This document discusses various aspects of the meteorological environment including atmospheric pressure, air temperature, humidity, precipitation, wind direction and speed, and cloud movement. It describes how these factors are measured using instruments like barometers, thermometers, hygrometers, rain gauges, anemometers, and wind vanes. The effects of temperature and humidity on human health are also covered, such as heat stress, heat stroke, and global warming.

1. METEOROLOGICAL
ENVIRONMENT
DR. SHREYASH R. MEHTA
PROFESSOR
DEPARTMENT OF COMMUNITY MEDICINE
GAIMS, BHUJ

2. METEOROLOGICAL
ENVIRONMENT
• 1.ATMOSPHERIC PRESSURE
• 2.AIR TEMPERATURE
• 3.HUMIDITY
• 4.RAINFALL
• 5.DIRECTION AND SPEED OF WIND
• 6.MOVEMENT OF CLOUDS AND CHARACTER OF
WEATHER

3. ATMOSPHERIC PRESSURE
• AT EARTH’S SURFACE
• MAN
• ALTITUDE
• 100,000 FEET ABOVE- ATM. PRESSURE<10 MM HG
• 33 FEET DEPTH- INCREASE 1 ATM. PRESSURE

4. MEASUREMENT
1. FORTIN’S BAROMETER
2. KEW PATTERN STATION BAROMETER-MOST
WIDELY USED BY INDIAN METEOROLOGICAL
DEPARTMENT
3. BAROGRAPH

5. BAROMETERS
Fortin’s barometer Kew pattern station Barometer

6. BAROGRAPH

7. EFFECTS OF ATMOSPHERIC
PRESSURE ON HEALTH
1.HIGH ALTITUDES-
• AIR DENSITY
• PARTIAL PRESSURE OF O2
• SURVIVAL
PHYSIOLOGICAL EFFECTS:
1.INCREASE IN RESPIRATION
2.INCREASE IN CONCENTRATION OF HB
3.INCREASE IN CARDIAC OUTPUT

8. EFFECTS OF ATMOSPHERIC
PRESSURE ON HEALTH
1. HIGHER ALTITUDES
• A. ACUTE MOUNTAIN SICKNESS
• B. HIGH ALTITUDE PULMONARY OEDEMA
2. LOWER ALTITUDES-
GASES O2, CO2 AND N2
EXCESS OF EACH
AIR EMBOLISM
CAISSON’S DISEASE

9. AIR TEMPERATURE
• FACTORS INFLUENCING:
1. LATITUDE
2. ALTITUDE
3. DIRECTION OF WIND
4. PROXIMITY TO SEA

10. AIR TEMPERATURE
• MEASUREMENT:
1. MERCURY THERMOMETER- WIDELY USED
2. ALCOHOL THERMOMETER
ESSENTIAL CONDITIONS-
1. FREE ACCESS OF AIR TO BULBS
2. PROTECTION AGAINST RADIANT HEAT
STEVENSON SCREEN-SPECIAL APPROVED SCREEN

11. AIR TEMPERATURE
1. DRY BULB THERMOMETER
2. WET BULB THERMOMETER
3. MAXIMUM THERMOMETER
4. MINIMUM THERMOMETER
5. SIX’S MAXIMUM AND MINIMUM
THERMOMETER
6. GLOBE THERMOMETER
7. WET GLOBE THERMOMETER
8. SILVERED THERMOMETER

12. AIR TEMPERATURE
9. KATA THERMOMETER: ALCOHOL THERMOMETER
WET KATA
DRY KATA
METHOD OF USE
COOLING POWER OF AIR
KATA FACTOR
THERMAL COMFORT

13. AIR TEMPERATURE
• TYPES:
• 1.STANDARD KATA- 100 DEG F- 95 DEG F- RED
• 2.HIGH TEMP. KATA- 130 DEG F- 125 DEG F-DARK BLUE
• 3.EXTRA HIGH TEMP. KATA- 150 DEG F- 145 DEG F-
MAGENTA
NOT USED IN TROPICAL COUNTRIES AS TEMP. ABOVE
100 DEG F

14. AIR TEMPERATURE
MAX & MIN THERMOMETER

15. AIR TEMPERATURE
DIGITAL THERMOMETER
GLOBE THERMOMETER KATA THERMOMETER

16. AIR TEMPERATURE
Stevenson Screen-special approved
screen

17. HEAT STRESS INDICES
• DEF- BURDEN/LOAD OF HEAT THAT MUST BE
DISSIPATED IF THE BODY IS TO REMAIN IN
THERMAL EQUILIBRIUM
• FACTORS INFLUENCING:
1. METABOLIC RATE
2. AIR TEMPERATURE
3. HUMIDITY
4. AIR MOVEMENT
5. RADIANT TEMPERATURE

18. HEAT STRESS INDICES
• MANY DEVISED, BUT NONE VALID
1. EQUATORIAL INDEX- THIS DENOTES THE
TEMPERATURE OF STILL AND
SATURATED AIR WHICH IS EQUIVALENT
PHYSIOLOGICALLY TO THE CLIMATE
UNDER CONSIDERATION.

19. HEAT STRESS INDICES
• 2. HEAT STRESS INDEX- THIS TAKES INTO CONSIDERATION
THE METABOLIC RATE AND THE PRINCIPAL CHANNELS OF
HEAT EXCHANGE BETWEEN THE HUMAN BODY AND THE
ENVIRONMENT.
• THE HEAT STRESS INDEX REPRESENTS THE PERCENTAGE
OF THE HEAT STORAGE CAPACITY OF AN AVERAGE MAN.
NOMOGRAMS HAVE BEEN PROVIDED FROM WHICH THE
VALUE OF THE HEAT STRESS INDEX COULD BE EASILY
CALCULATED.

20. HEAT STRESS INDICES
• 3. PREDICTED FOUR HOUR SWEAT RATE:
• THE RATE AT WHICH A MAN SWEATS IS A GOOD INDEX OF
THE HEAT STRESS TO WHICH HE IS SUBJECTED. A SWEAT
RATE OF 4.5 LITRES IN 4 HOURS IS THE UPPER LIMIT OF
TOLERANCE IN HEALTH FOR WORK IN HOT ENVIRONMENT.
A SWEAT RATE OF 2.5 LITRES IN 4 HOURS IS CONSIDERED
OPTIMAL FOR A WORKING MAN. P4SR IS APPLICABLE ONLY
IN THE SITUATION WHERE SWEATING OCCURS.

21. EFFECT OF HEAT STRESS
• 1. HEAT STROKE
• 2. HEAT HYPERPYREXIA
• 3. HEAT EXHAUSTION
• 4. HEAT CRAMPS
• 5. HEAT SYNCOPE

22. PREVENTIVE MEASURES
1. REPLACEMENT OF WATER
2. REGULATION OF WORK
3. CLOTHING
4. PROTECTIVE DEVICES
5. WORK ENVIRONMENT

23. EFFECT OF COLD STRESS
1. GENERAL-NUMBNESS, LOSS OF SENSATION,
MUSCULAR WEAKNESS, DESIRE FOR SLEEP, COMA
AND DEATH
2. LOCAL- IMMERSION/TRENCH FOOT, FROST BITE
TREATMENT- PROPER DRESS, WARMING AFFECTED
PART AT 44 DEG C FOR 20 MIN

24. GLOBAL WARMING
• EMISSION OF GREEN HOUSE GASES
• CO2 MAJOR COMPONENT
• EFFECT
• OVERWHELM CAPACITY TO ADAPT
• CHANGES IN CONFIGURATION
• TEMPERATE ZONE WARMING
• HEAT ISLAND PHENOMENON

25. HUMIDITY
• DEW POINT
1. ABSOLUTE HUMIDITY
2. RELATIVE HUMIDITY- RH EXCEEDS 65%-
AIR STICKY AND UNCOMFORTABLE, BELOW
30% UNPLEASANT

26. HUMIDITY MEASUREMENT
1. DRY AND WET BULB HYGROMETER
2. SLING PSYCHROMETER
3. ASSMANN PSYCHROMETER-PORTABLE
INSTRUMENT

27. HUMIDITY MEASUREMENT
DIAL HYGROMETER
SLING PSYCHROMETER
ASSMAN PSYCHROMETER
ELECTRONIC HYGROMETER

28. PRECIPITATION
• RAIN, SNOW, HAIL AND FROST
• MEASURED BY RAIN GAUGES
• SYMON’S RAIN GAUGE
• STRUCTURE
• LOCATION

29. PRECIPITATION
Symon’s rain gauge

30. AIR VELOCITY
• MEASURED BY ANEMOMETER
• STRUCTURE
• VELOCITIES
• KATA THERMOMETER

31. AIR VELOCITY
ANEMOMETER KATA THERMOMETER

32. WIND DIRECTION
• OBSERVED BY WIND VANE

33. CLOUDS AND WEATHER
OBSERVATION
• METEOROLOGICAL SATELLITES- AUTOMATIC
PICTURES
• MEASURE TEMPERATURE, HUMIDITY AND
GIVE IDEA OF CLOUDS

34. PRACTICAL APPLICATION
• DEFENSE FORCE
• HOUSING & CONSTRUCTION
• TRAVEL MEDICINE
• OCCUPATIONAL MEDICINE
• GEOGRAPHICAL INFORMATION SYSTEM