1.Solar Radiation.energy.temp 09

8/12/2019 1.Solar Radiation.energy.temp 09

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GLOBAL PATTERNS OF THE

CLIMATIC ELEMENTS:

(1) SOLAR ENERGY

(Linked to solar insolation& R, net radiation)


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REVIEW OF

INSOLATION


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DURATION


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INTENSITY


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RADIATION /

ENERGY BALANCE

Q* = ( K - K ) + ( L - L )where K = direct + diffuse shortwavesolar radiation


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Kiehl and Trenberth (1997) BAMS


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Trenberth et al. (2009) BAMS


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Radiative Components

Net short-wave radiation =short-wave down - short-wave up

Net long-wave radiation =long-wave down - long-wave up

Net radiation (R net) =

net short-wave radiation + net long-wave radiationPositive values represent energy moving towards the

surface, negative values represent energy moving away

from the surface.


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Net short-wave radiation =

Positive values represent

energy moving towards the

surface, negative values

represent energy moving

away from the surface.


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SW absorbed =

Function ofINTENSITY &

DURATION & sun

angle / albedo


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Net long-wave radiation =







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Net Surplus


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Annual mean absorbed solar radiation,

emitted longwave radiation(OLR) and net

radiationby latitude


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S = Solar radiation T = Terrestrial radiation


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Net Radiation =







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N R di ti C t


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Non-Radiative Components

Sensible heat flux (H) = direct heating, a function

of surface and air temperature

Latent heat flux (LE) = energy that is stored in

water vapor as it evaporates, a function of

surface wetness and relative humidity

Positive values for sensible and latent heat flux represent

energy moving towards the atmosphere, negative values

represent energy moving away from the atmosphere.


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Non-Radiative Components

Change in heat storage (G) =

net radiation - latent heat flux - sensible heat flux

G = R net - LE - H

Positive values for change in heat storage

represent energy moving out of storage,

negative values represent energy moving into

storage.


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Sensible Heat Flux = H

Positive values for sensible and latent

heat flux represent energy moving

towards the atmosphere, negative

values represent energy moving away

from the atmosphere.


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Latent Heat Flux = LE

Positive values for sensible and latent

heat flux represent energy moving

towards the atmosphere, negative

values represent energy moving away

from the atmosphere.


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Tropical wet-dry climate

Grassland /steppe climate

Tropical wet climate

Tropical desert

climate


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Change in Heat Storage = G

Positive values for change in heat

storage represent energy moving out of

storage, negative values represent

energy moving into storage.


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GLOBAL PATTERNS OF

THE CLIMATIC ELEMENTS:

(2) TEMPERATURE


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CONTROLS OF HORIZONTAL

TEMPERATURE PATTERNS

1. Sun angle & Duration

2. Land vs. water thermal contrasts

3. Warm & Cold surface oceancurrents

4. Elevation

5. Ice/Snow albedo effects

6. Prevailing atmospheric circulation


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1. Sun Angle & Duration

Sun angle(influences intensity of solar insolation & albedo)

Duration (based on day length)

- both change with latitude and time of year

Leads to: zonal (east-west) distribution of isotherms,

hot in low latitudes; cold in high latitudes

2 Land vs water thermal contrasts


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Given the same intensity of insolation, the surface of any extensivedeep body of water heats more slowly and cools more slowly than the

surface of a large body of land.

4 Reasons:

1) water has a higher specific heat and heat capacity than land

2) transmission of sunlight into transparent water

3) mixing is possible in water, but not soil

4) evaporation cools air over water during hot season (less evap

during winter)

Leads to: annual and diurnal temperature ranges will be less in coastal/marine

locations

the lag time from maximum insolation to time of maximum temperature

may be slightly longer in coastal/marine locations

2. Land vs. water thermal contrasts


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3. Warm and Cold Ocean Currents


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4. Elevation


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5. Ice /Snow Albedo & Other Effects


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6. Prevailing atmospheric circulation

Temperatures are affected by the temperature

"upwind" -- i.e. where the prevailing winds and

air masses originate

MAPPING HORIZONTAL


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MAPPING HORIZONTAL

TEMPERATURE PATTERNS

Isotherms= lines connecting points of equal temperature

Isotherms will be almost parallel, extending east-west if Control

#1 (sun angle) is the primary control.

If any of the other controls are operating, isotherms on a map

will have an EQUATORWARD shift over COLD surfaces and aPOLEWARD shift over WARM surfaces

The TEMPERATURE GRADIENT will be greatest where there

is a rapid change of temperature from one place to another

(closely spaced isotherms).

Continental surfaces in winter tend to have the steepest

temperature gradients.

Temperature gradients are much smaller over oceans, no

matter what the season.


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JANUARY JULYNorthern Hemisphere

Southern Hemisphere


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Southern Hemisphere

Northern Hemisphere

JANUARY JULY


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http://geography.uoregon.edu/envchange/clim_animations/

Constructed by:

Jacqueline J. Shinker, JJ

Univ of Oregon Climate Lab
http://geography.uoregon.edu/envchange/clim_animations/http://geography.uoregon.edu/envchange/clim_animations/


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The NCEP / NCARREANALYSIS PROJECT

DATASET

http://www.cdc.noaa.gov/cdc/data.ncep.reanalysis.html
http://www.cdc.noaa.gov/cdc/data.ncep.reanalysis.htmlhttp://www.cdc.noaa.gov/cdc/data.ncep.reanalysis.html


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The assimilated data are:

-- computed by the reanalysis

model at individual gridpoints

-- to make gridded fields

extending horizontally over the

whole globe

-- at 28 different levelsin theatmosphere.

(Some of these levels correspond to the

"mandatory" pressure height level at

which soundings are taken, e.g., 1000,

850, 700, 500, 250 mb, etc.)

The horizontal resolution of the gridpoints is based on the T62 model


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The horizontal resolution of the gridpoints is based on the T62model

resolution(T62 = "Triangular 62-waves truncation") which is a grid of 192

x 94 points, equivalent to an average horizontal resolution of a gridpoint

every 210 km.

The pressure level data are saved on a 2.5latitude-longitude grid.

Note thatthe gridpoints for computed model output are more numerous

and much closer together in the mid and high latitudes, and fewer and

farther apart over the low latitudes.


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Map of locations of Raobs soundings for the globe:

Raobs = rawindsonde balloon soundings
http://localhost/var/www/apps/conversion/tmp/GLOCLIM.2003/fig_3.5.gif


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Reanalysis Output Fields

The gridded output fields computed for different

variables have been classified into four classes ( A,

B, C, and D) depending on the relative influence (on

the gridded variable) of:

(1) the observational data

(2) the model

IMPORTANT: "the user should exercise cautionin interpreting results of the reanalysis,

especially for variables classified in categories B

and C." (p 448)


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Class A= the most reliableclass of variables; "analysis

variable is strongly influenced by observed data"

value is closest to a real observationClass A variables:

mean sea level pressure,

geopotential height (i.e. height of 500 mb surface, 700mb surface, etc.),

air temperature,

wind (expressed as two vectors dimensions: zonal = u

wind (west-east ) and meridional = v wind (north-

south),

vorticity (a measure of rotation)


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Class C = the least reliable class of variables


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Class C the least reliableclass of variables

-- NO observations directly affect the variable and it is

derived solely from the model computations

-- forced by the model's data assimilation process, not by

any real data.

Class C variables:

precipitation,snow depth,

soil wetness and soil temperature,

surface runoff,

cloud fraction (% high, middle, low),cloud forcing, skin temperature, surface wind

stress, gravity wind drag,

and latent and sensible heat fluxesfrom surface or top of

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1.Solar Radiation.energy.temp 09