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مباحث عمومی هواشناسی
- شروع کننده موضوع Amir Mohsen
- تاریخ شروع
- وضعیت
North Atlantic Oscillation (NAO)
I define the NAO as the first (varimax rotated) EOF of standardized daily 500 hPa height anomalies in an extended North Atlantic domain (20N-70N, 135W-45E) from 1979 through 2008. This pattern, shown below, is then projected onto recent and forecast data to create the index. The index is standardized by the mean and standard deviation of the base index (again, 1979 through 2008), which is just the first PC. Note that my definition is similar to, but not the same as, CPC’s definition. My index correlates with theirs at roughly r = 0.76.
Arctic Oscillation (AO)
I define the AO as the first (unrotated) EOF of standardized daily 700 hPa height anomalies poleward of 20N from 1979 through 2008. This pattern, shown below, is then projected onto recent and forecast data to create the index. The index is standardized by the mean and standard deviation of the base index (again, 1979 through 2008), which is just the first PC. Note that my definition is similar to, but not the same as, CPC’s definition. My index correlates with theirs at roughly r = 0.75.
Pacific/North American Pattern
I define the PNA as the fourth (varimax rotated) EOF of standardized daily 500 hPa height anomalies poleward of 20N from 1979 through 2008. This pattern, shown below, is then projected onto recent and forecast data to create the index. The index is standardized by the mean and standard deviation of the base index (again, 1979 through 2008), which is just the rotated PC. Note that my definition is similar to, but not the same as, CPC’s definition. My index correlates with theirs at roughly r = 0.65.
ENSO/SST Regions
These are SST forecasts from the CFSR for the specified regions. I only have data for the past couple of weeks, but it will fill in as time goes on.These are daily SST indices which is highly unusual since SSTs don’t change much on a daily scale. Therefore, they may look a little different than the weekly or monthly indices you are probably more used to. Each index is normalized by removing the seasonal cycle and dividing by the seasonal cycle of the standard deviation of the 1979-2010 base period.
Tropical Projections
Tropical projections use a modified version of Paul Roundy’s algorithm (explained here). The most notable change I’ve made is introducing a time period difference of 10 days between the upper end of the Kelvin waves (20 days) and the lower end of the MJO (30 days). This forces a separation between the two modes. Recent research suggests that this may not be a physically accurate separation, but for the purposes of tropical forecasting, I believe the separation helps to better understand the tropics.
Horizontal Maps
These maps are very similar to Paul Roundy’s OLR Diagnostics. I use the CFSv2 upward longwave radiation flux instead of OLR to produce these maps.
Updated ~10 a.m. Eastern Time. Analysis goes through yesterday. CFS forecast begins with today and goes out 90 days. The color bar on each of these maps ranges from -30 (Blue) to +30 (Red) W/m^2 anomalies.
The CFS forecast maps have anomaly correlation coefficients (ACC) in the lower right-hand corner.
Example: 2 day forecast. ACC shown is the average ACC of 2 day forecasts since March 26, 2012. ACCs will extend further as time goes on and I can actually verify. By June 25th (90 days), the ACCs should be filled in for each forecast time.
MJO Index
This is modeled after the Wheeler and Hendon (2004) RMM phase space and is most similar to a similar approach that I’ve written about in MacRitchie and Roundy (2012). This approach uses the CFS MJO projections, as used in other figures on this website, to track the MJO. This results in a smoother signal than the WH04 index with less interference from other modes.
I define the NAO as the first (varimax rotated) EOF of standardized daily 500 hPa height anomalies in an extended North Atlantic domain (20N-70N, 135W-45E) from 1979 through 2008. This pattern, shown below, is then projected onto recent and forecast data to create the index. The index is standardized by the mean and standard deviation of the base index (again, 1979 through 2008), which is just the first PC. Note that my definition is similar to, but not the same as, CPC’s definition. My index correlates with theirs at roughly r = 0.76.
Arctic Oscillation (AO)
I define the AO as the first (unrotated) EOF of standardized daily 700 hPa height anomalies poleward of 20N from 1979 through 2008. This pattern, shown below, is then projected onto recent and forecast data to create the index. The index is standardized by the mean and standard deviation of the base index (again, 1979 through 2008), which is just the first PC. Note that my definition is similar to, but not the same as, CPC’s definition. My index correlates with theirs at roughly r = 0.75.
Pacific/North American Pattern
I define the PNA as the fourth (varimax rotated) EOF of standardized daily 500 hPa height anomalies poleward of 20N from 1979 through 2008. This pattern, shown below, is then projected onto recent and forecast data to create the index. The index is standardized by the mean and standard deviation of the base index (again, 1979 through 2008), which is just the rotated PC. Note that my definition is similar to, but not the same as, CPC’s definition. My index correlates with theirs at roughly r = 0.65.
ENSO/SST Regions
These are SST forecasts from the CFSR for the specified regions. I only have data for the past couple of weeks, but it will fill in as time goes on.These are daily SST indices which is highly unusual since SSTs don’t change much on a daily scale. Therefore, they may look a little different than the weekly or monthly indices you are probably more used to. Each index is normalized by removing the seasonal cycle and dividing by the seasonal cycle of the standard deviation of the 1979-2010 base period.
Tropical Projections
Tropical projections use a modified version of Paul Roundy’s algorithm (explained here). The most notable change I’ve made is introducing a time period difference of 10 days between the upper end of the Kelvin waves (20 days) and the lower end of the MJO (30 days). This forces a separation between the two modes. Recent research suggests that this may not be a physically accurate separation, but for the purposes of tropical forecasting, I believe the separation helps to better understand the tropics.
Horizontal Maps
These maps are very similar to Paul Roundy’s OLR Diagnostics. I use the CFSv2 upward longwave radiation flux instead of OLR to produce these maps.
Updated ~10 a.m. Eastern Time. Analysis goes through yesterday. CFS forecast begins with today and goes out 90 days. The color bar on each of these maps ranges from -30 (Blue) to +30 (Red) W/m^2 anomalies.
The CFS forecast maps have anomaly correlation coefficients (ACC) in the lower right-hand corner.
Example: 2 day forecast. ACC shown is the average ACC of 2 day forecasts since March 26, 2012. ACCs will extend further as time goes on and I can actually verify. By June 25th (90 days), the ACCs should be filled in for each forecast time.
MJO Index
This is modeled after the Wheeler and Hendon (2004) RMM phase space and is most similar to a similar approach that I’ve written about in MacRitchie and Roundy (2012). This approach uses the CFS MJO projections, as used in other figures on this website, to track the MJO. This results in a smoother signal than the WH04 index with less interference from other modes.
بر اساس این پیش بینی باید دمای ناحیه NINO 3.4 تا 6 روز آینده به صفر نزدیک بشه حالا ببینیم چقدر این پیش بینی صحیح خواهد بود!!!
آنومالی دمای ناحیه NINO 3.4 با کاهش 0.027 درجه دیگر به 0.256 - درجه رسید!
Amir Mohsen
متخصص بخش هواشناسی
:گل::گل::گل:
برای دیدن انیمیشن آنومالی دمای در تراز 850 میلی بار بر روی لینک زیر کلیک کنید
http://www.esrl.noaa.gov/psd/forecasts/reforecast2/wx_maps/html/t850_anom_nhbg_animation.html
برای دیدن انیمیشن آنومالی دمای در تراز 850 میلی بار بر روی لینک زیر کلیک کنید
http://www.esrl.noaa.gov/psd/forecasts/reforecast2/wx_maps/html/t850_anom_nhbg_animation.html
Amir Mohsen
متخصص بخش هواشناسی
آخه که چقدر بدم میاد این گرمسیرات عربی برف و سرما باشه:تعجب2:
Amir Mohsen
متخصص بخش هواشناسی
Amir Mohsen
متخصص بخش هواشناسی
:غش2::غش2::غش2::دست::دست::دست::غش::غش::غش:
Amir Mohsen
متخصص بخش هواشناسی
استاد
میشه این نقشه رو توضیح بدید که یعنی چی؟
میشه این نقشه رو توضیح بدید که یعنی چی؟
- وضعیت