Data trends at meteoLCD: 1998 to 2012 


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 2012. http://meteo.lcd.lu

Older trends are here!

Most important conclusions (14 Apr 2013):

1. Solar dimming is happening at least since 2004 (Helioclim satellite: since 1985)
2. Local temperatures are declining
3. There is no trend in DTR, daily max. and daily min. temperatures
4. The winters are cooling by 0.43 C/decade
5. Ozone concentrations change for the better: ground O3 declines,  thickness of ozone layer increases
6. Long-term local CO2 mixing ratio increases by ~1.4 ppmV per year

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

negative trend: -1.1 ug/m3 per year

1998-2012 mean +/- stdev:
38.1 +/- 6.6 ug/m3
  

 

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

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


positive trend: +2.1 DU per year
, +0.3 since 2002
(Uccle
 gives +0.95  for the 1998-2010 period) (see also [16])
Calibration factors applied:
1998 to 2007: * 0.95
2008 to 2010: * 1.00
2011              : * 1.06

2012              : * 1.04

2
012 common days measurements results:
Diekirch = 325.6 DU
Uccle DS = 328.1 DU
Uccle data are from WOUDC (stat.53, Brewer#16)

1998 to 2012 mean +/- stdev:
Diekirch: 323.8  +/- 15.5
   Uccle.:  328.8 +/- 3.5
(Uccle without 2009/10/11
)
                                   

See [4] [8] ([8] shows strong positive trend starting 1990 for latitudes 45-75 North, Europe): [27] give +1.32 DU/y at the Jungfraujoch for 1995-2004.
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.

2002 to 2011 mean +/- stdev::
408.4 +/- 5.3 ppmV
trend = +1.35 ppmV per year

2007 to 2011:
trend: + 0.38 ppmV per year !


                                       


 


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 ppmV to respect the latitudinal gradient of approx. 0.06 ppm per degree (MLO December data not yet available, average of Jan to Nov. 2012 retained)
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 (1.35 and 1.22 ppmV*y-1). They are visibly lower than the Mauna Loa yearly gradient of 2.02 ppmV*y-1

See also [25]

Air temperature [C]

Trend from 1998 to 2012: +0.019 C per year

1998 to 2012 mean +/- stdev::
10.33  +/- 0.45 C                                        

2002 to 2011:
10.39 +/- 0.49 C

The sensor has not been moved since 2002!

Slightly cooling trend from 2002 to 2012:
meteoLCD:     - 0.02C/decade
Findel:              -0.19C/decade


Global Land temperature trends also show cooling:
CRU (Hadcrut3): - 0.03C/decad. [18]
UAH (satellite)   :- 0.07C/decad  [26]
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

1998 to 2012 mean +/- stdev::
8.53 +/- 0.55 C         

2002 to 2012: all trends flat!
 

Note that for 1998-2012 daily maximum rises faster than daily minimum! The increase in DTR is also documented here! Since 2002, all three parameters have trends lower than +/-0.005 C/y, i.e. these trends lines are essentially flat. Same conclusion reached by the BEST paper [29] on global land-based temperatures.

See [5], [13] and [30]

.
Winter temperatures [C]

Contrary to what is often suggested in the media, winters are cooling since 2002. The cooling rates per decade are:

Diekirch:   -0.43 C/decade
Findel:       -0.67 C/decade
Germany:  -1.02 C/decade [31]

The plot shows the mean temperatures of December (from previous year), January and February. It also shows in brown (right Y-axis) the NAO index for the months Dec to Mar [32]

The North Atlantic Oscillation clearly influences our winters; the correlation between the 3 different DJF series and DJFM_NAO are 0.76, 0.77 and 0.78, all significant at the 5% level. The NAO trend is also negative for the 2002 to 2012 period.

Total Yearly Rainfall [mm]

Trend from 1998 to 2012: - 17 mm per year

1998 to 2012 mean +/- stdev::mean :
708.7 +/- 148.3 mm         

2002 to 2012:
653.7 +/-
119.2 mm                                 

Rainfall in Diekirch may be very different from that at the Findel airport ! Total for 2012:
Diekirch = 800 mm, Findel = 951 mm

Good simple model: Sinus function of 7 years period with time dependant amplitude (R2 = 0.36). Model correctly reflects rising precipitation.
 

 

[6] gives medium term periods of 10 to12 years for the  region from England to eastern Germany.

Solar energy on a horizontal plane  

mean: 1113.5 kWhm-2
stdev:    48.8  kWhm-2


Visible negative trends:
1998 to 2012: -2.7 kWhm-2y-1
2004 to 2012: -5.8 kWhm-2y-1
(solar cycle #23 terminates December 2008).
The period 2005 to 2012 should cause a cooling of -0.04 Cy-1 , assuming solar energy being the sole radiative forcing and no feedbacks. ([19]). The meteoLCD observations show from 2005 to 2012 a cooling of -0.02 Cy-1 , reasonably close.
(see Addendum 1)
Helioclim satellite measurements show ongoing solar dimming over Luxembourg for 1985 to 2005  [33] (see graph)
[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)

Total for 2012:
meteoLCD: 1637.5 hours
Findel:          1856.3

Trend: + 2.2 hours per year

1998 to 2012 mean +/- stdev:  
1666  +/- 169 hours

Note negative trend from 2004 to 2012:
- 7.8 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.

1998 to 2012 mean +/- stdev:
0.129 +/- 0.010 eff. kWh*m-2y-1
 

Practically flat trend from 1998 to 2012, but
visible negative trend of - 1 eff. Whm-2y-1 from 2004 to 2012, in
accordance to the dimmimg measured  by the pyranometer over the same period. So 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)

The decrease in biologically effective UVB is also consistent with the increase of the total ozone column [28]
 

UVA dose on a horizontal plane in kWh/m2 

Positive trend: + 0.3 k Whm-2 per year, essentially caused by the very low 2004 reading.

1998 to 2012 mean +/- stdev:
54.40 +/-  4.92 kWh/m2y-1
 

Note exceptional high 2010 reading causing a small positive trend of +0.15 kWm-2y-1 . This positive trend is caused by the exceptional high 2010 value (which was an extrapolation due to 8% missing data, and is dubious).
Without the 2010 value, the UVA dose trend from 2004 to 2012 is clearly negative: - 245 Wm2y-1

The 3 independent measures of Solar energy, UVA and UVB dose all document a solar dimming since 2004.

NO concentration in ug/m3
 

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

2000 to 2012: trend = -0.3 ug/m3 per year

2002 to 2012  mean +/- stdev:
9.4 +/- 1.6 ug/m3
2002 to 2012 trend: -0.2 ug/m3 per year
i.e. a reduction of 20%

Many (about 20 to 25%) missing data in 2011 and 2012, so be careful!

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.

2000 to 2012: trend: - 0.014 ug/m3 per year ~ flat!

2002 to 2012  mean +/- stdev:
21.8 +/- 3.2 ug/m3
2002 to 2012: trend = + 0.16 ug/m3 per year

Many (about 20 to 25%) missing data in 2011 and 2012, so be careful!

 

Enthalpy of moist air in kJ/kg
 

See [24] on how the energy content of 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.

2002 to 2012 mean +/- stdev:
28.01 +/- 0.64 kL/kg
                       

Trend is clearly negative: -0.1 KJ/kg per year which is consistent with the trends in solar energy, UVA and UVB doses.
 

 

   

References:

1 Europe's Environment 4th AR (2007) Fig. 2.2.3 http://reports.eea.europa.eu/state_of_environment_report_2007_1/en/Belgrade_EN_all_chapters_incl_cover.pdf
2 EPA: Ozone trends. http://www.epa.gov/airtrends/ozone.html
3

Jonson et al: Can we explain the trends in European ozone levels? Atmos. Chem. Phys. Discuss., 5, 59575985, 2005. http://www.atmos-chem-phys-discuss.net/5/5957/2005/acpd-5-5957-2005.pdf

4 Ozone trends at Uccle  http://ozone.meteo.be/ozone/trends.php
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 http://global-warming.accuweather.com (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: ftp://ftp.kmi.be/dist/meteo/hugo/posters/20080630tromso_hdb.pdf (temporarly unavailable)
11 EEA: Emission trends of NOx 1990 - 2005
12 L. Motl: http://motls.blogspot.com/2009/12/uah-msu-temperatures-for-2009-and.html . 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
26 UAH MSU data: http://vortex.nsstc.uah.edu/public/msu/
27 Vigouroux et al:  Evaluation of ozone trends from g-b FTIR observations. Atmos. Chem. Phys., 8, 68656886, 2008
28 UNEP, Scientific Assessment: Stratospheric Ozone and Surface Ultraviolet Radiation
http://ozone.unep.org/Assessment_Panels/SAP/Scientific_Assessment_2010/04-Chapter_2.pdf
29 R. Mller et al: A New Estimate of the Average Earth Surface Land Temperature Spanning 1753 to 2011.
GIGS, vol.1, nr.1 Jan.2013
30 K. Makowski: The daily temperature amplitude and surface solar radiation. Dissertation ETH Zrich #18319, 2009
31 http://notrickszone.com/2013/02/12/germanys-winter-temperature-trend-in-a-nosedive-now-falling-6c-per-century/
32 Tim Osborne: NAO data (http://www.cru.uea.ac.uk/~timo/datapages/naoi.htm)
33 Helioclim satellite measurements of solar irradiation at http://www.soda-is.com/eng/services/services_radiation_free_eng.php

          

 


Addendum 1
updated!
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 -1.5 kWh*m-2y-1  (period 2005 to 2012) corresponds to ΔQ = - 1500/8760 = -0.171 Wm-2 and should yield a cooling of  ΔT0 = -0.25*0.171 = -0.04 K (or C).per year.
Scafetta defines a climate sensitivity in respect to changes in solar radiation by k1s = ΔT/ΔF and finds k1s = 0.053. Our data for the full period 2005 to 2012 give ΔT/ΔF= - 0.021/(-0.171) = 0.12.

Summary for the 2005 to 2012 period:
 
meteoLCD ΔT/ΔF = 0.12 ΔT = - 0.02 Cy-1
Lindzen & Choi G0 = 0.25 ΔT = - 0.04 Cy-1
Scafetta k1s  = 0.053 ΔT = -0.01 Cy-1

 

Addendum 2

(to be updated!)

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

francis.massen@education.lu
last revision: 14 Apr 13