NOAA/NESDIS/NCEI Daily Optimum Interpolation Sea Surface Temperature (SST) version 2.0 (DOISST v2.0) is a blend of in situ ship and buoy SSTs with satellite SSTs derived from Advanced Very High Resolution Radiometer (AVHRR). DOISST v2.0 exhibited a cold bias in the Indian Ocean, South Pacific, and South Atlantic due to a lack of ingested drifting-buoy SSTs in the system, which resulted from a gradual data format change from the Traditional Alphanumeric Codes (TAC) to the Binary Universal Form for the Representation of meteorological data (BUFR). The cold bias against Argo was about -0.14°C on global average and -0.28°C in the Indian Ocean from January 2016 to August 2019.We explored the reasons for these cold biases through six progressive experiments. These experiments showed that the cold biases can be effectively reduced by adjusting ship SSTs with available buoy SSTs, using the latest available ICOADS R3.0.2 derived from merging BUFR and TAC, as well as by including Argo observations above 5 m depth. The impact of using satellite MetOp-B instead of NOAA-19 was notable on high-latitude oceans but small on global average, since their biases are adjusted using in situ SSTs. In addition, the warm SSTs in the Arctic were improved by applying freezing-point instead of regressed ice-SST proxy.This paper describes an upgraded version, DOISST v2.1, which addresses biases in v2.0. Overall, by updating v2.0 to v2.1, the biases are reduced to -0.07°C (-0.04°C) and -0.14°C (-0.08°C) in the global and Indian Ocean, respectively, when compared against independent (dependent) Argo observations. The difference against the Group for High Resolution SST (GHRSST) multi-product ensemble (GMPE) product is reduced from -0.09°C to -0.01°C in the global oceans and from -0.20°C to -0.04°C in the Indian Ocean.

The past quarter century has seen an unprecedented increase in the number of new and emerging infectious diseases throughout the world, with serious implications for human and wildlife populations. We examined host persistence in the face of introduced vector-borne diseases in Hawaii, where introduced avian malaria and introduced vectors have had a negative impact on most populations of Hawaiian forest birds for nearly a century. We studied birds, parasites, and vectors in nine study areas from 0 to 1,800 m on Mauna Loa Volcano, Hawaii from January to October, 2002. Contrary to predictions of prior work, we found that Hawaii amakihi (Hemignathus virens), a native species susceptible to malaria, comprised from 24.5% to 51.9% of the avian community at three low-elevation forests (55-270 m). Amakihi were more abundant at low elevations than at disease-free high elevations, and were resident and breeding there. Infection rates were 24 -40% by microscopy and 55-83% by serology, with most infected individuals experiencing low-intensity, chronic infections. Mosquito trapping and diagnostics provided strong evidence for yearround local transmission. Moreover, we present evidence that Hawaii amakihi have increased in low elevation habitats on southeastern Hawaii Island over the past decade. The recent emergent phenomenon of recovering amakihi populations at low elevations, despite extremely high prevalence of avian malaria, suggests that ecological or evolutionary processes acting on hosts or parasites have allowed this species to recolonize low-elevation habitats. A better understanding of the mechanisms allowing coexistence of hosts and parasites may ultimately lead to tools for mitigating disease impacts on wildlife and human populations.Hemignathus virens ͉ host-parasite coevolution ͉ Plasmodium relictum ͉ Culex quinquefasciatus T he past quarter century has seen an unprecedented increase in the number of new and emerging infectious diseases throughout the world, with serious implications for human and wildlife populations (1). This rise in the emergence of new infectious diseases is attributed to many factors, among them human alteration of habitats, transportation of vectors and pathogens, and climate and weather patterns, including anthropogenic climate change (2, 3). Vector-borne diseases in particular may undergo geographic range shifts and large changes in abundance with climate change because rising temperatures will affect vector distribution, parasite development, and transmission rates (4).Identifying the factors that allow for coexistence of hosts and parasites has been a topic of intensive study in the ecological literature for decades (5, 6). Modeling and empirical studies have identified host and vector abundance, vector competence and behavior, host community, spatial and metapopulation dynamics, host demography, seasonality, parasite virulence, and host resistance, among others, as being of importance (7,8). A better understanding of the mechanisms of host-parasite coexistence may ultimately lead to t...