on a calm clear night, the only significant components of the energy balance are:

latent, sensible and soil heat fluxes - all directed towards the surface

for a given concentration difference, what would happen to the flux density if resistance to transfer was doubled?

it would be halved

the downward longwave emittance from the atmosphere is relatively constant throughout the day at night because:

water vapour and air temperature in the lower atmosphere change relatively little over the day

in a plot of windspeed (x-axis) against the logarithm of measurement height (y-axis), what variable can you derive from the gradient of the line drawn through the observations?

the friction velocity

in which of the following catchments will channel precipitation make the greatest contribution to runoff?

a catchment mainly covered by wetland

in which of the following environments does the process of horizontal interception make a significant contribution to precipitation outputs?

coastal deserts

the availability of which element is progressively restricted above and below neutral soil pH?

phosphorus

what is the current average of cropland on Earth per human inhabitant?

<0.25 hectares

what elements are integral components of typical clay minerals?

magnesium, aluminium, silicon, and oxygen

how is the soil positioned within the Earth system critical zone?

centrally

what law in radiation physics best describes NASA's use of gold foil to cover satellites in space?

Kirchoff's Law

what is the saturated hydraulic conductivity of a confined aquifer?

2m day^-1

what is the approximate stock of carbon in global soils?

2.1mil tonnes

if the soil in a lysimeter is correctly maintained at field capacity, what is it measuring?

potential evapotranspiration

you would expect the least extreme daytime and night-time temperatures within a few centimetres of the soil surface in a soil that:

had a high thermal diffusivity

what is a key indicator for soil texture?

clay content

evaporation from wet coniferous forest is most sensitive to changes in:

wind speed