?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Foar.icrisat.org%2F11637%2F&rft.title=The+Usefulness+of+Gridded+Climate+Data+Products+in+Characterizing+Climate+Variability+and+Assessing+Crop+Production&rft.creator=Joseph%2C+J+E&rft.creator=Akinrotimi%2C+O+O&rft.creator=Rao%2C+K+P+C&rft.creator=Ramaraj%2C+A+P&rft.creator=Traore%2C+P+S&rft.creator=Sujatha%2C+P&rft.creator=Whitbread%2C+A+M&rft.subject=Climate+Change&rft.description=A+sparse+rain+gauge+network+in+dryland+regions+has+been+a+major+challenge+for+accessing+high+quality%0D%0Aobserved+data+needed+to+understand+variability+and+trends+in+climate.+Gridded+estimates+of+weather+parameters+produced+through+data+assimilation+algorithms+that%0D%0Aintegrate+satellite+and+irregularly+distributed+on-ground+observations+from+multiple+observing+networks+are+a+potential+alternative.+Questions+remain+about+the+application+of+such+climate+data+sources+for+assessing+climate+variability+and+crop+productivity.+This+study+assessed+the+usefulness+and+limitations+of+gridded+data+from+four+different+sources+i.e.+AgMERRA%2C+CHIRPS%2C%0D%0ANASA+Power%2C+and+TAMSAT+in+estimating+climate+impacts+on+crop+productivity+using+Agricultural+Production+Systems+Simulator+(APSIM).+The+study+used+data+for+11+locations+from%0D%0AAfrica+and+India.+The+agreement+between+these+data+sets+and+observed+data+both+in+the+amount+and+distribution+of+rainfall+was+evaluated+before+and+after+bias+correction+statistically.+A+deviation+of+more+than+100+mm+per+season+was+observed+in+13%25%2C+20%25%2C+25%25%2C+and+40%25+of+the%0D%0Aseasons+in+CHIRPS%2C+AgMERRA%2C+NASA+Power%2C+and+TAMSAT+data+sets+respectively.+The+differences+were+reduced+significantly+when+data+sets+were+bias-corrected.+The+number+of+rainy+days+is+better+estimated+by+TAMSAT+and+CHIRPS+with+a+deviation+of+4%25+and+6%25+respectively+while+AgMERRA+and+NASA+Power+overestimated+by+28%25+and+67%25+respectively.+The+influence+of+these+differences+on+crop+growth+and+productivity+was+estimated+by%0D%0Asimulating+maize+yields+with+APSIM.+Simulated+crop+yields+with+all+gridded+data+sets+were+poorly+correlated+with+observed+data.+The+normalized+root-mean-square+error+(NRMSE)+of+maize+yield+simulated+with+observed+and+gridded+data+was+%3C30%25+for+two+locations+in+the+case%0D%0Aof+AgMERRA+and+CHIRPS+and+three+locations+in+the+case+of+NASA+Power.+The+NRMSE+was+%3E+30%25+for+all+locations+with+TAMSAT+data.+When+yields+were+simulated+with+data+after+bias%0D%0Acorrection+using+the+linear+scaling+technique%2C+results+were+slightly+improved.+The+results+of+our%0D%0Astudy+thus+indicate+that+the+gridded+data+sets+are+usefully+applied+for+characterizing+climate%0D%0Avariability%2C+i.e.+trends+and+seasonality+in+rainfall%2C+however+their+use+in+driving+crop+model%0D%0Asimulations+of+smallholder+farm+level+production+should+be+carefully+interpreted.&rft.publisher=CGIAR+Research+Program+on+Climate+Change%2C+Agriculture+and+Food+Security+(CCAFS)&rft.date=2020&rft.type=Monograph&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Foar.icrisat.org%2F11637%2F1%2FJoseph_CCAFS.pdf&rft.identifier=++Joseph%2C+J+E+and+Akinrotimi%2C+O+O+and+Rao%2C+K+P+C+and+Ramaraj%2C+A+P+and+Traore%2C+P+S+and+Sujatha%2C+P+and+Whitbread%2C+A+M++(2020)+The+Usefulness+of+Gridded+Climate+Data+Products+in+Characterizing+Climate+Variability+and+Assessing+Crop+Production.++Working+Paper.+CGIAR+Research+Program+on+Climate+Change%2C+Agriculture+and+Food+Security+(CCAFS)%2C+Netherlands.+++++