Data trends at meteoLCD: 1998 to 2007

Trends computed from yearly averages at meteoLCD, Diekirch, Luxembourg.
Graphs may be freely copied and used, under the condition to cite:
Massen F.: Data trends at meteoLCD, 1998 to 2007.

Older trends are here!

Ground Ozone [ug/m3]
("bad ozone")

negative trend: -1.22 ug/m3 per year


mean : 41.0 ug/m3
stdev:  6.0


See [1] [2] [3] and this figure

Total Ozone Column [DU]
("good ozone")

positive trend: + 4.2 DU per year

calibration factor applied if needed!

mean : 320.9 DU
stdev :   17.0 DU

See [4] 

CO2 mixing ratio in ppmV

The 1998-2001 data are too unreliable to be retained for the trend analysis.

For 2002-2007:

positive trend: + 2.3 ppmV per year

mean: 405.5 ppmV
stdev:     5.1 ppmV

See this figure

Air temperature [C]

positive trend: + 0.07 C per year


mean : 10.34 C
stdev:    0.34

As the sensor has been moved several times, this trend should be taken with caution!

Increase is smallest from 2006 to 2007.

Diurnal Temperature             
Range (DTR)  [C]

positive trend: + 0.07 C per year (right axis)

mean:  8.46 C
stdev:  0.59

Note that daily maximum rises faster than daily minimum. DTR increase could be related to increasing insolation (sunshine duration)

See [5]

Total Yearly Rainfall [mm]

negative trend: - 31 mm per year

mean : 737.8 mm
stdev : 155.8 mm

Note zig-zag pattern!

Rainfall in Diekirch may be very different from
that at the Findel airport:
ex: 2007: 
Findel = 1032 mm, Diekirch = 678 mm

Solar energy on a horizontal plane

positive trend: + 0.06 kWh/m2 per year


mean: 1123 kWh/m2
stdev:    50  kWh/m2


Note practically flat trend!
Would be slightly negative (-0.8) without heat-wave year 2003.

Sunshine duration
(derived from pyranometer data by Olivieri's method)

positive trend: + 25 hours per year

mean: 1692 hours
stdev:   188 hours

Trend would be +22 hours/year without
heat-wave year 2003.

Biologically eff. UVB dose on a horizontal plane in kWh/m2

positive trend: + 0.001 eff. kWh/m2 per year


mean:  0.131 eff. kWh/m2
stdev:  0.011 eff. kWh/m2

Trend would be negative (-0.0003)  without year 1998.

UVA dose on a horizontal plane in kWh/m2


mean:  54 kWh/m2
stdev:    5 kWh/m2


Trend would be flat without year 1998.

NO concentration in ug/m3

The 1998-1999 data are too unreliable to be retained.

For 2000-2007:

negative trend: -0.31 ug/m3 per year

mean: 10.4 ug/m3
stdev:   1.0 ug/m3

NO2 concentration in ug/m3

The 1998-1999 data are too unreliable to be retained.

For 2000-2007:

positive trend: + 0.11 ug/m3 per year
(nearly flat)

mean: 22.2 ug/m3
stdev:   1.8 ug/m3



1 Europe's Environment 4th AR (2007) Fig. 2.2.3
2 EPA: Ozone trends.

Jonson et al: Can we explain the trends in European ozone levels? Atmos. Chem. Phys. Discuss., 5, 59575985, 2005.

4 Ozone trends at Uccle
5 Rebetez, Beniston: Analyses of the elevation dependency of correlations between sunshine duration and diurnal temperature range this century in the Swiss Alps. 1998.



file: meteolcd_trends.html
last revision: 06 Jan 08 (16:00 UTC)