# part 1 Flashcards

Synoptic meteorology

meteorology traditionally involves the study of weather systems, such as

- extratropical high and low pressure systems,
- jet streams
- associated waves
- fronts.

mesoscale meteorology

- the study of convective storms,
- land–sea breezes,
- gap winds,
- and mountain waves

The earth system exhibits a continuous……………………….spectrum of motion that defies simple categorization.

spatial and temporal

Weather forecasting

necessitates understanding a wide range of processes and phenomena acting on a variety of spatial and temporal scales.

forecasting for a coastal location requires information concerning

- the near-shore water temperature,
- the potential for land–sea breeze circulations,
- and the strength and orientation of the prevailing synoptic-scale wind flow.

The prediction of precipitation type can benefit from

knowledge of atmospheric thermodynamics and cloud physics.

Other types of prediction, including ……………………………………… and ……………………………, also require knowledge that spans a broad spectrum of meteorological processes.

air quality forecasting and seasonal climate prediction

quasigeostrophic (QG) equations

simplified version of the full primitive equations

igoners small terms

momentum equations are

continuous

ideal gas

hydrostatic

geostraphic wind is a balance between

corriolis and PGF

scale analysis

a systematic strategy to determine which terms in the equations, often associated with specific physical processes, are most important and which are negligible in a given meteorological setting.

scale analysis is a systematic strategy to determine which terms in the equations, often associated with specific physical processes, are most important and which are negligible in a given meteorological setting. By

characterizing the temporal and spatial scales associated with specific weather systems, we can systematically neglect “small” terms in the governing equations in the study of those systems.

for **synoptic- and planetary-scale weather systems**, such as cyclones and anticyclones, we know that in the ……………………………, flow above……………………tends to be fairly close to a state of ……………………………balance

midlatitudes, ~1 km altitude, geostrophic

—flow above ~1 km altitude tends to be fairly close to a state of geostrophic balance, whereas for mesoscale weather systems, such as thunderstorms, it …………………………………………………….

does not, even in the same geographical location

geostrophic balance ignores

friction

whereas for mesoscale weather systems, such as thunderstorms, it does not, even in the same geographical location. **Why?**

cannot ignore friction

This is one example of why students in the atmospheric sciences are required to derive equations, because it is important to know what ……..

- assumptions were made in the development of a given technique
- this information is needed to deduce which tools are appropriate for which situations.
- the ability to apply a systematic approach to the governing equations allows atmospheric scientists to develop new equations and techniques to study unique problems.

The length scale can be related to

the size of a weather system, or how far an air parcel would travel within the system during a given time interval.

The time scale

can be related to how long it would take an air parcel to circulate within the system

Scale: Microscale

length:

less than 1 km

Scale: Microscale

time:

less than 1 hour

Scale: Microscale

example phenomena:

Turbulence, PBL

Scale: Mesoscale

Length:

1 - 1000 km

Scale: Mesoscale

time:

1 h - 1 day

Scale: Mesoscale

example phenomena:

Thunderstorm, land-sea breeze

Scale: synoptic

length:

1,000-4,000

Scale: synoptic

time:

1 day-1 week

Scale: synoptic

Example phenomena:

Upper level trough, ridges, fronts surface lows and highs

Scale: Planetary

Lenght:

less than 4000 km

Scale: planetary

time:

less than 1 week

Scale: planetary

Example phenomena:

polar front jet streams, trade winds

the dependent variables in the system

- the four
**independent**variables are the three spatial directions - and time, denoted as x, y, z, and t, respectively

governing equations are applied to a flat “cartesian” earth for

- qualitative work,
- or if we study weather systems that are sufficiently small in spatial scale, we can neglect the distortion that results.

shows unit vectors in an orthogonal Cartesian coordinate system. For some applications, the i and j unit vectors may be

grid relative

the horizontal coordinate directions here will be taken to align with

latitude and longitude lines

A and B represent

K^{^} (z, + upward)