UNIT 6ŚLESSON 6
Describe the uses of climatological data in meteo- rology and what References and services are
Methods of presentation
Availability of data
Application to weather prediction
Climatological records are based on themeteorological observations that are taken at a particular locality. This information may be presented in a number of ways. Temperature records generally include the following temperature values: daily maximums and minimums by months; the extremes; the average temperature by year and month; the mean monthly and annual temperature; the mean monthly maximum and minimum temperature; and (sometimes) the monthly and seasonal degree-days. Of great climatic significance is the range between the mean temperature of the warmest month and the coldest month. Other temperature data are sometimes given. These may include the number of days with the following temperatures: maximum of 90░F and above; maximum of 32░F and below; minimum of 32░F and below; and minimum of 0░F and below.
Precipitation records include the mean annualand monthly totals. The range between the highest and the lowest annual rainfall for a locality is the best indication of the dependability of the precipitation. The records often show the absolute maximum rainfall and snowfall for a 24-hour period by months, as well as the maximum and minimum precipitation for each month.
Climatic records usually show data on winds.Such information indicates the mean hourly speed and the prevailing direction by month. Also shown are the speed and direction of the strongest wind for the 12 months and the year in which it occurred. Data on cloudiness, humidity, thunderstorms, and heavy fog are often included. Other helpful data would be the frequency and distribution of cyclones and anticyclones; passage of fronts; pro-portion of rainfall and snowfall received from cyclonic storms and local, air mass thunderstorms; and climatological data on upper air conditions.
Learning Objective: Describe the use ofclimatological data in meteorology and what References and services are available.
METHODS OF PRESENTATION
Climatological information is presented inmany different ways. Tables are frequently used. Maps are particularly useful in presenting climatic information in cases where geography is an im-portant factor. Wind data can be given by means of a device called a wind rose, which presents in-formation on the prevailing wind directions. (See fig. 6-6-1.)
Graphs are usually divided into bar and linegraphs, or the graph maybe a combination of the two. Figure 6-6-2 is an example of a bar graph and a line graph showing the same information. Figure 6-6-3 shows a combination of a bar and line graph used to depict cloud cover. This type of depiction is used in the most recent Marine Climatic Atlas of the World.