Weather vs. Climate:Weather-The condition of the atmosphere at any given point in timeClimate-the long-term prevailing pattern of temperature, precipitation and other weather variables at a given

location, described by statistics, such as means and extremesClimate system-5 components: atmosphere, hydrosphere, cryosphere, land surface (upper geosphere), and biosphereClimate of a location is affected by its latitude, terrain, altitude, nearby water bodies and their currentsContinentality-Position from the influence of the sea, especially regarding climate. Occurs due to the specific heat (capacity) of water which is much higher than land (essentially the same amount of energy will heat land much more than water).Rain Shadow (orographic) Effect-Moist air is forced upwards by topography (e.g., mountains) in a process called orographic lift. The air will cool to its dew point, forming clouds and precipitation on that side of the mountain. However, the air will go down the other side of the mountain and warms up again, but by that time, most of the water vapor will have condensed and precipitated. This all results in low relative humidities that do not favor the formation of more clouds.Urban Heat Island Effect-Urban areas will be slightly warmer than outstate areas at similar latitudes and elevations. This occurs because what used to be vegetation and soil that lost heat due to latent heat during evaporation/transpiration, is now buildings/asphalt/etc. and water will just runoff instead of evaporating. Also, materials such as asphalt will store heat more effectively, and release that heat all through the night, hence why the effect is best observed at nightImportant climatic calculations-

Daily mean temperature-Average of daily maximum and minimum Daily temperature range-Maximum temperature minus minimum temperature Monthly mean temperature-the mean of all daily mean temperatures in a month Annual mean temperature-the mean of all monthly mean temperatures in a year Annual temperature range-hottest monthly mean minus coldest monthly mean

Köppen classification-Five primary types labeled A through E; incorporates monthly mean temperatures along with amount and seasonality of precipitationA-Topical (Megathermal)-all months have average temperatures of at least 18°C

Tropical rainforest (Af)-high rainfall, normal annual rainfall 1,750-2,000 millimeters, usually within 5-10° latitude of the equator under the influence of the ITCZ

Tropical monsoon (Am)-a seasonal prevailing wind, lasts for several months, ushers in a region's rainy season, occurs in regions within North America, South America, Sub-Saharan Africa, Australia and East Asia

Tropical savanna/wet and dry (Aw)-a grassland biome, have a pronounced dry season, rainfall between 750-1,270 millimeters a year, located in semiarid to semi-humid climate regions of subtropical and tropical latitudes, widespread in Africa, found in India, the northern parts of South America, Malaysia, and Australia, sometimes (As) is used if the wet season is in spring or summer

B-Dry (arid and semiarid)-actual precipitation less than a threshold value set equal to the potential evapotranspiration. How to calculate this is described below

Steppe Vs Desert: Multiply the average annual temperature in °C by 20, then add (a) 280 if 70% or more of the total precipitation is in the summer (depending on hemisphere), or (b) 140 if 30%–70% of the total precipitation is received during the applicable period, or (c) 0 if less than 30% of the total precipitation is so received.

If the annual precipitation is less than 50% of this threshold, the classification is BW (desert); if it is in the range of 50%-100% of the threshold, the classification is BS (steppe).

Steppe (BS)-dry grassland with an annual temperature range in the summer of up to 40°C (104°F) and during the winter down to −40°C (−40°F)

Desert (BW)-a region that receives very little precipitation, deserts usually have a large diurnal and seasonal temperature range, with high or low, summer daytime temps up to 45°C (113°F), and winter nighttime temperatures down to 0°C (32°F) due to extremely low humidity

Third letter=temperature; h=every monthly avg >0°C, k=at least 1 month avgs <0°C n=near coast (minor continentality), colder, low clouds and fogC-Mild mid-latitude (temperate/mesothermal)-average temperature above 10°C in their warmest months, and a coldest month average between −3 and 18°CSecond Letter=precipitation pattern, w=dry winters, s=dry summers, f=significant precipitation in all seasonsThird Letter=degree of summer heat, a=warmest month avg temp >22°C (72°F), ≥4 months avging >10°C, b=warmest month avging <22°C, ≥4 months averaging >10°C, c=≤3 months avging >10°C

Dry summer subtropical/Mediterranean climate (Csa,Csb)-characterized by hot, dry summers and cool, wet winters, resembles the climate of the Mediterranean Basin, parts of western North America, parts of Western and South Australia, in southwestern South Africa and in parts of central Chile.

Humid subtropical (Cfa,Cwa)-climate zone where winter rainfall (and sometimes snowfall) is associated with large storms that the westerlies steer from west to east. Most summer rainfall occurs during thunderstorms and from occasional tropical cyclones, lie on the east side continents, roughly between latitudes 20° and 40° degrees away from the equator

Maritime Temperate/Oceanic climate (Cfb,Cfc,Cwb,Cwc)-typically found along the west coasts at the middle latitudes of all the world's continents, and in southeastern Australia, and is accompanied by plentiful precipitation year round

Temperate highland tropical climate with dry winters (Cwb,Cwc)-characteristic of highlands inside tropics of Mexico, Peru, Bolivia, Madagascar, Zambia, Zimbabwe and South Africa, central Argentina (outside the tropics). Winters are noticeable and dry, and summers can be very rainy. In the tropics, rainy season is caused by the tropical air masses and the dry winters by subtropical high pressure.

Maritime subarctic climates/subpolar oceanic climates (Cfc)-occur poleward of the maritime temperate climates, confined either to narrow coastal strips on the western poleward margins of the continents, or to islands off such coasts

Dry-summer maritime subalpine climates (Csc)-occur in isolated highland areas adjacent to oceans where maritime influence keeps the average monthly temperature from dropping below -3°C

D-Cold mid-latitude (continental/microthermal)-have an average monthly temperature above 10°C, and a coldest month average below −3°CSecond Letter=precipitation pattern, w=dry winters, s=dry summers, f=significant precipitation in all seasonsThird Letter=degree of summer heat, a=warmest monthly average above 22°C with ≥4 months avging >10°C, b=warmest monthly average below 22°C with ≥4 months avging >10°C, c==≤3 months avging >10°CHot summer continental (Dfa, Dwa, Dsa)-usually occur in the high 30s and low 40s latitudes, warmest month of >22 °C, in Europe, these climates tend to be much drier than in North America. In eastern Asia, the influence of the Siberian high pressure system causes winters there to be dry, and summers can be very wet because of monsoon circulationWarm summer continental/hemiboreal (Dfb, Dwb, Dsb)-high 40s and low 50s latitude in North America and Asia, and also in central and eastern Europe and Russia, where it extends up to high 50s and even low 60 degrees latitude.Continental subarctic/boreal (taiga) (Dfc, Dwc, Dsc)-occur poleward of the rest of group D, mostly in the 50s and low 60s north latitude, sometimes as far north as 70°NContinental subarctic w/ extremely severe winters (Dfd, Dwd, Dsd)-average temperature in their coldest month lower than −38°C, occur only in eastern SiberiaE-Polar-monthly average temperatures below 10°C in all 12 months of the yearTundra (ET)-occurs in the far Northern Hemisphere, north of the taiga belt, tree growth is hindered by low temperatures and short growing seasons, warmest month has an average temperature between 0-10°CPolar ice cap (EF)-a high-latitude region that is covered in ice due to a lack of direct insolation, all twelve months have average temperatures below 0°C (32°F)Other climate classification systems-

Thornthwaite-monitors the soil water budget using values of evapotranspiration and precipitationo Moisture classifications include climatic classes with descriptors such as: hyperhumid, humid, subhumid, subarid, semi-arid, and arido Thermal classifications include microthermal, mesothermal, and Megathermal

Trewartha-similar to Köppen, created to redefine and further differentiate the middle latitudes to be closer to vegetation zoning

o Group A-Tropicalo Group B-Dry (arid and semi-arid)o Group C-Subtropicalo Group D-Temperate and continentalo Group E-Borealo Group F-Polaro Group H-Highlands

Climate Change-the change in weather patterns over an extended period of time; factors that can determine and affect climate are called forcing mechanisms

Internal Forcing Mechanisms-factors within Earth's climate system with the lithosphere limited to only surface formations. Includes changes in the oceans (such as El Niño-Southern Oscillation and variation of thermohaline circulation) and biological processes (such as the mass introduction of oxygen into the atmosphere by photosynthetic organisms and the Daisyworld Model).

External Forcing Mechanisms-factors independent from the Earth's climate system or involve the subsurface lithosphere. Includes changes in Earth's orbit (Milankovitch Cycles), variations in solar output, volcanic activity, movement of tectonic plates, and human activities.

Climate Change Feedback-the process in the context of climate change in which changing one quantity changes a second quantity, and the change in the second quantity in turn changes the first. Positive feedback amplifies the change in the first quantity while negative feedback reduces it. Can occur in a continual loop that will keep amplifying the change in the overall outcome.

Positive feedback loop-the effects of a small positive disturbance on a system include an increase in the magnitude of the perturbation; A produces more of B which in turn produces more of A

o Water vapor feedback-hotter airhigher evapotranspiration and water vapor capacityhigher concentration of water vaporincreased greenhouse effecthotter air

A similar feedback occurs for cloudso Ice-albedo feedback-ice meltsland/water exposedlower albedowarmermore ice melt

Negative feedback loop-the effects of a small negative disturbance on a system include an increase in the magnitude of the perturbation

Climactic Proxies-Preserved physical characteristics of the past that stand in for direct measurements to enable scientists to reconstruct the climatic conditions that prevailed during much of the Earth's history

Ice Cores-cylindrical samples extracted from ice sheetso The presence 16O and 18O in an ice core help determine past temperatures and snow accumulations. 18O condenses more

readily as temperatures decrease and falls as precipitation, while 16O can fall in even colder conditions.o Contains inclusions such as such as wind-blown dust, ash, pollen, bubbles of atmospheric gas and radioactive substanceso Analysis of the air contained in bubbles in the ice can reveal the palaeocomposition of the atmosphere, in particular CO2

o 10Be concentrations are linked to cosmic ray intensity which can be a proxy for solar strengtho The chronological resolution depends on the amount of annual snowfall, and reduces with deptho Different dating methods makes comparison and interpretation difficult

Tree Rings-wider when conditions favor growth, narrower when times are difficulto Clearly demarked in annual incrementso Responds to multiple factors, including temperature, moisture, and amount of light (cloudiness)o Temperature, moisture, amount of light, etc. work in conjunction to determine the rate of growtho Geographic coverage; trees aren’t found all over the eartho Variations in different times of the growing season may be more important than otherso A plethora of other factors also at play: soil, tree age, fire, tree-to-tree competition, genetic differences, logging or other human

disturbance, herbivore impact, pest outbreaks, disease, and CO2 concentration Coral-coral skeletal rings, or bands; cooler temperatures tend to cause coral to use heavier isotopes in its structure, while

warmer temperatures result in more normal oxygen isotopes Pollen-the identified plant community of the area at the relative time from that sediment layer (determined by inclusions of

pollen), will provide information about the climatic conditionSolar Variation-Variations in solar output

Most prevalent variation is the 11-year solar cycle in which the number of sunspots varieso Sunspots- relatively dark areas on the photosphere of the Sun where intense magnetic activity inhibits convection and cools the

photosphere. Although this may seem to produce a significant reduction in solar output, this effect is buffered by faculae (slightly brighter areas that form around sunspot groups), rendering the decrease in total solar output minimal

o solar output has recently been measured to vary by approximately 0.1%, or about 1.3 Watts per square meter Other long-term events of anomalies in sunspots (most estimated with proxies):

o Medieval Maximum (about 1100-1250)-a period of high solar activity; coincided with much of the medieval warm period

o Maunder Minimum (about 1645-1715)- sunspots became exceedingly rare, as noted by solar observers of the time; coincided with the middle part of the Little Ice Age

o Dalton Minimum (about 1790 to 1820 or 1830)-a period of low solar activity, during which there was a variation of temperature of about 1°C, although this is likely due to volcanism (e.g. the year w/out a summer)

o Modern Maximum (about 1914-2000)-the period of relatively high solar activity which began with Solar Cycle 15 in 1914. It reached a maximum in Cycle 19 during the late 1950s and may have ended with Cycle 23 in 2000

Past Climactic Anomalies- 1816-The Year Without a Summer-extremely abnormal cold conditions caused primarily by intense volcanism (most

notably the 1815 eruption of Mount Tambora), which occurred in conjunction with low solar activity (Dalton Minimum); average global temperatures decreased by about 0.4–0.7 °C (0.7–1.3 °F)

Little Ice Age-a period of cooling that occurred after the Medieval Warm Period; defined by NASA as a period between 1550 and 1850 C.E.; The IPCC suggests largely independent regional climate changes, rather than globally synchronous changes; could have been caused by orbital cycles, decreased solar activity (Maunder Minimum), increased volcanism, and/or altered ocean currents

Medieval Warm Period-a time of warm climate in the North Atlantic region (may not have been global) lasting from about 950 to 1250 C.E.; globally, temperatures were probably between 0.1 °C and 0.2 °C below the 1961 to 1990 mean

Effects of Volcanism on Climate-Greenhouse Gas (GHG)-A gas in an atmosphere that absorbs and emits radiation within the thermal infrared range; allow insolation to reach the Earth's surface unimpeded. As the shortwave energy heats the surface, longer-wave energy is reradiated to the atmosphere. Greenhouse gases absorb this energy, thereby allowing less heat to escape back to space, and 'trapping' it in the lower atmosphere, known as the greenhouse effect.

Can be naturally occurring (although also man-made), such as such as CO2, CH4, H2O, nitrous oxide (N2O) Can be synthetic, such as CFCs, HFCs, Perfluorocarbons (PFCs), sulfur hexafluoride (SF6)

Water Vapor-the most abundant greenhouse gas in the atmosphere (up to 4% concentration in tropics)o Water vapor feedback-warmer air temperaturehigher evapotranspiration and water vapor capacityhigher concentration of

water vaporincreased greenhouse effectwarmer airCarbon Dioxide-An important greenhouse gas that is both naturally occurring and anthropogenic

o Before the industrial revolution, was present at concentrations of around 280 ppm, however today it has recently reached levels as high as 400 ppm due to burning of fossil fuels and vegetation

o Is a product of respiration, and a reactant of photosynthesis; can undergo a seasonal variation in concentration along with variations in deciduous vegetation

Methane-