Abstract. We identify solar cycle signals in 155 years of global sea level pressure (SLP) and sea surface temperature (SST) data using a multiple linear regression approach. In SLP we find in the North Pacific a statistically significant weakening of the Aleutian Low and a northward shift of the Hawaiian High in response to higher solar activity, confirming the results of previous authors using different techniques. We also find a weak but broad reduction in pressure across the equatorial Pacific. In SST we identify a weak El Niño-like pattern in the tropics for the 155 year period, unlike the strong La Niña-like signal found recently by some other authors. We show that the latter have been influenced by the technique of compositing data from peak years of the sunspot cycle because these years have often coincided with the negative phase of the ENSO cycle. Furthermore, the date of peak annual sunspot number (SSN) generally falls a year or more in advance of the broader maximum of the 11-year solar cycle so that analyses which incorporate data from all years represent more coherently the difference between periods of high and low solar activity on these timescales. We also find that studies of the solar signal in SST over the second half of the 20th century may alias as ENSO signal if this is not properly taken into account.
We identify solar cycle signals in 155 years of global sea level pressure (SLP) and sea surface temperature (SST) data using a multiple linear regression approach. In SLP we find in the North Pacific a statistically significant weakening of the Aleutian Low and a northward shift of the Hawaiian High in response to higher solar activity, confirming the results of previous authors using different techniques. We also find a weak but broad reduction in pressure across the equatorial Pacific. In SST we identify a weak El Niño-like pattern in the tropics for the 155 year period, unlike the strong La Niña-like signal found recently by some other authors. We show that the latter have been influenced by the technique of compositing data from peak years of the sunspot cycle because these years have often coincided with the negative phase of the ENSO cycle. Furthermore, the date of peak annual sunspot number (SSN) generally falls a year or more in advance of the broader maximum of the 11-year solar cycle so that analyses which incorporate data from all years represent more coherently the difference between periods of high and low solar activity on these timescales. We also find that studies of the solar signal in SST over the second half of the 20th century may alias as ENSO signal if this is not properly taken into account.
An overview of the processes involved in determining the Sun's influence on climate is presented in the form of a flow chart. Evidence and hypotheses concerning the combined influences of the El Niño-Southern Oscillation, the Quasi-Biennial Oscillation and the Solar Cycle on the Hadley and Walker circulations are discussed in the context of atmosphere-ocean coupling, focussing on the Pacific region. It is shown that the Sun plays a crucial role in ocean-atmosphere coupling but that this coupling appears to be disturbed during the latter half of the 20th century, probably related to climate change. The identification of a solar influence can lead to improved skill in prediction so as to better inform communities to address/mitigate some of the crucial issues that are associated with climate change.
The Hispanic Health and Nutrition Examination Survey (HHANES) was the first special population survey undertaken by the National Center for Health Statistics. The HHANES was designed to assess the health and nutritional status and needs of Mexican Americans, mainland Puerto Ricans and Cuban Americans. Data were collected using five data collection techniques: direct physical examinations, diagnostic testing, anthropometry, laboratory analyses, and interviews. Unlike other surveys conducted by the National Center for Health Statistics, the HHANES was not designed as a national survey. The HHANES was a survey of three Hispanic subgroups of the population in selected areas of the United States with a survey universe that included approximately 76 percent of the 1980 Hispanic-origin population in the United States. This article discusses statistical issues that should be addressed by researchers when analyzing HHANES data. Specifically, analysts need to account for the complex sample design, nonresponse bias, potential non-coverage bias, and the regional nature of the HHANES sample.
The solar cycle signal in sea level pressure during 1856-2007 is analyzed. Using composites of data from January-February in solar cycle peak years the strong positive signal in the region of the Aleutian low, found by previous authors, is confirmed. It is found, however, that signals in other regions of the globe, particularly in the South Pacific, are very sensitive to the choice of reference climatology. Also investigated is the relationship between solar activity and sea surface temperatures in the tropical eastern Pacific. A marked overall association of higher solar activity with colder temperatures in the tropical Pacific that is not restricted to years of peak sunspot number is noted. The ENSO-like variation following peak years that has been suggested by other authors is not found as a consistent signal. Both the SLP and SST signals vary coherently with the solar cycle and neither evolves on an ENSO-like time scale. The solar signals are weaker during the period spanning approximately 1956-97, which may be due to masking by a stronger innate ENSO variability at that time.
The teleconnections of different types of El Niño Southern Oscillation (ENSO) to the Indian summer monsoon are investigated in observations and models. We find that, not all regions in India are strongly affected by ENSO, so we focus on two regional teleconnections: (1) a negative rainfall signal around central north east (CNE) India and ‘hilly’ region during El Niño (and vice versa for La Niña) and (2) similar signal for parts of southern peninsular region. Using correlations, it is found that >50% of the fifth phase of the Coupled Model Inter‐comparison Project models capture these two regional teleconnections, with first captured by >80% of models. Furthermore, using a compositing technique that may better capture asymmetries in response to warm and cold events, the authors find that most models again agree on the sign of regional teleconnection around the CNE and hilly region, suggesting the robustness of ENSO signal in that region. The peninsular teleconnection is less well simulated in models. We find a clear connection between the Walker circulation and Indian summer monsoon rainfall around central India in models.
The teleconnection between the El Niño–Southern Oscillation (ENSO) and Indian summer monsoon rainfall is analysed in CMIP5 simulations in both historical and future scenario. A subset of models is selected, based on their ability to simulate mean rainfall and the ENSO teleconnection in the historical simulations, and those are used to examine future predictions in the central northeast region of India. For canonical and mixed canonical Modoki ENSO events, the rainfall teleconnection is spatially extended over most of India in the future. For pure Modoki ENSO events, the teleconnection disappears, and practically no influence is detected in any parts of India. Analysis of zonal wind at 200 mb indicates that for the Modoki events, there is a larger spread of changes across the models, while for canonical events there is more inter‐model consistency. A rainfall decomposition technique reveals a battle between changes in circulation which act to weaken the rainfall teleconnection and changes in moisture change which act to strengthen it. The picture is most consistent in the sub‐ensemble of models in the central northeast region but less consistent in regions covering southern India.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.