TY - Generic T1 - Seasonal Snow Extent and Snow Mass in South America Using SSM/I Passive Microwave Data (1988-2003) T2 - 75th Annual Western Snow Conference Y1 - 2007 A1 - Foster, J.L. A1 - Hall, D.K. A1 - Chiu, L. A1 - Kelly, R./Powell, H. KW - Seasonal snow cover, SSM/I, South America, satellite AB - Seasonal snow cover in extra-tropical areas of South America was examined in this study using passive microwave satellite data from the Special Sensor Microwave Imagers (SSM/I) on board the Defense Meteorological Satellite Program (DMSP) satellites. For the period from 1988-2003, both snow cover extent and snow mass were estimated for the months of July, typically the coldest winter month. Most of the seasonal snow in South America is in the Patagonia region of Argentina. The average snow cover and snow mass for the 16-year period was 284,492 km2 and 0.763 x 1013 kg, respectively. The year with the greatest average snow extent and snow mass during the 16-year period of record was 1992 -- 551,875 km2 and 2.073 x 1013, respectively. If the strong El-Nino years of 1991-1992 and 1997-1998 are excluded, the July snow mass shows a linear trend of 28% over the 16 years period, with a p-value of 0.0098, which is significant at the 85% level. JF - 75th Annual Western Snow Conference T3 - Proceedings of the 75th Annual Western Snow Conference PB - Western Snow Conference CY - Kailua-Kona, HI UR - sites/westernsnowconference.org/PDFs/2007Foster.pdf ER - TY - Generic T1 - Change in the Date of Snow Disappearance in the High Arctic T2 - 74th Annual Western Snow Conference Y1 - 2006 A1 - Foster, J.L. A1 - Robinson, D.A. A1 - Hall, D.K. A1 - Estilow, T. KW - Arctic snow cover, satellite, snowline retreat, climate change AB - In this paper, we show changes in the dates of snow disappearance in the high Arctic (70° north latitude) between the late 1960s and the early 2000s. NOAA satellite data were employed to make these snow observations (from snow cover to snow free conditions), using arbitrary but consistent boundaries. Continuing the study presented by Foster et al, (1992) on springtime snow disappearance in the high Arctic, the date the snowline retreats during the spring (when it first moves north of the 70 degree parallel), for many Arctic locations, has occurred approximately a week earlier in recent years compared to the late 1960s. The tendency toward earlier snowmelt previously observed during the past several decades has apparently neither been a local phenomenon nor a short-term fluctuation. However, unlike other markers of climate warming in the Arctic, since 1990, the date of snow disappearance has not occurred noticeably earlier. It is possible that the date of snow disappearance is not an adequate benchmark for detecting warming signal. JF - 74th Annual Western Snow Conference T3 - Proceedings of the 74th Annual Western Snow Conference PB - Western Snow Conference CY - Las Cruces, NM UR - sites/westernsnowconference.org/PDFs/2006Foster.pdf ER -