Weather and Climate Studies (Chapter 3)

Statistical analysis

Interpretation and presentation of large quantities of data utilized to make sense of the vast amounts of data

Two types of statistics

Descriptive - data is described as given quantitively

Inferential - tests of hypotheses, making predictions, drawing conclusions

Descriptive statistics

A quantitative summary of the characteristics of a variable or data set

Mean

The sum of a set of values divided by the number of observations in the same set

Median

Middle value in a set of ranked observations

Equal number of values above and below it

Mode

Value that occurs the most frequently or appears most often in a data set

Ranger

Arithmetic difference between the smallest and the largest values of the group

Average deviation

Average amount of spread of the numbers from the middle value

Variance

Square of standard deviation

Provides a measure of the average squared deviation

Standard Deviation

Common measure of the spread of the values about a middle position in a group

Distribution

Shape of a frequency graph that is repeatable

What is the most common distribution?

Normal distribution (bell curve)

Peak values

Standard Score

Mean is set to 0 and each deviation is set to 1

Frequency distribution

Describes how many of each value exists in the group within a simple set one-dimensional of numbers

What are common standards when creating graphs for data?

Axes scale linear or logarithmic

Two-dimensional data

Two values associated with each point, scatter plot used

Time series

Analysis accounting for climate observations taken over time that may have internal patterns, such as trends or seasonal variations

Two major objectives in climatic time series analysis

Understand variation in an ECV

Use understanding to forecast future changes in ECV behavior

Trend

General tendency of the values to increase or decrease over time for a series

Cycles

Regular fluctuations of similar magnitude and time span that can be identified in a data series

Recurrence interval

Statistical measure based on historic data representing the average reoccurrence of a similar event over an extended period of time

Commonly used with flood data

Climate normals

Tool used to characterize surface climate conditions at a specific location using just a couple ECVs

Geospatial climatology

A powerful, emerging method of study that examines spatial patterns of climate and their relationships with geographic features

Global positioning system (GPS)

A satellite-based geospatial location system that uses radio frequencies to provide geographic reference information for most places on Earth

Requires 4 GPS-specific satellites about the location’s horizon

Geographic Information Systems (GIS)

A system designed to capture, store, manipulate, analyze, manage, and present all types of geographical data

Allows for greater interactivity with users when used in climate mapping

Applied Climate Information System (ACIS)

Gathers archived climate data and presents it to users in an easier to read format

Parameter-elevation Regressions on Independent Slopes Model (PRISM)

A principal example of climate mapping which seeks to address elevation challenges in characterizing climate analysis over complex terrain

Regional climate analysis

Define clear geographic bounds to a spatial area and identify the intrinsic climatic characteristics that describe that area for a specific time

Dynamic climatology

Assumes that Earth’s climate system is governed by the well-known laws of physics and behaves accordingly

Applied climatology

A multi-disciplinary approach to describing, defining, interpreting and explaining relationships between climate conditions and weather-sensitive activities that focuses on how climatic variations affect humans and human interests

Koppen classification system

Empirical approach to organize Earth’s many regional climate zones that uses native vegetation as an indicator regional climate as well as patterns in mean annual and monthly temperature and precipitation

Spatial synoptic classification (SSC)

A hybrid classification scheme based on both manual and automated processes of identifying climate types