2001 CEDAR-SCOSTEP. Longmont, Colorado. June 17-22, Tutorial Lecture #2. by Karin Labitzke Free University of Berlin, Germany

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1 2001 CEDAR-SCOSTEP Longmont, Colorado June 17-22, 2001 Tutorial Lecture #2 by Karin Labitzke Free University of Berlin, Germany Influence of the 11-Year Solar Variation on Atmospheric Circulation

2 STP-10, Tutorial Lecture, Longmont/Colorado, June 2001 Influence of the 11-Year Solar Variation on Atmospheric Circulation K. Labitzke Institut fur Meteorologie, Freie Universitat Berlin K. Labitzke

3 STP-10, Tutorial Lecture, Longmont/Colorado, June Years of Climate Change...We are living in unusual times. 20th centu ry climate was dominated by near universal war ming. Almost all parts of the globe had tempe ratures at the end of the 20th century that were significantly higher than when it began....how unusual was the last century when pla ced in the longer-term context of climate in the centuries and millennia leading up to the 20th century? (quoted from Raymond S. Bradley, IGBP Newslet ter44, December 2000) K. Labitzke

4 STP-10, Tutorial Lecture, Longmont/Colorado, June A wide variety of annually resolved paleoclimate proxies are available to answer this question. These include: historical documentary records, tree rings, ice cores, varved lake sediments, etc., Studies of these and other proxies reveal that temperatures declined from A.D.IOOO until the late 19th century, followed by warming at a rate that is unprecedented in the record, leading to temperatures in the late 20th century that were unique in the context of the entire millennium. Statistical studies and energy balance models in dicate that much of the variability of tempera ture over the millennium can be accounted for by variations in the output of energy from the Sun, explosive volcanic eruptions and internal variabi lity of the ocean-atmosphere system. The 20th century warming is inexplicable by the se mechanisms. Only increased levels of green house gases appear to explain the unusual war ming... (quoted from Raymond S. Bradley, IGBP Newslet-

5 ((«1900 tn H H O o Year (AD) a u Q Figure 1 Various estimates of large-scale (northern hemisphere) temperature variations over the last millennium reference to the average from The differences relate, in part, to the fact that they do not all repr the same season, or geographical domain (from Briffa et al., J. Geophys. Res., in press).

6 CD g s 00 8 <0 O Number of Sunspots 00 o 3CD o o p-

7 90 l i i I '» I ' ' I * i I ' ' l i »» i»»'»v'»i '*' * I»' i ' i. i. i. t. t i. i. t. i Figure 1. (a) Eleven-year running mean of the annual sunspot numbers (upper light curve) and of the annual mean global sea-surface temperature shown as depanures from the average in units of0.0ik (lower light curve). Heavy curves areleast-squares 7th degree polynomial fits to the data, (b) Same as (a) for the three major ocean basins. &. ReU, laoo

8 i i i i r q V o 5 i I ITropical Pacific SST Anomalies 1.0» i i i I i l» L» i J I L j i i i l r IIIII 1 1! P I I I I I i q 1!! I!!!! Year 8.0 Tropical Pacific SST o Oh J* Period (years)

9 Solar Activity and Temperature During 400 Years NJ t. t I I I I 1 I I t I t t I II n I I II I I H I I 1 I l I I I I I M Year Cycle Length (years) 12.5 Global temperature T -11-y running average of Northern Hem. lam temperature, before 1860 estimated by means of tree-ring analyses. Long-term variation of solar activity - length of the sunspot or auroral (before 1850) cycle L efc#5 6-jul-99 C

10 ZBDAT kunze Fach: F3 strat27.met :51 sun Seite 1 von 1 Baxctyeraciw rta$ettisphefeai^ wind (red), and Earth (black). COSMIC RAYS

11 Solar Variability and Climate: Suggested Mechanisms Variations in spectral irradiance in the ultraviolet Changes in stratospheric temperature and winds Changes in planetary wave propagation Changes in tropospheric dynamics Variations in total irradiance (the solar "constant") Changes in the earth's radiation budget Regional and global climate change Variations in the solar wind Varying cosmic-ray fluxes Changes in the global electric circuit Modification of global cloudiness

12 SOLAR IRRADIANCE I «I» ' I ' S0 82_ SUNSPOT NUMBER ] 250 r cycle 0, [20 ; 200 \r 150 h Maunder 100 h Minimum ) \ I 50 rtt^ A'VaV' ~ i i in ^ ^ ilimmmr1- ** * \800 COSMOGENIC ISOTOPES -i i i r «i i L ILMV YEAR (AD) 1000 ISOO 2000

13 SHORT TERM. DIRECT INDICES OF SOLAR VARIABILITY 1 ICC C g- i i i i i i i *- * "1" * ' S lar Irradiance ^5 1- E f&8 t ^ ^ " ' i A-- AS /o 45:244 h c-,r: 1550 t0 175 nm 0.01Wm"2 j r E rn ^ r j- tiw n rat^. J i^_i i a ib_jb t d i _ F/gwrg 9. Model estimates of long-term variability in the total solar irradiance and in two spec tral bands in the UV and IR. In these calculations, the adopted amplitude of the long-tenn faculai* component is approximately equal to its contemporary solar cycleamplitude.

14 ZSDAT krueger stratl6.met :30 folien Seite 3 von 11 Variability of the Solar Irradiance between Solar Maximum and Solar Minimum in the Ultra Violet ( nm) Difference in Solar Irradiance t o.oo* Wavelength [nm] (data from Laan «t al. 1087) Solar Irradiance Variability Wavelength [nm] 4O0 420 (data from Laan at al. 1907) Institut fiir Meteorologie, FU Berlin

15 The SUN has an influence on the stratosphere through more UV radiation during solar maximum than during the minimum. This leads to more ozone and this couples back to the troposphere and to our climate.

16 ZEDAT weber Fach: F3 stratl6.met :45 talk Seite 13 von 15 Temperature Differences between Solar Maximum and Solar Minimum (K) T max-min (K) annual mean 20y Latitude Institut fiir Meteorologie, FU Berlin

17 ZEDAT kunze Fach: P3 strat27.met :26 diff Seite 4 von [km] 110 IONOSPHERE/ THERMOSPHERE Mesopaus Noctilucent clouds m (/) o (/) D X m ;u m / Arctic, July Arctic, December Equator Stratopause CO H (nb) O (/) no x m 7) m Mother of pearl clouds Tropopauses TROPOSPHERE T[ C]

18 ZEDAT kunze Fach: F3 strat27.met :19 c Seite 1 von 1 Detrended Annual Mean NCEP/NCAR N 60N 30N EQ 30S 60S 90S r(solar Cycle; Temp) N 60N 30N EQ 30S Temperature Diff [K] 60S 90S

19 ZEDAT kunze Fach: F3 strat27.met :25 meanjd2000_c Seite 1 von 1 u Annual Mean NCEP/NCAR N 30N EQ 30S r(solar Cycle; Geop) 30** Height Diff. [gpm] 90S

20 90N Detr. Annual 100 hpa Temp NCEP/NCAR 30N W 60W 0 r(solar Cycle) n=33 min = 60E 120E max = N > I.?&' 60N- 60N- 30N- EQ- 30S- 60S- 90S W 60W 0 60E Temperature Diff. [K]

21 ZEDAT kunze Fach: F3 strat27.met :37 OOjd-c Seite 1 von 1 Annual Mean 30H NCEP/NCAR W 60W 0 60E 120E r(solar Cycle) n=33 min =-0.07 max=0.71 Height Diff. [gpm]

22 Ls'.itjde, degrees F,g 4 Latitudinal cross section of the atmosphere dep:c'jr.g the locations o( the (a) polar tropopause; (b) pola jet; (c) subtrop* rojopausi (d) sublropic jet; (e) tropical tropopause; (!) oonveo'ive PBL; (g) frontal systems; (h) trade nvers.on; and (,) m,dla.,.ude stem 4Wb C&AHS) >*& --,,.-.

23 ZEDAT kunze Fach: F3 9trat27.met :15 c Seite 1 von 1 Detrended (Jul+Auq)/ NCEP/NCAR N 60N 90S r(solar Cycle; Temp) N 60N 30N 90S Temperature Diff [K]

24 ZEDAT kunze Fach: F3 strat27.met :13 c Seite 1 von 1 (Jul+Auq)/ NCEP/NCAR N 60N 30N EQ 30S r(solar Cycle; Geop) 90S N 60N Height Diff. [gpm] 90S

25 ZEDAT kunze Fach: F3 strat27.met :15 c Seite 1 von 1 Solar Cycle;30hPa Height (Jul+Aug)/ NCEP/NCAR corr Height Diff. [gpm] min=0.39 max=0.74 corr Height Diff. [gpm]

26 ro 00 ro OJ 00 o> a IO GJ ro CO o ueopotenuui vunv ro CO ro ro OJ CO ro OJ CO ro oj CO oo j. ro o o ro ro ro i> -* 4* o o o ro -i* o> Solar Flux 10.7 cm X TlOA I 9^T S S2:60 T002*fr0*9Z?9W LZlvxiB z& :tpe,3 ezun^ ivohz

27 ZEDAT kunze Fach: F3 strat27.met :03 c Seite 1 von 1 Detr. Temp Differences (Jul+Aug)/2 NCEP/NCAR W 60W 60E 120E 180

28 ZEDAT kunze Fach: F3 strat27.met :59 c Seite 1 von 1 r(solar Cycle;30hPa Height) NCEP/NCAR

29 STP-10. Tutorial Lecture. Longmont/Colorado, June 2001 CONCLUSION Reconstruction of historical solar constant da ta and comparison with historical temperature records indicate a possible link between chan ges of the total solar irradiance and changes of the global temperatures. Until 1800, the statistical studies imply a pre dominant solar influence on the climate; ex tending the studies to the present suggests that solar forcing may have contributed about half of the observed 0.55K surface warming since I860, and one third of the warming sin ce Calculations of the magnitude of the solar si gnal on the time-scale of 11-years show that over a large vertical and latitudinal range the Heights and temperatures are higher during solar maxima than during solar minima. We suggest that the solar effect influences the diabatic meridional circulation, and particular ly the Hadley circulation in the sense that the cniar cscrn^l intensifies the Hadley circulation