抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

https://cimss.ssec.wisc.edu/dbs/China2011/Day2/Lectures/MODIS_MOD13_NDVI_referenc.pdf

Overview of the radiometric and biophysical performance of the MODIS vegetation indices

The Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) provides a calibration-based sequential scheme for combining precipitation estimates from multiple satellites, as well as gauge analyses where feasible, at fine scales (0.25° × 0.25° and 3 hourly). TMPA is available both after and in real time, based on calibration by the TRMM Combined Instrument and TRMM Microwave Imager precipitation products, respectively. Only the after-real-time product incorporates gauge data at the present. The dataset covers the latitude band 50°N–S for the period from 1998 to the delayed present. Early validation results are as follows: the TMPA provides reasonable performance at monthly scales, although it is shown to have precipitation rate–dependent low bias due to lack of sensitivity to low precipitation rates over ocean in one of the input products [based on Advanced Microwave Sounding Unit-B (AMSU-B)]. At finer scales the TMPA is successful at approximately reproducing the s...

/pdf/the-trmm-multisatellite-precipitation-analysis-tmpa-quasi-3wulgfnahi.pdf

The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-Global, Multiyear, Combined-Sensor Precipitation Estimates at Fine Scales

Changes in Atmospheric Constituents and in Radiative Forcing

Black carbon aerosol plays a unique and important role in Earth's climate system. Black carbon is a type of carbonaceous material with a unique combination of physical properties. This assessment provides an evaluation of black-carbon climate forcing that is comprehensive in its inclusion of all known and relevant processes and that is quantitative in providing best estimates and uncertainties of the main forcing terms: direct solar absorption; influence on liquid, mixed phase, and ice clouds; and deposition on snow and ice. These effects are calculated with climate models, but when possible, they are evaluated with both microphysical measurements and field observations. Predominant sources are combustion related, namely, fossil fuels for transportation, solid fuels for industrial and residential uses, and open burning of biomass. Total global emissions of black carbon using bottom-up inventory methods are 7500 Gg yr−1 in the year 2000 with an uncertainty range of 2000 to 29000. However, global atmospheric absorption attributable to black carbon is too low in many models and should be increased by a factor of almost 3. After this scaling, the best estimate for the industrial-era (1750 to 2005) direct radiative forcing of atmospheric black carbon is +0.71 W m−2 with 90% uncertainty bounds of (+0.08, +1.27) W m−2. Total direct forcing by all black carbon sources, without subtracting the preindustrial background, is estimated as +0.88 (+0.17, +1.48) W m−2. Direct radiative forcing alone does not capture important rapid adjustment mechanisms. A framework is described and used for quantifying climate forcings, including rapid adjustments. The best estimate of industrial-era climate forcing of black carbon through all forcing mechanisms, including clouds and cryosphere forcing, is +1.1 W m−2 with 90% uncertainty bounds of +0.17 to +2.1 W m−2. Thus, there is a very high probability that black carbon emissions, independent of co-emitted species, have a positive forcing and warm the climate. We estimate that black carbon, with a total climate forcing of +1.1 W m−2, is the second most important human emission in terms of its climate forcing in the present-day atmosphere; only carbon dioxide is estimated to have a greater forcing. Sources that emit black carbon also emit other short-lived species that may either cool or warm climate. Climate forcings from co-emitted species are estimated and used in the framework described herein. When the principal effects of short-lived co-emissions, including cooling agents such as sulfur dioxide, are included in net forcing, energy-related sources (fossil fuel and biofuel) have an industrial-era climate forcing of +0.22 (−0.50 to +1.08) W m−2 during the first year after emission. For a few of these sources, such as diesel engines and possibly residential biofuels, warming is strong enough that eliminating all short-lived emissions from these sources would reduce net climate forcing (i.e., produce cooling). When open burning emissions, which emit high levels of organic matter, are included in the total, the best estimate of net industrial-era climate forcing by all short-lived species from black-carbon-rich sources becomes slightly negative (−0.06 W m−2 with 90% uncertainty bounds of −1.45 to +1.29 W m−2). The uncertainties in net climate forcing from black-carbon-rich sources are substantial, largely due to lack of knowledge about cloud interactions with both black carbon and co-emitted organic carbon. In prioritizing potential black-carbon mitigation actions, non-science factors, such as technical feasibility, costs, policy design, and implementation feasibility play important roles. The major sources of black carbon are presently in different stages with regard to the feasibility for near-term mitigation. This assessment, by evaluating the large number and complexity of the associated physical and radiative processes in black-carbon climate forcing, sets a baseline from which to improve future climate forcing estimates.

/pdf/bounding-the-role-of-black-carbon-in-the-climate-system-a-1fc3novd9r.pdf

Bounding the role of black carbon in the climate system: A scientific assessment

/pdf/comment-on-reversal-of-trend-of-biomass-burning-in-the-4ngyigp5q8.pdf

Comment on “Reversal of trend of biomass burning in the Amazon” by Ilan Koren, Lorraine A. Remer, and Karla Longo

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2003JD003548

Comment on “Seasonal, intraseasonal, and interannual variability of global land fires and their effects on atmospheric aerosol distribution” by Y. Ji and E. Stocker

Abstract. In fire emission models, the spatial resolution of both
the modelling framework and the satellite data used to quantify burned area
can have considerable impact on emission estimates. Consideration of this
sensitivity is especially important in areas with heterogeneous land cover
and fire regimes and when constraining model output with field
measurements. We developed a global fire emissions model with a spatial
resolution of 500 m using MODerate resolution Imaging Spectroradiometer
(MODIS) data. To accommodate this spatial resolution, our model is based on
a simplified version of the Global Fire Emissions Database (GFED) modelling
framework. Tree mortality as a result of fire, i.e. fire-related forest
loss, was modelled based on the overlap between 30 m forest loss data and
MODIS burned area and active fire detections. Using this new 500 m model, we
calculated global average carbon emissions from fire of 2.1±0.2
(±1σ interannual variability, IAV) Pg C yr−1 during
2002–2020. Fire-related forest loss accounted for 2.6±0.7 %
(uncertainty range =1.9 %–3.3 %) of global burned area and 24±6 % (uncertainty range =16 %–31 %) of emissions, indicating that fuel
consumption in forest fires is an order of magnitude higher than the global
average. Emissions from the combustion of soil organic carbon (SOC) in the
boreal region and tropical peatlands accounted for 13±4 % of
global emissions. Our global fire emissions estimate was higher than the 1.5 Pg C yr−1 from GFED4 and similar to 2.1 Pg C yr−1 from GFED4s.
Even though GFED4s included more burned area by accounting for small fires
undetected by the MODIS burned area mapping algorithm, our emissions were
similar to GFED4s due to higher average fuel consumption. The global
difference in fuel consumption could mainly be explained by higher SOC
emissions from the boreal region as constrained by additional measurements.
The higher resolution of the 500 m model also contributed to the difference
by improving the simulation of landscape heterogeneity and reducing the
scale mismatch in comparing field measurements to model grid cell averages
during model calibration. Furthermore, the fire-related forest loss
algorithm introduced in our model led to more accurate and widespread
estimation of high-fuel-consumption burned area. Recent advances in burned
area detection at resolutions of 30 m and finer show a substantial amount of
burned area that remains undetected with 500 m sensors, suggesting that
global carbon emissions from fire are likely higher than our 500 m
estimates. The ability to model fire emissions at 500 m resolution provides
a framework for further improvements with the development of new
satellite-based estimates of fuels, burned area, and fire behaviour, for use
in the next generation of GFED.


/pdf/global-biomass-burning-fuel-consumption-and-emissions-at-500-1cd7mqd5.pdf

Global biomass burning fuel consumption and emissions at 500 m spatial resolution based on the Global Fire Emissions Database (GFED)

Global fire activity is an important contributor to the atmospheric trace gas and aerosol burdens. New burned area datasets and top-down constraints from atmospheric concentration measurements of pyrogenic gases have decreased the large uncertainty in fire emissions estimates, but little is known about the contribution of deforestation, agricultural waste, peat, forest, and savanna fires to total global fire emissions. Here we used a revised version of the CASA biogeochemical model and improved satellite-derived estimates of area burned, fire activity, and plant productivity to calculate fire emissions for the 1997-2008 period on a 0.5°×0.5° spatial resolution with a monthly time step.

The improved Global Fire Emissions Database (GFED) version 3: contribution of savanna, forest, deforestation, and peat fires to the global fire emissions budget

Louis Giglio

Papers

Comment on “Reversal of trend of biomass burning in the Amazon” by Ilan Koren, Lorraine A. Remer, and Karla Longo

Comment on “Seasonal, intraseasonal, and interannual variability of global land fires and their effects on atmospheric aerosol distribution” by Y. Ji and E. Stocker

Global biomass burning fuel consumption and emissions at 500 m spatial resolution based on the Global Fire Emissions Database (GFED)

The improved Global Fire Emissions Database (GFED) version 3: contribution of savanna, forest, deforestation, and peat fires to the global fire emissions budget

Validation of MCD64A1 and FireCCI51 cropland burned area mapping in Ukraine