The height of the mean sea surface above the reference ellipsoid is a time independent reference model that can be removed from radar altimeter measurements to isolate the oceanographic signals. This document explains how the CLS mean sea surface model is updated at short wavelengths using the 30-years of sea surface slope measurements that have been archived and computed at Scripps Institution of Oceanography. The data are available at https://topex.ucsd.edu/pub/ .
This report documents changes to the CO2 calibration scale of the Scripps O2 program to bring it in line with the SIO X12 scale. The update involves new assignments on six primary CO2 reference gases used by the O2 program, which were used to assign cubic coefficients to the instrument response function for the Siemens CO2 analyzer used by the O2 program. The new assignments correct for drift in the CO2 concentration of these cylinders which is now well resolved. The update also entails changing the functional form for the instrument response function for the Licor CO2 analyzer, also used by the Scripps O2 program, from a cubic to a double inverse hyperbole. This update impacts all data from the Scripps O2 program from program inception onwards. We designate the updated CO2 scale as the VH344-2020 scale. The previous scale, which had no designation, is now called the VH344-2015 scale. The changes from the VH344-2015 to VH433-2020 scales involve changes at the level of a few tenths of a ppm, typically towards higher CO2 . This report also compares the VH344-2020 scale to the NOAA X2007 scale based on tanks provided by Britt Stephens of the National Center of Atmospheric Research.
We report here on several details that apply to updating the primary in situ Mauna Loa CO2 record from the Scripps CO2 program to the X12 calibration scale from the previous X08A scale. The update incorporates revised determinations of the primary reference gases on the constant-volume mercury-column manometer (CMM) based on improved assessments of manometer volumes and other parameters (Keeling et al., 2016). The changes, which impact data only after 1974, are typically of order 0.1 to 0.2 ppm or less at ambient concentrations. In this update, we also incorporate two changes that are unrelated to the revised manometric determinations and are relevant only for the in situ Mauna Loa record but not relevant for flask data from Mauna Loa or other stations. The first involves a reassignment of a secondary calibration cylinder used for the in situ Mauna Loa measurements starting April 2015. The second involves eliminating a +0.12 ppm adjustment that had been applied only to the in situ Mauna Loa record to correct for offset between flasks and the continuous analyzer.
This report details calibration method for measurements of 13C/12C and 18O/16O ratios of atmospheric CO2 by the Scripps CO2 program from 1992-2018. The method depends principally on repeat analysis of CO2 derived from a suite of high-pressure gas cylinders filled with compressed natural air pumped at La Jolla. The first set of three cylinders were given isotopic assignments in 1994 based on comparisons with material artifacts NBS16, NBS17, and NBS19. Six cylinders subsequently brought into service were assigned values by comparing directly or indirectly with this first set. A tenth cylinder with natural CO2 in air was obtained from MPI Jena. Aliquots of CO2 from these cylinders, which serve as secondary standards, were extracted into heat-sealed glass ampoules (“flame-off tubes”) before introduction into the mass spectrometer. Some of these ampoules have been stored for many years before analysis, allowing long-term isotopic drift of the cylinders to be quantified. All secondary standards contain natural levels of N2O. The method corrects for any detected drift, while also applying corrections for N2O interference, for isobaric interferences (“Craig correction”) and for an inter-lab offset identified in early comparisons with the isotope lab at the University of Groningen. The Jena cylinder was found to be drifting upwards in δ18O at a rate of +0.10 ‰ per decade. Five of the other nine cylinders were found to be drifting downwards in δ18O, δ13C, or both, at rates of up to -0.11‰ per decade. The secondary standards were applied uniformly across a transition to a new mass spectrometer in 2000, thereby establishing continuity across this transition. Results are presented also for instrumental precision based on replicate analyses of standards. Drift-corrected analyses of the Jena cylinder establishes offsets of +0.037 ‰ in δ13C and +0.041 ‰ in δ18O between the Scripps and JRAS isotopic scales (Scripps more positive).
As a consequence of the prevailing geographic diversity, the county has an extraordinary variety of plants and animals. It is an internationally recognized "biodiversity hot spot" and has very few equals in that regard, in all of North America or elsewhere on our planet.
The County of San Diego has both "Coastal Sage Scrub" and "Chaparral" in abundance. In fact, these two ecosystems cover most of the ground in the county, albeit with many different types. Many of the plants involved in the two systems are deceptively similar, although they quite commonly belong to different species. Naturally, one would like to know how to keep the two communities apart. The criteria, evidently, are plant species distributions. These have been and are being mapped by various methods, including field work by expert observers, collections of specimens in museum repositories, and the study of air photos and satellite images.
Hans Suess was interested in the question of how the sun’s activity changes through time, and whether the variations in activity can be recognized in climate proxy records.
These protocols are designed to provide the information needed by researchers or managers to conduct natural abundance stable isotopic analyses of marsh food sources (suspended particulate organic matter [SPOM], vascular plants, benthic microalgae[BMI], benthic macroalgae) and sediments, as well as common invertebrate and vertebrate consumers (snails, mussels, crabs, macroinfauna and fish). A list of supplies required to carry out the protocols is given in Table A-1.