MetLink Activity
31 (age 16+)
Advanced case
study: An investigation of the weather across Europe on 6,
7 and 8 February 2006
Please note that the resource
links in this activity will remain locked to 6, 7 and 8 February so that it can
be used at any time in the future.
The aims:
+ to use ICT skills in finding information, particularly the selection and
extraction of data appropriate to a specific task
+ to use research skills to gain knowledge and understanding of weather
processes
+ to interpret, describe, interrelate and explain weather observations
The Activity:
This is a long and very detailed case
study. Completing the whole study will provide a detailed understanding of the
interrelationships in the weather systems of Europe. However, teachers and students
may wish to extract and adapt particular sections for a more limited study. If
this latter approach is followed, teachers and students will need to be aware
of the possible dependence on one section with its interrelationship with
another.
Students should try to structure their answers within each numbered question in
sentences, responding to each part of the question. The sentences then naturally build into a complete
paragraph for that section.
Section A: Temperatures across Europe:
1. Compare the temperatures on the Europe overview maps:
For 06:00UTC on 6 February, click here
For 12:00UTC on 6 February, click here
For 06:00UTC on 7 February, click here
For 12:00UTC on 7 February, click here
For 06:00UTC on 8 February, click here
For 12:00UTC on 8 February, click here
These are generalised maps which attempt to divide Europe into zones of
different temperatures, and in so doing may disguise local variations of
temperature.
Description:
+Are there any areas which could be
regarded as relatively warm for early February (over 10°C)? How extensive are
they and where are they?
+Where are the cold areas (below freezing)?
+Where are the very cold areas (below minus 10°C and below minus 20°C)?
+Where are the areas between 0°C and 10°C? The term for these temperatures in
early February would be cool at the lower end of the range and mild at the
upper end of the range.
+ How do these areas differ between the 06:00UTC maps and the 12:00UTC overview
maps each day?
+ How has the position and extent of these temperature zones changed over the
three days under investigation?
Let us now turn to the maximum and minimum temperature
maps:
For minimum temperatures in the 24 hours
ending at 06:00UTC on 6 February, click here
For maximum temperatures in the 24 hours ending at 18:00UTC on 6 February, click here
For minimum temperatures in the 24 hours ending at 06:00UTC on 7 February, click here
For maximum temperatures in the 24 hours ending at 18:00UTC on 7 February, click here
For minimum temperatures in the 24 hours ending at 06:00UTC on 8 February, click here
For maximum temperatures in the 24 hours ending at 18:00UTC on 8 February, click here
These show the actual recorded temperature at numerous
locations and are therefore more precise in detail but do not give such a clear
overall impression of the zoning of temperatures.
+ Is what they show consistent with the overview maps? Give examples to support
your arguments.
+ Do they show any locations which have experienced greatly fluctuating
temperatures during the three-day period?
2. Explanation:
During winter months, the large land masses of Europe and northern Asia lose
heat and become very cold. Research the reasons for this happening.
Conversely, the oceans and seas retain the heat energy which they gained in
summer for a much longer time. This means that the oceans and seas are usually
warmer than the land masses in winter. In the case of the North Atlantic, there
is a further vital factor that causes the waters north of 40° latitude to have
much higher temperatures than would otherwise be the case. Again, research
these two matters.
Pressure systems and atmospheric circulations bring about the transfer of air
outwards from its sources where it had either become cooled over the cold
interiors of the land mass or warmed over the oceans and seas. The transfer and
influence of relatively cold and drier air is referred to as a continental
influence. The transfer and influence of relatively warm and more humid air is
referred to as a maritime influence.
+Study the pressure maps of Europe. Remember that the air moves outwards from
the centres of areas of high pressure (anticyclones) and moves inwards towards
centres of low pressure (depressions). In doing so, winds blow at an angle to
the isobars, clockwise around anticyclones in the northern hemisphere and
anticlockwise round depressions in the northern hemisphere. The angle is
typically 10 to 30 degrees for depressions, about five degrees for anticyclones.
Research the reasons for the inflow and outflow happening.
+Fronts exist where flows of air from different source regions meet. There is
little mixing between the two masses because of the marked difference in their
temperature and humidity and therefore their density. If either air mass is
pushing actively forwards and the other air mass is retreating, on weather
charts the fronts have symbols on them indicating the direction of advance and
the type of air which is gaining dominance. To confirm how these cold fronts
and warm fronts are shown on weather charts click
here, and for further information click here.
Fronts are often seen to have moved as each successive pressure map is examined. At times, though, the two opposing air masses may be in equilibrium with neither gaining ground. The front will then remain in a similar position over time and may have alternating cold front symbols facing away from the cold air mass and warm front symbols facing away from the warm air mass. These are known correctly as quasi-stationary fronts, or simply called stationary fronts.
Study the weather charts for the period under
investigation:
For 06:00UTC on 6 February, click here
For 12:00UTC on 6 February, click here
For 06:00UTC on 7 February, click here
For 12:00UTC on 7 February, click here
For 06:00UTC on 8 February, click here
For 12:00UTC on 8 February, click here
+ Identify the locations of the main anticyclones and depressions
which have influenced the weather over Europe during these three days.
+ Identify the main places where either relatively cold air is being advected
(moved horizontally) from one location to another and thus influencing the
temperatures in the receiving area.
+ Identify the main frontal zones over and close to Europe.
+ Identify locations where there is little change taking place in the position
and nature of the anticyclones, depressions and fronts affecting Europe and
therefore little change has been occurring in the weather.
+ Identify places where significant changes have been taking place and describe
these changes.
Section B: Cloud, precipitation and lightning across
Europe:
1. Bands of deep cloud and precipitation form along the lines of fronts and
around depressions. These lines of cloud are visible on satellite images and
often take a curving form. Cloud associated with depressions is seen in the
form of swirls around the depression or as commas of cloud extending from the
centre of the depression.
+ Research and review the reasons for this, including the reasons for different
types of precipitation occurring, such as rain or snow.
+ Study the cloud distributions across Europe as shown by the satellite maps
listed here:
Click here for infra red image on 6 February at 12:00UTC
Click
here for visible image on 6 February
at 12:00UTC
Click
here for infra red image on 7 February
at 12:00UTC
Click
here for visible image on 7 February
at 12:00UTC
Click
here for infra red image on 8 February
at 02:20UTC
Click
here for infra red image on 8 February
at 06:00UTC
Click
here for infra red image on 8 February
at 10:47UTC
Click
here for infra red image animation for
7-8 February
Click
here for infra red image on 8 February
at 12:00UTC
Click
here for visible image on 8 February
at 12:00UTC
+ Refer to these satellite images and again refer to the pressure charts. Again
refer to the overview maps of Europe which show precipitation using a series of
symbols. The key for the overview maps can be found by clicking
here. Identify the locations where
cloud and precipitation have
been occurring and describe the types of precipitation.
2. Shallow low cloud may form in association with
anticyclones as a result of temperature inversion. Research this further. If
you have not already done so, you could also work on MetLink Activity 21, which
deals with this (click here).
+ Identify any areas in Europe where this is the case by comparing the
satellite images with the pressure charts.
3. To what extent have the locations of the cloud and depression changed over the three days of study and how is this related to the movement of the fronts and pressure systems? Give examples of areas of change and areas of little change in these respects.
4. Lightning: Review the causes for lightning. Then study these two sources which show the distribution of lightning discharges in Europe over recent days.
Click here for 6 February animation of lightning discharges
Click
here for 7 February animation of
lightning discharges
Click
here for 8 February animation of
lightning discharges
For further information on how lightning observations are made click
here.
+ Describe the location of the lightning and any movements in its location,
both on the days in question and from one day to the next.
+ Compare the locations of the lightning and how the lightning has changed
location, using the pressure charts. Attempt to explain the reasons for what
has occurred.
Section C: The observations of MetLink participants:
1. Firstly, how do the observations of your own school or
college weather station over the three days of this study relate to the weather
patterns observed in the previous answers?
2. Select a number of MetLink participants from contrasting
areas of Europe and comment how the observations of each of them over the
three-day period are consistent with the weather patterns observed in the
previous answers. To find the participants, first go to the MetLink Homepage (click here) and work from the Home page.
Click Data central
Click Search observations data
Leave the name
contains box blank
Select one of the European countries listed below using the drop-down menu
Set the dates as From 06
February To 08 February
Click Search now
You will need to know where each
participant whose observations you are referring to is located. To find this,
click on the name of the participant.
This will take you to their Details page
where you can find the name of their location, maps
of their locations and nearest webcam
link.
Repeat this operation for some or all of the other European countries listed.