EAS 270: Numbers (approx. magnitude, and unit) you are expected to remember
Knowledge to two significant digits will suffice; if you need greater precision, the number will be given as data. Thus for example, the solar "constant" is given by the textbook as 1365 W m-2 (four significant digits, p105) but it will suffice that you to remember it is ~1400 W m-2 (true to two significant digits). As we encounter new numbers it is useful to learn and remember, they will be noted here. All will have been given, either in the instructor's lecture pdfs, or in the textbook. (In general we will use MKS units, and you should know the meanings of the related units designated by "milli," "micro", "nano", "hecta", "deca" etc.)
- offset between Edmonton's local standard time and GMT (MST=GMT-7h, MDT=GMT-6h)
- latitudes of southern and northern borders of the Canadian prairie provinces
- Kelvin temperature corresponding to 0oC
- distance in kilometers corresponding to one degree of latitude
- latitude and elevation ASL of Edmonton
- approximate depth of the troposphere
- nominal value for atmospheric pressure at sea-level
- nominal value for air density ρ at sea-level
- sampling duration for Environment Canada "climate normals"
- gravitational acceleration g
- proportions of the permanent gases (N2, O2, Ar) and of CO2
- nominal heights (ASL) of the 850 hPa, 700 hPa, 500 hPa and 250 hPa levels
- density of water ρw
- pressure values and approximate heights ASL of the four mandatory levels above the surface
- latent heat of evaporation/condensation of water (nominally 2.5 x 106 J/kg, which applies at 0oC)
- contour interval between neighbouring isobars (or height contours) on CMC surface (or upper air) analyses
- earth's solar constant S0
- increase (decrease) in 1000-500 hPa thickness corresponding to a 1 K increase (decrease) in mean temperature of that layer
- specific heat capacity of dry air cp
- the unsaturated ("dry") adiabatic lapse rate, symbolized as DALR or as Γd
- wavelength (nominally 3 μm) separating shortwave from longwave radiation
- wavelength (nominally 5 μm) of peak in solar spectrum
- recognize wavelength range of the "atmospheric window" (about 8 - 11 μm)
- nominal value for longwave emissivity of natural terrestrial materials (solid and liquid), i.e. ε=1
- wavelength of GOES IR channel (10.7 μm)
- earth's climatological whole-planet albedo (i.e. shortwave reflectivity)
- approx. upper limit to the net radiation Q* on horizontal ground (about S0/2)
- latitudes of Tropic of Cancer and Tropic of Capricorn
- near-surface nominal value for the saturated ("moist") adiabatic lapse rate, symbolized as SALR or MALR or as Γm (-0.4 K per 100 m)
It is taken for granted that some numbers need not be placed on the above list, as being a matter of everyday knowledge: for instance, the number of seconds in one hour (etc).
Last Modified: 31 Oct. 2016