Climate is defined as the average weather conditions in a particular region over a long period of time. It is characterized by factors such as atmospheric pressure, temperature, humidity, wind speed, and sunlight. Weather describes the short term atmospheric conditions at a specific time and place. The key difference is that climate considers weather conditions averaged over 30 years, while weather refers to day-to-day changes. Many geographic factors influence climate, including latitude, elevation, proximity to bodies of water, ocean currents, winds, and relief or landforms. Climate zones are classified based on average annual temperatures.

1. Climate
Climate: sum of all statistical weather info
that helps describe a place or region. It is a
dynamic complex of meteorological and
cosmic factors for a long period of time and
is characterized by a middle expression of:
 Atmospheric pressure
 Air temperatute
 Air humidity
 Air velocity (winds)
 Sun radiation, Raining

2. The particularity of the climate are
defined by:
Geografic latitude and attitude
 Relief of the territory
 Vegetation (forests)
 Water reservoirs (see, lakes, rivers)

3. For more detailed evaluation the climate
could be divided into:
 Macro-climate – in given geographic zone
 “Middle-climate” – in a given place
 “Micro-climate” – in closed rooms

4. The climatic zones are confined within the
isothermal lines. These lines connect all points
with equal annual air temperatures.
- Tropical climate – between equator and 25°C
isotherm
- Subtropical climate - between 25°C and 15°C
isotherm
- Moderate climate - between 15°C and 5°C
isotherm
- Cold climate
Bulgaria is in the moderate climate zone.

5. Weather
 Weather: State of the atmosphere at a given
time and place; constantly changing.
 Weather is described by variables such
as:
 Temperature
 Pressure
 Wind Speed and Direction
 Precipitation
 Cloud Cover

6. Depending on the meteorological factors
WEATHER could be:
 Optimal – with small daily air temperature
amplitude (2°C) and air velocity less than 3
m/s
 Irritating – one or more of the
meteorological factors are out of their
optimal levels; air velocity is up to 8 m/s;
high daily air temperature amplitude
 Sharp – significant changes of
meteorological factors

7. The adaptation of people to slow changes of
meteorological factors is good, but isn’t such
to sharp ones.
More sensitive people could suffer some
unfavorable health conditions like
cardiovascular problems (hypertension),
neuroses, arthritis, cerebro-vascular
diseases, bronchial hypersensitivity.
The prophylactic measures include
healthful style of living, training, healthy
nutrition, suited clothing, medicaments.

8. What is the difference between
weather and climate?
 Weather is what you see outside of the
window, climate is the weather
conditions of an area averaged over a
long period (30 years)

9. Weather or Climate???
 The average high temperature for the month of
July in Chicago is 84oF.
 Cumulus clouds presently cover the entire sky.
 Snow is falling at a rate of 1 inch per hour.
 The summers here are warm and humid.
 At 3:00 p.m, winds were blowing from the
NW.
 Total precipitation at O’Hare Airport for 2003
was 32.02 inches, which is 4.25 inches below
normal.

10. How do we measure climate factors?
Anemometer
Wind and
rain Gauge
Aneroid
Barometer
Radiosonde

11. Latitude
 (T) The further away from the equator"
the colder it is.
 (P) Closer to the poles results in lower
precipitation

13. Unequal Earth Heating
Incident light is spread over a greater area near the
poles, less heat is radiated from the earth.

14. Ocean Currents
 (T) When warm, they raise temperatures along
the coast (especially in winter) and when cold,
they lower temperatures (especially in
summer)
 (P) When warm, they help to create wet
coastal climates, when cold, they help to create
drier coastal climates

15. Ocean Currents

16. Heat Conveyor Belt

17. Figure 4.5

18. Winds
 (T) When they move off large bodies of
water onto land they moderate
temperatures
 (P) When they move from ocean areas
onto land they bring moisture. Land to
Land = Drier climates

20. Global atmospheric circulation. Note the prevailing winds and
areas where there is little horizontal air movement, the horse
latitudes and doldrums.

21. Elevation
 (T) The Higher you go, the colder it gets!
Dry air decreases temperature at a rate of
1OC per 100m.
 (P) The Higher you go the more
precipitation you are likely to get

22. Relief
 (T) Landforms block winds and air
masses, so temperatures from one side to
the other can be quite different

23. Relief
 (P) Windward areas are wet, as air rises
and deposits moisture. Leeward areas are
dry as winds descend, warm up and
evaporate moisture.

24. Windward
warmer Leeward
colder

25. Nearness to Water
 Maritime climates (by the ocean) are
moderated (cooler summers, warmer
winters) by the ocean.
 Precipitation is higher in maritime
climates than in continental (inland)
climates.

30. Review: World climate patterns
 Concepts:
 The earth heats unevenly
 Because of its tilt and the fact that it is a
sphere
 This uneven heating drives global circulation
 There is predictable variability in climate, at
local to global scales
 Because it is a sphere:
 Radiation is spread over more area at the high
latitudes than at the equator

31. Hygienic characteristic of physical
factors of atmosphere
Physical factors of atmosphere could be
divided into:
- Meteorological factors – atmospheric
(barometric) pressure, air temperature,
humidity, atmospheric electricity and
ionization of the air.
- Factors, arising from the cosmos – sun
radiation, heliomagnetic factors

32. Meteorological factors
Atmospheric pressure
It is an important factor in climate formation.
Atmospheric pressure over the surfaces and
bodies is due to the weight of air layers because
of the gravitation.
At the sea level, vertical air column of 1
square sm. Has middle mass of 1013 g and is
balanced by Hg column with 760 mm altitude. It
is 1 atmosphere and is accepted as a normal
value at the sea level.

33. Air pressure inside and outside the body has been
equalized by the respiratory tract with greater
amounts of gases being absorbed to the tissues and
compressed into body cavities.
As the atmospheric pressure is increased or
decreased some discomfort or diseases could be
manifested.
1. Health problems related with increased
atmospheric pressure
Such could occur during work under water
(diving, work in barocamera). During compression
the following health efects could be manifested:

34. - Ear trauma – as a result of a relative
vacuum in the middle ear – acute of chronic
inflammation caused by a reduction in air
pressure in the tympani cavity. There is a
feeling of fullness in the ears, decreased sound
density, discomfort and desire to “clear the
ears”.
- The “squeeze” – dyspnea, heavy
sensation in the chest, a bulging sensation in
the head and eyes, edema and even small
hemorrhages in lungs, gastrointestinal tract,
nose, ears and facial skin.

35. - Nitrogen narcosis – occurs at depths
greater than 30 m. The symptoms are
numbness, discoordination, hallucinations
and unconsciousness – at depth over 90 m.
These effects may be prevented by
breathing mixtures depleted in nitrogen
by helium.

36. - Decompression sickness – during the
decompression, when the organism is
exposed again to surface atmospheric
pressure, the compressed gases in the body
tend to come out of the solution. When it’s
rapid, bubbles (primary of nitrogen) are
formed in tissues and blood resulting in
blockage of capillaries or even emboli.
Symptoms depend on the localization of
emboli (lungs, brain etc.). If the
decompression is slow the gases can be
exhaled without problems.

37. 2. Health problems related with decreased
decreased atmospheric pressure. They appear
because of the diminished ambient pressure of
oxygen.
- Acute mountain illness – very often quickly
transiting, manifested with headache, vomiting and
impaired vision.
- High attitude pulmonary edema - the symptoms
are usually manifested at the 3th day at high
altitude. At the beginning they are similar to these of
mountain disease, but further pulmonary edema
develops with cough and even Cheyne-Stokes
breathing.

38. Air temperature
Direct heating of air from the sun is
unimportant – only about 0.02%. Air heating is
mainly from the infrared irradiation from the
ground. Factors affecting air temperature are:
- latitude of the place
- altitude
- direction of the wind
- proximity of sea
- big water reservoirs (lakes), vegetation zones
The mean year temperature in Bulgaria is 11.5C

39. Air humidity
The humidity of the air depend on its
temperature. Humidity could be expressed as
absolute and relative. Relative humidity is
used more commonly in health practice.
Air velocity
A meteorological parameter, which
together with temperature and humidity of the
air determine the microclimate at a certain area
and determining the thermal comfort.

40. Factors, arising from the cosmos
A. Sun radiation
The spectrum of sun radiation consists of
ultraviolet radiation – UV (wave length under
400 nm), visible radiation (400-760 nm) and
infrared radiation (over 760 nm).
Health effects of UV radiation
- Non – specific effects – stimulation of
protein, lipid and carbohydrates metabolism,
improved immunological reactivity, increased
melanin production.

41. - Specific effects – short UV waves
possess bactericidal and mutagenic effects.
Limited skin exposure to middle UV waves
results in photochemical conversion of pro-
vitamin D to the active compound.
Cumulative effect of repetitive
occupational exposure to long UV waves
may cause cataract, retinal damage, skin
erythema (sunburn) or skin cancer.

42. Effects of visible radiation (VR)
Prolonged and intensive exposure to light
could cause serious eye damage. Less traumatic
effect is astenopia (eye strain) – tired eye, visual
discomfort, irritation, headache. Also, disturbance
of cardiac rhythm, influencing physical activity,
sleep, food consumption etc. could appear.
Effects of infrared radiation (IR)
It penetrates skin and induces heating. IR may
cause thermal damage of cornea, iris and retinal
lesions. Chronic, long-term exposure may cause
cataract.

43. B. Electromagnetic radiation
It could be defined as a series of waves
composed of oscillating electric and magnetic
fields traveling through space with the speed
of light. Electromagnetic radiation can
transmit energy to biological molecules and
affect the biological systems. For example, the
absorbed energy could be transmitted to heat
and increase the tissues temperature. The exact
biological effects depend on the characteristic
of the radiation involved and the sensitivity of
the organism.

44. Air ionization
It is characterized the grade of formation of
positive and negative air ions. The concentration
of positive air ions is increased in polluted urban
areas and indoor air.
The concentration negative air ions is higher in
mountains, wood areas, near the see and
waterfalls. They are indicator of air purity and
have favorable health effects.

45. Health effects of physical factors of
the atmosphere
 Positive – negative air ions
 Negative
- heat stroke (disturbed mechanisms of
thermoregulation); -
- sun stroke (directs exposure of head to
sun); - heat exhaustion;
- heat syncope;
- effects of cold stress etc.