has an average temperature higher than -3°C (27°F) but below 18°C (64°F). Summers can be hot.
Physical Mechanism
Modifications to the surface energy balance that result when natural surfaces are paved and built upon and/or when human activities release heat into the environment
Nitrogen
Most abundant gas in the atmosphere
Samples of highland climate conditions
Mt Logan and Annapurna temperature contrasts - effects of latitude Annapurna, Nepal vertical variation of solar radiation Colorado Rockies spatial variation of solar radiation Himalayas, Alaska, Hawaii, precipitation in mountains - gradients and vertical changes
Tundra (ET)
Named for vegetation extending beyond coniferous forest giving way to low-growing mosses, lichens, flowering plants. Severe winters. Mild summers of long daylight. Permafrost (permanently frozen layer below the surface) region - only low-growing vegetation can occur has at LEAST one month with an average temperature above 0C (32F).
General Circulation Models
Near surface air temperature projections for select time slices and emission scenarios.
S↓(1-a)
Net shortwave radiation
Tropical Wet and Dry (Aw)
Occur along poleward margins of the tropics, bordering dry climates on one side and tropical wet climates on the other. On an annual basis, these climates receive less precip. than Af or Am climates (i.e., driest of the "A" climates). Periods of dryness are more pronounced and longer lasting than tropical monsoonal climates.
Humid Subtropical (Cfa, Cwa)
Occur within the lower midlatitudes of eastern N. America, S. America, and Asia. Muggy (tropical feel) summers but cooler winter temperatures relative to Mediterranean climates (continentality). Summer is always the season of moisture deficit because of greater potential evapotranspiration (combination of evaporation and transpiration).
What is the reason for the lack of persistent vegetation over polar climates?
Permafrost
Koeppen E
Polar. All months have mean temperatures below 10°C (50°F).
Grid Cell Communication - 4D (time)
Primitive equations are solved at all grid cells, plus in time (i.e., the 4th dimension). Transport (horizontal and vertical) of quantities (e.g., moisture, heat fluxes) occurs between adjacent grid cells as model is integrated into the future.
Modes of Natural Variability
Quasi-Biennial Oscillation, QBO (troposphere/stratosphere interactions) Madden-Julian Oscillation, MJO Northern Annular Mode Southern Annular Mode All of these modes act in concert, sometimes opposing one another sometimes acting n the same direction ... anthropogenic climate change?
Emissitivity
Ratio of the emitted radiation from a surface to the radiation from an ideal surface (i.e., blackbody) at the same temperature; The ratio varies from 0 to 1; characterizes how efficiently an object emits radiation.
Importance of Resolution
Recall significant processes such as (i) adiabatic (no tranfser of heat across parcel, the system of interest) and (ii) diabatic ascent. 1) Temperature of a parcel may change without the addition/removal of heat from said parcel (i.e., our system of interest). 2) Temperature of a parcel may change due to the addition/removal of heat from said parcel.
Rainbows
Reflection Refraction Deflection
RCMs
Regional Climate Models
Types of Models
Regional Climate Models (RCMs) Global Climate Models (GCMs) Atmosphere-Ocean Global Climate Models (AOGCMs) Air Quality Models Building Energy Models Hydrologic Models
Evolution of Global Climate Models with Time
Resolution has increased considerably (currently about 1-degree for state-of-the-art [Global Climate Models] GCMs). Number of simulated processes have increased (e.g., carbon cycle, chemistry, UHI, oceanic representation).
climate models
Resolution: Spatial and Temporal combine data from atmospheric and ocean circulation and interactions
The Cretaceous
Roughly ~50-70 MYA: Globally averaged temps were 5-15°C > today. Sea level was 150-200m > today. Coral reefs thrived more than 15-degrees pole-ward of their location today. Dinosaurs roamed beyond the Arctic Circle. No annual ice cover on the planet
Surface Energy Balance
S down (1-α) + L down - L up + Q = SH + LH +G
SH
Sensible Heat (flux)
Koeppen D
Severe Midlatitude. Winters have at least occasional snow cover, with the coldest month having a mean temperature below -3°C (27°F). Summers are typically mild.
Monsoonal (Am)
Some months can experience very heavy rainfall (more than tropical wet [Af] climates) while others can be nearly bone dry. Annual total precipitation totals can be among the highest in the world, and vegetation does not experience moisture stress.
Southernmost point that the last major glaciation reached to is...
St. Louis, MO
Shortcomings: Koeppen System
System is based on vegetation boundaries associated with mean temperature and precipitation. Do these 2 variables uniquely determine geographic limits of natural vegetation? NO!
Southern Oscillation Index (SOI)
Tahiti SLP - Darwin SLP, where SLP = sea level pressure another term for ENSO - El Niño Southern Oscillation
Historical Climate Change
Temperatures have increased, and increased greenhouse gas concentrations have followed and amplified the initial temperature perturbation
forcing agents
The (external) factors are driving climatic change, or acting Examples: Milankovitch Cycles Sun Spots and Solar Flares Plate Tectonics Major Volcanic Eruptions El Nino/La Nina (e.g., modes of natural climate variability) Forest Fires
boundary conditions
The Earth's climate is a system that responds to the configuration of external factors
NAO's negative phase
The NAO is in a negative phase when both the sub-polar low and the subtropical high are weaker than average. During negative NAO phases, the Atlantic jet stream and storm track have a more north-south orientation (i.e., "meridional", as opposed to "zonal"):. Impacts: - In eastern North America, the negative phase of - NAO generally is associated with stronger cold-air outbreaks and increased storminess.
NAO's positive phase
The NAO is in a positive phase when both the sub-polar low and the subtropical high are stronger than average. During positive NAO phases, the increased difference in pressure between the two regions results in a stronger Atlantic jet stream and a northward shift of the storm track. Impacts: - Northern Europe experiences increased precipitation, and warmer-than-average temperatures; - Southern Europe experiences below-average precipitation. - Eastern North America experiences fewer cold-air outbreaks and decreased storminess.
Key strengths of AMO
The SST-based AMO index provides a simple, concise way to describe multidecadal climate variability in the North Atlantic; Associated with important climate impacts, such as the multidecadal variability of Atlantic Hurricane activity, North American and European summer climate, northern hemispheric mean surface temperature, and Arctic sea ice anomalies; The AMO pattern is robust across different datasets (i.e. HadISST, ERSST, Kapan SST).
intrinsic variability
The assumption that variability in behavior is in one way or another inherent to the nature of organisms.
Composition of the Atmosphere
The atmosphere is a mixture of gases, suspended particles, and liquid/solid water. Gases and particles are readily exchanged between the Earth's surface and the atmosphere through physical (e.g., volcanic) and biological (e.g., photosynthesis, respiration) processes. When atmospheric Input Rate = Output Rate the concentration of the gas exists in steady state or equilibrium. These gases are categorized in two types: permanent and variable gases.
Conduction
The direct transfer of heat from one substance to another substance that it is touching.
Coriolis effect
The effect of Earth's rotation on the direction of winds and currents.
Stefan-Boltzmann Law
The intensity of radiation depends on the temperature raised to the fourth power I = σT4 [W m-2]
Changes in Heat Storage
The release of heat from buildings plays an important role in urban heat island intensity.
Convection
The transfer of heat by the movement of a fluid
Kclear Kext
Transmissivity
Koeppen A
Tropical. Climates in which the average temperature for all months is greater than 18°C (64°F). Almost entirely confined to the region between the equator and the tropics of Cancer and Capricorn.
Sensible and Latent Heat Transfer
Urbanization affects the routing of precipitation in a way that favors increased sensible heat transfer. With more runoff, the reduction in available water increases the input of sensible heat to the atmosphere at the expense of latent heat and helps increase the temperature of the urban environment.
shortwave radiation
Wavelengths less than 4 microns, emitted by sun
longwave radiation
Wavelengths longer than 4 microns, emitted by stuff with earthly temperatures
Paleoclimate
a climate prevalent at a particular time in the geological past.
Mitigation
a human intervention to reduce the sources or enhance the sinks of greenhouse gases
the atmosphere
a mixture of gas molecules, small suspended particles of solid and liquid, and falling precipitation.
Continentality
a region's distance from the moderating influence of the sea
Carbon Dioxide (CO2)
a trace gas accounting for 0.04% (400 ppm) of the atmosphere's volume. important to Earth's energy balance. added through biologic respiration, volcanic activity, decay, and natural and human-related combustion. removed through photosynthesis, the process whereby plants convert light energy to chemical energy.
Methane
a variable gas in small but recently increasing concentrations. Released to the atmosphere through fossil fuel activities, livestock digestion, and agriculture cultivation (esp. rice). works as a very effective absorber of terrestrial radiation and it plays an active role in near surface warming
most widely measured atmospheric parameters are
air temperature and precipitation
α (alpha)
albedo
Inter-Tropical Convergence Zone (ITCZ)
appears as a band of clouds consisting of showers, with occasional thunderstorms, that encircles the globe near the equator.
Aerosols
are any solid and/or liquid particle, other than cloud droplets, which exists in the atmosphere (synonymous with the term particulate). Aerosols are both natural (sea spray, dust (e.g., haboobs), combustion) and human (combustion) produced products. Due to their small size, they can easily remain in suspension for long periods. contribute to precipitation processes as condensation nuclei.
In looking at past climates, very different pictures emerge, depending on the ...
area considered and time scale adopted.
Positive phase of ENSO
associated with anomalously cool sea surface temperatures in the equatorial central/eastern Pacific Ocean
Residence Time (RT)
average length of time that individual molecules of a given substance remain in the atmosphere. mass of atmos. substance (kg) / rate of transport (kg/time)
El Nino
band of warm waters spreads eastward across the equatorial Pacific Ocean, this phenomenon is colloquially to as __________
Thornwaite Classification
based on soil moisture availability
UV waves
can cause sunburn and skin cancer from radiation - positive--> creation of vitamin D in human skin
One of the key concerns associated with determination of temperature variability change...
changing number of observing stations over time
Periodic variability
climate abnormality that recurs with constant regularity (e.g., El Niño/La Niña)
Vertical zonation
climate changes with height (mountainous regions; e.g., Mt. Kilimanjaro (~6k meters above sea level) located near the equator). Climate therefore changes as one moves higher and higher.
The Koeppen System
climate classification system is based on natural vegetation types as indicators of average temperature and precipitation.
random (noise) variability
climate fluctuations that are not systematic
National Climatic Data Center (NCDC; now referred to as National Centers for Environmental Information [NCEI])
climatological LIBRARY and research center for the U.S. (world's largest); operated by the National Oceanic and Atmospheric Administration; to describe, monitor and assess climate and support efforts to predict changes in the Earth's environment (Est. 1978)
Atlantic Multidecadal Oscillation (AMO)
coherent mode of natural variability (based on estimates of SSTs) occurring in the North Atlantic Ocean with an estimated period of 60-80 years
Walker Circulation
conceptual model of tropical air flow; easterly trade winds move water and air warmed by the sun towards the west
Subarctic (Dfc, Dfd, Dwc, Dwd)
contains the coniferous boreal forest taiga--asia warm, short summers and extremely cold winters low annual precipitation with the moistest season being summer
Atmospheric optics
deals with how the unique optical properties of the Earth's atmosphere cause a wide range of spectacular optical phenomena (e.g., mirages, rainbows, halos). These are generally unimportant to radiative transfers, but are of considerable public interest. The optics are often illusions that cannot be physically approached
Sky View Factor
dimensionless parameter that represents the fraction of visible sky for some reference location relative to sky fraction over a flat horizontal surface with no obstructions
Flaw of Koeppen system
does not take into account full system like potential evapotranspiration just precipitation isn't enough
L ↓
downwelling longwave radiation
S ↓
downwelling shortwave radiation
Urban sustainability
ensuring environmental, socio-cultural, and economic dimensions of a city to meet the needs of its residents over a long-term period (United Nations World Commission on Environment and Development 1987). Focus has been largely on decreasing emissions of greenhouse gases.
Intergovernmental Panel on Climate Change (IPCC)
established by WMO and United Nations in 1988; "to understand the scientific basis of risk of human-induced climate change"; no research & no monitoring; assessment based on scientific literature (READS AND REVIEWS)
ENSO variability
every 2-7 years
Oceanic/lake sediments
examination of fossil remnants, chemical composition
synoptic climatology
focuses on atmospheric circulation, but at the regional to larger scale (e.g., continental); geared toward solving problems or for use in operations ("applied climatology").
dynamic climatology
focuses on atmospheric motion on large scales and how that dictates climate variability (spatially and temporally).
permanent gases
gases that remain at stable concentrations
Proxy (indicators)
geologic and biologic records used as indicator of past/historical climate, known as paleoclimate(s), or climate(s) of the past.
ultraviolet waves
have frequencies slightly higher than visible light; can damage skin
Considerable variability
highlights uncertainty among suite of GCMs for the suitable range of emissions scenarios, and even within a particular emissions scenario
How are Climate Models Tested?
hindcasting
Atlantic Multi-decadal Oscillation (AMO)
identified as a coherent mode of natural variability (based on estimates of SSTs) occurring in the North Atlantic Ocean with an estimated period of 60-80 years (sometimes noted as 65-70 years).
World Meteorological Organization (WMO)
international agency (U.N.) responsible for worldwide climatic data/instrument standards; authoritative voice on Earth's atmosphere, its interaction with oceans, climate, and the distribution of water resources (Est. 1950)
Kext
is the amount of radiation from the sun at the top of the atmosphere
Kclear
is the amount of radiation from the sun reaching the mountain site
Climatology
is the long-term study of the atmosphere and the processes that cause what we refer to as "climate." Climate is defined as: The slowly varying aspects of the atmosphere-hydrosphere-land surface system (i.e., climate system).
Panel with LONGER arrows shows
least residence time
Climate change requires holistic assessment
looking at totality of climate impacts (i.e. also including the warming due to the built environment), hydrologic impacts and impacts due to GHG increases, together ... and .
Density
mass (kg) per unit volume (m3); note P(ressure) = F(orce) per unit area. Due to compressibility, near surface air is more dense than that above. This may be expressed in terms of the mean free path, or average distance a molecule travels before colliding with another molecule. mass/volume
GCMs (Global climate models)
mathematical representations (in computer code) of the Earth atmosphere-ocean-land system that are run on supercomputers.
radiative forcing
measure of how the energy balance of the earth-atmosphere system is influenced when the factors that affect climate are altered
MaRTY
name of ASU heat walker
Observations of ocean heat content
new evidence suggests that this is the best way to monitor ongoing climate change (whether natural or anthropogenic) and is required
modern treatment of the nature and theory of climate
opposed to a purely descriptive account, must deal with the dynamics of the entire atmosphere-ocean-land surface (climate) system, in terms of its internal interactions and its response to external factors, for example, incoming solar radiation
Significant concentrations of O3 may be found in the..
peak of the ozone and urban areas
epoch
period of time
Pollen/Past Vegetation
pollen diagrams can provide information on vegetation abundance at a local site, from which past climate can be inferred - vegetation occupies a region, some of its pollen and spores can be deposited and preserved indefinitely in lake beds or bogs (age of organic material is assessed by radiocarbon dating (technique for determining age of an object that contains organic material), which provides a good estimate of the age of material <50K years). - pollen grains deposited in sediment layers
El Nino Southern Oscillation (ENSO)
pool of warm water off the tropical central and eastern Pacific Oceans (e.g., western coasts of northern South and Central America).
Change in temperature or density changes . . .
pressure - Density increases cold air high pressure - Density decreases warm air low pressure
Adaptation
process of adjustment to actual or expected climate and its effects
Feedback mechanisms
processes in which changes in one variable lead to changes in another
pressure profile
provides a useful aid for visualizing the distribution of air pressure across a map - decreases with height
energy budget
provides an equation that quantifies the balance of incoming and outgoing energy flows, or fluxes
physical climatology
pursues an explanation of climate rather than presentation of it; focuses on energy and water budgets (i.e., employs a "systems approach"); sub-areas include boundary-layer climatology (atmosphere-surface interface processes) and hydroclimatology (land-atmosphere water exchange).
Climate
refers to long term patterns (30 years)
Weather
refers to short term phenomena
Urban Heat Island (UHI)
refers to the increased local temperatures that result from urbanization (e.g., TemperatureA - TemperatureB).
Anthropocene
relating to or denoting the current geological age, viewed as the period during which human activity has been the dominant influence on climate and the environment.
Polar cell
rising motion at 60° and sinking motion at poles
Hadley cell
rising motion at equator and sinking motion at 30°N and 30°S
Monsoon
seasonal reversal of winds
Warmer objects radiate energy at...
shorter wavelengths than do cooler bodies.
regional climatology
simple presentation of climatological data to describe the climate of a region.
Ferrel cell
sinking motion at 30°and rising motion at 60°, weak
PET > PCP
soil moisture (in soil column) is reduced
PCP > PET
soil moisture (in soil column) is replenished
Answers to questions about future climate change must be referenced to both a ...
spatial and a temporal scale.
Corals
temporal resolution of data obtained can be as fine as annual to seasonal; very useful for detecting past marine conditions (e.g., sea surface temperature, El Nino).
Tree rings
temporal resolution of data obtained is seasonal; conditions of the past up to a few thousand years can be inferred.
Sediments
temporal resolution of data obtained is variable (annual to century scale); sedimentary analysis can provide climate information (e.g., presence of charcoal can be used to infer info. on fire) dating back hundreds of millions of years (or longer).
Warmer bodies radiate more energy...
than do cooler bodies at all wavelengths.
Potential Evapotranspiration (PET)
the amount of water that could be evaporated from the soil and transpired by plants, given the average temperature and humidity
Applied climatology
the climate factors involved in a broad range of problems relating to the planning, design, operations, and other decision-making activities of climate sensitive sectors of modern society
anomaly
the difference between the instantaneous state of the climate system and its longer term mean. Climate variability and change are characterized in terms of these
Wind is always named for
the direction it is coming FROM
Divergence Problem
the disagreement between the temperatures measured by thermometers and temperatures reconstructed from width of tree rings in northern forests since the 1950's
Transpiration
the emission of water vapor from the leaves of plants
urban heat island effect
the heat that cities generate as a result of having many buildings and few trees or other vegetation
Water vapor
the most abundant variable gas, as it is added or removed from atmosphere through the hydrologic cycle. Concentrations exist from nearly 0% over desert and polar regions to nearly 4% near tropics. contributor to Earth's energy balance and many important atmospheric processes
Scientific Climatology
the nature and controls of the earth's climate and the causes of climate variability and change on all timescales
Frequency
the number of complete wavelengths that pass a point in a given time
visible light waves
the only part of the electromagnetic spectrum you can see, all colors of light
Meteorology
the study of the atmosphere and the processes that cause what we refer to as "weather."
Radiation
the transfer of energy requiring no physical medium (can occur through empty space). - Continually emitted by all substances, but for our purposes the primary source is our Sun
Ozone
the tri-atomic form of oxygen and is essential to life on Earth (~10ppb [~50ppb in urban areas] - 15ppm [in stratosphere]). near the surface is a pollutant but in the stratosphere it is an essential absorber of ultraviolet radiation (harmful to life). Chlorofluorocarbons (CFCs), specifically chlorine atoms, react with ozone in the stratosphere and destroys ozone. destruction peaks over the southern hemisphere and persists through spring.
Primitive Equations
those which quantify the motions of the atmosphere in many climate models.
Thermal Layers of the Atmosphere
troposphere, stratosphere, mesosphere, thermosphere (from low altitude to high
L ⬆
upwelling longwave radiation
microwaves
very short electromagnetic wave
Rainbows require...
water droplets
variable gases
water vapor, carbon dioxide, ozone, methane
xrays
waves with higher frequencies and shorter wavelengths than UV light
negative feedback mechanism
where the feedback acts to inhibit further change in a variable (i.e. damping [initial] effect).
positive feedback mechanism
where the feedback acts to magnify further change in a variable (i.e. amplifying [initial] effect).
