GLOBAL PATTERNS OF THE CLIMATIC ELEMENTS: (1) SOLAR ENERGY

1
GLOBAL PATTERNS OF THE CLIMATIC ELEMENTS (1)
SOLAR ENERGY (Linked to solar insolation R,
net radiation)
2
CONTROLS OF SOLAR INSOLATION 1) Sun angle
(intensity) -- changes with latitude, time of
day, time of year 2) Duration (day length) --
changes with latitude, time of year 3) Cloud
cover (and general reflectivity of
atmosphere) 4) Surface albedo (water, soil,
snow, ice, vegetation, land use) In general,
land areas (with lower atmospheric moisture)
receive more insolation than adjacent water areas
and the highest values occur over subtropical
deserts.
3
REVIEW OF INSOLATION
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
DURATION
9
(No Transcript)
10
(No Transcript)
11
INTENSITY
12
RADIATION / ENERGY BALANCE
Q ( K? - K? ) ( L? - L? ) where K? direct
diffuse shortwave solar radiation
13
(No Transcript)
14
Kiehl and Trenberth (1997) BAMS
15
Trenberth et al. (2009) BAMS
16
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
radiation Positive values represent energy moving
towards the surface, negative values represent
energy moving away from the surface.
17
Net short-wave radiation
Positive values represent energy moving towards
the surface, negative values represent energy
moving away from the surface.
18
SW absorbed Function of INTENSITY DURATION
sun angle / albedo
19
Net long-wave radiation
Positive values represent energy moving towards
the surface, negative values represent energy
moving away from the surface.
20
(No Transcript)
21
(No Transcript)
22
Annual mean absorbed solar radiation, emitted
longwave radiation (OLR) and net radiation by
latitude
23
S Solar radiation T Terrestrial radiation
24
Net Radiation
Positive values represent energy moving towards
the surface, negative values represent energy
moving away from the surface.
25
(No Transcript)
26
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. 
27
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.
28
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. 
29
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. 
30
(No Transcript)
31
Humid Tropical / Equatorial rainforest
Tropical desert
32
Tropical wet climate
Tropical wet-dry climate
Tropical desert climate
Grassland /steppe climate
33
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.
34
(No Transcript)
35
Air Temperature (at the surface) T (?C)
Seasonal temperature variations can be explained
in terms of the latitudinal seasonal
variations in the surface energy balance. 
The pattern of temperatures are a function of net
short-wave radiation, net long-wave radiation,
sensible heat flux, latent heat flux and change
in heat storage. 
36
GLOBAL PATTERNS OF THE CLIMATIC ELEMENTS (2)
TEMPERATURE
37
CONTROLS OF HORIZONTAL TEMPERATURE PATTERNS

1. Sun angle Duration
2. Land vs. water thermal contrasts
3. Warm Cold surface ocean currents
4. Elevation
5. Ice/Snow albedo effects
6. Prevailing atmospheric circulation

38
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
39
2. Land vs. water thermal contrasts

•   Given the same intensity of insolation, the
  surface of any extensive deep 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

40
3. Warm and Cold Ocean Currents
41
4. Elevation
42
5. Ice /Snow Albedo Other Effects
43
6. Prevailing atmospheric circulation
Temperatures are affected by the temperature
"upwind" -- i.e. where the prevailing winds and
air masses originate
44
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 a POLEWARD 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.

45
JANUARY
JULY
Northern Hemisphere
Southern Hemisphere
46
JANUARY
JULY
Northern Hemisphere
Southern Hemisphere
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
http//geography.uoregon.edu/envchange/clim_animat
ions/
Constructed by Jacqueline J. Shinker, JJ Univ
of Oregon Climate Lab
51
The NCEP / NCAR REANALYSIS PROJECT DATASET
http//www.cdc.noaa.gov/cdc/data.ncep.reanalysis.h
tml
52
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 levels in the
atmosphere. (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.)
53
The horizontal resolution of the gridpoints is
based on the T62 model 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 2.5?
latitude-longitude grid. Note that the
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.
54
Map of locations of Raobs soundings for the
globe
Raobs rawindsonde balloon soundings
55

• 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
• the observational data
• the model

IMPORTANT "the user should exercise caution in
interpreting results of the reanalysis,
especially for variables classified in categories
B and C." (p 448)
56
Class A the most reliable class of variables
"analysis variable is strongly influenced by
observed data" value is closest to a real
observation Class A variables mean sea level
pressure, geopotential height (i.e. height of
500 mb surface, 700 mb 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)
57
Class B the next most reliable class of
variables "although some observational data
directly affect the value of the variable, the
model also has a very strong influence on the
output values." Class B variables surface
pressure, surface temperature (and near-surface
2-m temperature) , max and min
temperature, vertical velocity, near-surface
wind (u v wind at 10 m), relative humidity,
mean relative humidity, precipitable water
content, and snow cover
58
Class C the least reliable class 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 fluxes from surface or
top of the atmosphere.