News Article | November 18, 2015
In spite of the coordinated attacks in Paris on Nov. 13, the United Nations Framework Convention on Climate Change (UNFCCC) will proceed as scheduled on Nov. 30 to Dec. 11, 2015. One of the proposals to combat climate change comes from the University of Washington's Joint Institute for the Study of the Atmosphere and Ocean (JISAO) which believes that climate engineering techniques can be humanity's weapon against the continuing increase in temperature and extreme weather worldwide. More specifically, JISAO scientists believe that misting the clouds with saltwater, a cloud reflectivity modification technique would help in brightening up the clouds and aid it with reflecting sunlight back to lessen amount of heat that will enter through the atmosphere. "If you can reflect away some of that radiation... you will cool the planet," Tom Ackerman, an atmospheric scientist at JISAO said. Ackerman directs this specific research on climate change at JISAO. "People have this sort of innate response that somehow we're tinkering with Mother Nature, and we shouldn't be doing that," Ackerman said, explaining why there have been oppositions to such plans. However, he also said that humans already emit carbon dioxide into the atmosphere due to fossil fuel use. Clive Hamilton, an Australian ethicist, argued against using Geoengineering as a remedy to climate problems. He believes that the humanity's attitude is what needs to be changed in order to reach a long term solution. "Technofixes-technical solutions to social problems-are appealing when we are unwilling to change ourselves and our social institutions... There is a long history of technological interventions entrenching the behaviors that created the problem," he wrote in an article in March. The Geoengineering techniques for climate change will be discussed in the Paris Climate Change Conference as a Plan B, with Plan A involving agreements to reduce carbon emissions in developing countries.
Shi L.,National Oceanic and Atmospheric Administration |
Matthews J.L.,National Oceanic and Atmospheric Administration |
Matthews J.L.,North Carolina State University |
Ho S.-P.,University Corporation for Atmospheric Research |
And 2 more authors.
Remote Sensing | Year: 2016
A project for deriving temperature and humidity profiles from High-resolution Infrared Radiation Sounder (HIRS) observations is underway to build a long-term dataset for climate applications. The retrieval algorithm development of the project includes a neural network retrieval scheme, a two-tiered cloud screening method, and a calibration using radiosonde and Global Positioning System Radio Occultation (GPS RO) measurements. As atmospheric profiles over high surface elevations can differ significantly from those over low elevations, different neural networks are developed for three classifications of surface elevations. The significant impact from the increase of carbon dioxide in the last several decades on HIRS temperature sounding channel measurements is accounted for in the retrieval scheme. The cloud screening method added one more step from the HIRS-only approach by incorporating the Advanced Very High Resolution Radiometer (AVHRR) observations to assess the likelihood of cloudiness in HIRS pixels. Calibrating the retrievals with radiosonde and GPS RO reduces biases in retrieved temperature and humidity. Except for the lowest pressure level which exhibits larger variability, the mean biases are within ±0.3 °C for temperature and within ±0.2 g/kg for specific humidity at standard pressure levels, globally. Overall, the HIRS temperature and specific humidity retrievals closely align with radiosonde and GPS RO observations in providing measurements of the global atmosphere to support other relevant climate dataset development. © 2016 by the authors.
Carter B.R.,Joint Institute for the Study of the Atmosphere and Ocean |
Carter B.R.,National Oceanic and Atmospheric Administration |
Frolicher T.L.,ETH Zurich |
Dunne J.P.,Princeton University |
And 3 more authors.
Global Biogeochemical Cycles | Year: 2016
We use a large initial condition suite of simulations (30 runs) with an Earth system model to assess the detectability of biogeochemical impacts of ocean acidification (OA) on the marine alkalinity distribution from decadally repeated hydrographic measurements such as those produced by the Global Ship-Based Hydrographic Investigations Program (GO-SHIP). Detection of these impacts is complicated by alkalinity changes from variability and long-term trends in freshwater and organic matter cycling and ocean circulation. In our ensemble simulation, variability in freshwater cycling generates large changes in alkalinity that obscure the changes of interest and prevent the attribution of observed alkalinity redistribution to OA. These complications from freshwater cycling can be mostly avoided through salinity normalization of alkalinity. With the salinity-normalized alkalinity, modeled OA impacts are broadly detectable in the surface of the subtropical gyres by 2030. Discrepancies between this finding and the finding of an earlier analysis suggest that these estimates are strongly sensitive to the patterns of calcium carbonate export simulated by the model. OA impacts are detectable later in the subpolar and equatorial regions due to slower responses of alkalinity to OA in these regions and greater seasonal equatorial alkalinity variability. OA impacts are detectable later at depth despite lower variability due to smaller rates of change and consistent measurement uncertainty. ©2016. The Authors.
Chang B.X.,University of Washington |
Chang B.X.,Princeton University |
Chang B.X.,Joint Institute for the Study of the Atmosphere and Ocean |
Rich J.R.,Brown University |
And 6 more authors.
Limnology and Oceanography | Year: 2014
The three major oxygen deficient zones (ODZs) of the world oceans (eastern tropical North and South Pacific (ETNP and ETSP, respectively), and Arabian Sea (AS) host the vast majority of pelagic fixed nitrogen (N) loss and up to half of total marine N loss. The input of organic matter is an important control on the absolute and relative importance of the two main pathways of N removal (denitrification and anammox). We investigated the response of N loss in the ETSP and AS ODZs to additions of organic matter in the form of glucose and naturally derived dissolved and particulate organic matter (DOM and POM, respectively). In the ETSP ODZ, the addition of glucose stimulated denitrification (1.6-fold increase after 5 d) but not anammox (14-fold decrease after 5 d). In the AS ODZ, only POM, not DOM, significantly increased rates of denitrification at the base of the oxycline (5.4-6.4-fold increase after 2 d), but not at the secondary nitrite maximum. These results suggest that denitrification was generally limited by organic matter supply at the time of this study in both the ETSP and AS ODZs, although the lability of the organic matter supplied was important. Interestingly, 15N2 produced in ETSP and AS incubations was not binomially distributed relative to the reactants after the influence of anammox was taken into account, suggesting an unknown production mechanism or pathway of N removal. © 2014, by the Association for the Sciences of Limnology and Oceanography, Inc.
Giddings S.N.,University of Washington |
Giddings S.N.,University of California at San Diego |
Maccready P.,University of Washington |
Hickey B.M.,University of Washington |
And 7 more authors.
Journal of Geophysical Research: Oceans | Year: 2014
Harmful algal blooms (HABs) pose a significant threat to human and marine organism health, and negatively impact coastal economies around the world. An improved understanding of HAB formation and transport is required to improve forecasting skill. A realistic numerical simulation of the US Pacific Northwest region is used to investigate transport pathways from known HAB formation hot spots, specifically for Pseudo-nitzschia (Pn), to the coast. We show that transport pathways are seasonal, with transport to the Washington (WA) coast from a northern source (the Juan de Fuca Eddy) during the summer/fall upwelling season and from a southern source (Heceta Bank) during the winter/early spring due to the predominant wind-driven currents. Interannual variability in transport from the northern source is related to the degree of wind intermittency with more transport during years with more frequent relaxation/downwelling events. The Columbia River plume acts to mitigate transport to the coast as the plume front blocks onshore transport. The plume's influence on alongshore transport is variable although critical in aiding transport from the southern source to the WA coast via plume entrainment. Overall transport from our simulations captures most observed Pn HAB beach events from 2004 to 2007 (characterized by Pseudo-nitzschia cell abundance); however, numerous false positives occur. We show that incorporating phytoplankton biomass results from a coupled biogeochemical model reduces the number of false positives significantly and thus improves our Pn HAB predictions. Key Points Potential PNW HAB transport is seasonal, consistent with regional currents Transport is blocked by the Columbia River plume unless entrainment occurs A coupled hydrodynamic-biological model can predict PNW Pn HAB transport paths © 2014. American Geophysical Union. All Rights Reserved.