Solar Influence on Global and Regional Climates     

Mike Lockwood 《Surveys in Geophysics》2012,33(3-4):503-534

The literature relevant to how solar variability influences climate is vast—but much has been based on inadequate statistics and non-robust procedures. The common pitfalls are outlined in this review. The best estimates of the solar influence on the global mean air surface temperature show relatively small effects, compared with the response to anthropogenic changes (and broadly in line with their respective radiative forcings). However, the situation is more interesting when one looks at regional and season variations around the global means. In particular, recent research indicates that winters in Eurasia may have some dependence on the Sun, with more cold winters occurring when the solar activity is low. Advances in modelling “top-down” mechanisms, whereby stratospheric changes influence the underlying troposphere, offer promising explanations of the observed phenomena. In contrast, the suggested modulation of low-altitude clouds by galactic cosmic rays provides an increasingly inadequate explanation of observations.  相似文献   

Tests of Sunspot Number Sequences: 1. Using Ionosonde Data     

M. Lockwood  C. J. Scott  M. J. Owens  L. Barnard  D. M. Willis 《Solar physics》2016,291(9-10):2785-2809

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Photometric variability of Uranus and Neptune, 1950-2004     

G.W. Lockwood  Miko?aj Jerzykiewicz 《Icarus》2006,180(2):442-452

Photoelectric intermediate-band b and y photometry of Uranus and Neptune obtained at each apparition since 1972, combined with broadband B and V photometry from 1950 to 1966, provide a record of planetary variability covering 2/3 of Uranus' 84-year orbital period and 1/3 of Neptune's 165-year orbital period. Almost all of the data were obtained with a dedicated 21-inch photometric telescope at Lowell Observatory. The data are quite homogeneous, with yearly uncertainties typically smaller than 0.01 mag (1%). The lightcurve of Uranus is sinusoidal with peaks at the solstices. The b amplitude slightly exceeds the expected 0.025 mag purely geometrical variation caused by oblateness as the planetary aspect changes, seen from Earth. The y amplitude is several times larger, indicating a strong equator-to-pole albedo gradient. The lightcurve is asymmetrical with respect to southern solstice, evidence of a temporal albedo variation. Neptune's post-1972 lightcurve exhibits a generally rising trend since 1972 interpreted by Sromovsky et al. [Sromovsky, L.A., Fry, P.M., Limaye, S.S., Baines, K.H., 2003. Icarus 163, 256-261] as a lagged sinusoidal seasonal variation. However, the 1950-1966 lightcurve segments are much fainter than expected, missing the proposed seasonal sinusoid by 0.1-0.2 mag. A major unknown component is therefore needed to explain Neptune's long-term variation. The apparent relationship between Neptune's brightness variation and the 11-year solar cycle seen in cycles 21-22 (1972-1996) has apparently now faded away. Further interpretation of the data in this paper will be found in a companion paper by Hammel and Lockwood [Hammel, H.B., Lockwood, G.W., 2005. Icarus. Submitted for publication].  相似文献   

Tests of Sunspot Number Sequences: 3. Effects of Regression Procedures on the Calibration of Historic Sunspot Data     

M. Lockwood  M. J. Owens  L. Barnard  I. G. Usoskin 《Solar physics》2016,291(9-10):2829-2841

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A New Calibrated Sunspot Group Series Since 1749: Statistics of Active Day Fractions     

I. G. Usoskin  G. A. Kovaltsov  M. Lockwood  K. Mursula  M. Owens  S. K. Solanki 《Solar physics》2016,291(9-10):2685-2708

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Rapid nutrient load reduction during infiltration of managed aquifer recharge in an agricultural groundwater basin: Pajaro Valley,California     

C. M. Schmidt  A. T. Fisher  A. Racz  C. G. Wheat  M. Los Huertos  B. Lockwood 《水文研究》2012,26(15):2235-2247

Artificial recharge of groundwater is an increasingly important method for augmenting groundwater supply and can have a positive or negative influence on the quality of water resources. We instrumented a managed aquifer recharge (MAR) pond in central coastal California to assess how patterns of infiltration and recharge affect the load of nitrate delivered to the underlying aquifer. The concentration of nitrate in infiltrating water consistently decreased during passage through the first metre of subsurface soils. Enrichment of ¹⁸O and ¹⁵ N in the residual nitrate in infiltrating water proceeded in a ratio of 1:2, indicating that denitrification plays a significant role in the quantitative reduction of nutrients exported during infiltration through shallow soils. The extent and rate of nitrate removal was spatially and temporally variable across the bottom of the recharge pond, with 30% to 60% of the nitrate load being removed over the first 6 weeks of managed aquifer recharge operation. During the period of highest N loading to the system, when the average infiltration rate was > 1 m/day, the recharge pond achieved a load reduction efficiency of 7 kg NO₃^?‐N/day/ha, which compares favourably to nitrate load reductions achieved by treatment wetlands. Groundwater mounding and water composition below the recharge pond suggest that recharge and subsequent lateral transport occur heterogeneously in the underlying aquifer. Nitrate concentrations in the aquifer following infiltration were lowered primarily by dilution, with little evidence for additional denitrification occurring in the aquifer in comparison to high rates documented during shallow infiltration. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Simulation and Analysis of Conjunctive Use with MODFLOW's Farm Process     

R. T. Hanson  W. Schmid  C. C. Faunt  B. Lockwood 《Ground water》2010,48(5):674-689

The extension of MODFLOW onto the landscape with the Farm Process (MF-FMP) facilitates fully coupled simulation of the use and movement of water from precipitation, streamflow and runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. This allows for more complete analysis of conjunctive use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” comprised of one or more model cells that can represent a single farm, a group of farms, or other hydrologic or geopolitical entities. Simulation of micro-agriculture in the Pajaro Valley and macro-agriculture in the Central Valley are used to demonstrate the utility of MF-FMP. For Pajaro Valley, the simulation of an aquifer storage and recovery system and related coastal water distribution system to supplant coastal pumpage was analyzed subject to climate variations and additional supplemental sources such as local runoff. For the Central Valley, analysis of conjunctive use from different hydrologic settings of northern and southern subregions shows how and when precipitation, surface water, and groundwater are important to conjunctive use. The examples show that through MF-FMP's ability to simulate natural and anthropogenic components of the hydrologic cycle, the distribution and dynamics of supply and demand can be analyzed, understood, and managed. This analysis of conjunctive use would be difficult without embedding them in the simulation and are difficult to estimate a priori.  相似文献   

A simple method for analysing trends in recruitment     

Lockwood  Stephen J. 《ICES Journal of Marine Science》1987,43(3):279-284

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Effect of chlorine on unsaturated lipids     

R.J. Morris  F. Culkin  A.P.M. Lockwood  A.C. Jenson 《Marine pollution bulletin》1982,13(11):390-391

In this note evidence is presented which suggests that an initial effect of chlorine treatment on fouling organisms could involve a deleterious halogenation of membrane lipid components.  相似文献   

The identification of some lipophilic contaminants in the gill neutral lipids of Gammarus duebeni     

R.J. Morris  M.E. Dawson  A.P.M. Lockwood 《Marine pollution bulletin》1982,13(1):13-18

Two experimental populations of Gammarus duebeni have been found to contain high levels of what appeared to be pollutants in their gill neutral lipids. Detailed analysis, involving capillary gas chromatography-mass spectrometry, confirmed the presence of hydrocarbons, a plasticizer and silicone compounds. Such a localized concentration of lipophilic pollutants in a tissue such as the gills might be sufficient to influence the metabolism of the whole organism even though the total body burden is low.  相似文献