[1] We present the Met Office Hadley Centre's sea ice and sea surface temperature (SST) data set, HadISST1, and the nighttime marine air temperature (NMAT) data set, HadMAT1. HadISST1 replaces the global sea ice and sea surface temperature (GISST) data sets and is a unique combination of monthly globally complete fields of SST and sea ice concentration on a 1° latitude-longitude grid from 1871. The companion HadMAT1 runs monthly from 1856 on a 5° latitude-longitude grid and incorporates new corrections for the effect on NMAT of increasing deck (and hence measurement) heights. HadISST1 and HadMAT1 temperatures are reconstructed using a two-stage reduced-space optimal interpolation procedure, followed by superposition of quality-improved gridded observations onto the reconstructions to restore local detail. The sea ice fields are made more homogeneous by compensating satellite microwave-based sea ice concentrations for the impact of surface melt effects on retrievals in the Arctic and for algorithm deficiencies in the Antarctic and by making the historical in situ concentrations consistent with the satellite data. SSTs near sea ice are estimated using statistical relationships between SST and sea ice concentration. HadISST1 compares well with other published analyses, capturing trends in global, hemispheric, and regional SST well, containing SST fields with more uniform variance through time and better month-to-month persistence than those in GISST. HadMAT1 is more consistent with SST and with collocated land surface air temperatures than previous NMAT data sets.

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2002JD002670

Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century

A weekly 1° spatial resolution optimum interpolation (OI) sea surface temperature (SST) analysis has been produced at the National Oceanic and Atmospheric Administration (NOAA) using both in situ and satellite data from November 1981 to the present. The weekly product has been available since 1993 and is widely used for weather and climate monitoring and forecasting. Errors in the satellite bias correction and the sea ice to SST conversion algorithm are discussed, and then an improved version of the OI analysis is developed. The changes result in a modest reduction in the satellite bias that leaves small global residual biases of roughly −0.03°C. The major improvement in the analysis occurs at high latitudes due to the new sea ice algorithm where local differences between the old and new analysis can exceed 1°C. Comparisons with other SST products are needed to determine the consistency of the OI. These comparisons show that the differences among products occur on large time- and space scales wit...

An Improved In Situ and Satellite SST Analysis for Climate

Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

/pdf/climate-change-2007-the-physical-science-basis-1x93ttz9jt.pdf

Climate Change 2007: The Physical Science Basis.

With digital equipment becoming increasingly networked, either on wired or wireless networks, for personal and professional use alike, distributed software systems have become a crucial element in information and communications technologies. The study of these systems forms the core of the ARLES' work, which is specifically concerned with defining new system software architectures, based on the use of emerging networking technologies. In this context, we concentrate on the study of distributed systems which bring to life the vision of ubiquitous computing systems, also known as ambient intelligence.

반도체 공정 overview

This chapter assesses long-term projections of climate change for the end of the 21st century and beyond, where the forced signal depends on the scenario and is typically larger than the internal variability of the climate system. Changes are expressed with respect to a baseline period of 1986-2005, unless otherwise stated.

Chapter 12 - Long-term climate change: Projections, commitments and irreversibility

The accuracy of gridded elevation models interpolated to higher resolutions

Inspired by a 2019 conference, Moana Water of Life, and including real-life insights from a diverse range of participants, this book showcases the potential fruits of open dialogue between stakeholders to navigate the critical challenges to planetary health caused by the climate crisis.

https://books.emeraldinsight.com/resources/pdfs/chapters/9781839829871-TYPE23-NR2.pdf

Science, faith and the climate crisis

. Here, we document changes for the Mittivakkat Gletscher, the glacier in Greenland (disconnected to the Greenland Ice Sheet, GrIS) having the longest observed mass balance and surface velocity time series (since 1995). Between 1986 and 2011, this glacier decreased by 15% in mean ice thickness and 30% in volume. We attribute these changes to summer warming and less winter snowfall. The vertical strain was able to compensate about 60% of the elevation change due to surface mass balance (SMB) in the lower part, and about 25% in the upper part. The annual mean ice surface velocity decreased by 30%, likely as a dynamic effect of ice thinning. Mittivakkat Gletscher summer surface velocities were on average 50–60% above winter background values, and up to 160% higher during peak velocity events.

/pdf/thinning-and-slowdown-of-greenland-s-mittivakkat-gletscher-j1g5a3e43h.pdf

Thinning and slowdown of Greenland's Mittivakkat Gletscher

Concerted observational and modelling programmes are underway to determine the mass balance of the Greenland Ice Sheet, and therefore help predict its response to future climatic change. We give results of meteorological modelling based on ERA-40 reanalysis data from the European Centre for Medium Range Weather Forecasts (ECMWF). Our novel annual and seasonal surface-mass-balance history of the ice sheet for 1957-2003, is based on accumulation modelling and a new monthly melt-water runoff model by Janssens & Huybrechts (Huybrechts 2002). This yields valuable insights into the past and present state and variability of the Greenland ice mass and links with climate. Aspects of the validation of the new accumulation, runoff and SMB series are discussed. There was considerable interannual variability in snow accumulation, runoff and mass balance over the last 45 years. By comparing with long-term temperature, precipitation and accumulation records from the met. stations and ice cores, we discuss possible climatic factors forcing the ice in this period. We also derive sensitivity of the ice sheet to climatic forcing, based on real meteorological observations (ERA-40). Massive snow accumulation over south-east Greenland during winter 2002/03, well shown in our analysis, led to unprecedented thickening in recent NASA aircraft surveys. Is this recent thickening signal a sign of more extreme weather conditions over the Ice Sheet, more storminess and higher accumulation events, due to global warming?

Current state and variability of surface mass balance of Greenland ice sheet, and links with climate

The GRACE satellite mission, launched in March of 2002, provides monthly measurements of time variable gravity at scales of a few hundred kilometers and larger These data can be used to estimate temporal variations in the distribution of surface mass We examine here the nineteen monthly GRACE gravity field solutions that are currently available for analyses We find that these fields can be used to recover mass imbalance and net snow accumulation for the Greenland and Antarctic ice sheets GRACE estimates of Greenland mass change agree with ice mass imbalance estimates from altimeter heights within measurement errors We also estimate net snow accumulation from the nonsecular component of the GRACE signal If precipitation minus evapo-transpiration (P-E) and runoff (R) are known it is possible to obtain monthly estimates of ice discharge through the grounding line from GRACE We estimate ice discharge for the Greenland ice sheet by combining GRACE estimates of nonsecular net snow accumulation with ERA40-derived P-E-R

Edward Hanna

Papers

The accuracy of gridded elevation models interpolated to higher resolutions

Science, faith and the climate crisis

Thinning and slowdown of Greenland's Mittivakkat Gletscher

Current state and variability of surface mass balance of Greenland ice sheet, and links with climate

Snow Accumulation, Ice Discharge and Mass Balance in Greenland and Antarctica from GRACE