Wednesday, January 23, 2013

New paper finds solar & lunar forcing regulated Mediterranean temperature & precipitation over past 500 years

A new paper published in the Journal of Sedimentary Research demonstrates evidence for solar and lunar tidal forcing of climate and ocean oscillations, which "represent the main climate forcing mechanisms that regulated temperature and precipitation in the Mediterranean in the past 500 years."

h/t to Tom Nelson

From the paper:

The periodicities recognized in our study resemble the ones associated to the QuasiBiennial Oscillation, the El Nino Southern Oscillation, the sunspot number solar cycle and, interestingly, the 9 year periodicity related to a lunisolar tidal cycle. All of these represent the main climate forcing mechanisms that regulated temperature and precipitation in the Mediterranean in the past 500 years (Camuffo et al. 2010; Scafetta 2010, 2012a; Wang et al. 2012). We suggest that during the MSC, at least during the insolation minima when evaporites precipitated, the Mediterranean did not have a constant hydrological budget but was rather characterized by a highly dynamic climate. In such a dynamic scenario the conditions of the Mediterranean seasonally switched between oversaturated evaporative and diluted non-evaporative conditions. This implies that, even during insolation minima, evaporitic conditions were achieved and lasted only for short time intervals (i.e., at seasonal scale) and not for the entire duration of the arid portion of the insolation cycle.

Moreover, we suggest that the role of astronomical high-frequency forcing, as from lunar and solar periodicities, can be reasonably extended back to the late Miocene, or maybe even to more ancient periods, as demonstrated for the longer-term ones (precession, obliquity, eccentricity), because they are independent of local factors such as basin physiography and ocean and atmospheric circulation.

High-Frequency Cyclicity In the Mediterranean Messinian Evaporites: Evidence For Solar–Lunar Climate Forcing

  1. B. Charlotte Schreiber5
+Author Affiliations
  1. 1 Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parco Area delle Scienze, 157/a, 43124 Parma, Italy
  2. 2 Alpine Laboratory of Palaeomagnetism (ALP), Via Madonna dei Boschi 76, 12016 Peveragno (CN), Italy
  3. 3 Dipartimento di Scienze della Terra, Universitá degli Studi di Modena e Reggio Emilia, Piazza S. Eufemia 19, 41100 Modena, Italy
  4. 4 Active Cavity Radiometer Irradiance Monitor (ACRIM) Lab and Duke University, Durham, North Carolina 27708, U.S.A.
  5. 5 Department of Earth and Space Sciences, University of Washington, Seattle, Washington 98195, U.S.A.
  1. e-mail:


The deposition of varved sedimentary sequences is usually controlled by climate conditions. The study of two late Miocene evaporite successions (one halite and the other gypsum) consisting of annual varves has been carried out to reconstruct the paleoclimatic and paleoenvironmental conditions existing during the acme of the Messinian salinity crisis, ∼ 6 Ma, when thick evaporite deposits accumulated on the floor of the Mediterranean basin. Spectral analyses of these varved evaporitic successions reveal significant periodicity peaks at around 3–5, 9, 11–13, 20–27 and 50–100 yr. A comparison with modern precipitation data in the western Mediterranean shows that during the acme of the Messinian salinity crisis the climate was not in a permanent evaporitic stage, but in a dynamic situation where evaporite deposition was controlled by quasi-periodic climate oscillations with similarity to modern analogs including Quasi-Biennial Oscillation, El Niño Southern Oscillation, and decadal to secular lunar- and solar-induced cycles. Particularly we found a significant quasi-decadal oscillation with a prominent 9-year peak that is commonly also found in modern temperature records and is present in the contemporary Atlantic Multidecadal Oscillation (AMO) index and Pacific Decadal Oscillation (PDO) index. These cyclicities are common to both ancient and modern climate records because they can be associated with solar and solar-lunar tidal cycles.
During the Messinian the Mediterranean basin as well as the global ocean were characterized by different configurations than at present, in terms of continent distribution, ocean size, geography, hydrological connections, and ice-sheet volumes. The recognition of modern-style climate oscillations during the Messinian suggests that, although local geographic factors acted as pre-conditioning factors turning the Mediterranean Sea into a giant brine pool, external climate forcings, regulated by solar–lunar cycles and largely independent from local geographic factors, modulated the deposition of the evaporites.







  6. chapter on luni-solar climate effects, etc's%20Rotation%20and%20Geophysical%20Processes%20(Wiley,%202009)(ISBN%203527408754)(O)(319s)_PGp_.pdf