A5076544123- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Air Quality Monitoring and Forecasting
- Spectroscopy and Laser Applications
- Geology and Paleoclimatology Research
- Soil Geostatistics and Mapping
- Soil erosion and sediment transport
- Soil Carbon and Nitrogen Dynamics
- Groundwater and Isotope Geochemistry
- Ocean Acidification Effects and Responses
- Atmospheric aerosols and clouds
- Plant Water Relations and Carbon Dynamics
- Meteorological Phenomena and Simulations
- Plant responses to elevated CO2
- Cryospheric studies and observations
- Soil and Water Nutrient Dynamics
- Remote Sensing in Agriculture
- Climate variability and models
- Ionosphere and magnetosphere dynamics
- Polar Research and Ecology
- Water Quality Monitoring and Analysis
- Calibration and Measurement Techniques
- Advanced Sensor and Control Systems
- Geochemistry and Geologic Mapping
Washington State University
2003-2023
American Numismatic Society
2019-2020
NOAA Earth System Research Laboratory
2008-2019
National Oceanic and Atmospheric Administration
2009-2017
Cooperative Institute for Research in Environmental Sciences
1985-2016
University of Colorado Boulder
1985-2016
NOAA National Environmental Satellite Data and Information Service
2014
New Mexico Institute of Mining and Technology
2003
United States Geological Survey
2003
University of Nevada, Reno
2003
A large reservoir of bioavailable nitrogen (up to approximately 10(4) kilograms per hectare, as nitrate) has been previously overlooked in studies global distribution. The accumulating subsoil zones arid regions throughout the Holocene. Consideration raises estimates vadose-zone inventories by 14 71% for warm deserts and shrublands worldwide 3 16% globally. Subsoil nitrate accumulation indicates long-term leaching from desert soils, impelling further evaluation nutrient dynamics xeric...
Abstract NOAA, through the Joint Polar Satellite System (JPSS) program, in partnership with National Aeronautical and Space Administration, launched Suomi Polar‐orbiting Partnership (S‐NPP) satellite, a risk reduction data continuity mission, on 28 October 2011. The JPSS program is executing S‐NPP Calibration Validation to ensure that products comply requirements of sponsoring agencies. Ozone Mapping Profiler Suite (OMPS) consists two telescopes feeding three detectors measuring solar...
Abstract. Accurate long-term monitoring of total ozone is one the most important requirements for identifying possible natural or anthropogenic changes in composition stratosphere. For this purpose, NDACC (Network Detection Atmospheric Composition Change) UV-visible Working Group has made recommendations improving and homogenizing retrieval columns from twilight zenith-sky visible spectrometers. These instruments, deployed all over world about 35 stations, allow measuring twice daily with...
Dobson and Brewer spectrophotometer filter ozonometer data available from the World Ozone Ultraviolet Data Centre (WOUDC) were compared with satellite total ozone measurements TOMS (onboard Nimbus 7, Meteor 3, Earth Probe satellites), OMI (AURA satellite) GOME (ERS‐2 instruments. Five characteristics of difference calculated for each site instrument type: mean difference, standard deviation daily differences, monthly amplitude seasonal component range annual values. All these five...
Abstract. The primary ground-based instruments used to report total column ozone (TOC) are Brewer and Dobson spectrophotometers in separate networks. These make measurements of the UV irradiances, through a well-defined process, TOC value is produced. Inherent algorithm use laboratory-determined cross-section data set. We five sets: three sets that based on Bass Paur; one derived from Daumont, Brion Malicet (DBM); new set determined by Institute Experimental Physics (IUP), University Bremen....
The Dobson spectrophotometer is the primary standard instrument for ground‐based measurements of total column ozone. accuracy its data depends on knowledge ozone absorption coefficients used reduction. We document an error in calculations that led to set currently recommended by World Meteorological Organisation (WMO). This has little effect because empirical adjustment was applied original before were adopted WMO. provide evidence this physically sound. WMO are network without correction...
Abstract. The trends and variability of ozone are assessed over a northern mid-latitude station, Haute-Provence Observatory (OHP: 43.93° N, 5.71° E), using total column observations from the Dobson Système d'Analyse par Observation Zénithale spectrometers, stratospheric profile measurements light detection ranging (lidar), ozonesondes, Stratospheric Aerosol Gas Experiment (SAGE) II, Halogen Occultation (HALOE) Aura Microwave Limb Sounder (MLS). A multivariate regression model with...
Abstract. A comparison of retrieved total column ozone (TCO) amounts between the Pandora #34 spectrometer system and Dobson #061 spectrophotometer from direct-sun observations was performed on roof Boulder, Colorado, NOAA building. This paper, part an ongoing study, covers a 1-year period starting 17 December 2013. Both standard TCO retrievals required correction, TCOcorr = (1 + C(T)), using monthly varying effective temperature, TE, derived temperature profile climatology. The correction is...
Abstract. Three reference Dobsons (regional standard No. 064, Germany and 074, Czech Republic as well the world 083, USA) were optically characterized at Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig 2015 Metrology Institute (CMI) Prague 2016 within EMRP ENV 059 project “Traceability for atmospheric total column ozone”. Slit functions related parameters of instruments measured compared with G. M. B. Dobson's specifications his handbook. All show a predominantly good match slit...
Total ozone measurements made with Dobson spectrophotometers in polluted air are subject to errors caused by interfering trace gas species that absorb solar ultraviolet radiation. While such interference is probably non‐existent or small at the majority of instrument stations throughout world, up 25% and 5%, resulting from absorption SO 2 NO respectively, may occur occasionally a few located extremely atmospheres. Interference other absorbers, including N O 5 , H HNO 3 acetyldehyde, acetone,...
Nitrogen (N) is an essential element for life. N compounds such as ammonium ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:msubsup><mml:mrow><mml:mtext>NH</mml:mtext></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:math> ) may act electron donors, while nitrate...
Abstract. Remote sounding methods are used to derive ozone profile and column information from various ground-based satellite measurements. Vertical profiles measured in Dobson units (DU) currently retrieved based on laboratory measurements of the absorption cross-section spectrum between 270 400 nm published 1985 by Bass Paur (BP). Recently, US National Aeronautics Space Administration (NASA) European Agency (ESA) proposed using set made at Daumont 1992 (BDM) for revising Aura Ozone...
The Dobson ozone spectrophotometer is the primary ground-based instrument making measurements of total column ozone. Knowledge layer prior to satellite derived from these instruments' more than 80-year record. Internal stray light within limits its ability make accurate at high amounts and solar zenith angles (SZAs). Additionally, a recent analysis comparative observations Umkehr effect (an SZA-dependent series on clear that are used produce an vertical profile) has shown internal produces...
Abstract. Dobson and Brewer spectrophotometers are the primary, standard instruments for ground-based ozone measurements under World Meteorological Organization's (WMO) Global Atmosphere Watch program. The accuracy of data retrieval both depends on a knowledge absorption coefficients some assumptions underlying analysis. Instrumental stray light causes nonlinearity in response to at large slant paths. In addition, it affects effective extraterrestrial constants that instrument-dependent....
Dobson spectrophotometer observations conducted since the early‐to‐mid 1960s at Bismarck, North Dakota; Caribou, Maine; Boulder, Colorado; Wallops Island, Virginia; Nashville, Tennessee; and Fresno, California, 1983, have revealed record low total ozone values during 1993. The tendency toward began in May 1992, but accelerated early During January–August 1993, monthly means stations were more than 2 standard deviations below long‐term normal 72% of time 3 normals 42% time. On average,...
Umkehr observations have been routinely conducted at Japanese stations, Sapporo, Tsukuba, Kagoshima, and Naha, the Antarctic station, Syowa, for more than 50 years. data are a valuable source of information on long‐term changes in ozone vertical profile; however, record stations has evident discontinuities. The majority discontinuities related to exchange instruments calibration (for total measurements) replacement instruments. These may be difference instrument characteristics. In this...
Abstract. The United States government has operated Dobson ozone spectrophotometers at various sites, starting during the International Geophysical Year (1 July 1957 to 31 December 1958). A network of stations for long-term monitoring total column content (thickness layer) atmosphere was established in early 1960s and eventually grew 16 stations, 14 which are still operational submit data America's National Oceanic Atmospheric Administration (NOAA). Seven these sites also part Network...
Abstract. A one-time-calibrated (in December 2013) Pandora spectrometer instrument (Pan #034) has been compared to a periodically calibrated Dobson spectroradiometer (Dobson #061) co-located in Boulder, Colorado, and with two satellite instruments over 3-year period (December 2013–December 2016). The results show good agreement between Pan #034 #061 within their statistical uncertainties. Both records are corrected for ozone retrieval sensitivity stratospheric temperature variability...
Total ozone levels, which were 10–15% below normal over the U.S. during winter of 1992–1993, returned to levels slightly above 1993–1994. Investigation vertical profiles indicates that in region where severe depletion occurred 1992–1993 (25% reductions at 12–22 km), had normal, while this region, was abnormally high. Thus total also Low values believed be related heterogeneous chemistry on Pinatubo volcanic aerosol. This interpretation is strengthened by these observations since particle...
Abstract. Continuous measurements of total ozone (by Dobson spectrophotometers) across the contiguous United States began in early 1960s. Here, we analyze temporal and spatial variability trends from five US sites with long-term records. While similar changes are detected at all sites, find differences patterns on shorter timescales. In addition to standard evaluation techniques, STL-decomposition methods (Seasonal Trend decomposition time series based LOESS (LOcally wEighted Scatterplot...
A new method for describing long‐term changes in total ozone was developed so that variations on time scales greater than of the QBO may be examined. The technique fits a flexible tendency curve to data after explained have been removed. derivative is growth rate curve. average along this comparable trends reported past. Statistical uncertainty determined using bootstrap techniques. Dobson column measurements with (30+ years) records from NOAA/CMDL Cooperative Network were analyzed. Total...
The technique of producing a vertical ozone profile using ground-based observations the Umkehr effect is well established and widely used for trend analysis. Still, by Dobson spectrophotometers have documented problem: simultaneous measurements from collocated instruments produce noticeably different results, with difference shown to be dependent on solar zenith angle total ozone. Ozone profiles are thus difficult compare station station. Current investigations into level effects stray light...