Search Results
1. Introduction There is, as yet, no accepted mechanism for producing the temperature response in the lower terrestrial atmosphere to the 11-yr solar cycle forcing, although the candidates are numerous and perhaps too many [see the reviews by Gray et al. (2005) ; Gray et al. (2010) ; Haigh (2007) ]. Since the response is expected to be small given the small radiative forcing of 0.1% from solar minimum (min) to solar maximum (max), which is imbedded in a larger climate noise, many of the
1. Introduction There is, as yet, no accepted mechanism for producing the temperature response in the lower terrestrial atmosphere to the 11-yr solar cycle forcing, although the candidates are numerous and perhaps too many [see the reviews by Gray et al. (2005) ; Gray et al. (2010) ; Haigh (2007) ]. Since the response is expected to be small given the small radiative forcing of 0.1% from solar minimum (min) to solar maximum (max), which is imbedded in a larger climate noise, many of the
correlated with the TSI during the period 1800–1920 and positively correlated from 1920 to the present, and a sign reversal was observed in the apparent dependence of water levels in Lake Victoria around 1920 ( Clayton 1940 ). This phase reversal, if true, is difficult to understand on physical grounds and makes the search for the mechanism of the solar cycle response more elusive. One possibility could be that our sun is at the borderline between overcompensation and undercompensation of the dimming
correlated with the TSI during the period 1800–1920 and positively correlated from 1920 to the present, and a sign reversal was observed in the apparent dependence of water levels in Lake Victoria around 1920 ( Clayton 1940 ). This phase reversal, if true, is difficult to understand on physical grounds and makes the search for the mechanism of the solar cycle response more elusive. One possibility could be that our sun is at the borderline between overcompensation and undercompensation of the dimming
substantially between solar minima and solar maxima. In addition, photochemical processes leading to diabatic heating are enhanced at solar maxima. Higher temperatures and reduced amounts of water vapor during high solar activity should cause a significant decrease in NLC brightness and frequency of occurrence. It is therefore surprising that the solar cycle signal traced in NLC satellite records vanishes in the mid-1990s ( Fiedler et al. 2011 ; Siskind et al. 2013 ; DeLand and Thomas 2015 ; Hervig et al
substantially between solar minima and solar maxima. In addition, photochemical processes leading to diabatic heating are enhanced at solar maxima. Higher temperatures and reduced amounts of water vapor during high solar activity should cause a significant decrease in NLC brightness and frequency of occurrence. It is therefore surprising that the solar cycle signal traced in NLC satellite records vanishes in the mid-1990s ( Fiedler et al. 2011 ; Siskind et al. 2013 ; DeLand and Thomas 2015 ; Hervig et al
1. Introduction An understanding of the mechanisms of influence of the 11-yr solar cycle (SC) on climate and their inclusion in climate models is important to accurately model past climate change and predict future trends. Changes in stratospheric temperatures during the SC are believed to originate primarily from a combination of changes in the incoming solar irradiance and the resulting changes in ozone concentrations ( Haigh 1994 ; Solomon et al. 2007 ). There are other suggested mechanisms
1. Introduction An understanding of the mechanisms of influence of the 11-yr solar cycle (SC) on climate and their inclusion in climate models is important to accurately model past climate change and predict future trends. Changes in stratospheric temperatures during the SC are believed to originate primarily from a combination of changes in the incoming solar irradiance and the resulting changes in ozone concentrations ( Haigh 1994 ; Solomon et al. 2007 ). There are other suggested mechanisms
1. Introduction There is substantial evidence to suggest that changes in the solar irradiance influence variations in the temperature and circulation of Earth’s atmosphere over the 11-yr solar cycle. Many of these results are based on correlations with the 10.7-cm solar flux (e.g., Labitzke and van Loon 1995 ; van Loon and Shea 1999 ) or the wavelength-integrated total solar irradiance (TSI) [see Haigh (2003) and references therein]. While TSI is a good indicator of the total solar forcing
1. Introduction There is substantial evidence to suggest that changes in the solar irradiance influence variations in the temperature and circulation of Earth’s atmosphere over the 11-yr solar cycle. Many of these results are based on correlations with the 10.7-cm solar flux (e.g., Labitzke and van Loon 1995 ; van Loon and Shea 1999 ) or the wavelength-integrated total solar irradiance (TSI) [see Haigh (2003) and references therein]. While TSI is a good indicator of the total solar forcing
1. Introduction The quasi-periodicity of the 11-yr sunspot cycle has been well documented by the international sunspot number (SSN) record from 1755 to present (the so-called modern era of recording sunspot activity). Prior to this modern period, the telescope was used to observe sunspots (beginning in 1610); however, there was a prominent period of solar inactivity known as the Maunder minimum (1645–1715). Historically, this quiet period (QP) has been attributed to a cold era known as the
1. Introduction The quasi-periodicity of the 11-yr sunspot cycle has been well documented by the international sunspot number (SSN) record from 1755 to present (the so-called modern era of recording sunspot activity). Prior to this modern period, the telescope was used to observe sunspots (beginning in 1610); however, there was a prominent period of solar inactivity known as the Maunder minimum (1645–1715). Historically, this quiet period (QP) has been attributed to a cold era known as the
period of the QBO averages about 28 months but is known to have interannual variations of a few months about the average. While it is not surprising for this phenomenon arising from wave–mean flow interaction to have a variable period, the possibility that it could be affected by external forcing such as the 11-yr solar cycle (SC) is intriguing. Using radiosonde data from the Free University of Berlin (FUB) near the equator at 45 hPa between 1956 and 1996, Salby and Callaghan (2000) found that the
period of the QBO averages about 28 months but is known to have interannual variations of a few months about the average. While it is not surprising for this phenomenon arising from wave–mean flow interaction to have a variable period, the possibility that it could be affected by external forcing such as the 11-yr solar cycle (SC) is intriguing. Using radiosonde data from the Free University of Berlin (FUB) near the equator at 45 hPa between 1956 and 1996, Salby and Callaghan (2000) found that the
1. Introduction The possible influence of the 11-yr solar cycle on the tropical Pacific Ocean has received considerable attention in recent years (e.g., Gray et al. 2010 ). Yet, it remains under debate mainly due to the shortness of reliable observations of sea surface temperatures (SSTs), which cover only a few solar cycles ( Deser et al. 2010 ). Besides this, modes of natural variability, such as the El Niño–Southern Oscillation (ENSO), and external forcings, such as volcanic eruptions, may
1. Introduction The possible influence of the 11-yr solar cycle on the tropical Pacific Ocean has received considerable attention in recent years (e.g., Gray et al. 2010 ). Yet, it remains under debate mainly due to the shortness of reliable observations of sea surface temperatures (SSTs), which cover only a few solar cycles ( Deser et al. 2010 ). Besides this, modes of natural variability, such as the El Niño–Southern Oscillation (ENSO), and external forcings, such as volcanic eruptions, may
action oscillator shared by the interannual and decadal oscillation ( Knutson and Manabe 1998 ; White et al. 2003 ). For the externally forced TPDV, Power et al. (2021) reviewed the tropical Pacific responses from both anthropogenic forcing and volcanic eruptions. However, the 11-yr solar cycle forcing, as a periodical external forcing, is presumed to have a smaller influence than other forcings and is almost ignored in most TPDV studies because of the small decadal changes in solar irradiation
action oscillator shared by the interannual and decadal oscillation ( Knutson and Manabe 1998 ; White et al. 2003 ). For the externally forced TPDV, Power et al. (2021) reviewed the tropical Pacific responses from both anthropogenic forcing and volcanic eruptions. However, the 11-yr solar cycle forcing, as a periodical external forcing, is presumed to have a smaller influence than other forcings and is almost ignored in most TPDV studies because of the small decadal changes in solar irradiation
1. Introduction Efforts to detect a solar 11-yr cycle influence in sea surface temperatures (SSTs) have found differing signals in the tropical Pacific Ocean. Van Loon et al. (2007) , van Loon and Meehl (2008) , Meehl et al. (2008) , and Meehl and Arblaster (2009) detected a strong La Niña–like cooling of the eastern Pacific whereas White et al. (1997) , Tung and Zhou (2010) , and Roy and Haigh (2010) found weak warming in the same region. The apparent disparity has been explained as
1. Introduction Efforts to detect a solar 11-yr cycle influence in sea surface temperatures (SSTs) have found differing signals in the tropical Pacific Ocean. Van Loon et al. (2007) , van Loon and Meehl (2008) , Meehl et al. (2008) , and Meehl and Arblaster (2009) detected a strong La Niña–like cooling of the eastern Pacific whereas White et al. (1997) , Tung and Zhou (2010) , and Roy and Haigh (2010) found weak warming in the same region. The apparent disparity has been explained as
