6. System requirement
Hardware
* Dual Core Intel 2 Ghz Processor Machine
* Decent Broadband Connection
Software
* A linux distro in my case Ubuntu 9.10
* CDAT
* Dependencies of CDAT
41. What is Contour ?
Contour is line drawn on a map connecting points of equal
height .
Contour lines (also isolines) connect a series of points of
equal elevation and are used to illustrate topography, or
relief
on a map.
They show the height of ground above Mean Sea Level
(M.S.L.) in either feet or meters and can be drawn at any
desired interval.
42.
43.
44.
What is Isotherm ?
An isotherm ( meaning 'heat') is a line that connects
points on a map that have the same temperature.
Therefore, all points through which an isotherm
passes have the same temperatures at the time
indicated.
45.
What is Isobar ?
A line of constant pressure. Isobars are found ONLY
on surface charts.
They most commonly connect lines of equal pressure
in the units of millibars.
High pressure isobars generally occurs with isobars
above 1010 mb while low pressure isobars occur with
lower than 1010 millibars.
46.
What are the Uses of Isotherm ?
Isotherms are used to find regions with
* Warm air advection
* Cold air advection
* Short waves
* Fronts
* Temperature gradient boundaries and
* Instability zones.
They are most commonly used at pressure
surfaces below 500 millibars and on surface charts.
54. What is NetCDF File ?
NetCDF (network Common Data Form)
is a set of software libraries and machine-
independent data formats that support the creation,
access, and sharing of array-oriented scientific data.
55. Purpose of NetCDF (.nc)File
The main purpose of netCDF is to protect
the user from having to know the details of how
the data is stored in the netCDF file.
Cdat have clt.nc file which is reason to
create isolines on map.
58. $ sudo apt-get install netcdf-bin
To convert .nc binary into editable text
$ ncdump clt.nc > clt.cdl
To generate clt.nc from edited clt.cdl file
$ ncgen -b clt.cdl
59. What is My Project ?
My Project going to create the isotherm
lines, which will be plot on India Cdat Map.
We have 4 processes to do this . . .
.
60. Process 1:
1.1 WebScrape the current temperature and
barometer (millibar) of all over cities in India and
its surroundings countries from the Internet.
1.2 Store the city name, temperature, millibar
into the file.
65. Data Flow Diagram For Generating Isothermal Lines From Google Temperature
Google Web Scraping
Temperature Program
Values
Store the Google
Temperature Values
into the File
Draw Isothermal Isothermal Lines
Lines from the On Cdat Map
File Values
81. Applications :
.
Advection The horizontal transfer of
heat
Forecaster Someone who makes
predictions of the future
82. Applications of isolines :
By Meteorologist Jeff Haby
Q1. What is meteorologically significant about isobars or
isohypses being closely spaced?
Answer: A forecaster can determine the amount of thermal
advection (temperature advection). Closely spaced contours
indicate stronger wind.
Source : http://www.theweatherprediction.com/basic/isopleths/
83. Applications of isolines :
By Meteorologist Jeff Haby
Q2. Negative thickness advection is lower values of
thickness moving toward a fixed point. How can this be
determined by examining a thickness chart?
Answer: If height contours or isobars are overlaid on the
thickness field, a forecaster can determine the speed and
direction cold air will have. If the lower thicknesses are
advected by the height contours or isobars toward a fixed
point, that fixed point will experience a cooling of weather.
Source : http://www.theweatherprediction.com/basic/isopleths/
