1. Bioclimatology & Weather
We talk about climatology b/c it has so much to do with the activity of our tree. We need to understand some of the basics so that we can discuss in more detail how they affect the productivity of that tree

2. Montana Water Desert Tropical forest Tundra Boreal (Temperature)
Energy
MT is in a climate transition area for both energy and water.

3. Distribution of forest trees in an area of west-central Montana
grassland
PINUS PONDEROSA SERIES
PSEUDOTSUGA MENZIESII SERIES
ABIES GRANDIS SERIES
ABIES LASIOCARPA
SERIES
timberline
alpine tundra
2700
2450
1650
1050
ELEVATIONS
(approx.) 10
255 18 35
MEAN JULY TEMPERATURE (°C)
MEAN ANNUAL PRECIPITATION (cm)
Distribution of forest trees in an area of west-central Montana
(Arrows show the relative elevational range of each species: solid portion of the arrow indicates where
a species is the potential climax and dashed portion shows where it is seral.
(Modified from Pfister et al., 1977)
Pinus ponderosa
Pseudotsuga menziesii
Larix occidentalis
Pinus contorta
Abies grandis
Abies lasiocarpa
Picea engelmannii
Pinus albicaulis
Larix lyallii
Elevation also plays a big role as it affects both T and PPT.
Leads to concept of biogeography.
Pinus ponderosa = Ponderosa pine
Pseudotsuga menziesii = Douglas fir
Pinus contorta = lodgepole pine
Abies grandis = grand fir
Abies lasiocarpa = subalpine fir
Picea engelmannii = Engelmann spruce
Pinus albicaulis = whitebark pine
Larix lyallii = subalpine larch
Treeline
Alpine tundra

4. Climate vs. Weather Climate Weather Microclimate
characteristic patterns, means, and extremes of weather (usually a 30-year period is chosen)
Weather
local short-term
atmospheric conditions
Microclimate
local variation in
climate
Microclimate – local variation in climate, influencing spatial patterns of local ecosystems and their species composition; especially influential in maintaining some species near the limit of their ranges.
Why climate can be predicted despite the chaotic nature of the weather:
Predicting climate is like predicting what will happen when you boil a large pot of water (100 ºC at sea level, but only 90 ºC at a particular altitude in the mountains). Anyone with a good knowledge of physics could predict approximately how long it will take to boil, what range of temps and what kinds of convections might arise. Predicting weather is like trying to predict where the next bubble will rise in the boiling pot. This illustrates that the former is a boundary value problem - the mean temperature of the boiling water depends in a predictable way on boundary conditions, i.e. air pressure, just like the global mean temperature depends on the CO2 concentration. The latter, in contrast, is an initial value problem in a highly turbulent system and therefore a much harder problem.
Climate is a major factor in: Genetic differentiation and speciation, Species distributions, Growth rates, Carbon balance
Variation in climate with latitude, elevation and proximity to large water bodies and mountain ranges is closely tied to distribution of vegetation on global, regional, and local scales.
Characteristic temperature and precipitation patterns, as they interact with vegetation, parent materials, and physiographic position, are important in determining soil processes and soil development.
Long-term changes in climate have continuously altered the spatial distribution and species composition of forested ecosystems globally. Both natural and anthropogenic changes in climate could potentially alter the distribution of forests and their productivity in the future.

5. Missoula, MT Lat/Lon 46.92,-114.08 Elevation 3,220 Feet Temperate Coniferous Forest
Precipitation
Period of Relative Drought
Precipitation
Temperature
Temperature

6. Jackson, MS Lat/Lon 32.32, -90.08 Elevation 283 Feet Subtropical Pine Forest
Precipitation
Precipitation
Temperature
Temperature

7. Flagstaff, AZ Lat/Lon 35.13, -111.67 Elevation 6,894 Feet Dry Mixed Conifer Forest
Precipitation
Precipitation
Period of
Relative
Drought
Temperature
Temperature

8. Lansing, MI Lat/Lon 42.77, -84.60 Elevation 828 Feet Temperate Mixed Forest
Precipitation
Precipitation
Temperature
Temperature

9. Radiation & Temperature

10. Insolation: Solar Radiation Striking the Earth’s Surface
I = insolation
S ~ 1000 W m-2 (clear day solar insolation on a surface
perpendicular to incoming solar radiation.
This value actually varies greatly due to
atmospheric variables.)
Z = Zenith Angle (the angle from the zenith (point directly
overhead) to the Sun’s position in the sky)
The zenith angle is dependent upon
latitude, solar declination angle, and time
of day.
We discuss radiation because it provides the energy used by plants.
The zenith angle is the angle between directly overhead and the sun.
I = S cos(Z)

11. Insolation: Zenith Angle
Z = cos-1 {sin(Latitude) * sin(Solar Decl.) +
cos (Latitude) * cos(Solar Decl.) * cos H}
Latitude = latitude at site of interest (Missoula ~46°)
Solar Decl. = solar declination; the latitude on the earth where
the sun is directly overhead at solar noon.
At Vernal Equinox (Mar. 21/22) = 0°
At Summer Solstice (Jun. 21/22) = +23.5°
At Autumnal Equinox (Sept. 21/22) = 0°
At Winter Solstice (Dec. 21/22) = -23.5°
H = hour angle = 15° x (Time – 12)
This is the angle of radiation due to the time of day
Time is given in solar time as the hour of day from
midnight.
This equation is how we determine the zenith angle.
It depends on your latitude and the solar declination.
+23.5 is Tropic of Cancer.
solar declination: the latitude on Earth where the sun is directly overhead at solar noon

12. Light is most concentrated from an overhead source
Light hitting at an angle is less concentrated

13. Why are there seasons? Basically, it is because the Earth is tilted at 23.5°.
At the Vernal and Autumnal Equinox, energy hits the Earth equally in both hemispheres.
At the summer solstice, incoming solar energy is greatest in the Northern Hemisphere (sun is perpendicular to Earth at the Tropic of Cancer).
At the winter solstice, incoming solar energy is greatest in the Southern Hemisphere (sun is perpendicular to Earth at the Tropic of Capricorn).
The Arctic Circle defines the circle on the earth above which, on December 21, the sun doesn’t rise above the horizon.
The Antarctic Circle defines the point on the earth above which, on June 21, the sun doesn’t rise above the horizon.
In the tropics,there is no real change in daylength => no real change in incoming energy => no seasonal change in temperature.
Seasonality comes from the monsoon season.
June-September in India
November-April in Australia

14. Daylength

16. Electro-magnetic Spectrum
Energy is a spectrum of which we can only see a very small part.

17. Important Radiation Laws & Concepts
Stefan-Boltzmann Law
E =   T4
Everything above absolute 0 (0K) emits energy at a rate to the 4th power of its temperature.
So, if it is warmer, it emits much more energy. Since it is at the 4th power, the relationship
Shoots up quickly as the temperature increases. It is easy to see why the sun (6000K) (hot) emits much more than the earth (300K).

18. Solar radiation Earth radiation
We are primarily concerned with two types of radiation – the short-wave (visible/nearIR) from the sun and the thermal (long-wave) from the earth.
We need to think of this as a spectrum. A good example is a wood stove in a dark room.
Notice that much of the radiation from the sun is in the visible and near infrared range. In fact, about ½ of all of the energy from the sun is in the visible, also called Photosynthetically Active Radiation (PAR).
Earth radiation

19. Radiation Radiation Conduction Convection
There are 3 ways in which energy transfer occurs:
Radiation – transfer through the air (e.g., sun)
Conduction – transfer along/between objects (e.g., touch a hot poker)
Convection – movement caused by convective air movement (e.g., thermals from a stove)
When it is cold, you don’t feel or see any thermal energy coming from it. As you begin to pile on the logs, though, you can start feeling the energy. If you keep adding logs, then it will eventually start to glow a reddish tint.
If you switch to coal, it can eventually get white-hot (visible), but then, you’d better leave, b/c your house is about to explode!

24. Important Radiation Laws & Concepts
Wien’s Law
m (m) = 2897 / T
Wien’s law explains the relationship between the temperature and the wavelength of an object.
So, for the earth, temperature is 300 K, meaning the wavelength is ~ 10 microns.
The sun has a T = 6000K, so it’s wavelength is ~0.5 microns
m  wavelength of maximum intensity;
the higher the temperature,
the shorter the wavelength &
the more intense the light

25. Also, from Wien’s Law, the hotter the object, the more intense the light.
Wien's Law tells us that objects of different temperature emit spectra that peak at different wavelengths.
Hotter objects emit most of their radiation at shorter wavelengths; hence they will appear to be bluer .
Cooler objects emit most of their radiation at longer wavelengths; hence they will appear to be redder.
Furthermore, at any wavelength, a hotter object radiates more (is more luminous) than a cooler one.
m (m) = 2897 / T

26. Simple addition and subtraction.
What comes in – what goes out = what is left for work
And, Missoula has more energy than Seattle b/c of less atmosphere even if all other conditions are the same.
Incoming:
Absorbed at Earth surface: 51
Absorbed in atmosphere: = 19
Reflected: = 30
Total: 51 + (16+3) + (6+20+4) = 100
Outgoing Longwave:
Originating at Earth Surface: = 51
Originating in Atmosphere: = 19
Total: (21-15) + ( ) + (3+23) = 70
Outgoing Shortwave:
Originating in Atmosphere: = 26
Originating at Earth Surface: 4
Total: (6+20) + 4 = 30
Balance = 100 – (70+30) = 0 

27. Thermal Radiation From Atmosphere Reflected Sunlight Transfer by
Reradiation
Direct
Sunlight
Transpirational
Transfer
Scattered
Sunlight
wind
Convective
Transfer
Here is what happens to our tree energy-wise.
Total incoming =
direct shortwave radiation from the sun,
diffuse shortwave radiation from the sky,
reflected shortwave radiation from nearby surfaces,
longwave radiation from atmospheric emission,
longwave radiation from nearby surfaces.
Total outgoing = longwave radiation from the surface
Thermal
Radiation
Reflected
Radiation

28. Important Radiation Laws & Concepts
Net radiation for a tree
Rn = incoming – outgoing
Rn = (1- )Is + EL T4(surface) -  T4(sky)
 is albedo, which is the
reflectivity of a surface
fresh snow has a high albedo (0.9)
dark forest has a low albedo (0.05 – 0.15)
light colored soils are in between (0.4 – 0.5)
mean albedo for earth  0.36
And here is how we write it in equation form.

29. Important Radiation Laws & Concepts
Surface Energy Balance
Rn – G = H + E
Net radiation – Soil heat storage = Sensible heat + Latent heat
Bowen Ratio
The ratio of Sensible heat to Latent heat
This just summarizes some of our basic equations.
First, net radiation = what comes in – what goes out
represents what is available for work
Energy balance
available energy is lost in 2 main ways:
sensible heat, evaporation
PSN represents <1% of all available energy,
so we ignore it.

30. Bowen Ratio
Now, scientists have come up with a way to determine which of the two ways of energy loss is dominated – Bowen ratio
Think of a parking lot – really hot. This is because most of the heat is used to heat up the parking lot
The lake is much cooler, ~90% of the energy is used to evaporate water from the surface.
While the parking lot will warm tremendously in one afternoon, the lake will
take months to warm up (Flathead Lake from 32F [mid-April] to 76  F [late July]).

31. White box = “official temperature” (34°C = 93°F)
Decayed log – dark, but very wet, well-connected to surface
Humus
Litter so hot – dry, dark, little heat conductivity to surface
Charred surface – even hotter (poor connection to soil, very low thermal conductivity.
Residue – little more water content than litter
Bare Soil – thermal connectivity
To get a maximum temperature at Lubrecht, need all of these:
High radiation, No wind, Dry Surface
If it is cloudy, windy, rainy, the box is a good indicator of surrounding temperature
Drier surface gets hotter during the day and cooler at night.
These are reasonable estimates for the area. On a cloudy day, will be cooler (70-80 °F) & nights warmer, and wind also has an effect.
Think of the impact on seedlings: Protein denaturation at ~53°C

32. White box = “official temperature”
Decayed log – wet, connected to surface, loses energy slowly
Humus
Residue
Litter – dry, little connection to surface, loses energy quickly
Drier surface gets hotter during the day and cooler at night.
These are reasonable estimates for the area. On a cloudy day, will be cooler (70-80 °F) & nights warmer, and wind also has an effect.

34. Coram Site 06-29-76 Here are temperatures for the same area
daytime, not much difference
nighttime, about 15C warmer just upslope from valley
think about this when backpacking
Again, cold air drainage at night – cold air denser, so
sinks, settles in the bottoms – like water

35. Number of Days to First Frost
Coram Site
1976
Take what we learned and put it on a slope
Not much difference on hillside regardless of
silvicultural practice – all about 1 month
later than valley
Example of cold air drainage – occurs in Missoula about
half the time during the 6 months of “winter”

36. -1.8°C -3.7°C 150 m +2.3°C -1.1°C -12.4°C -15.6°C -28.8°C
All time temperature difference record!
Vertical distance from here to the “M”
At top of valley – about 1C (34 F),
as go into valley, -30C (30 BELOW ZERO!!) (-22 F)
extreme case of cold air drainage!
Gstettneralm Sinkhole, Austria
Elevation = 1270 m
21 January 1930
Coldest temperature = °C (-63 °F)
Photo: Bernhard Pospichal,
November 2001

37. Clouds Why do clouds form???? There are 3 ways that clouds form:
convective
orographic (mountains)
air mass frontal systems
Why do clouds form????

38. Convective Cloud Formation

39. Orographic Cloud Formation

40. Frontal Cloud Formation
A cold front forms when a mass of relatively cold air advances toward a mass of warmer air. Because cold air is denser than warm air, it wedges underneath the mass of warm air, forcing the warm air to rise and cool. The cold front moves quickly and has a steep edge that creates the rapid uplift needed to form cumulus clouds. A strong cold front may produce cumulonimbus clouds and thunderstorms, tornadoes, or snow squalls. Cold fronts also bring abrupt temperature changes. As a cold front advances, temperatures can drop more than 8°C (15°F) within a couple of hours.
When a mass of warmer air advances to replace colder air, the boundary is called a warm front. This type of front moves more slowly than a cold front. Warm fronts also have gentle slopes and are associated with less severe weather. As the warm air advances, it gently slides over and replaces the cold air. Typically, the leading edge of the warm front first produces high cirrus clouds. Later, the gradual lifting of the rest of the front produces layered clouds such as cirrostratus, altostratus, and nimbostratus clouds. Because of the gentle slope and slow movement, warm fronts can produce steady precipitation that lasts for days.

41. 80 cal/gram absorbed 540 cal/gram absorbed 80 cal/gram released
At sea level (0-ft; 0-m), water boils at 100°C.
In Missoula (3210-ft; 978-m), water boils at 96.8°C.
At the peak of Mt. Sentinel, (5158-ft; 1572-m), water boils at 94.9°C.
In Laramie (7277-ft; 2218-m), water boils at 92.8°C.
On top of Mt. McKinley [Denali] (20320-ft; 6194-m), water boils at 77.7°C.
80 cal/gram
released
540 cal/gram
released

42. Adiabatic Lapse Rates 15°C 20°C 30°C Dry Adiabatic Lapse Rate:
10.0°C/1000 m
5.5°F/1000 ft
Saturated Adiabatic Lapse Rate:
6.0°C/1000 m
3.3°F/1000 ft
15°C
Lifting Condensation Level (Saturation Level)
20°C
“Average” Environmental Lapse Rate:
6.5°C/1000 m
3.6°F/1000 ft
This varies WIDELY at any given place at any given time.
30°C

43. Vapor Pressure

44. Vapor Pressure Deficit
(VPD)

47. In the summer, the sun rises to the northeast of Missoula and sets to the northwest. So, do north-facing slopes near Missoula ever get direct sun? Yes, of course, during sunrise/sunset in the summertime.

48. Recorded
Dewpoint
Temperature (F)
09/30/05
Recorded
Minimum
Temperature (F)
09/30/05

49. Effects of Precipitation on the Carbon Balance of Mount Jumbo
Biggest slope effects are found in the Northern Rockies. Around Missoula, we can really see this near the “L” on Mount Jumbo. It is not an issue during the summer. But, during the winter, snow that falls on the south-facing slopes will melt – they will even have less snow than flat surfaces. On northern slopes, however, the snow piles up, increasing available moisture after snowmelt. Therefore, trees in this area grow on north-facing slopes since there is more moisture there. South-facing slopes get too hot and dry during the summer since there is no buildup of moisture to both support trees & evaporate to cool the area.

50. Longitudinal variations of. - precipitation (mm y-1),
Longitudinal variations of - precipitation (mm y-1), - temperature (oC), - vapor pressure deficit (kPa), and - rainfall fraction to precipitation (%) are averaged for each column for [A shaded graph shows column-mean elevation ( m) from the coast (Seattle) to the Rocky Mountain area (near Missoula).]
Range: Seattle to almost Missoula
Resolution: 1-km

51. Land Surface Temperature, Aug. 21, 2003 @ 6:14 p.m.
August 21, 6:14 p.m.
Min = C (-99.7F)
Max = 58.25C (136.85F)
Mean = 18.55C (65.40F)
August 21, 6:14 p.m.
Min = C (-99.7F)
Max = 58.25C (136.85F)
Mean = 18.55C (65.40F)
Darker = Cooler

52. Land Surface Temperature
Wild Horse Island
Mission
Mountains
ASTER image draped over DEM
Cool tone = cool; Red = warm
July 2003, Flathead Lake

53. Land Surface Temperature