Albedo is
the fraction of incoming solar radiation (sunlight) that is
reflected back into space. Albedo values range from 0 to 1, and
because they are expressed as fractions, they have no units.
Objects that are very dark in color absorb most of the
incoming radiation (causing them to heat up) and have a low
albedo, while objects that are very light in color reflect
most of the incoming radiation and have a higher albedo.
Anomaly
An anomaly is
the departure from the average over a certain period of time.
For example, a positive temperature anomaly indicates that the
observed temperature is warmer than the climate averaged over a
period of time, while a negative anomaly indicates that the
observed temperature is cooler than the average climate.
Biome
A biome is
a major ecological community that extends over a large
geographic area, characterized by an abundant type of
vegetation. The organisms of a biome are adapted to the climate
conditions associated with the region.
Climate
Climate is
the long-term patterns of weather. This is often measured as the
average of weather of a 30-year period (see 'Climate Normal'
below). For example, the annual temperature averaged over the
past 30 years in Durham, NH was 8°C.
Climate Normal
Climate
normal is the average of a climate variable (temperature,
precipitation, etc.) over a 30-year period.
Ecosystem
An
ecosystem in a community plus its physical surroundings.
Emission Scenario
Emission
scenarios characterize the heat-trapping gasses that we expect
to find in the atmosphere based on different scenarios
describing future trends in human population growth, energy use,
economic development, and technology use. For more information
on specific emission scenarios see information from the World
Meteorological Organization.
Global Climate Model
Global Climate
Models (GCMs) are complex mathematical representations of the
physical processes occurring throughout the Earth's
land-ocean-atmosphere system. They generate predictions
extending 100 years into the future.
MODIS
MODIS
stands for MODerate-resolution Imaging Spectroradiometer. It is
a scientific instrument (aboard the Terra and Aqua satellites)
launched by NASA that captures data in 36 spectral bands. It
images the entire Earth every 1 to 2 days. For more information,
see http://modis.gsfc.nasa.gov.
NDVI
NDVI stands
for Normalized Difference Vegetation Index. It measures the
greenness of an area, and is calculated using a combination of
red and infrared bands. It is often measured by Earth
observing satellites with instruments such as MODIS (see
above). For more information on NDVI, see NASA's
Measuring Vegetation website.
Vegetation Index
Vegetation
Indices are mathematical combinations of surface reflectance
(measured from the reflectance of the vegetation), and are
designed to highlight a certain property of the vegetation. An
example of a vegetation index is NDVI (see above).
Weather
Weather is
the mix of events (precipitation, humidity, temperature, etc.)
that happen over a short period of time (minutes to months) in
a specific location. For example, the temperature on June
12th, 2012 in Durham, NH was 18.9°C.
