Digitizing weather observations from World War II US naval ship logbooks

The number and coverage of weather observations over the oceans were considerably reduced during World War II (WW2) due to disruptions to normal trade routes. The observations that do exist for this period are often unavailable to science as they are still only available as paper records or scanned images. We have rescued the detailed hourly weather observations contained in more than 28,000 logbook images of the US Navy Pacific Fleet stationed at Hawai'i during 1941–1945 to produce a dataset of more than 630,000 records. Each record contains the date and time, positional information and several meteorological measurements, totalling more than 3 million individual observations. The data rescue process consisted of a citizen science project asking volunteers to transcribe the observations from the available images, followed by additional quality control processes. This dataset not only contains hourly weather observations of air temperature, sea surface temperature, atmospheric pressure, wind speed and wind direction, mainly in the Pacific Ocean but also includes some observations from the Atlantic and Indian Oceans. The new observations are found to be of good quality by inter-comparing independent measurements taken on ships travelling in convoy and by comparing with the 20th-Century Reanalysis. This dataset provides invaluable instrumental weather observations at times and places during WW2, which fill gaps in existing reconstructions

The importance and scientific value of long weather and climate records; examples of historical marine data efforts across the globe

The rescue, digitization, quality control, preservation, and utilization of long and high quality meteorological and climate records, particularly related to historical marine data, are crucial for advancing our understanding of the Earth’s climate system. In combination with land and air measurements, historical marine records serve as foundational pillars in linking present and past weather and climate information, offering essential insights into natural climate variability, extreme events in marine areas, baseline data for assessing current changes, and inputs for enhancing predictive climate models and reanalyses. This paper provides an overview of rescue activities covering marine weather data over the past centuries and presents and highlights several ongoing projects across the world and how the data are used in an integrative and international framework. Current and future continuous efforts in data rescue, digitization, quality control, and the development of temporally high-resolution meteorological and climatological observations from oceans, will greatly help to further complete our understanding and knowledge of the Earth’s climate system, including extremes, as well as improve the quality of reanalysis

Reconstruction of the historical climate of the Southern Ocean from whaling ships’ logbooks

The estimated century-long trends in the Southern Ocean climate are uncertain, as the data used to estimate these changes are relatively short (~60 years) compared to possible long-term climate variability found in the region. Due to the lack of longer land-based meteorological records, logbooks of Christian Salvesen Whaling Company’s whaling ships operating in the Southern Ocean in the 1930s and 1950s are investigated in this thesis. A historical climate dataset is produced from the meteorological observations from the whaling logbooks. The mean sea-level pressure (MSLP) changes across the Southern Ocean diverge: for example, in the northern reaches (55°S latitudinal band) MSLP in the historical period (the 1930s and 1950s) is found to be lower than modern climatology (1981-2010). It is in contrast to the southern reaches (65°S latitudinal band) where MSLP is found to be decreasing over the same period. A historical Southern Annular Mode (SAM) index from 1930-1960 is generated from the whaling dataset, and a significant positive trend is found. Subsequently, historical cyclonic frequency is estimated using a semi-supervised cyclone identification algorithm. The average number of cyclones per year for the historical period is statistically lower than the average for the 1999-2008 period over a control area in the Weddell Sea. Finally, the whaling dataset is assimilated into two (CERA-20C and 20CRv2c) current- generation reanalyses using an offline data assimilation method. The uncertainty in MSLP fields over the assimilation window decreased in both reanalyses by ∼40% in the area of observations post-assimilation. Overall it is shown that meteorological observations from the whaling logbooks can be utilised to reconstruct historical climate in terms of MSLP variability, climate modes (e.g. SAM) and identification of individual cyclones, and to improve the representation of past climate in the reanalyses. In summary, it has been demonstrated that the Southern Ocean climate near the Antarctic coast in the early/mid-20th Century was characterised by higher MSLP and less cyclonic activity compared to the modern period.Nehru Trust for Cambridge University and Christ's Colleg

A historical Southern Ocean climate dataset from whaling ships’ logbooks

Historical ship logbooks provide vital historic meteorological observations in the Southern Ocean, one of the largest climate-data deficient regions on the Earth. Christian Salvesen Whaling Company logbooks from whaling ships operating in the Southern Ocean, starting from the 1930s through the 1950s, are examined. Meteorological information contained in these logbooks has been extracted to produce a historical climate dataset. We discuss various instructions recommended by the British Admiralty to observe and record weather conditions on board whaling ships. Statistical tests were used to flag erroneous values and corrections were made using neighbouring values. Meteorological parameters such as air pressure, air and sea temperature and wind force on the Beaufort scale were standardised, converting imperial to metric units. The data were structured according to the internationally accepted International Maritime Meteorological Archive (IMMA) format, which includes the most commonly reported meteorological variables, including the time, location, and ship-related meta-data. Hence, a readily accessible, error-corrected and standardised historical climate dataset of the Weddell Sea sector of the Southern Ocean is presented

Remineralization potential of varnish containing casein phosphopeptides-amorphous calcium phosphate with fluoride and varnish containing only fluoride: A comparative study

Background: Fluoride varnishes have been the standard of practice for the professional application of fluoride. The primary reason for wide acceptance of fluoride varnish is that the procedure is easy, safe, convenient, and well-accepted by patients. Aim: The aim of this study is to evaluate and compare the remineralizing potential of varnish containing casein phosphopeptides-amorphous calcium phosphate (CPP-ACP) and fluoride (MI Varnish®), with that of varnish containing only fluoride (Fluor Protector®). Materials and Methods: Fifty premolar teeth samples were used for this part of the study. They were divided into two Groups (1 and 2), consisting of 25 samples each. Two windows on the buccal surface of these samples were made and assigned randomly as control and experimental window. Initial depth of carious lesions of both windows was measured in all the samples. No varnish was applied on control windows. On the experimental window of Subgroup 1, varnish containing CPP-ACP with fluoride was applied, and on samples of Group 2, varnish containing only fluoride was applied. After varnish application, all the samples were subjected to pH-cycling. Following, the final depth of carious lesion was calculated using polarized light microscope. The data obtained were tabulated and subjected to statistical analysis. Results: The final depths of artificial carious lesion of experimental window of Group 1 and 2 were 131.26 ± 7.01 μm and 134.11 ± 5.95 μm, respectively. Conclusion: There was no significant difference in the remineralizing potential of varnish containing CPP-ACP and fluoride and varnish containing only fluoride