are many computer models used by meteorologists around the world. For example,
the United States National Weather Service’s weather predictions are carried out at
the National Centers for Environmental Prediction (NCEP). The NCEP runs several
different computer models each day to determine the best weather forecasts. Some are
used for short-term forecasting, others for the longer term; and some are used for
global or hemispherical predictions, while others are only regional. They include sev-
eral mathematically intensive computer models (for more information about comput-
er modeling, see “Math in Computing”).
NGM—NGM, or the Nested Grid Model, is one in which observations are convert-
ed to values at various points that are evenly spaced, making it easy for the computer
programs to plug them into equations. This model is now considered to be obsolete.
ETA—The ETA model was named after the ETA coordinate system, which is a
mathematical coordinate system that takes into account topographical features, such
as mountains. It is similar to the NGM model and forecasts the same atmospheric
variables, but its smaller grid gives a more detailed forecast.
AVN, MRF, and GSM—The AVN model, MRF (Medium Range Forecast), and the
GSM (Global Spectral Model) convert data into a large number of mathematical waves;
they then return the waves in a manner that will produce a forecast map.
ECMWF—The ECMWF (European Center for Medium-Range Weather Forecasts)
is considered to be one of the most advanced weather forecast models in the world; it
is mostly used for the Northern Hemisphere.
UKMET—The UKMET (United Kingdom meteorology offices) model also gives
forecasts for the entire Northern Hemisphere.
MM5—The MM5 (Mesoscale Model #5) and WRF (Weather Research Forecast
model) are actually the same models. The MM5 has long been a research computer
model for smaller geographic forecast regions such as Antarctica; the WRF is the
name for MM5 as an operational model, not just for research.MATH IN BIOLOGY
What is biology?
Biology is the science of life. It includes the study of the characteristics and behaviors
of organisms; how a population, species, or individual comes into existence and
evolves; and the interaction of organisms with the environment and each other.What is mathematical biology?
Mathematical biology is another word for biomathematics, the interdisciplinary field
314 that includes the modeling of natural biological processes using mathematical tech-