Climatology Project
Dylan Green 2022
Cover
Page
Bar and Line Graph showing
rainfall and average
temperature for Durban.
(Used as reference in the
introduction)
Synoptic chart over south Africa on the 2nd of February showing MlC’s as well as tropical
cyclone badsery about to go over Madagascar
Contents page
Contents
Cover Page .............................................................................................................................................. 1
Contents page ......................................................................................................................................... 2
Introduction and limitations ................................................................................................................... 2
Collected data ......................................................................................................................................... 3
General Observations ............................................................................................................................. 4
Using My collected data.......................................................................................................................... 5
1)
Record temperature data present on a line graph and rainfall combined with humidity ......... 5
Week 1 .................................................................................................................................................... 6
WEEK 2 .................................................................................................................................................... 7
Week 3 .................................................................................................................................................... 9
Week 4 .................................................................................................................................................. 10
Tertiary Circulation ............................................................................................................................... 11
Conclusion ............................................................................................................................................. 12
Bibliography .......................................................................................................................................... 12
Introduction and limitations
Durban is the largest city in KZN and is located on the east coast of South Africa and looks onto the
Indian Ocean. Durban has a natural harbour and is the busiest port in south Africa. Durban has a
warm climate and has an average annual temp of 20.9 degrees and has 893mm rainfall per year.
With the driest month being June. For February (which is shown in the cover page) we can expect
according to the data 85mm throughout the month and an average temperature of about 23 being
the second highest average temperature month. Durban has an altitude of 16m which allows
onshore and offshore winds to take place which can affect temperature and other conditions such as
humidity and precipitation. With Durban being in the southern hemisphere summer starts in
December and ends in March, it will be interesting to compare the results to the data and see how
accurate it was :). However, there are some limitations, If I miss day of r=collecting data and images
such as synoptic weather maps then I will be unable to use them for that day as the websites do not
allow you to go into the history of previous days without a paywall or some method, I am unaware
of. I am countering this by collecting data at the same time every day (6am) on the same website
which is weather SA. the issue with this is that weather SA does not have dew point, so I had to
resort to using minimum temperature as the dew point.
Collected data
DAY MAX DP
RAINFALL humidity Weather
AT
TEMP (MM)
condition
(C)
Wind
Wind
Direction Speed
(KM)
Precipitation Cloud
type
cover
(x/8)
1
30
23
3
85
partly cloudy
NNE
19km/h
rain
3/8-5/8
2
32
22
0
90
Clear sky
NNE
19km/h
none
0/8
3
32
24
3
85
Partly cloudy
NNE
19km/h
rain
3/8-5/8
4
24
21
30
90
SSW
28km/h
thunderstorm
8/8
5
24
20
25
90
Showers and
thunderstorm
RAIN
SHOWERS
SSE
19km/h
rain
8/8
6
25
19
3
85
SSW
9km/h
rain
5/8
7
27
21
0
85
MODERATE
RAIN
Partly cloudy
N
9km/h
none
3/8-5/8
8
29
20
0
85
Partly Cloudy
WNW
9km/h
none
3/8-5/8
9
30
20
0
85
Clear skies
N
9km/h
none
0/8
10
29
21
3
85
Partly cloudy
NW
9km/h
drizzle
3/8-5/8
11
29
22
0
85
Cloudy
SSW
9km/h
none
6/8
12
29
22
0
85
CLOUDY
NNW
9KM/h
none
6/8
13
32
23
0
85
Clear skies
NNE
19km/h
none
0/8
14
26
23
15
85
Rain showers
S
9km/h
rain
8/8
15
28
22
3
85
Rain showers
E
9km/h
drizzle
7/8
16
31
22
15
85
Partly cloudy
NNE
9km/h
thunderstorm
3/8-5/8
17
25
21
5
85
Rain showers
SW
28km/h
rain
8/8
18
25
20
3
80
Overcast
W
9km/h
drizzle
8/8
19
28
20
5
85
Cloudy
NNE
19km/h
rain
6/8
20
29
22
3
85
Partly cloudy
NNE
28km/h
drizzle
3/8-5/8
21
28
21
3
85
Cloudy
SW
9km/h
drizzle
6/8
22
29
21
3
85
Slight rain
SSW
9km/h
drizzle
5/8
23
28
22
3
85
Slight rain
ENE
9km/h
Rain
5/8
24
28
22
3
90
cloudy
NE
19km/h
rain
6/8
25
28
21
3
80
Cloudy
W
9km/h
Rain
6/8
26
26
21
3
75
Cloudy
WSW
9m/h
rain
6/8
27
26
20
5
80
Slight rain
E
9km/h
rain
5/8
28
28
20
3
85
Cloudy
NNE
9km/h
drizzle
3/8-5/8
AVG
27,8
22
5
81
NA
NA
13km/h
NA
NA
Key
Light Blue: End of Week
Yellow: Day of the Week I chose in detail
General Observations
Day
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9
Day 10
Day 11
Day 12
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Day 23
Day 24
Day 25
Day 26
Day 27
Day 28
Overall
KEY
THE GENERAL OBSERVATION
Hot and cloudy
Even hotter than before with a higher humidity and no rainfall
Humidity higher than before with partly cloudy and later throughout the day more clouds appeared, a lot of
them are dark clouds foretelling rain.
Dark clouds and some thunder, started raining in the morning and stayed all day
Rain not as bad as day 4 and low amount of rain throughout the day
The sun is out half the time and drizzles of rain appear sometimes
A bit cloudy with no rain, feels warmer than the two days before
Not too hot with some clouds in the sky with a humidity that made it feel hotter, cool winds made the day
bearable
Slightly hotter than yesterday and there were no clouds to give shade but still bearable
Hot in in the afternoon and very humid, later in the day clouds started to become darker
Very cloudy and warm, hoping for rain but none so far
Same as day 11 but wind direction has changed
Hot today and no clouds to help with shade so it is awfully hard to go outside due to the heat
Rainy all day and cold during the evening. good day to study hard and focus
Temperature felt moderate, did not notice any rain and there was a bit less clouds than the day before
Cloudy all day with a little bit of rain, thunder storming in the evening with no sky in sight
Raining throughout the day but no thunder and very cloudy
Medium temperatures with a little bit of drizzle and no blue in the sky
Bluer in the sky than yesterday and a little bit more rain
Partly cloudy with lots of blue open sky and kind of hot
Did not see any rain and I could see a moderate amount of blue sky
Did not see any rain but cloudy and the clouds cleared in the afternoon
Cloudy and hot rained in the morning as I woke up, by breakfast it was one
Same as yesterday but I did not see any rain in the morning
Cloudy and warm during the day, expecting rain
Raining as I woke up here in Paddock however the forecast says otherwise for Durban
It rained a lot yesterday in paddock and in the coast, cannot comment for Durban but I wonder if it was the
same, its cloudy and a bit of rain but its mostly gone now
No rain but a fair number of clouds
Hot and humid with big rains once in a while and common for light rains of 3-5mm a day
Light Blue: End of Week
Yellow: Day of the Week I chose in detail
Using My collected data
1) Record temperature data present on a line graph and rainfall combined with
humidity
Dew Point and Air Temp. Correlation
35
30
25
20
15
10
5
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
Max AT
DP temp
Max air Temperature is in Every Recorded day always higher than the dew point, this is as dew point is how
much the air must be cooled to reach 100% RH (relative humidity). if the temperature was at dew point it can no
longer hold water and it causes rain. On the 4th the Max AT was close to the Dew point temperature so it is likely
it would have rained/rained more if they were to intercept. It is interesting to note that there was 30mm on the
4th and 25mm on the 5th where the temperature was closer to the dewpoint. BY observing this trend, it is logical
to conclude that if the DP temp and AT are closer than there Is more rain. I believe this graph would have been
more accurate if real DP temperatures were recorded and we did not have to substitute the min temp as DP
temp due to the SA weather services failing to provide a full report of weather.
Rainfall and Humidity in February
35
95
30
90
25
85
20
80
15
75
10
70
5
0
65
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
rainfall
humidity
The Humidity shown in the Graph rises with the rainfall and it seems to drop at the time of or after a decrease in
rainfall ( see D2 no rain causing less humidity on D3 and the decrease in humidity on D18 as there was less rain on
D18) humidity seems to rise slowly and then fall quickly if there is constant changes and when there is no change in
humidity for a while such as in D6-D17 it seems to fall decrease quickly. When it rains the humidity should increase
due to evaporation which can be seen on D4 where rainfall increased and so did humidity, when it stopped raining
on D5 the humidity dropped to 85. Humidity depends on Rainfall which can be seen on the graph by the humidity
levels changing due to the change of rainfall.
Week 1
Week 1 started on Tuesday the 1st of February and ended on Monday the 7th of February
I have chosen to do day 5 in Detail as it shows many weathers pressure patterns. Below is a synoptic
chart of the 5th of February, it also rained, and thunder stormed on this day which caused it to be
memorable
Max air
temperature
Day
5
24
Dew
point
temp
20
Rainfall
(MM)
Humidity
Weather
conditions
Wind
Direction
Wind
Speed
Precipitation
Type
Cloud
Cover
25
90
RAIN
SHOWERS
SSE
19km/h
rain
8/8
On Day three it was extremely hot with a lot of moisture as well as dark clouds foretelling that a
storm was coming and on Day 3 it rained with thunderstorms the whole day and Day 5 was the day
after a major part of the storm however there was still a lot of rain and 8/8 cover. There are two
pressure cells over the interior of south Africa in which the low pressure Is attracting due to the anticyclonic airflow that would bring the clouds onshore. The low pressure causes clouds as the air has
risen in the atmosphere and the water vapor within condenses and forms clouds, these clouds could
have come from the SIA as well as the present South Easter. The lower Pressure could also bring
with it precipitation. (Annotated diagram can be seen in higher quality in booklet)
Annotated Diagram
Station Model on Day 5
Day 5
Max air
temperature
Dew point
temp
Weather
conditions
Wind Direction
Wind Speed
Cloud Cover
24
20
RAIN SHOWERS
SSE
19km/h or
8/8
To Be noted: 19km/h is 10,25 knots
but as instructed it is in km/h, 19km
rounds of to 20 so two lines shown
24
20
WEEK 2
I have chosen to do day 8 as it clearly shows a moisture trough.
Day Max
Dew
point
rainfall
Humidity
Weather
condition
Wind
direction
Wind
Speed
Precipitation
Type
Cloud
Cover
8
20
0
85
Partly Cloudy
WNW
9km/h
none
3/8-5/8
air
temp
29
Below is the synoptic chart for day 8 which I will be describing and that can be used as reference.
In the Interior you can see two low pressures which create clear stable sinking conditions, clouds,
and rain. on the southern side of SA, there is a low-pressure cell in front of the cold front. this cell
might detach if the flow in the mid-levels of the atmosphere is disturbed and a trough can form and
become more intense and develop into a low-pressure stem carrying lot of rain, if this happens part
of the east coast can expect rain and overcast conditions for a short amount of time as it goes over
each area until it weakens and dissipates. In the interior is experiencing continental climate bringing
lots of heating in the day forming a low pressure, alongside with the low pressure that has been
moving over the interior for the past few days. the winds from SIA and SAA are brought from the
high to the low. The Sia brings warm moist air, and the SAA brings cool dry air in SW winds. when
these 2 airs meet it forms a moisture front which coincides with the low-pressure cells and the warm
air rises to great hights and the cool air forms cumulonimbus clouds which bring thunderstorms hail
and heavy rain.
(Annotated Diagram below, can be seen in higher quality in booklet, refer to back)
Day
8
Max
air
temp
29
Dew
point
Weather
condition
Wind
direction
Wind
Speed
Precipitation
Type
Cloud Cover
20
Partly Cloudy
WNW
9km/h
none
3/8-5/8
29
20
9km/h is rounded up to 10 so only
one line is shown on the station
model and 4/8 is equal to half so
half cloud cover is shown
Week 3
I have chosen to do day 16 on week 3 as it clearly shows an unseasonal MLC as it moved between
the saddle of the SAA and was pushed by the westerly side of the saddle along with the entire SAA.
and I have been observing the saddle waiting for something to happen in which I can record data
and annotate a diagram for, and it played off.
DAY
MAX
AT (C)
DP
TEMP
RAINFALL
(MM)
humidity
Weather
condition
Wind
Direction
Wind
Speed
(KM)
Precipitation type
Cloud
cover
(x/8)
16
31
22
15
85
Partly cloudy
NNE
9km/h
thunderstorm
3/8-5/8
Today it was a high temperature, and it was very cloudy due to the MLC bringing unstable air with
clouds and thunderstorms as well as possible cumulonimbus clouds in the cold front and these
thunderstorms would have been further developed by the hot air temperature rising and cooling as
the day progressed making the thunderstorms bigger. the cloud cover prediction was inaccurate as it
ended up being very cloudy and safe to say overcast. the SAAs anti cyclonic air flow could have
helped bring the conditions of the mlc further inland and not only to the coast as the SAA has gone
over land in some areas allowing the winds to carry conditions into the interior in an NNW direction
even though Durban has NNE winds on this day. The annotated diagram is shown below
the diagram you
can see the
possible affected
areas in orange
and the red
arrows show
how the anticyclonic airflow
can move
conditions to kzn
and the interior.
The small green
dot represents
Durban, and the
red circle shows
the main area
affected which Is
MAINLY KZN.
Max air
temperature
Day 31
16
Dew
point
temp
Weather
conditions
Wind
Direction
Wind
Speed
Cloud
Cover
Precipitation TYPE
22
Partly cloudy
NNE
9km/h
3/8-5/8
THUNDERSTORMS
31
22
9km/h rounded off to 10km which is
1 line
Week 4
I have chosen to do the 27th as it is the only day of the week which clearly shows some sort of event
as well as the reason that it rained a lot the day before which was not shown in the data from SA
weather and today was the day after the rain making it memorable. Sadly, not much occurred this
week so it was so difficult in comparison to the previous weeks where I could find a good day to do.
DAY
MAX
AT (C)
DP TEMP
RAINFALL
(MM)
humidity
Weather
condition
Wind
Direction
27
26
20
3
80
Slight rain
E
Wind
Speed
(KM)
9km/h
Precipitation type
rain
Cloud
cover
(x/8)
5/8
All of what I am describing is show on my annotated diagram above . the main feature was the moisure
trough on the 27th and its degradation which is shown in green on the diagram and it deteriorated on the
28th into a low pressure and a high pressure developed on the 28 th which is shown, on the 27th the
tropical cylcoine under mozamique ( the low pressure ) is going south and on the 28th it dissepated and
became nothing . on the 27th you can see this massive MLC on the south that has a huge cold front going
on , part of this is a cut off low that is breaking off and it shown in the red and this cut of low brings
thunderstorms and a lot of rain over its slow movement , I don’t know if the cut off low will reach SA as it
is slow and far into the atlantic but if it does it will bring rain to the cape , the cut off low was formed by
the SAA ridging and cutting off a part of the mlc . This same Mlc is busy occluding and it will soon weaken
and dissipate . on the left you can see two mlcs in which one is backing the other and the top mlc does
not have a warm front and the westerlty mlc will psuhg the more easterie one . this happaned a bit but
on the 28th they combined . I believe this is due to a lack of a warm fron ton the easterlie mlc.
DAY Max air
temperature
27
26
Dew
point
temp
20
Weather
conditions
Wind
Direction
Wind
Speed
Cloud
Cover
Precipitation TYPE
Slight rain
E
9km/h
5/8
Rain
26
20
9km/h rounded off to 10km which is
1 line
Tertiary Circulation
Tertiary Circulations are (according to the American meteorological society) Generally small,
localized atmospheric circulations so for e.g., the Cape doctor in Cape Town. So, for Durban we
would have: Land and Sea breezes (onshore offshore winds), Berg Winds, anabatic, katabatic winds
and Urban Climate as Durban is a city.
•
Onshore/Offshore
During the Day, the warm rising air in
Durban creates low pressure as the
warm air ascends and warms and this
draws in cool air from the Warm
Agulhas current which has warm moist
air but is cooler than the rising warm
air of Durban which creates an onshore
flow, and this is How Onshore winds
work (Diagram shown and included in the booklet).
During the Night, the cool air subsides inland and goes towards the warmer air that
is rising over the Ocean which has low pressure due to the rising air while the land
has high pressure due to the descending cool air. And this pushes the air towards the
ocean creating an Offshore wind.
•
•
•
Berg Winds
Berg winds occur when cool moist
air goes towards the berg
mountains and it cools as it rises at
1 degree per 100m and as It cools it
forms clouds and precipitates and
rains losing its moisture , this dry
cool air reaches the high altitude
and goes down the east side of the
mountain and as the dry air
descends it warms at the dry
adiabatic lapse rate and can warm up to 30 degrees if the altitude was 3000m due to 1 per
100m , this results in hot dry air that can kill crops as well as the temperature and dryness
can increase risk of fire and people may lose their lives due to dehydration and loss of
livelihood if houses and farms are burnt down.
Anabatic, Katabatic
During the Day these upslope winds are caused by
warmer surface temperatures on a mountain
slope than the surrounding air causing the air to
rise. these are Anabatic winds.
During the night, the downslope winds are caused
by colder temperatures on the surface of a slope
which is colder than the surrounding air and it
causes the air to move down. these are all as
warm air rises and cold air sinks.
Urban Heat islands
Urban heat islands area when the urban area (especially business districts) is warmer than
the rural area and surrounding suburban area. such as in Johannesburg. Hot air rises in the
city centre and the cool air comes from the rural areas to replace the hot air and the rural
area air takes longer to heat up as the
heat evaporates dew. and a dome
shaped cushion of warm air called the
heat island is formed as the main air
pressure above the city is anticyclonic
meaning there is subsiding warm air
and the warm polluted air cannot
leave trapping it during the Day. in the night, the heat island is smaller as the city cools
causing the upward air currents to not be as strong and the surfaces in the city such as office
buildings loose heat quickly unlike the grass, cultivated land and trees in the rural areas
resulting in a big difference between the city and its urban area
Conclusion
In conclusion this project taught me a lot about climatology, and it was fun to record the results and
use them in data, I had struggles trying to choose the days to do, especially with week 4 where
nothing happened throughout the first half of the week. in future I want to find a way to find reliable
data more accurately and not have to substitute minimum temperature for DP temperature. This
was a fun interactive project to do, and I have learnt so much. in the end the average temp was
higher than the graph on the cover page shows and next time I hope to learn from my mistakes. The
rainfall was very sporadic with some days it poured and then it was dry for days at a time, the graph
said an average of 83mm of rain for February and we recorded 129mm, so it seems the rain was
above usual. possibly climate change.
Bibliography
•
•
•
•
•
•
•
•
•
•
•
https://en.wikipedia.org/wiki/Durban
https://en.climate-data.org/africa/south-africa/kwazulu-natal/durban-511/
https://glossary.ametsoc.org/wiki/Tertiary_circulation
Gr12 Focus Textbook
Notes from Mrs Lambourn
Map skills book
Any previous knowledge learnt in schooling career
http://www.weatherphotos.co.za/
https://www.meteoblue.com/en/weather/week/durban_south-africa_1007311
https://www.weathersa.co.za/home/synopticcharts
https://www.weathersa.co.za/
END