Data trends at meteoLCD: 1998 to 2010

Trends computed from yearly averages at meteoLCD, Diekirch, Luxembourg.
Graphs may be freely copied and used, under the condition to cite:
MASSEN, Francis: Data trends at meteoLCD, 1998 to 2010.

Older trends are here!

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

negative trend: -1.2 ug/m3 per year


mean : 39.1 ug/m3
stdev:     6.5


See [1] [2] [3] [17]

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

positive trend: +2.3 DU per year

(+1.4 without year 1999; Uccle
 gives +0.95  for the 1998-2010 period) (see also [16])

calibration factor applied if needed!

Uccle data from WOUDC (stat.53, Brewer#16)

mean : 322.0   (Uccle: 328.4)
stdev :   15.5    (Uccle:     7.1)

See [4] [8] ([8] shows strong
positive trend starting 1990 for
latitudes 45-75 North, Europe):
See also recent EGU2009 poster [16].

CO2 mixing ratio in ppmV

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

For 2002-2010:
positive trend: + 1.4 ppmV per year

For 2007-2010:
negative trend: -1.32 ppm per year !

mean:   407.1 ppmV        2007 to 2010: 411.2 ppmV
stdev:        4.9                                                 2.3   

See this figure
for a comparison between meteoLCD and Mauna Loa CO2 trends.



The next picture shows the asymptotic CO2 values derived from the model published in [21] .
The blue upper curve shows the yearly mean values at Diekirch; the middle red curve the asymptotic CO2 values that would exist if wind velocity was infinite, and the lower green curve the yearly averages at Mauna Loa, augmented by +1.8 ppm to respect the latitudinal gradient of approx. 0.06 ppm per degree.
The asymptotic mixing ratios are reasonably close to those of Mauna Loa (adjusted); the yearly trends calculated from the mean and asymptotic values at Diekirch are very close (1.38 and 1.39 ppm*y-1). They are visibly lower than the Mauna Loa yearly gradient.

Air temperature [C]

Trend from 1998 to 2010: - 0.005 C per year


mean : 10.26 C      2000 to 2010:  10.31C
stdev:    0.40

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

Distinctive cooling from 2000 to 2010:
meteoLCD:     - 0.4C/decade

CRU (Hadcrut3) trend for the past 10 years:
0 0C/decad. [18]
Highest decadal Central England warming trend from 1691 to 2009: +1.86C/decade for 1694-1703!
See also [15]

Diurnal Temperature             
Range (DTR)  [C]

DTR = daily max - daily min temperature

positive trend: + 0.05 C per year

mean:  8.47 C
stdev:  0.55

Note that daily maximum rises faster than daily minimum! The increase in DTR is also documented here!

See [5] and [13]

Total Yearly Rainfall [mm]

negative trend: - 22 mm per year

mean : 717.4 mm
stdev : 146.5 mm

Rainfall in Diekirch may be very different from that at the Findel airport !

Findel: NA mm

Note the deviation from the 10 years period sinus fit by a simple sinus function of period 10 years.
[6] gives medium term periods of 10 to12 years for the  region from England to eastern Germany.

Note: Rainfall readings are possibly too low, as there were several occasions of sensor blocked by bird droppings.

Solar energy on a horizontal plane

mean: 1097.2 kWhm-2
stdev:    47.9  kWhm-2

Negative trend: -4.3 kWhm-2 per year
and -9.9 kWhm-2y-1 since 2004 (solar cycle #23 terminates December 2008).
This last period should cause a cooling of
0.14 Cy-1 , assuming a feedback parameter
f =-1 ([19]). The meteoLCD observations show a cooling of 0.06Cy-1 (from linear regression)

Our data suggest: ΔT =0.053*ΔF
where ΔT = temperature change per year in C
ΔF = change in solar irradiance per year in Wm-2
assuming solar energy being the sole driver. This is in excellent agreement with the "fast process sensitivity k1s" given by Scafetta [20]

[14] finds 0.7 Wm-2y-1 for West-Europe 1994-2003 , meteoLCD +1 Wm-2y-1 for 1998-2003.See also [9]

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

Nearly flat trend: + 0.8 hours per year

mean:  1657 hours
stdev:     178

Note strong negative trend from 2004 to 2010:
- 34.7 hours per year.

Paper by F. Massen comparing 4 different methods to compute sunshine duration from pyranometer readings in the works.


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

Practically flat trend line for the whole period.


mean:  0.130 eff. kWh*m-2
stdev:  0.010 eff. kWh*m-2

Note negative trend of - 1 eff. Whm-2y-1 from 2004 to 2010, in accordance to the dimmimg measured  by the pyranometer.

So this dimming is confirmed by 2 independent instruments!

See [10] and [22] (poster finds slight positive trend in June (+2%) and negative trend in August (-1%), no trend for other months, for period 1991 to 2008)

UVA dose on a horizontal plane in kWh/m2

Positive trend: + 0.4 k Whm-2 per year, essentially caused by the first and last readings.

mean:  54 kWh/m2
stdev:    5 kWh/m2


Note exceptional high 2010 reading causing a visible positive trend of +0.3 kWm-2y-1 : This 2010 reading should be taken with caution, as it leads to a trend opposite to that of both the total irradiance and the UVB dose.

NO concentration in ug/m3

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

For 2000-2010::

negative trend: -0.5 ug/m3 per year
( = 40% reduction relative to 2000)

mean:   9.5 ug/m3
stdev:   1.8 ug/m3

see [11] which gives ~30% reduction from 1990 to 2005 for the EU-15 countries.

NO2 concentration in ug/m3

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

For 2000-2010:

negative trend: - 0.2 ug/m3 per year

mean: 21.6 ug/m3
stdev:   2.1 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.
6 R.G. Vines, CSIRO: European rainfall patterns. International Journal of Climatology, vol.5, issue 6, p. 607-616.
7 (15 Jan 2009).
8 J.W. Krzyscin, J.L.Borkowski: Total ozone trend over Europe: 1950 - 2004. ACPD, 8, 47-69, 2008.
9 NASA: Solar Physics: The Sunspot Cycle.
10 de Backer et al: (temporarly unavailable)
11 EEA: Emission trends of NOx 1990 - 2005
12 L. Motl: . Dec.2009
13 K. Makovski: The daily temperature amplitude and surface solar radiation..Dissertation for the degree of doctor of sciences. ETHZ 2009.
14 A. Ohmura: Observed long-term variations of solar irradiance at the earth's surface. Space Science Reviews (2006) 125: 111-128
15 J. van Oldenvorgh: Western Europe is warming much faster than expected. Clim.Past. 16Jan.2009
16 Van Malderen, De Backer, Delcloo: Revision of 40 years of ozone measurements in Uccle, Belgium. Poster, EGU2009, Vienna.
17 EEA: Air pollution by ozone across Europe during summer 2009
18 Climate4 you: Global temperature trends
19 Lindzen & Choi: On the determination of climate feedback from ERBE data (GRL, 2009)
20 Scafetta, N.: Empirical analysis of the solar contribution to global mean air surface temperature change. Journal of Atmospheric and Solar-Terrestrial Physics, 2009 (doi:10.1016/j.jastp.2009.07.007)
21 Massen, F., Beck, E. :Accurate estimation of CO2 background level from near ground measurements at non-mixed environments
in: Leal, W., editor: The Economic, Social and Political Elements of Climate Change
Climate Change Management, 2011, Part 4, 509-522. Springer. DOI: 10.1007/978-3-642-14776-0_31
22 De Backer & Van Malderen: Time series of daily erythemal UVB doses at Uccle Belgium. Poster, July 2009.




file: meteolcd_trends.html
last revision:11 Sep 11