Search Results

You are looking at 61 - 70 of 154 items for :

  • Anthropogenic effects x
  • Journal of Atmospheric and Oceanic Technology x
  • User-accessible content x
Clear All
Jamie D. Shutler, Peter E. Land, Jean-Francois Piolle, David K. Woolf, Lonneke Goddijn-Murphy, Frederic Paul, Fanny Girard-Ardhuin, Bertrand Chapron, and Craig J. Donlon

essential for monitoring climate and predicting future scenarios. The global ocean is thought to annually absorb ~25% of anthropogenic CO 2 emissions ( Le Quéré et al. 2015 , 2014 ), and it constitutes the only true net sink for anthropogenic CO 2 over the last 200 years ( Sabine et al. 2004 ). The North Atlantic sink in particular has been shown to be highly variable ( Watson et al. 2009 ) and the mechanisms driving this variability are not well understood. Therefore, isolating and reducing the

Full access
Scott E. Giangrande and Alexander V. Ryzhkov

, suggested methodologies have certain limitations. First, the reliability of these methods is questionable when beam blockage exceeds 60%. The degree of beam blockage depends on atmospheric refractive conditions. This may result in large errors in Z calibration, particularly if anomalous propagation occurs ( Bech et al. 2003 ). In addition to large-scale terrain features, smaller-scale anthropogenic structures (e.g., towers, buildings) and nearby trees that are not accounted for by DEMs cause

Full access
David C. Rogers

-scattering properties, depending on the orientation of the crystal and alignmentof illumination and collection optics. Nevertheless, thegeneral trends in Fig. 2 are as expected, if there werea better instrument to measure or capture images ofthese small crystals (5-20 tzm), it might be possible todiscriminate the separate effects of nucleation and diffusion growth.3. D~scuss~ena. Limitations There are several limitations to the CFD technique,and they are described here. Future changes to the instrument are

Full access
David R. Brooks, Forrest M. Mims III, and Richard Roettger

1. Introduction Of all the earth’s greenhouse gases, both anthropogenic and natural, water vapor is the most important. However, the global distribution and variability of total precipitable atmospheric water vapor (PW) is still significantly uncertain. A summary of current knowledge of PW and techniques used to measure it can be found in a report published by the American Geophysical Union ( Mockler 1995 ). Space-based measurements are critical for global monitoring of PW. However, as with

Full access
Josh K. Willis, John M. Lyman, Gregory C. Johnson, and John Gilson

1. Introduction As the earth warms due to the buildup of greenhouse gasses in the atmosphere, the vast majority of the excess heat is expected to go toward warming the oceans ( Levitus et al. 2005 ; Hansen et al. 2005 ). Changes in globally integrated upper-ocean heat content anomaly (OHCA) therefore have very important implications for understanding the earth’s energy balance and the evolution of anthropogenic climate change. A large and apparently significant cooling in OHCA between 2003 and

Full access
Laura Mihai and Sabina Stefan

eruptions ( Solomon et al. 2007 ). The anthropogenic aerosol, which is mainly derived from various combustion processes (urban traffic and industrial activity), dominates in densely populated areas, very industrialized zones, and areas where intense biomass burning takes place ( Houghton et al. 2001 ). Examples of aerosol types that strongly scatter and absorb the solar radiation are organic particles, water-soluble inorganic particles (sulfates and nitrates) from biomass/fuel burnings, ammonium from

Full access
B. W. Blomquist, B. J. Huebert, S. G. Howell, M. R. Litchy, C. H. Twohy, A. Schanot, D. Baumgardner, B. Lafleur, R. Seebaugh, and M. L. Laucks

1. Introduction The direct and indirect effects of atmospheric aerosols on radiative forcing are topics of intense interest and of direct relevance to climate change. They remain the greatest source of uncertainty in global climate models ( IPCC 1995 ). Diverse origins and short lifetimes for atmospheric aerosols ensure that concentrations vary widely and fluctuate rapidly. As a result, measurements of aerosol characteristics from a wide variety of locations, during representative periods of

Full access
William R. Leslie and Kristopher B. Karnauskas

smaller island ecosystems throughout the equatorial Pacific such as Jarvis Island ( Gove et al. 2006 ) and the Gilbert Islands ( Karnauskas and Cohen 2012 ), where the strength of topographic upwelling (and thus delivery of cold, nutrient-rich water) is dependent on EUC velocity. Nonetheless, global climate models do not adequately simulate the EUC ( Karnauskas et al. 2012 ) and may, therefore, suffer in predictions of how the mean circulation and ENSO system may respond to natural and anthropogenic

Full access
Lars E. Kalnajs and Linnea M. Avallone

1. Introduction Ozone is one of the most important gases present in our environment. It is critical to all life as a filter of harmful solar ultraviolet (UV) light in the stratosphere and it is a significant component of anthropogenic pollution and a health hazard in the troposphere. Accurate and reliable measurements of ozone concentrations are vital to understanding the protective layer of stratospheric ozone, diagnosing its depletion, and monitoring its subsequent recovery. Ozone is also the

Full access
Junyong Zheng, Xinyan Mao, Xianqing Lv, and Wensheng Jiang

tidal gauge stations and T/P altimeter and further used in the DCIM. As mentioned by Talke and Jay (2020) , tidal properties are changing for natural and anthropogenic factors, such as astronomical forcing, wetland reclamation, and channel dredging, especially for shallow water and coastal areas. Therefore, a total of 37 observations from tidal gauge stations and 419 from the T/P altimeter with at least 25 km offshore (haversine distance formulation) and 10 m depth, are chosen as the effective

Restricted access