Data trends at meteoLCD: 1998 to 2011

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 2011.

Older trends are here!

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

negative trend: -1.2 ug/m3 per year


mean : 38.5 ug/m3
stdev:     6.6


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

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

positive trend: +1.4 DU per year

 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 : 320.8   (Uccle:  na          )
stdev :   15.5    (Uccle:  na           )

Small negative trend of -1.5 DU/year since 2002.

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 - 2011:
positive trend: + 1.4 ppmV per year

For 2007 - 2011:
flat trend: - 0.17 ppmV per year !

mean:   407.8 ppmV        2007 to 2011: 411.7 ppmV
stdev:        5.0                                                 2.3   

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



The right picture shows the asymptotic CO2 values (CO2wind) 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 close (1.36 and 1.31 ppm*y-1). They are visibly lower than the Mauna Loa yearly gradient.

See also [25]

Air temperature [C]

Trend from 1998 to 2010: +0.024 C per year


mean : 10.33 C      2002 to 2011:  10.39C
stdev:    0.45

The sensor has not been moved since 2002!

Essentially flat trend from 2002 to 2011:
meteoLCD:     + 0.03C/decade

CRU (Hadcrut3) trend for 2001-2010:
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:  8.52 C          2002 to 2011: all trends flat!
stdev:  0.57

Note that for 1998 -2011 daily maximum rises faster than daily minimum! The increase in DTR is also documented here! Since 2002, all three parameters have trends lower than 0.003 C/y, i.e. these trends lines are flat.

See [5] and [13]

Total Yearly Rainfall [mm]

Trend from 1998 to 2011: - 24 mm per year

mean : 702.2 mm          2002 to 2011: 639.1 mm
stdev : 146.2 mm                                    114.9 mm

Rainfall in Diekirch may be very different from that at the Findel airport !
Diekirch = 505, Findel = 700 mm

Best simple model: Sinus function of 7 years period with time dependant amplitude (R2 = 0.45). Model suggest rising precipitations during the next 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: 1113.5 kWhm-2
stdev:    48.8  kWhm-2

Negative trend: -2.3 kWhm-2 per year
and -2 kWhm-2y-1 since 2004 (solar cycle #23 terminates December 2008).
This last period should cause a cooling of
0.06 Cy-1 , assuming no feedback. ([19]). The meteoLCD observations show a warming of 0.03Cy-1 (from linear regression)

Our data suggest: ΔT =- 0.13 * 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. Thus the previous agreement with the "fast process sensitivity k1s" given by Scafetta [20] does not exist anymore.  (see Addendum 1)

[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)

Trend: + 3.6 hours per year

mean:  1668 hours
stdev:     175

Note negative trend from 2004 to 2011:
- 9.1 hours per year.

See paper [23] by F. Massen comparing 4 different methods to compute sunshine duration from pyranometer

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 small negative trend of - 0.6 eff. Whm-2y-1 from 2004 to 2011, in accordance to the dimmimg measured  by the pyranometer over the same period..
Dimming is confirmed by both pyranometer and UVB sensor

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:  54.59 kWh/m2
stdev:     5.05 kWh/m2


Note exceptional high 2010 reading causing a visible positive trend of +0.5 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 (without 2010 data trend would be slightly negative from 2004 to 2011)

NO concentration in ug/m3
(no update to 2011)

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

For 2000-2011::
negative trend: -0.3 ug/m3 per year

mean:   9.1 ug/m3
stdev:   1.8 ug/m3

Many (about 25%) missing data in 2011, so this trend and the last data point should be taken with caution!

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 2000-2011:
negative trend: - 0.4 ug/m3 per year

mean:   19.8 ug/m3
stdev:      4.2 ug/m3

Many (about 25%) missing data in 2011, so this trend and the last data point should be taken with caution!


Enthalpy of moist air in kJ/kg

See [24] on how the energy contentof moist air is calculated. Several authors, as Prof. Roger Pielke Sr. insist that air temperature is a poor metric for global warming/cooling, and that the energy content of the moist air and/or the Ocean Heat Content (OHC) are better.
Mean yearly moist enthalpy values are very close, but they may change from close to zero up to 60 Kj/kg during a year. Moist enthalpy can not be calculated for temperatures <= 0 C.

2004 - 2011: mean = 28.01
                        stdev = 0.64

Trend is slightly negative: -0.036 KJ/kg per year which is consistent with the trend in solar energy and UVB dose..




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.
23 Massen, F.: Sunshine duration from pyranometer readings, 2011
24 Massen F.,  Calculating moist enthalpy from usual meteorological measurements (July 2010) and Calculating moist enthalpy revisited (Sep. 2010)
25 CDIAC: Online Trends



Addendum 1 Lindzen & Choi [19] define the non-feedback climate sensitivity as ΔT0 = G0*ΔQ, where G0 = 0.25 Wm-2 and ΔQ is the change in radiative forcing. A change of -2 kWh*m-2y-1  corresponds to ΔQ = -0.23 Wm-2 and should yield a cooling of  ΔT0 = -0.25*0.23 = -0.06 K (or C).
Scafetta defines a climate sensitivity in respect to changes in solar radiation by k1s = ΔT/ΔF and finds k1s = 0.053. Our data give ΔT/ΔF= + 0.03/(-0.23) = - 0.13.
The relatively good agreement found with both Lindzen's and Scafetta's results that existed in 2010 does not hold anymore at 2011.
Addendum 2 It makes for an interesting exercise to compare the influence of mean yearly solar forcing on moist enthalpy and air temperature for the decade 2002 to 2011.

Both air temperature and moist enthalpy are positively correlated to changes in solar forcing ( = mean solar irradiance). Neither correlation is significant at the p = 0.05 level, and both correlation coefficients are very close (R2 = 0.096 and 0.084).

A change of 1 Wm-2 of solar irradiance would cause an average heating of 0.025 C per year; a change of 1 kJ/kg of moist enthalpy would cause about 0.031  C per year, numbers of similar magnitude.

So even if the period 2004 to 2011 does not validate Scafetta's k1s sensitivity, the full decade 2002 to 2011 gives numbers of a comparable magnitude. Possibly taking into account some lag (as for instance 4 months for temperature lagging solar forcing) would change these numbers.






file: meteolcd_trends.html
last revision: 01 Nov 12