|
Chapter 9 Weather and
climate
Mark scheme
AS questions on page 256
| Question |
Mark |
|
1
|
a
|
Simple identification
of gas envelope, layering, + e.g. gas or depth.
|
3
|
| |
b
|
2 separate accounts
1 or 2 marks. 2 marks for specific contrast statement.
|
4 |
| |
c
|
Identification
of solar energy input + 1 mark for developments e.g. amounts/cascade
factors.
|
4
|
| |
d |
2 + 2 (CO2 =
warming, clouds reflect both insolation & terrestrial re-radiation).
|
4 |
| |
e |
Effect on specified
solar inputs & implications for health etc.
|
5 |
| |
f |
Up to 2 marks
for controls on ozone depleting chemicals (+ 1 for named chemical)
2 marks for changes to lifestyles/protection.
|
5 |
| Question |
Mark |
| 2 |
a i
|
Seasonal warmth/cooling
+ increased humidity in affected areas; 1 mark for exemplification.
|
4 |
| |
ii
|
3 max for explanation
of each of windward side and leeward side.
|
6
|
| |
b
|
Adret & Ubac
explanation (terms not required or credited) related to land
use variations. Allow 2 max for specific contrasts noted.
|
6 |
| |
c
|
1 mark per valid
point (contrast with effects of a clear sky valid both sides).
|
4 |
| |
d
|
Level
I
long
days, high sun.
|
1 - 2
|
| |
|
Level
II
Effects of the day length - in terms of insolation & angle of incidence
of sun. Short night with terrestrial re-radiation also valid. Accept
that these are differences.
|
3
- 5 |
A2 questions on page 256
| Question |
Mark |
|
3
|
a i
|
Mark for each
correct 'pause' identified by temperature change in the correct
direction. Pressure steep decline curve. Keep 2 marks for
pressure changes.
|
6
|
| |
ii
|
Identification
of each reduction in insolation in %.
|
6 |
| |
b i
|
Any of earth
only figures, atmosphere only figures, &/or combined figures may
be used. Explanation 4 + 2 max for quantified data from table.
|
6
|
| |
ii
|
Level
I
Identification of wind/ocean current as a mechanism
|
1
- 3 |
| |
|
Level
II
Use of specific e.g. (e.g. a named ocean current) or mechanism for
heat transfer into the air.
|
4
- 7 |
| Question |
Mark |
|
4
|
a
|
Level
I
Reduction at different stages identified with little explanation.
|
1 - 3
|
| |
|
Level
II
Quantification
of % loss & transfer, explanation is mainly by association (e.g.
'because clouds are white').
|
4
- 8 |
| |
|
Level
III
Sequence of transfer
& loss complete with explanation. based on density of atmosphere
etc.
|
9 - 10
|
| |
b
|
4 max each (in
each case keep 2 marks for 'importance' specifically).
|
10 |
| |
c |
Heat transfer
mechanisms identified.
|
5 |
| Question |
Mark |
|
5
|
a
|
Identification
of equipment, 2 max; recognition of time difficulty (all
at once), explanation of use of equipment & recording method.
|
7
|
| |
b
|
Level
I One or more reason related only to conditions in urban
area or not linked to either location (e.g. tarmac heat reservoir).
|
1 - 3
|
| |
|
Level
II One or more explanation/s has a direct link to location
(e.g. more tarmac in urban areas …) reasons by 'association'.
|
4 - 8
|
| |
|
Level
III Two
good level II responses can achieve low III or developed
response making direct reference to situation in both urban
and rural areas in a developed explanation.
|
9
- 10 |
| |
c |
Problems
include:- stronger winds, increased fog, pollution dome, etc. 4
max (include 1 mark for identification of a problem) for either
choice. |
8 |
AS questions on page 257
| Question |
Mark |
| 6 |
a
|
Transfer system
sea/land or surface/air with exemplification.
|
4
|
| |
b |
Level
I Transfers out = transfers in + sources of each.
|
1
- 3 |
| |
|
Level
II
Addition of amount of water cycle over sea areas & other developments.
|
4
- 6 |
| |
c
|
Cause
of rise = 1, expansion cooling = 1, condensation of water vapour
= 1, accretion of solid/liquid in cloud = 1 & drop = 1 |
6 |
| |
d
|
Level
I
amount
of water in air.
|
1
- 2 |
| |
|
Level
II Developed to be absolute, specific or relative humidity.
|
3
- 4 |
| |
e
|
3 max annotated
diagram /other description of hygrometer + 3 max explanation of
use. To five max.
|
5 |
| Question |
Mark |
|
7
|
|
Point mark
throughout
|
|
| |
a
|
Identification
of information sources 1 mark each.
|
4 |
| |
b
i |
High winds &
heavy rain from a depression in the Channel.
|
3 |
| |
ii
|
Wave on cold
front deepened to 958mbs + steep pressure gradient.
|
3 |
| |
iii
|
North
to 'Lands End' by 0000h and then NE across Southern England to be
located in North Sea by 0600h. |
4 |
| |
iv |
Winds to 50kph
by 0030h, rising to 100kph on channel coast by 0500h, heavy rain,
followed by much less strong winds as the depression passed.
|
4 |
| |
v
|
1
mark for each chosen effect |
3 |
| |
c
|
2 max
for each explanation
|
4 |
| Question |
Mark |
|
8
|
a
i
|
Identification
of shape, height, associated weather.
|
3
|
| |
ii
|
Identification
of shape, height, associated weather.
|
3 |
| |
b
|
Diagram identifying
onshore wind, land higher, & therefore rising windward air 3 marks;
written explanation 4 max.
|
7 |
| |
c |
Point marked
advection fog explanation.
|
6 |
| |
d
|
4 max radiation
fog explanation + 2 max for smoke input into it.
|
6 |
| Question |
Mark |
|
9
|
a
|
1 basic mark
+ 1 for development (*3).
|
6
|
| |
b i
|
1 mark for meaning
of initials + change with height in still air.
|
4 |
| |
ii
|
Read from graph
(dew point level)
|
1 |
| |
iii |
Definition of
dew point
|
4 |
| |
iv
|
Name & identified
as unstable
|
2 |
| |
v |
Allow 1 for
0°C: Extension from 0°C to height of unstable air for 2nd mark.
|
2 |
| |
c |
Response must
refer to the stability of the air for level II
|
|
| |
|
Level
I
Relevant weather conditions identified (1 mark each).
|
1
- 3 |
| |
|
Level
II
Relationship to rising/stable air.
|
4
- 6 |
A2 questions on page 257
| Question |
Mark |
|
10
|
a
|
Level
I
Two separate accounts or definitions
|
1 - 3
|
| |
|
Level
II
Account combined to directly show differences
|
4
- 8
|
| |
b
|
Point mark Air
rises, expands, cools (adiabatically) RH increases, reaches 90+%,
water vapour condenses, forming cloud & ppt. in text or on
diagram. Do not 'double count' but diagram may show relationships
not in text.
|
10 |
| |
c |
Point mark causes
of radiation fog rising to low cloud.
|
7 |
| Question |
Mark |
| 11 |
a
|
1 mark for
the meaning of the abbreviation ITCZ
|
|
| |
|
Level
I (a i) ITCZ = Rising heated air mass at the equator; (a
ii) qualitative (e.g. 'hot & wet all year') answer and (a iii) described
without explanation.
|
1
& 1 - 3 |
| |
|
Level
II (a i) Role of warming trade winds developed (into warmer
areas thus warm rise ….) (a ii) one to three quantified statistics
for the climate = 1 L II credit and daily weather sequence
described (a iii) role of movement of the heat equator probably
by 'association'.
|
4
- 8 |
| |
|
Level
III (a i) Both (converging) trade winds included
in the explanation, (a iii) seasonal movement linked to apparent
movement of the overhead sun.
|
9
- 13 |
| |
b |
Level
I Description of Jet air movement and locations. |
1
- 3 |
| |
|
Level
II Upper air pressure linked to lower level pressure pattern
(converse). |
4
- 8 |
| |
|
Level
III Weather associated with the lower air conditions & linked
to movement of the upper air jet 'waves'. |
9
- 12 |
| Question |
Mark |
| 12 |
|
Credit each
situation separately to 9 max with 4 max for description
of weather in the 'contrasting locations' = 3 *9 to 25 max.
|
25
|
| Question |
Mark |
| 13 |
a
|
Point marked
with 4 max for any one source area or any one required characteristic.
|
10
|
| |
b |
Level
I Simple description of weather (rising winds, eye, declining
winds), little explanation.
|
1
- 3 |
| |
|
Level
II Sequence of weather identified showing differences in
front & behind eye. Simple explanation.
|
4
- 8 |
| |
|
Level
III Explanation developed from 'engine' of latent heat.
|
9
- 10 |
| |
c |
3 max
for any one response - includes weather watch & notification system
and response to actual storm.
|
5 |
| Question |
Mark |
| 14 |
a
i
|
Axes numbered
& labelled = 1; Dew point identified; DALR to dew point SALR above
dew point; three plots start at 10°C mark for temperature at 2000m.
|
7
|
| |
ii |
1 mark each
|
3 |
| |
iii
|
Where Air stream
3 crosses SALR (750m)
|
1 |
| |
b
|
Difference between
low level & higher level cooling & relationship to environmental
air temperature.
|
6 |
| |
c
i |
Stationary air
body conditions develop from surface upwards, air takes on surface
conditions.
|
4 |
| |
ii |
Moving
air mass conditions change from surface thus gives different ELR between
lower & upper air. |
4 |
AS questions on page 258
| Question |
Mark |
| 15 |
a
|
1 mark for
the name of any individual component of the low pressure system.
2 marks for 'depression' or 'cyclone' or 'low pressure system'.
|
2
|
| |
b |
Point mark
each component of the weather station symbol.
|
4 |
| |
c
|
Level
I
Point mark 'Warm','Front'.
|
2 |
| |
|
Level
II
Development suggesting the separation of warm and cooler air and
direction of movement.
|
3 |
| |
d
|
Point mark
- location by name of a place, or country, coast & compass direction
etc.
|
2 |
| |
e
i |
Level
I
Identification of the aspects of the situation from (figure 9.82). |
0
- 3 |
| |
|
Level
II
Changes from one situation leading to the other described. |
4
- 6 |
| |
ii
|
Level
I
Identification that a weather system moves and the weather from one
location is experienced later elsewhere. |
0
- 3 |
| |
|
Level
II
Reasons for the changes in terms of the changing frontal pattern over
the area. |
4
- 6 |
A2 questions on page 258
| Question |
Mark |
| 16 |
a
|
Level
I
Identification of individual weather descriptions from either or
both times.
|
0 - 3
|
| |
|
Level
II
Direct reference made to changes (e.g. both sides of a weather
aspect).
|
4
- 8 |
| |
b
|
Level
I
Identification of the shift in location to a new location and possible
naming of the new frontal system (occlusion).
|
0
- 3 |
| |
|
Level
II
Changes to the system (causes of an occlusion) and the relationship
between warmer & colder sectors.
|
4
- 8 |
| |
c
|
Level
I
Identification
of the location/s and type/s of precipitation.
|
0
- 3 |
| |
|
Level
II
IDescription of distribution in terms of pattern of locations. Explanation
of showery air stream. |
4
- 8 |
| |
|
Level
III
Identification of the instability in a NW air stream as the cause
of precipitation. |
9 |
| Question |
Mark |
| 17 |
a
|
Mark (i)
& (ii) as one response.
|
|
| |
|
Level
I
Identification of atmospheric pressure and possibly units for measuring
it or name of equipment. In (ii) a name is presented for the pressure
system
|
0
- 3 |
| |
|
Level
II
Description of a measuring device for pressure with suggestion how
it works. In (ii) identification of the major pressure systems on
fig 9.83
|
4
- 8 |
| |
|
Level
III
Device explained in terms of pressure effects and mechanisms. In
(ii) the relationships between isobar patterns and the identified
pressure systems made clear.
|
9
- 10 |
| |
b |
Level
I
Names
for one or more of the two frontal systems, and for identifying
which is which.
|
0
- 3 |
| |
|
Level
II
Development to show the third dimension relationship indicated by
one or both of the frontal systems. |
4
- 8 |
| |
c |
Level
I
Indication of the relationship between synoptic situations and the
later weather. |
0
- 3 |
| |
|
Level
II Importance
of direction of air flow and other aspects of weather from a chart
for use in forecasting weather at a later time made clear. Examples
of the use of the system from Fig 9.82 and 9.83 used in the discussion. |
4
- 7 |
| Question |
Mark |
| 18 |
|
Credit each
sector of the depression separately to 9 max with 4 max
for description of weather = 3 * 9 to 25 max.
|
25
|
|