Tag Archives: climate changes

South China Sea coral confirm Little Ice Age, Medieval Warming

Wenfeng Deng, Xi Liu, Xuefei Chen, Gangjian Wei, Ti Zeng, Luhua Xie, Jian-xin Zhao. A comparison of the climates of the Medieval Climate Anomaly, Little Ice Age, and Current Warm Period reconstructed using coral records from the northern South China Sea. Journal of Geophysical Research: Oceans 122(1):264-275 DOI:10.1002/2016jC012458

For the global oceans, the characteristics of high-resolution climate changes during the last millennium remain uncertain because of the limited availability of proxy data. This study reconstructs climate conditions using annually resolved coral records from the South China Sea (SCS) to provide new insights into climate change over the last millennium. The results indicate that the climate of the Medieval Climate Anomaly (MCA, AD 900–1300) was similar to that of the Current Warm Period (CWP, AD 1850-present), which contradicts previous studies. The similar warmth levels for the MCA and CWP have also been recorded in the Makassar Strait of Indonesia, which suggests that the MCA was not warmer than the CWP in the western Pacific and that this may not have been a globally uniform change. Hydrological conditions were drier/saltier during the MCA and similar to those of the CWP. The drier/saltier MCA and CWP in the western Pacific may be associated with the reduced precipitation caused by variations in the Pacific Walker Circulation. As for the Little Ice Age (LIA, AD 1550–1850), the results from this study, together with previous data from the Makassar Strait, indicate a cold and wet period compared with the CWP and the MCA in the western Pacific. The cold LIA period agrees with the timing of the Maunder sunspot minimum and is therefore associated with low solar activity. The fresher/wetter LIA in the western Pacific may have been caused by the synchronized retreat of both the East Asian Summer Monsoon and the Australian Monsoon.

Solar activity affects all surface geophysical systems

Yavor Chapanov, Cyril Ron and Jan Vondrak.   Decadal Cycles of Earth Rotation, Mean Sea Level and Climate, Excited by Solar Activity. Acta Geodyn. Geomater., Vol. 14, No. 2 (186), 241–250, 2017  DOI: 10.13168/AGG.2017.0007 

The solar activity affects all surface geosystems, including weather and climate indices, winds, rains, snow covers, mean sea level, river streamflows and other hydrological cycles. The mean sea level and polar ice changes cause common variations of the principal moments of inertia and Earth rotation with decadal, centennial and millennial periods. The mean sea level, Earth rotation
and climate indices have also some oscillations with periods below 40 years, whose origin is not connected with the known tidal and solar effects. The shape of solar cycles is rather different from sinusoidal form, so they affect geosystems by many short-term harmonics. A possible solar origin of decadal variations of Earth rotation, mean sea level and climate indices is investigated by the harmonics of Jose, de Vries and Suess cycles with centennial periods of 178.7, 208 and 231 years. The common decadal cycles of solar-terrestrial influences are investigated by long time series of Length of Day (LOD), Mean Sea Level (MSL) variations at Stockholm, ElNiño/Southern Oscillation (ENSO), temperature and precipitation over Eastern Europe, Total Solar Irradiance (TSI), Wolf’s Numbers Wn and North-South solar asymmetry. A good agreement exists between the decadal cycles of LOD, MSL, climate and solar indices whose periods are between 12-13, 14-16, 16-18 and 28-33 years. The new linear models of the decadal
common Earth and solar cycles may help for long term forecasts of many global and local changes.

Solar Activity Influences Atmospheric Ozone, Climate

Hema Bisht, Bimal Pande, Ramesh Chandra, and Seema Pande. Statistical study of different solar activity features with total column ozone at two hill stations of Uttarakhand. Indian Journal of Radio and Space Physics. Vol. 43,
August-October 2014, pp 251-262.

This paper presents a statistical study of different solar activity features (DSAF), viz. sunspot number (SN), solar active prominences (SAP), solar flares (SF) and solar proton events (SPE) with total column ozone (TCO) amount using 28 years (1986-2013) data. The ozone data has been taken for two hill stations in Uttarakhand, viz. Nainital (29deg 23min N, 79deg 27min E) and Mussoorie (30deg 27min N, 78deg 06min E). The study reveals a positive correlation between yearly averaged TCO and DSAF. The value of linear correlation coefficient (r) for TCO-Nainital with SN, SAP, SF, and SPE is found to be 0.51, 0.30, 0.49, and 0.54, respectively and for TCO-Mussoorie with SN, SAP, SF, SPE is found to be 0.45, 0.27, 0.44, and 0.51, respectively. This supports the fact that solar activity features contribute to the production of ozone. Also the trend in TCO over both the stations annually, monthly and seasonally has been studied. A negative trend is observed indicating a decrease in the ozone concentration over these stations in given time period.

Equilibrium Climate Sensitivity Cs = 0.7 degC

Hermann Harde. Radiation Transfer Calculations and Assessment of Global Warming by CO2. International Journal of Atmospheric Sciences Volume 2017, Article ID 9251034, 30 pages https://doi.org/10.1155/2017/9251034

We present detailed line-by-line radiation transfer calculations, which were performed under different atmospheric conditions for the most important greenhouse gases water vapor, carbon dioxide, methane, and ozone. Particularly cloud effects, surface temperature variations, and humidity changes as well as molecular lineshape effects are investigated to examine their specific influence on some basic climatologic parameters like the radiative forcing, the long wave absorptivity, and back-radiation as a function of an increasing CO2 concentration in the atmosphere. These calculations are used to assess the CO2 global warming by means of an advanced two-layer climate model and to disclose some larger discrepancies in calculating the climate sensitivity. Including solar and cloud effects as well as all relevant feedback processes our simulations give an equilibrium climate sensitivity of 𝐶𝑆 = 0.7∘ C (temperature increase at doubled CO2) and a solar sensitivity of 𝑆𝑆 = 0.17∘ C (at 0.1% increase of the total solar irradiance). Then CO2 contributes 40% and the Sun 60% to global warming over the last century.

Solar Cycle Impacts Earth’s Weather and Climate

Lesley J. Gray, Will Ball and Stergios Misios. Solar Influences on climate over the Atlantic / European SectorRadiation Processes in the Atmosphere and Ocean (IRS2016) AIP Conf. Proc. 1810, 020002-1–020002-8; doi: 10.1063/1.4975498

There is growing evidence that variability associated with the 11-year solar cycle has an impact at the Earth’s surface and influences its weather and climate. Although the direct response to the Sun’s variability is extremely small, a number of different mechanisms have been suggested that could amplify the signal, resulting in regional signals that are much larger than expected. In this paper the observed solar cycle signal at the Earth’s surface is described, together with proposed mechanisms that involve modulation via the total incoming solar irradiance and via modulation of the ultraviolet part of the solar spectrum that influences ozone production in the stratosphere.

California Drowning in the Swamp of SB 32 Emission Goals

“The emissions reduction leadership role for California championed by the L A Times is touted despite the fact that our state doesn’t have the foggiest idea of how it can achieve its SB 32 emissions goals nor does it have any idea of how many tens of billions it will cost nor care at all about how the state will end up dictating how all Californians must live their lives.” click here

Dilbert Wins Climate Debate!

“A communications group at Yale University has put out a video that seems to be a rebuttal to a Dilbert cartoon by Scott Adams poking fun at climate scientists and their misplaced confidence in models. The video is full of impressive-looking scientists talking about charts and data and whatnot. It probably cost a lot to make and certainly involved a lot of time and effort. The most amazing thing, however, is that it actually proves the points being made in the Dilbert cartoon. Rather than debunking the cartoon, the scientists acted it out in slow motion.” click here