Temperature Reading AK Chapter3 Surface Temperature Surface Energy

Temperature (Reading AK Chapter-3) Surface Temperature Surface Energy Budget Temperature Cycles Nasa’s Solar Dynamics Observatory, 17 Mar 2015 Annual Temperature Cycles Interannual Temperature Variations : Volcanoes and Temperature Diurnal Temperature Cycle : Record Cold and Record Heat Across the United States Temperature Variation with Height Lapse Rates and Stability Temperature Inversions Near the Ground Wind-Chill Temperature : Temperature and Your Health Temperature and Agriculture

Average Global Surface Temperature Things to consider: -Land vs. Sea -Mountains vs. Plains -North vs. South -Temperature Advection -Albedo -Specific Heat

Avg Global Temp 15ºC or 59ºF Global Record Low -89ºC -129 F Global Record High 57ºC 134 F California Bodie 8, 300 ft Death Valley – 282 ft Links Global Extremes http: //en. wikipedia. org/wiki/List_of_weather_records

Global Monthly Temperature Warmest on record From https: //weather. com/news/climate/news/record-warmest-february-global-2016

Record Lows by State

Urban Heat Island The urban heat island was first recognized in London in 1820 with Luke Howard’s observation “night is 3. 7°F (2. 1°C) warmer…in the city than in the country” Landsberg (1981) The Urban Climate (Academic Press)

Napoleon’s 1812 March (AK)

Table 3 -1, p. 78 AK

Normal (Climatological) - Interannual (year-to-year) = Anomilies Diurnal Temp Cycle

Annual Temperature Cycles • • Latitude Insolation Elevations Surface type Ocean temp and currents Evaporation Cloud Cover Aspect Day in June ~15 hr NY <14 hr Miami Insolation- The amount of solar radiation reaching the top of the earth atmosphere.

Annual Temperature Cycles • • Latitude Insolation Elevations Surface type Ocean temp and currents Evaporation Cloud Cover Aspect Specific Heat of water 3 times that of land thus the land heats and cools about 3 x faster than water. Also ocean evaporation reduces extremes Specific heat- energy to raise 1 gram by 1 deg C

Annual Temperature Cycles • • Latitude Insolation Elevations Surface type Ocean temp and currents Evaporation Cloud Cover Aspect

Annual Temperature Cycles • • Latitude Insolation Elevations Surface type Ocean temp and currents Evaporation Cloud Cover Aspect

Moisture 0 -10 m Surface Temperature 2 m July 16 2006 Pierre S. D. 117 F

1930’s Dust Bowl A warmer tropical Atlantic and cooler tropical Pacific. Weaken low level jet, which brings moisture to central U. S. “When rain is scarce and soil dries, there is less evaporation, which leads to even less precipitation, creating a feedback process that reinforces lack of rainfall. ” http: //www. nasa. gov/centers/goddard/news/topstory/2004/0319 dustbowl. html www. wtamu. edu/~crobinson/Erosion/index. html

Annual Temperature Cycles • • Latitude Insolation Elevations Surface type Ocean temp and currents Evaporation Cloud Cover Aspect

Annual Temperature Cycles • • Latitude Insolation Elevations Surface type Ocean temp and currents Evaporation Cloud Cover Aspect

Thermodynamic Diagrams http: //weatherfaqs. org. uk/book/export/html/168

Potential Temperature (PT) (The potential temperature is the temperature an air parcel at a specific pressure level and temperature would have if it were lowered or raised adiabatically to 1000 mb. This is defined by Poisson's equation. Poisson's Equation PT = T(1000/P)^Rd/cp = T(1000/P)^0. 286 T = temperature in Kelvins P = pressure in millibars Rd = gas constant for dry air Cp = constant pressure process + Eg. -20 deg. C @ 500 mb PT = (253° K) (2)^0. 286 = 308° K 243 0 deg C = 273 K 253 263 273 283 293 303 313 k PT

243 253 263 273 283 293 303 313 k PT

Remember: atmospheric stability depends on the environmental lapse rate.

absolutely stable Environment Inversions fit into this category environmental lapse rate less than the moist adiabatic lapse rate Figure from Meteorology Today, C. Ahrens, 6 th Ed, 1991

Absolutely Unstable Environment Rarely occurs for very long due to mixing environmental lapse rate greater than the dry adiabatic lapse rate Figure from Meteorology Today, C. Ahrens, 6 th Ed, 1991

Conditionally Unstable Environment between dry and moist lapse rate Atmosphere is stable if the rising air is unsaturated but unstable if the air is saturated

Skew. T CAPE CIN

http: //met. nps. edu/~ldm/mr 3222/files/helpful/ skewt. AWS-TR-79 -006 -skewt. pdf skewt. NWS_Skewt-Manual. doc

Surface Inversions

Processes that Alter Stability stabilize destabilize DLA Fig. 5. 18

Clouds Due to Cooling at the Earth’s Surface – Radiation Fog DLA Fig. 5. 26 radiational cooling under clear skies and light wind can lead to condensation and formation of fog

Parcel Behavior and Atmospheric Static Stability Examples of specific processes that cause cooling above or warming below, and thereby destabilize the atmosphere: 1. cold air advection (CAA) aloft 2. warm air advection (WAA) below 3. radiative cooling of the air aloft 4. radiative warming of the air below (especially during the daytime) 5. sensible heating as air moves over a warm surface 6. lifting of a layer 7. convective or turbulent mixing

Parcel Behavior and Atmospheric Static Stability Mixing serves to steepen the environmental lapse rate (destabilize the atmosphere). This mixing can be induced by convective processes or turbulent processes. Such mixing can be important in breaking up a stable environment (e. g. , breaking up morning inversions as convection and turbulence increase during the daytime) Figure from Meteorology Today, C. Ahrens, 4 th Ed, 1991

Remember: atmospheric stability depends on the environmental lapse rate.

Remember: atmospheric stability depends on the environmental lapse rate.